:<small>Um shouldn't you get a job before you worry about tithing [http://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Science&diff=prev&oldid=407059406]? Also have you considered donating a bidet? Considering how wonderful they are perhaps the church will find more members come because of the bidet? This would seem to be the greatest gift of all at least for most churches. From your POV you'll get converts both ways! [[User:Nil Einne|Nil Einne]] ([[User talk:Nil Einne|talk]]) 11:05, 14 January 2011 (UTC)</small>
:<small>Um shouldn't you get a job before you worry about tithing [http://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Science&diff=prev&oldid=407059406]? Also have you considered donating a bidet? Considering how wonderful they are perhaps the church will find more members come because of the bidet? This would seem to be the greatest gift of all at least for most churches. From your POV you'll get converts both ways! [[User:Nil Einne|Nil Einne]] ([[User talk:Nil Einne|talk]]) 11:05, 14 January 2011 (UTC)</small>
::Apractical suggestion is touse$200tobuyasolarpanelandasmallmotorattachedtoa[[Prayerwheel]]. You will thereby make a pious gesturetowards a religionthatdoesnotencourage propitiation to a bloodthirsty deity. You can give the remaining $200 to [[Poverty|thepoor]] if you are not preoccupied with self interest. [[User:Cuddlyable3|Cuddlyable3]] ([[User talk:Cuddlyable3|talk]]) 12:43, 14 January 2011 (UTC)
::<small>That's an interesting suggestion. A [[Bidet]] is a low-mounted plumbing fixture or type of sink intended for washing the genitalia, inner buttocks, and anus. As a church fixture a bidet could additionally serve as a novel [[Baptismal font]]. [[User:Cuddlyable3|Cuddlyable3]] ([[User talk:Cuddlyable3|talk]]) 15:06, 14 January 2011 (UTC)</small>
:A practical suggestion is to use $200 to buy a solar panel and a small motor attached to a [[Prayer wheel]]. You will thereby make a pious gesture towards a religion that does not encourage propitiation to a bloodthirsty deity. You can give the remaining $200 to [[Poverty|the poor]] if you are not preoccupied with self interest. [[User:Cuddlyable3|Cuddlyable3]] ([[User talk:Cuddlyable3|talk]]) 12:43, 14 January 2011 (UTC)
== Hiroshima/Nagasaki and radiation ==
== Hiroshima/Nagasaki and radiation ==
Revision as of 15:06, 14 January 2011
Welcome to the science section of the Wikipedia reference desk.
The best answers address the question directly, and back up facts with wikilinks and links to sources. Do not edit others' comments and do not give any medical or legal advice.
Articles showing the wave/particle duality of electrons and maybe photons demonstrate aiming individual particles at slits with a resultant interference pattern.However they never explain how single particles are produced and aimed(especially a photon which I assume cannot be magnetically influenced). John Cowell. 118.208.9.92 (talk) 00:59, 10 January 2011 (UTC)[reply]
Thanks for reference,(though the maths was beyond me) ,the articles did not explain how to produce,aim and fire the particles from an engineering standpoint. John Cowell. 01:36, 10 January 2011 (UTC) —Preceding unsigned comment added by 118.208.9.92 (talk)
Presumably this: [1] reference (from the article) would be at that level of detail. If not, it itself would have references you could follow to earlier descriptions of such methods. --Jayron3201:56, 10 January 2011 (UTC)[reply]
Laser and polarization filter
All the photons in a laser are entangled together, right? Does that mean that if one of the photons passes through a polarization filter, the rest will as well? In other words, do they always either let all or none of the light through? — DanielLC03:17, 10 January 2011 (UTC)[reply]
No, all the photons in a laser are not entangled. And if you had a beam of entangled photons, just because one went through a polarization filer does not mean all of them do. And finally if you did send all the photons in a beam of entangled photons through a polarization filter it does not mean all or none - quite the opposite, some will go through, some won't, and some will end up in sort of a partial state of going though and not going though. But in total, half will end up going through and half won't. Additionally a polarization filter is (one) method of creating entangled photons in the first place. Ariel. (talk) 09:20, 10 January 2011 (UTC)[reply]
Actually, many semiconductor lasers do produce polarized light. The waveguide in the semiconductor is not rotationally symmetric, and somehow this induces polarized lasing.--Srleffler (talk) 06:24, 15 January 2011 (UTC)[reply]
Zero Transit Time
In days of yore we were told that atoms had a nucleus with electrons "orbiting" at a relatively large distance away.In an airforce avionics lecture we were taught that electrons changed orbit/energy levels/shells/fuzzy balls/etc emitting or gaining energy depending on circumstance and this involved travelling a very small but finite distance in zero time.I feel a warpdrive coming on!
John Cowell.04:10, 10 January 2011 (UTC) —Preceding unsigned comment added by 118.208.9.92 (talk)
I've not seen anywhere that de Broglie waves aren't limited by the same physical laws as the objects that are associated with them? --Jayron3216:53, 10 January 2011 (UTC)[reply]
An electron occupying an atomic orbital is in a de Broglie wave more properly associated with a probability distribution than a point, even considered as a solution to the Schroedinger equation. Therefore it can be said to be occupying disjoint space simultaneously whereas a more point-like nucleus can not, until several orders of magnitude smaller distances are considered. 71.198.176.22 (talk) 17:28, 10 January 2011 (UTC)[reply]
Yeah, but that doesn't mean the electron "jumps" magically between different points instantly; it just means that a single electron is "smeared out" over a certain volume of space; it is partially and simultaneously in multiple locations. --Jayron3219:29, 10 January 2011 (UTC)[reply]
Guys, this is easy. Apply Heisenberg's uncertainty relation. Whether the jump is instantaneous or not is irrelevant, because we can't measure it instantaneously. Any change of the quantum state ΔE is accompanied by a characteristic Δt. Specifically, the change in electron energy follows the relations laid out in this section; the more "resolution" you want on the energy scale, (in other words, if you want to measure a single quantum of energy), the more time your measurement necessarily gets smeared out over. Nimur (talk) 22:52, 10 January 2011 (UTC)[reply]
Motor oil leakage in cold weather
I bought my car knowing that it had some problems; among these is a slow oil leak. I've been advised that a repair job might be difficult (no clue where the leak is, for example) and that it's not at all necessary, so I take care of the situation by checking the oil regularly and adding more when necessary. As we've descended into the North American winter, I've noticed that the oil level changes less between times that I check it, even though I don't think to check it as frequently. Is there any chance that the cold weather reduces the rate at which the oil leaks? Please note that the rate at which I was losing oil before, while not great, was far faster than could be accounted for by the oil that I wipe off the dipstick when I check it. Nyttend (talk) 04:20, 10 January 2011 (UTC)[reply]
Motor oil (see article) may increase Viscosity at low temperature, especially if it is not fresh, which could explain the slower leak. Your real problem is to locate the leak so is a web page that can help[2]. Warning: Are you sure it is only motor oil leaking? A leak of brake or transmission fluid is a serious fault that needs immediate attention. Cuddlyable3 (talk) 04:54, 10 January 2011 (UTC)[reply]
With modern multigrade motor oils the viscosity shouldn't change that much. Maybe one of the rubber seals is stiffer? Or the cold is causing parts to shrink a bit tightening the gap? Or it could simply be self-sealing (i.e. gunk is blocking the hole) - you won't know till summer. Ariel. (talk) 05:49, 10 January 2011 (UTC)[reply]
Cuddlyable — I know that it's motor oil, because the levels on the engine oil dipstick go down (or went down) from week to week. Nyttend (talk) 23:19, 10 January 2011 (UTC)[reply]
dear sir,
i have an idea of to produce electricity by using mechanical energy that is produced when a cycle wheel rotates so what are the apparatus to be used and the design and the important thing is that it should be a low cost model —Preceding unsigned comment added by 117.204.69.78 (talk) 09:05, 10 January 2011 (UTC)[reply]
I think you mean a generator. But the hard part (meaning the expensive part) is not producing electricity, the hard part is producing the mechanical energy. How are you going to make the mechanical energy? Ariel. (talk) 09:09, 10 January 2011 (UTC)[reply]
It should be noted that this is only as eco-friendly as your diet and lifestyle. Using beasts of burden (human beings, in this case) is not a very efficient or a priori eco-friendly way to utilize mechanical energy. --Mr.98 (talk) 14:10, 10 January 2011 (UTC)[reply]
Presented only as information, and not a suggestion that anyone should undertake the experiment: It would be possible to generate a respectable amount of electric power with a stationary bike. A single bike alternator only produces a small amount of electricity, with more output voltage at higher speed. It is only designed to power the headlight and taillight of the bicycle, putting out only 6 watts or so. Their efficiency is only 70% or so, per Bicycle lighting. One might collect several old bicycle alternators, and mount them on the bike frame so they can be placed in normal contact with the rear tire. One could connect a bridge rectifier to each one to produce DC electricity. Various connections could produce 12 volts DC to power a battery charger. An inverter connected to the 12 volt battery could power small appliances such as a small TV. Peddle like hell, so that you are producing a small fraction of a horsepower of mechanical energy. I would not expect more than 60 watts of output for an extended period if I were peddling such a bike generator. Some experimenters have gone a step beyond and connected a stationary bike to a salvaged 12 volt car alternator, perhaps via a v belt rather than the low efficiency connection of a bike alternator rubbing on the tire. The alternator might be able to put out 100 watts, depending on the model used, but the human power source might limit the long-term output. Edison (talk) 03:23, 11 January 2011 (UTC)[reply]
If the stationary bike I use is accurate, it really is not all that difficult for a reasonably in shape human to produce 150 watts of power for 30 min. If you want more then that, you might want to see if Lance Armstrong is busy. Googlemeister (talk) 14:22, 11 January 2011 (UTC)[reply]
If you merely reverse the polarity of the single phase AC power supply to an electric fan, it will still rotate in the same direction. Consider the phase relation of the armature and field, to find a way to reverse it. If it had a three phase power supply and motor, switching any two of the supply connections would cause it to rotate in the reverse direction. Edison (talk) 03:06, 11 January 2011 (UTC)[reply]
It depends on the kind of motor it has. You'll probably have to open it and change wiring. A D/C fan can be reversed by changing the polarity. A/C fans are more complicated and it depends on the exact type. Ariel. (talk) 20:21, 10 January 2011 (UTC)[reply]
AC power doesn't have a "polarity" of course, just one terminal that has a higher potential with respect to the earth, so there is no point in reversing the incoming wires in a fan that runs on mains electricity (unless it happens to be an enormous 3-phase industrial fan as mentioned above). Altering the internal circuitry might work on some AC motors, but should only be attempted by a professional who understands the circuitry. For a DC motor, there is no need to open anything to reverse the motion, just change the polarity at the source. In either case, best safety advice is don't open it. Dbfirs17:06, 11 January 2011 (UTC)[reply]
Hiding gold in ink
In the Mr. Monk Gets Married episode of the popular television series, the secret hoard of gold is found to be in the ink of a prospector's journals. Monk says that the prospector had melted down the gold and mixed in black ink, and that "any amateur chemist could do it". Now, I have my doubts - I would expect the ink to evaporate explosively on coming into contact with the molten gold (at over 1000°C). So - is there a way in which an amateur chemist could have hidden his gold in ink? DuncanHill (talk) 11:59, 10 January 2011 (UTC)[reply]
Gold paint can be made with powdered gold. I'm not sure of the technical difference between paint and ink, but it could take several volumes of writing to use up one ounce of ink, so I can't see how this would be practical way to conceal any appreciable quantity of gold.--Shantavira|feed me13:01, 10 January 2011 (UTC)[reply]
He did write a lot of journals. I should have mentioned that the ink needs to look like ink and not like gold, as the purpose was concealement. DuncanHill (talk) 13:07, 10 January 2011 (UTC)[reply]
I haven't tried this, but it might work with finely powdered gold and high-carbon ink because the gold powder would tend to sink under the layer of carbon. This would not be a very practical method because the concentration would need to be low to conceal the gold. If Monkthe prospector had the facility for melting gold, then casting it into an everyday object and painting it to match would be a better option, though care would need to be taken that the object could not be "lifted" (in either sense). Dbfirs13:21, 10 January 2011 (UTC)[reply]
He had a clue! The prospector had let it be known that his gold could be found in his journals, so everyone assumed you had to read the journals, which Monk started to do. However, they were full of inconsequential ramblings, and eventually Monk realised that the volumes were very heavy, and he realised that the gold was literally in the journals. DuncanHill (talk) 13:32, 10 January 2011 (UTC)[reply]
Gold(III) chloride is a green liquid that can be mixed with ink. What one need to avoid however, is anything which will cause the gold to precipitate out as metal. Also, it is a salt and will corrode your nib. --Aspro (talk) 13:48, 10 January 2011 (UTC)[reply]
The journals were discernibly heavy? Think of how little ink goes onto a page compared to the weight of the page. Even if the ink was ten times heavier (gold instead of carbon), would you be able to notice the difference between a journal and a journal with writing on? APL (talk) 21:27, 10 January 2011 (UTC)[reply]
The weight must have been increased by at least 7000 ounces of gold, even at today's prices. That's a lot of ink to hide so much gold! Dbfirs11:01, 11 January 2011 (UTC)[reply]
I tried Googling for it; no straight answers. Also, I called the WORLD HEADQUARTERS of it in Chino, and the lady who answered didn't know either. Does anyone know? Is there a supergoogle they can use to figure out why Alorica closed its doors in Manhattan? Thanks. --70.179.178.5 (talk) 12:22, 10 January 2011 (UTC)[reply]
This isn't really a science question. Alorica appears to be a privately owned corporation, which means that (in the United States), the corporation is not required to disclose anything about their business and financial decisions. If they want to close an office, or set fire to a pile of cash, they aren't really accountable to anyone over it. Nimur (talk) 22:58, 10 January 2011 (UTC)[reply]
My laptop has been all paid off. It was manufactured in Fall 2007 so thanks to the rapidly-depreciating nature of these devices, hardly anyone should think it's worth stealing. (I'd still use a Kensingtonlock on it.)
So let's say I find a 24-hour coffee shop to camp out in, since I probably might not have much of a choice. I may still have my debit card that I have now, so I could still get started somehow.
However, I might not have all that much money in the first place, so on this laptop, how do I get started on a very low-overhead online business, in order to get back on my feet and earn a living again? What ideas do you have in regards to that? (Ebay's out of the question; when much of my possessions would already be gone, there isn't much to sell on there. Besides, their fees are the highest of any auction site and I'm only allowed to sell up to 100 items/$5,000 a month. I need to be able to make money without physically possessing much.) --70.179.178.5 (talk) 12:29, 10 January 2011 (UTC)[reply]
I can't really help because I had the same idea when I was living on an income below the poverty line, but I didn't find any good money-making schemes. My reason for replying is just to warn you to beware because most of the "money-making schemes" are really just scams designed to defraud you either by asking for money up-front or by paying ridiculously low rates of pay. I hope you have more success than I did, and I hope you don't end up homeless. Is there no ordinary work available in Compton? Dbfirs12:43, 10 January 2011 (UTC)[reply]
What he said. If there were straightforward and reliable ways to make an adequate living from a coffeeshop using only a laptop and their wireless internet connection, I suspect you'd see a lot more people doing so. Unless you can actually come up with a solid business plan for yourself and you have some particularly desirable (valuable!) skills that you will be able to market and use effectively over the Internet, then you're probably better off just getting a job working at the coffee shop. TenOfAllTrades(talk) 13:58, 10 January 2011 (UTC)[reply]
Proof-reading, translation, website design, marketing consultancy, but you have to have the necessary skills. Either use your existing contacts to drum up business or sign up with agencies. Itsmejudith (talk) 14:34, 10 January 2011 (UTC)[reply]
If you have to ask, then I really doubt if you have the entrepreneurial qualities to exploit the opportunities out there. For instance; you dismiss Ebay -why? You might not have stuff but you do have time on your hands and other people are always throwing away stuff and may even be willing to pay you to take it away, which you can then sell on Ebay. Via Ebay you can advertise your website (you do have a web site don't you) on which you can also advertise other peoples products and get another income stream (but this will be usually peanuts)(that said, the local cat-house might offer good rates of several dollars a click if you can show you are attracting lots of local traffic to your site). You can also use it to advertise your own personal services which you can do because of all that time on your hands. With time on your hands you can travel out and about -take a compact camera with you which can also record video. Keep an eye out for trouble and sell the footage to news channels. Even local papers might of a few dollars for a good action photo. Bank robberies in progress etc., you can syndicate world wide for bigger bucks. Upload to the studio immediately from the scene of the crime. If your out every day you will see these opportunities. Also, for every 20 local businesses you ask. about two will be willing to have a sort video advert posted on Youtube (taken with you camera – with your personal testimony voice-over that it is the kebab shop in Compton or whatever ). Again place links to your website (and their's of course) etc., etc. You have to work as hard at it, as any other job. Plan for being told NO! 25-30 times a day. The few that say 'yes' will more than make up for those that say no. Do lots of small cheap jobs and those bigger ones will just come along by themselves unexpectedly. Don't forget to put money aside for paying taxes.--Aspro (talk) 14:37, 10 January 2011 (UTC)[reply]
You can Turk. Its generally small amounts of money, but if you have time and select jobs wisely, you can make a reasonable amount of cash doing it. --Jayron3216:09, 10 January 2011 (UTC)[reply]
A lot of web money-making opportunities are not simple things that you can turn on like a switch. For instance some blogs and webcomics are profitable, but only after years of slowly gaining a readership and a following. They're essentially creative businesses that have to be slowly built up from absolute zero. APL (talk) 17:49, 10 January 2011 (UTC)[reply]
I think the safest choice is to put all your energy into getting a normal job working 8 hours a day, and once you have landed that and thus secured the means of survival, in your spare time use the laptop to learn a computer-based marketable skill like web design or computer programming or database programming or 3D modeling or the like. Do whatever you can to network with like-minded professionals. After a year or two of such training, depending on how far you progress, you may have enough experience to build a decent portfolio and apply for jobs in a more lucrative field, thus beginning a career. Comet Tuttle (talk) 19:20, 10 January 2011 (UTC)[reply]
Agreed. Tech job stuff is high risk (and no benefits) even in better economies, and when one has resources to fall back upon. The best "no skills required" jobs I've seen lately are working at Whole Foods, which has excellent benefits plans and huge discounts on food. But really anything is better than trying to make money from your laptop when you have no home. (The "ghetto paparazzi" option of Aspro is perhaps the silliest one I've seen so far.) --Mr.98 (talk) 19:46, 10 January 2011 (UTC)[reply]
Yes, it is a shared IP (from a previous questions), but the style seemed familiar and seemed to belong to the owner of the router. Apologies if I guessed wrongly. Dbfirs07:46, 12 January 2011 (UTC)[reply]
If you want a lucrative job that can be performed in a cafe, just write the next hyper-successful work of popular fiction. --Anonymous, 06:59 UTC, 1/11/11 (or 11/1/11, or...).
I don't know if this is useful to you, but if you have some writing or coding skill there are sites like elance.com and guru.com that will pay rather low rates for such work. Wnt (talk) 14:03, 13 January 2011 (UTC)[reply]
Cheapest source of ethanol for sterlisation
A while ago, I asked where is the cheapest place for ethanol (for sterilisation) in the UK and it now seems to me that we already have a reasonably-priced source, compared to alternatives that I've checked. The cost is £6.60 for 2.5 L analytical grade (100%), or £2.64/L. How much do you pay per litre at your laboratory? ----SeansPotato Business15:40, 10 January 2011 (UTC)[reply]
Hi! I have to linearize a hyperbolic graph. Data: x:1,2,3,4,5,6,7,8 y:8,1;4,7;3,1;2,0;1,4;1,0;0,7;0,5. I've already squared x bu got a hyperbola again. Please help. — Preceding unsigned comment added by Atacamadesert12 (talk • contribs) 18:02, 10 January 2011 (UTC)[reply]
Do you want an equation for a linear approximation for this graph? You can use Microsoft Excel to construct a linearization for you; here are instructions from Purdue University and from the official Microsoft Office help page. A linear least-squares fit from Microsoft Excel produced y = -0.9536x + 6.9786 with an R2 of 0.8 (in other words, not a very good fit - but hyperbolae aren't linear! So this poor fit is not unexpected). Knowing something about your purposes would help us pick a better methodology; you can linearize with other techniques than least squares; I would vote for a tangent-line at x=5 or x=6 value; or a set of two linear segments to account for the "steep part" and "shallow part". You could also linearize the logarithm of your hyperbola. Nimur (talk) 23:16, 10 January 2011 (UTC)[reply]
Oh, I thought he was trying to derive the best-fit equation to the hyperbola using the linear method. You can often do so by brute force; if you do stuff like square or take the inverse or take the natural logatithms or some combination thereof, and replot the data, if the manipulated data is linear you can back-derive the best-fit equation for your original data. Its a common method used in deriving the Rate equation in chemical kinetics, the integrated rate law is manipulated and plotted to see if the graph is linear; if it is the order of the original rate law can be determined. --Jayron3223:56, 10 January 2011 (UTC)[reply]
Those responses are correct but they leave out an important factor. A solid object exposed to the sky on a clear night will lose a lot of heat by radiating to space -- the result is that things like cars can become a lot colder than the surrounding air. If there is a cover over the object, it radiates heat back, greatly reducing this effect. Even a cloud cover will considerably reduce radiative heat loss. Looie496 (talk) 20:59, 10 January 2011 (UTC)[reply]
Solutions of [Mn(H2O)6]2+ in water are pretty much colourless to the naked eye, at least all the ones I've seen. You can see the pink colour in the solid because the solid is more "concentrated". Physchim62(talk)00:19, 11 January 2011 (UTC)[reply]
The rule of thumb is that a buffer is effective in the range of plus or minus one pH unit from its pKa. Glycine has a pKa of 2.34, but I have seen some more or less reliable sources list its effective range as 2.2-3.6. Why would a buffer have a skewed effective range like this? ike9898 (talk) 21:52, 10 January 2011 (UTC)[reply]
Amino acids, being zwitterionic, are far more complicated. Also, you have not designated the complete buffer system. Are we talking about, say, a sodium glycinate/glycine system? An ammonium glycinate/glycine system? A glycinium chloride/glycine system? --Jayron3222:04, 10 January 2011 (UTC)[reply]
I don't know about the terminology but I suppose it would be glycinium chloride/glycine (essentially a solution of glycine acidified to pH 2.2 with HCl). Does the presence of the amine group matter? The proportion of these groups that are protonated won't change appreciably between, say pH2 and pH3. ike9898 (talk) 14:28, 11 January 2011 (UTC)[reply]
I think part of the issue is that the "+/- 1 pH unit from the pKa" is a rule of thumb that works best, like all chemical systems, in simple situations where there isn't a lot of factors to consider. I am just speculating here, but the deal with glycine is likely some sort of hydrogen bonding effects whereby the effective pKa of the glycine in buffer is slightly different than the actual pKa of glycine as measured by other methods. I did find this source which lists the same effective range you did, but I do not know what methods they used to arrive at that range. --Jayron3216:00, 11 January 2011 (UTC)[reply]
The term "critical mass" in relation to repopulation
Is "Critical Mass", as a term to describe the number of a population in a natural environment, that would be needed to repopulate itself, actually used as such in science?
Google Book-ing the terms "critical mass population extinction" brings up a few examples of the term being used in this context, but it seems to be used as a metaphor for the physics term, not a normally used one in ecology. This is probably because, as Findlay indicates, there are alternative terms that are more precise. The MVP is more complicated than a simple repopulation issue, no doubt because there are more factors involved for actual animal populations, and because unlike fissioning nuclei, there are inbreeding issues to take into account. --Mr.98 (talk) 22:58, 10 January 2011 (UTC)[reply]
Small populations have decreased per-capita growth rates due to Allee effects. In sexually reproducing animal populations, Allee effects can arise from problems finding mates once the population drops below a critical threshold. As others point out, 'critical mass' is not a phrase commonly used by ecologists. SemanticMantis (talk) 23:45, 10 January 2011 (UTC)[reply]
I'm asking in comparison to most of the discovered exoplanets, including the rocky kepler10b. These tend to be extremely close to their parent star, often closer than mercury is to our own sun. Are planets of such small orbits simply easier to locate, or is our solar system truly unusual in this respect? 131.215.3.204 (talk) 00:00, 11 January 2011 (UTC)[reply]
The reason that discovered exoplanets are closer to their respective stars is that our methods of discovering them require that they be located so close to their stars. Presumably there are lots of different ways in which solar systems may be organized. The type of organization we find in our solar system may be far-and-away the most common way they are organized, we just don't know because there's not really a good method to find a solar system which would look like ours. We definately have no way to locate an Earth-sized planet in the goldilocks zone using those techniques. --Jayron3200:08, 11 January 2011 (UTC)[reply]
Doing a bit more research, it turns out that discovering a solar system like ours may just be possible; a similar system to our own has been discovered around the red dwarf star Gliese 581, the smallest identified planet around which, Gliese 581 e, is the smallest ever discovered exoplanet and is about 2x the size of earth. So it looks like, as of about 2009 we may have the means to correct the biases in the data I noted above. We probably just have a lot more looking to do. --Jayron3200:13, 11 January 2011 (UTC)[reply]
It's a bit like asking what is the most common animals in that hay-meadow? The cows, the rabbits, the field mice, the crickets? We can't (yet) detect Earth-like planets 1AU from a sun-like star. The radial detection method favours massive planets, close to the star. See some earlier queries here. CS Miller (talk) 00:55, 11 January 2011 (UTC)[reply]
Reread the Gliese 581 article. There are several "Earth-like" candidates around that star's habitible zone. That's just one system. Given time and refinement of methods, we may be able to do better in the not-so-distant future. Still, most of the stuff so far discovered is of the "massive planet rediculously close to the star" type, for the reasons you note. --Jayron3201:25, 11 January 2011 (UTC)[reply]
I read that it was discovered by the Kepler space telescope and "Kepler relies on the 'transiting' technique, which looks for planets that pass between their host star and the Earth." [4]. This implies that planets that go round their star faster are easier to spot - to spot one with an orbit the same length as the earth's, Kepler would have to stare at the star for a year. I assume (apologies for guessing) a planet closer to its star will generally have a shorter orbit. Kepler-10b's orbit is less than a day. 81.131.69.118 (talk) 05:59, 11 January 2011 (UTC)[reply]
Dammit, I even read that recently while trying to absorb what "gravitational mass" is (for the question about falling feathers and hammers). "The concept of active gravitational mass is an immediate consequence of Kepler's third law of planetary motion", as it says in the Kepler section of mass. These things are hard to take in. 81.131.69.118 (talk) 06:23, 11 January 2011 (UTC)[reply]
Hi, I'm drawing the Lewis structure for NO2–. Because of the – there is one extra electron available to use, but who gets it? I was taught oxygen is more electronegative than nitrogen and thus should get it, but which oxygen? In the structure I made it actually makes more sense to give it to the nitrogen, then you have one unbonded pair per atom and two covalent bonds and one coordinate bond between each oxygen and the nitrogen in the center. Thanks. 24.92.70.160 (talk) 02:20, 11 January 2011 (UTC)[reply]
Yes, an oxygen gets it. In simple terms, the nitrogen is double-bonded to one oxygen, and single-bonded to one negatively-charged oxygen. In reality, they are both half-bonded, but this can't really be shown in a drawing. --T H F S W (T·C·E)02:46, 11 January 2011 (UTC)[reply]
See nitrite for a more thorough description, and some pictures. The bond order of each nitrogen-oyxgen bond in the nitrite ion is 1.5; they are the same length and strength; but a lewis structure does not allow you to draw fractional bond orders so you have to use resonance structures to fudge it. In your lewis structure, you should make sure each atom obeys the octet rule (that is some combination of 4 bonding pairs and lone pairs). --Jayron3203:10, 11 January 2011 (UTC)[reply]
They can be if you draw them as free radicals. Indeed, I think it is standard to draw both nitric oxide and nitrogen dioxide as have whole-number bond order and leaving the nitrogen as being electron deficient (with seven electron). Such a lewis structure would highlight the tendency of these compounds to spontaneously dimerize, as they do. --Jayron3204:26, 11 January 2011 (UTC)[reply]
Sorry, by "good-looking" I meant "obeying the octet rule". Yes, you can draw them as radicals, and the dot on the nitrogen is a lot more common than the dotted line bond used in those articles. On the other hand, they don't dimerize with the eagerness you'd expect from the run of the mill free radical compound; and consider that molecular oxygen is also sort of a free radical compound despite its deceptively simple Lewis structure. The Lewis structure is a lovely idea, but these compounds are what show its weaknesses. Wnt (talk) 06:49, 12 January 2011 (UTC)[reply]
Not all radicals are created equal. Oxygen (a diradical) does not dimerize because it's radical-containing orbitals are antibonding orbitals; thus forming bonds using these orbitals is actually destabilizing rather than stabilizing. In nitrogen dioxide, the radical is in a bonding orbital, which is why it dimerized. --Jayron3202:39, 13 January 2011 (UTC)[reply]
Well, the theory of evolution has been added to and modified continuously during the century and a half since Darwin's initial writings. I am not sure what you mean by "loop holes". Can you elaborate on what sort of things you are looking for? --Jayron3204:28, 11 January 2011 (UTC)[reply]
Well, the theory suggests the mutation of species from one form to another. It may seem childish, but does it actually imply extinction of one specie while giving rise to another more developed and well suited for surroundings? I do actually think the answer to be negative, but i'm still doubtful about my own opinion,
Also the intermediate stages that the theory speaks of seem to be absent, or maybe well disguised. Why does no one see the intermediate stages between us humans and the apes, when we are supposed to be evolved from the apes themselves and they still do exist?! —Preceding unsigned comment added by 116.73.242.109 (talk) 04:47, 11 January 2011 (UTC)[reply]
To answer your first question, no, it does not mean that one species must go exitinct. It may, or it may not. For example, many types of Crocodiles have remained essentially unchanged as a species for millions of years. Certain specific crocodile species likely descended from earlier forms, and both the earlier form and its descendent still exist today. Also, evolution doesn't produce better forms on an absolute scale; it produces forms better suited to the environment contemporaneous to that form; but since the climate of the earth often changes dramatically as well, what is "best" at one time is not "best" at other times. Also, the fact that new species are evolving is itself changing the environment. As far as intermediate forms go, we actually do have some very good records for intermediate forms for some species lines, and not so much for others. One explanation is that of punctuated equilibrium; that is that sometimes changes happen rapidly, often too rapidly to leave much data behind, while at other times changes happen slowly and gradually. The other explanation is that we likely only have, as yet, found evidence of a tiny fraction of the total number of species ever to exist; there are clearly enough "complete" lines with transitional forms to show the concept of evolution works as expected, but the lack of a complete record of every species ever to exist isn't itself a problem for evolution. Heck, we don't even have anything close to a complete record of every species alive today, not even CLOSE. Never mind those species likely to have lived in the past. Finally, human evolution does not show that humans evolved from (modern) apes. Humans and our modern ape cousins evolved from a common ancestor, not one from the other. In that sense, chimpanzees and humans are equally "evolved" from that common ancestor, we are just evolved in different manners. There are hundreds of intermediate forms between humans and that "nearest common ancestor" with Chimpanzees. The best candidate right now for the closest common ancestor between humans and chimpanzees is probably Nakalipithecus or Ouranopithecus. To an earlier question you had, that doesn't mean that such an ancestor had to die out. It did in the case of modern humans, but there are many times in the fossil record where earlier human species lived for long periods of time side-by-side with an ancestor species. --Jayron3205:09, 11 January 2011 (UTC)[reply]
Depending on how you look at it, many forms of genetic engineering may provide us with 'loop holes' that let us get evolution's positive effects without the negative effects, and without waiting a zillion generations.
If a scientist can design a new bacteria on his computer instead of waiting for one to evolve naturally, then I'd call that a loophole. In the future that same loophole may let our species skip the more tedious aspects of the process. APL (talk) 06:42, 11 January 2011 (UTC)[reply]
I wouldn't call sex tedious :) Anyway punctuated equilibrium does explain that you don't get all intermediate steps at equal frequencies. The theory is basically that the species gets suited to its surroundings like water at one end of a pan. If the pan is slightly tipped the water may run over to another section. New species would normally arise in the same way by the environment changing or a new environment being exploited which leads to a quick burst of change followed by equilibrium again. Dmcq (talk) 10:50, 11 January 2011 (UTC)[reply]
Sure, but even those faster changes are going to be slower than a scientist fiddling genes on his computer and injecting them into an egg. Especially as the scientist can create organisms with traits that do not benefit the organism. (bacteria that produce some chemical that's worthless to the bacteria but valuable to us.)
I would call that a loophole. I dunno if that's the sort of "loop hole" the question-asker was looking for, though. He might have just been looking for a "Oops, didn't carry the two, turns out God did it after all." sort of thing. APL (talk) 15:17, 11 January 2011 (UTC)[reply]
The biggest loopholes are surprisingly reminiscent of Lamarckism and Lysenkoism. Organisms can respond to their environment in some way which (hopefully) has evolved to be adaptive in nature, and pass this acquired characteristic to their offspring. See epigenetics. Now epigenetics per se is not a long-term force in evolution, because it simply marks genes to be more or less active in the next few generations. Exposure to the right environmental stimulus reverts the epigenetic change. However, one component of these epigenetic marks is DNA methylation, and this methylation encourages nucleotide transitions from methylcytosine to thymidine. This alters (typically decreases) activity of CpG islands, for example. In this way it is possible that altered environmental circumstances can permanently alter the expression level of a gene, or perhaps even encourage more rapid exploration of the effect of other mutations to it. This is an ongoing topic of current research, and one expects interesting news. See [5], [6], [7], etc. - search terms like "transgenerational", "epigenetic", "vernalization" (for a classical Lysenkoist case) or a favorite organism. However, bear in mind that such mechanisms only work when some regulatory mechanism has evolved to make them work - at least most of the time they cannot replace standard Darwinian selection. Wnt (talk) 18:59, 12 January 2011 (UTC)[reply]
The OP refers to "the intermediate stages between us humans and the apes." (As mentioned above, both humans and other modern primates evolved from earlier species, but that's not my point here.) Why do evolution skeptics always refer to the human race only in regard to "apes" (or "monkeys," etc.)? The fact is, we evolved "from" e.g. small shrew-like mammals; and we evolved "from" bacteria. A big clue to the ignorance of evolution skepticism is the obsession with "apes." Why aren't "shrews" (so to speak) or "bacteria" the typical sound-bite? 63.17.73.245 (talk) 03:44, 15 January 2011 (UTC)[reply]
Negative Matter
Can darkmatter be negative matter? How would negative matter interact with a blackhole? If the antiproton is made from antiquarks, then what would a negative proton be made of? Does negative matter fall under the domain of supersymmetry? --Plasmic Physics (talk) 05:12, 11 January 2011 (UTC)[reply]
Another name for negative matter is antimass. Antimass is to easy to confuse with antimatter; I chose to use negative matter. If negative matter was more then just a hypothetical placeholder concept, then it would be measured in kg⊖, or if you want to go relativistic, J⊖ s2 m-2.
Another question, would negative matter be visible, since it would radiate negative photons which, are gravitationally repelled by positive matter hence, darkmatter? --Plasmic Physics (talk) 06:51, 11 January 2011 (UTC)[reply]
Well, if you invent concepts like antimass and negative photons, you can give them any properties you like. It is like asking "I just drew a purple dragon, what does it eat?" 88.112.59.31 (talk) 07:06, 11 January 2011 (UTC)[reply]
We have a negative mass article, which has some discussions about its properties. However, it also states that it is a hypothetical concept, so although it's a real idea, it really is in part "let's make up stuff for it based on what we propose it to be" based on existing rules, and given that one has to choose which existing rule(s) to follow vs knowingly violate. DMacks (talk) 07:46, 11 January 2011 (UTC)[reply]
I have read it, but it does not discuss my questions? There are some verified discoveries which breaks or contradicts scientific paradigms, such as the heavy proton recently observed. --Plasmic Physics (talk) 09:04, 11 January 2011 (UTC)[reply]
The problem with calling it negative matter is that you do not specify which property is negative (for example, electrons are negative matter because they have negative charge or would it be better to call the positron "negative"?). If you do mean negative mass, then no, this could not be dark matter because this is known to have positive mass. It is interesting to speculate, but, as far as I know, no exotic particles have ever been discovered that exhibit any of the properties expected of negative mass. Our best guess at the moment is that negative mass does not exist, but at one time it was believed that antimatter wouldn't exist, so who knows what will be discovered in the future? An antiproton is indeed made of antiquarks, and is a negative proton in the charge sense, but it has positive mass equal to that of the positive proton. Current theories of supersymmetry do not include any particles with negative mass. Dbfirs09:49, 11 January 2011 (UTC)[reply]
A similiar case exists for antimatter, the term does not define what antimatter is anti to. Your answer is nonetheless helpful. How would darkmatter behave differently if it was nagative mass? Since it does not associate with positive mass, would we have to search for it in a different place all together? --Plasmic Physics (talk) 07:19, 12 January 2011 (UTC)[reply]
You are correct, of course. The original suggestion of "antimatter" had negative mass, but the modern definition applies only to matter with the opposite charge (at quark level in the case of the antineutron). Because people often think of charge as being positive and negative, the term "negative matter" is often taken to mean antimatter in the modern charge sense. Perhaps "unmatter" could be used for matter with negative mass? I don't quite understand how the antineutrino fits my analysis, other than in its helicity. Why is it not its own anti-particle? Perhaps an expert can explain? Dark matter was proposed purely to explain the extra mass in rotating galaxies, so it must have positive mass. This does not preclude the possibility that dark "unmatter" (your negative matter, with negative mass) could not also exist between galaxies, though it might eventually be detectable if it occurs in large quantities. Dbfirs08:25, 12 January 2011 (UTC)[reply]
Dark Matter does associate with matter of positive mass. The way we know Dark Matter exists is due to it's gravitational interaction with visible matter of positive mass. Are you thinking of the idea that Dark Matter is Weakly Interacting Massive Particles (WIMPs)? Wevets (talk) 17:06, 12 January 2011 (UTC)[reply]
The big problem with "negative matter" as dark matter is that the only way we know about dark matter is that it contributes unexplained positive mass to a system. For example, galaxies spin like dinner plates rather than with central portions greatly outpacing the more distant parts, which is explained by the presence of a vast unseen shroud of dark matter in a rough ball, which makes the galaxy seem heavier and heavier the further you go out.
There are other problems with negative matter, like that one expects negative matter to have negative gravity, pushing positive matter away from it - but positive matter exerts normal gravity that pulls in things at the same rate regardless of mass (even if it is negative!). So a pair of positive and negative matter objects should start flying away at faster and faster speeds through the cosmos. (Actually this doesn't violate conservation of energy because the negative matter gets a more and more negative energy the faster it goes, cancelling out the increased energy of the positive matter...) Wnt (talk) 19:24, 12 January 2011 (UTC)[reply]
Thank you all, these are good answers, I have all I need.
In my opinion, dark matter seems like a bunch of hooey - I think it is just an illusion caused by some undiscovered modification to an existing physical law which, only becomes apparent at extreme distances, just like relativistic effects. At the moment it looks like an astrophysical fudging like the cosmological constant.
Yes, it is possible that dark matter, dark energy and dark flow will all turn out to be unnecessary like Phlogiston theory and Aether theories when more sophisticated theories are developed. Antimatter (in the modern sense of "opposite charge") is, of course, real, and work is continuing to "make" a significant quantity of it. Dbfirs21:20, 13 January 2011 (UTC)[reply]
Chevrolet Volt heater operation
A typical gasoline engine car provides no heat for the first several minutes/miles of operation, until the engine is hot and the thermostat opens. I've heard that some cars of the 1940's and 1950's had additionally a gasoline-burning heater which provided instant heat, which would be highly pleasing in the northern US in the winter. My question is, does the Chevy Volt heat the passenger compartment only with waste heat from the gasoline engine, or does it provide instant electric resistance heat? If so, does it also use waste heat from the gasoline engine to heat the passenger compartment after the gas engine has started and warmed up after long distance driving? Instant heat would be a big selling point for those in areas where it gets extremely cold in winter. Edison (talk) 05:15, 11 January 2011 (UTC)[reply]
Yes to both[8] it uses both waste heat and electric heat. But using electric heat cuts the range significantly. Apparently this problem is one of the reasons that pure electric cars are not more common - it's very hard to store enough power to both heat the cabin (or cool it) and power the wheels. Ariel. (talk) 06:39, 11 January 2011 (UTC)[reply]
Even if the all electric range decreased significantly, it would seem like a strong selling point. A car plugged in could also be "preheated" off the grid, by a timer or by electric signalling (Tweet your car heater). I wonder if an electric block heater on a gas engine car provides heat immediately, or if it does not get the engine and coolant warm enough for that? Edison (talk) 15:33, 11 January 2011 (UTC)[reply]
You might be interested to know how the Prius handles the early heating issue: when you turn off the car, it pumps the coolant into an enormous thermos which keeps it hot for a few days! --Sean16:32, 11 January 2011 (UTC)[reply]
Is there an article or website somewhere which describes this? With gasoline engines, there is a danger of damaging the block if hot coolant is placed in a very cold engine or vice versa. Edison (talk) 20:24, 11 January 2011 (UTC)[reply]
on what basis the inversions are classified....the inversions are provided a specific number why?..
for single slider crank chain..
1.steam engine
2.whitworths mechanism
3.crank and slotted leverquick return
4.hand pump,pendulum pump
so my basic question is that why the inversions are number specific.is there any rule that says we must fix this link first and this one to be fixed second.
dplease help me —Preceding unsigned comment added by 115.248.161.154 (talk) 05:20, 11 January 2011 (UTC)[reply]
Electric utilities are generally required to limit the amount of high speed recurring voltage variation so that the lights do not "flicker" noticeably due to industrial operations such as motor starting or arc furnaces at some other customer. This often has required putting in much heavier power supplies than would otherwise be required, at a cost of millions of dollars. "My friend flicker". Edison (talk) 15:37, 11 January 2011 (UTC)[reply]
Flickering flame is a form of combustion instability. Mechanical and aerospace engineers study flame stability in the design of combustion engines (including automobiles engines, jet engines, and rocket motors). Controlling "flicker" may involve careful timing of fuel injection, valve control, and mechanical design of the combustion chamber. Nimur (talk) 19:29, 11 January 2011 (UTC)[reply]
Hi, several times I have found when I place a book (or road map etc) on the front passenger floor, I get condensation, enough to leave significant water damage on the book. It seems to mainly happen when I have the aircon on, but I think it has happened at other times too. I'm more careful these days with books, but it seems to still happen on the carpet, although it is less noticeable then, perhaps because it doesn't accumulate. Does it mean I have a leak, or is it just something that happens to cars? It's been emotional (talk) 06:43, 11 January 2011 (UTC)[reply]
I know that on many Jeep Wrangler models, the drain for the air conditioner goes through the firewall of the vehicle on the passenger side. This drain often becomes clogged and the water will then spill over into the cabin by the passenger side foot well. If you open the hood and look for a small tube coming out of the firewall on that side of the vehicle, you should be able to see it and clear it. See this link for an example of what I'm talking about. Or there is water coming in from the engine cowl. See this link for more on that. Note: I'm familiar with Jeeps, so both links are to a Jeep forum that I'm familiar with. You didn't mention what kind of car you have or if you drive a Jeep, so your mileage may vary. :-) Dismas|(talk)08:06, 11 January 2011 (UTC)[reply]
It could be condensation on the airconditioning pipe that feeds cold air to the footwell dripping down onto the carpet. I vaguely recall someone I know who had a car that actually DRIPPED water slowly onto the carpet when the aircon was run. Can't remember the car, whether or not it was old or new or had a known problem etc. Zunaid12:04, 11 January 2011 (UTC)[reply]
Can we collect nectar collected by the bees before it becomes honey? Will it taste like, say, maple syrup?
On the other hand, can we use natural or artificial enzyme to process collected nectar? Is it possible to "brew" honey in a factory? Let's say we may build a man-made beehive with a built-in nectar collector. Then we collect the nectar from the beehive and let the poor bees work day by day without getting anything. We can "brew" honey using the high-tech regurgitation vessel.
I just finished watching Bee Movie the third time. This movie gives me some kind of desire to control the nature and enslave the animals and destroy small farmers. -- Toytoy (talk) 08:34, 11 January 2011 (UTC)[reply]
Yes, but the average honey bee will make only one twelfth of a teaspoon of honey in its lifetime and I doubt whether a human could do the work much faster. The nectar tastes of the flower from which it is collected. You can drink the nectar from clover flowers quite easily, but in minute quantities.--Shantavira|feed me09:48, 11 January 2011 (UTC)[reply]
Where do you get the 1/12 of a teaspoon per bee-life from please? I've heard that before, I'd like to check its validity, as I'm awed that a teaspoon of honey is the life's work of twelve bees. 92.24.190.219 (talk) 21:28, 11 January 2011 (UTC)[reply]
I think the fuschia has a lot of nectar because it's pollinated by hummingbirds. (This fact, coupled with the absence of any British hummingbirds, only increases the puzzlement I expressed in that thread. Will have to look out for insects on fuschias ... maybe a butterfly with a long tongue could get at the nectar.) 81.131.11.15 (talk) 15:24, 11 January 2011 (UTC)[reply]
Fuchsias (note spelling) are not native to Britain; they are (or originally were) imported, propagated artificially by nurserymen and gardeners, and probably never get pollinated naturally in Britain (although it's just possible that some hawk moths, such as the Elephant hawk moth whose caterpillars will apparently eat fuchsias, might adapt themselves to some varieties of the plant. 87.81.230.195 (talk) 16:42, 11 January 2011 (UTC)[reply]
What puzzles me is that I like to rob their nectar myself, which worked great in the cold north of the country in my childhood, but I never seem to get any these days, so something else must be getting there first, but what? Like you say, maybe it's hawk moths depriving me of what's rightfully mine. I've consciously noted the spelling before, it doesn't help. 213.122.45.159 (talk) 17:19, 11 January 2011 (UTC)[reply]
I had a similar objection to those sorts of redirects years ago when I first arrived at WP. But I got over it. We have to deal with the fact that vast numbers of people say "few-she-ah", not having the slightest idea, and even less care, that it was named after anyone calld Fuchs, and if they were to be so advised, they'd still in most cases avoid "fooks-ia", partly because it sounds quasi-rude and partly because nobody else they know ever calls it that, and they don't want to be the odd man/woman out. This is a good example of what I call the Schnitzel Syndrome. People tend to say "snitzel", or worse, "snitchel" - and then spell the word to conform to their mispronunciation. The world is full of people with tin ears when it comes to anything that's even slightly out of the ordinary for their idiolect, and for those who do hear the differences, it can be very unsafe to risk appearing pretentious. -- Jack of Oz[your turn]19:03, 11 January 2011 (UTC)[reply]
To complicate matters, I imagine many people hear of it as a color name first. While 'fooks-ia' can be argued as correct pronunciation of a (latin-ish) scientific name, I'm not sure this applies to the color. Also, my copy of the (descriptivist-leaning) NODE gives /ˈfyoō sh ə/ as the only pronunciation for the color and plant. SemanticMantis (talk) 20:01, 11 January 2011 (UTC)[reply]
I understand your question is somewhat tongue-in-cheek, but the whole point of eating honey is that the bees do all the 'leg-work', and we get a delicious treat with a long shelf life. I don't think you'll find a way to harvest nectar that is more efficient or less costly. SemanticMantis (talk) 20:05, 11 January 2011 (UTC)[reply]
Anyone with new ideas for theories in creation of solar system
I am A. Mohammadzade, and I live in Iran, and graduated in Iran University of Science and Technology. I have some studies in astronomy and physics thus, I want to have scientific discussions about my favourite course, without political or religion based matters.
I wrote some letters to physicists and scientific researchers, to send my new idea to them. In these contacts, I learned some knowledges, and will use them for further researches.
I named my theory "Great Cojunction" which, is based on the new observations in astronomy. I want to publish that.
As we know, the explaining of world creation guides us to two parts of observations:
Are there such as our solar sytem in other places and galaxies?
Are there some universes same to our one?
I think that is not correct that we say something about God and creation when we have so shortages in our theories and calculations, and I try to find out that our solar system is special one.
Finally, I say it is so.
First, I wrote some questions to them about the shortages in recent theories of Big Bang and solar system mechanism, such as this (that I copy from my letters):
Some questions:
If the matter and space in 0.0001 second of Big Bang expanded in the radius of solar system, then the first hadrons might have 1000c speed, because the light moves this radius in time about 1000 seconds. If hadrons were 10 to the power of 14 degrees centigrade hot, then all nuclei of atoms might have such tempreature now. Cand we use thermodynamic rules for first hadrons or quasars?
And for the solar system:
Otherquestions:
How can invisible fine particle orbit in any orbital around the Sun?
The cloud in density, 3 atoms or 100 atoms in one cubic centimeter can be visible? We live in ocean of atoms of air 1 milion atoms in one cubic centimeter and it is not visible.
What made the center of earth 6000 degrees centigrade? Can condensing make this heat, and it still be warm for 4 billion years?
Where did made the water?
Why Phobos is not spiral and Icarus has such orbital?
What made Titan so seemed to Earth?
What made heavy metals and elements in Earth?
What made Cassini discontinue in Saturn?
What made the sun spots?
How did the fine particles condense together?
Smallest moon of Mercury, Fubus has more density than semi-star Jupiter, why?
Why the orbital of Pluto has so angle with orbital of other planets?
The coma of comets move ahead of that and has about 150 million kilometers length with any core.
Less than moon, which gravity formula can display thus movement?
My remarks are these. And I hope that I be sucsessful to publish them and and day write them here. Thoses problems in desription are not for my less knowledge about the solar system, those are some real undiscript subjects in recent theories, I hope to solve.—Preceding unsigned comment added by 78.38.28.3 (talk) 10:00, 11 January 2011 (UTC)[reply]
I've tried to understand your questions as best as possible. Your English isn't always very understandabale but that isn't a problem. Here are some answers:
I didn't understand this question
Nebulae are visible because the gasses absorb light from stars then re-emit them, some in the direction of earth. We can see them because of the light they re-emit and because they are against a background of black space. Air in Earth's lower atmosphere is not excited by radiation in the same way and we look through it to a background of tress mountains, whatever is in the way, not against empty black space, thus we do not see this effect. For something similar on earth see aurora (astronomy).
Phobos is a captured asteroid rather than a moon that was formed at the same time as Mars. You'll need some understanding of orbital mechanics to understand why the orbit is the shape it is (or someone with more knowledge will come along to explain). Same with Icarus.
In which way do you mean Titan is similar to Earth?
All the heavy metals (heavier than oxygen) are created in supernovas when VERY massive stars die and explode, which scatters the elements all throughout the universe. See supernova nucleosynthesis.
You mean "smallest moon of Mars". Phobos is composed of mostly rock. Jupiter is composed of mostly gas. In fact all the rocky planets are denser than the gas giants.
Much of the guts of the question is beyond me. But the header grabbed my attention, reminding me of what King Alfonso X The Wise of Galicia, Castile and Léon, said:
Had I been present at the creation, I would have given some useful hints for the better ordering of the universe.
Thank you for correcting my remarks and for your replies. I ought to explain some of my questions. The gravity roles for all objects in universe is so that we have for planets and stars. I say that is there any formula for particls and icy matters in density less than gas in coma of comet that tide them togather in such distance 150 - 800 million kilometers?
I know how the elements are made in supernovas thus, I think that if chondrites brought them here to our Earth, then they might be equal part of them in all over the earth, but we have so mines in parts of Earth: iron, copper, gold, and aluminum. So, what made the asteroids? Why such asteroids are not near the outer planets? Where did the temprture of Earth's core come from? If chondrites made the planets so the Jupiter, Sun, Saturn, and Uranus had more density, that observed that Earth is 4.5 billion years old, but the rocks of Moon are 3.5 billion years old? The Titan has atmosphere only nothing, no life condition and else other, I say: what happened that the Pluto lie in such orbital and else others?
I have good replies to these questions based on my developed theory development of the solar system mechanism theories by Coiper and Whitsicher. Best regards. —Preceding unsigned comment added by 78.38.28.3 (talk) 04:24, 12 January 2011 I WANT PUBLISH MY THEORY BUT I KNOW SOME MAGAZINS WONT BELIVE MY NEW THEORY > AND THAT FELT AWAY >SO I CHOSE UNUSAL WAY
this is my CV:
a. mohammadzade
birth: may 23 1973
Ms in traffic and transportation engineering
graduated in (IUST)iran university ofr science and technology
1998
Last night on a TV show called Into the Universe with Stephen Hawking Dr. Michio Kaku said the mathematical models for black holes and those for the big bang are very similar. "Similar" is a subjective word, and if I saw the models on paper next to each other, the best I could do is look at them as pictures. So I wonder out loud to any of you who have more understanding of the two models, how similar are they really? 20.137.18.50 (talk) 13:38, 11 January 2011 (UTC)[reply]
This is perhaps not a very helpful answer, but they have in common the fact that they are singularities, we can't see or measure anything in them, and we don't understand them. I'm sure an expert can give a much more useful and informed answer. Dbfirs16:51, 11 January 2011 (UTC)[reply]
Roger Penrose has pointed out that a black hole and the big bang are fundamentally different in that in a black hole there are tidal effects that increase towards infinity as you come near the singularity, whereas there is not supposed to have been any tidal effects close to the big bang singularity. –Henning Makholm (talk) 19:52, 11 January 2011 (UTC)[reply]
I'm not sure that "outside" makes sense even in scare quotes here. If I remember correctly, there are big bang models where there are spacelike geodesics that end at the singularity; that would be as close to "spacetime outside the singularity" as one could reasonably hope for. –Henning Makholm (talk) 12:08, 12 January 2011 (UTC)[reply]
Michio Kaku, though technically a professional physicist, is not well regarded by his peers. He mostly talks to talk-show hosts and documentary filmmakers because none of his colleagues will listen to him. That said... he's correct about this. The general-relativistic model used to describe the big bang is the only way of modeling, in general relativity, a perfectly homogeneous and isotropic ball of matter that's expanding or contracting. That means that the perfectly homogeneous and isotropic big bang and an idealized black hole collapse (starting with a spherical cow) look basically the same. Maybe this means they are the same in some deeper way, or maybe it's just an example of the Strong Law of Small Numbers. But it's also true (as Penrose said) that the tidal forces near the singularity go to infinity in a Schwarzschild black hole, but to zero in the big bang. How do you reconcile these contradictory statements? I wish I knew. It may have to do with the Schwarzschild black hole being a vacuum (there's no matter anywhere), whereas real black holes would have to form from collapsing matter. If you looked at a more realistic model, the tidal forces would be small in the collapsing matter region, but large in the outside vacuum (which would be "before the big bang"/"after the big crunch"). Penrose thinks that the tidal force difference has deep implications related to the arrow of time, but he's certainly wrong about the philosophical implications of Gödel's theorems (The Emperor's New Mind) and he might be wrong about this too. -- BenRG (talk) 09:20, 12 January 2011 (UTC)[reply]
It's unclear to me how you get from "The general-relativistic model used to describe the big bang is the only way of modeling, in general relativity, a perfectly homogeneous and isotropic ball of matter that's expanding or contracting" to "the perfectly homogeneous and isotropic big bang and an idealized black hole collapse look basically the same". The premise does not seem to say anything about black holes. Even in an idealized black hole collapse, the initial situation is not isotropic at most points. –Henning Makholm (talk) 12:08, 12 January 2011 (UTC)[reply]
(I guess this is a science question. Maybe it could be a humanities question too.) It is part of legend that incarcerated hoodlums spend their time lifting weights, such that they leave the penitentiary much bigger and stronger - and therefore more dangerous - than they entered it. But considering the restrictions of prison life, how is this nutritionally possible? Wouldn't it require a lot of protein-rich food to build up large muscles? Would not an inmate, in order to acquire and maintain such a physique, require a much richer diet than his sedentary fellows? How would he acquire the calories? By bartering with other prisoners? Or is penal alimentation handled in such a way that prisoners can decide for themselves how much they will eat? LANTZYTALK13:41, 11 January 2011 (UTC)[reply]
I assume many a skinnier inmate's lunch is stolen by, er, given to a guy who starts out bigger and/or meaner who gets bigger, thus forming a cycle. 20.137.18.50 (talk) 14:22, 11 January 2011 (UTC)[reply]
There is an over-supply of protein in most Western diets. Adults eat far more protein than they need, and the surplus is normally just converted to calories. 92.24.181.78 (talk) 15:19, 11 January 2011 (UTC)[reply]
They aren't fed gruel. They're fed what is basically cafeteria food. Googling "prison food" comes up with many articles describes common practices in the US. It doesn't sound hard to get enough calories or protein. All-you-can-eat buffet style seems common for certain categories of food (e.g. potatoes, beans, etc.). --Mr.98 (talk) 16:52, 11 January 2011 (UTC)[reply]
Nutraloaf discusses just where US courts have considered the edge of "adequately nutritious" to be. There's not enough information there, or enough of a standard, to gauge whether that has enough protein to allow for much muscle building. -- Finlay McWalter ☻ Talk21:21, 11 January 2011 (UTC)[reply]
In unconventional prisons operated by the United States federal government, including those operated to detain enemy combatants, "dietary manipulation" enhanced interrogation techniques (feeding prisoners nothing but Ensure drink) is considered acceptable and legal. "“This technique involves the substitution of commercial liquid meal replacements for normal food, presenting detainees with a bland, unappetizing, but nutritionally complete diet. ... “Although we do not equate a person who voluntarily enters a weight-loss program with a detainee subjected to dietary manipulation as an interrogation technique, we believe that it is relevant that several commercial weight-loss programs available in the United States involve similar or even greater reductions in caloric intake.”" Nimur (talk) 22:08, 11 January 2011 (UTC)[reply]
In "unconventional prisons operated by the US federal government", plain old torture is also used, both officially and unofficially. As we now know, neither the eights amendment nor basic human rights or decency count anything if the Shrub in the White House determines that somebody is an "enemy combatant" (no matter if that is true or not). --Stephan Schulz (talk) 02:21, 12 January 2011 (UTC)[reply]
After a cursory read of some of the references at Nutraloaf, it does not appear that any of the prisoner suits attempted to challenge the nutritional value of the food, so they don't really tell where courts would draw the nutritional line, were that question before them. As for Nimur's links, those who defend such techniques also seem to argue in general that the constitutional protections afforded domestic criminals do not apply to WoT detainees at all, so we cannot really infer anything about what they think about the effects of the 8th amendment when it does apply ... –Henning Makholm (talk) 22:37, 11 January 2011 (UTC)[reply]
I do believe that the original genesis of the US RDA (recommended daily allowance) of essential vitamins and trace minerals was the definition of the amount of such nutrients required to prevent disease in federal prisoners. Franamax (talk) 01:24, 12 January 2011 (UTC)[reply]
In a letter to Flex (Flex 28.10 (Dec 2010): p32(1).) a body-building inmate in Alaska's prison system states that he has access to as much whole food and protein as he wants and that he eats 5-6 meals a day. He adds that he has put on 30 lbs of muscle since the beginning of his incarceration. While anecdotal, this suggests that at least some of the US's prison population has access to additional nutrition if they need it to support a body building program. Cla68 (talk) 05:10, 12 January 2011 (UTC)[reply]
Excitation of electron
A photon interacts with an electron in an atom which excites the electron causing it to jump to a higher energy level. but what happens to that particular photon involved in the process. I mean a photon is a particle and it doesn't makes sense for it to just go poof! -Raky rough (talk) 14:33, 11 January 2011 (UTC)[reply]
Well sometimes it is useful to think of photons as particles, and at other times it is clearer to think of them as waves that can be generated or absorbed by electrons or in many other situations. See Photon#Stimulated_and_spontaneous_emission and Absorption_(electromagnetic_radiation) for some examples. Remember that the photon as a particle has zero rest-mass (all of its apparent mass is "really" just energy), so it can appear and disappear as energy levels change. You say "particular photon", but they are actually indistinguishable because they can all be considered as just "packets of energy". Dbfirs17:22, 11 January 2011 (UTC)[reply]
Richard Feynman compared the absorption and emission of photons to an acoustic wave (as a metaphor only - don't try to read too deeply into this). Here's his explanation in The Pleasure of Finding Things Out... "The view is that photon numbers aren't conserved, they're just created by the motion of the electron." Then Feynman makes an analogy of emitting and absorbing photons as a comparison to a person speaking or hearing words. There's no "word bag" that runs out of the word "cat" if you say it too often, or don't hear/absorb enough words. You aren't conserving the count of the words - the words only exist as a phenomenon of interaction when you speak or hear something. Similarly, photons only exist as a "phenomenon" that exchanges energy and momentum when matter undergoes an electromagnetic interaction. Nimur (talk) 19:36, 11 January 2011 (UTC)[reply]
Actually, photons aren't just packets of energy - they also have a certain fixed angular momentum (irrespective of wavelength, interestingly enough). This angular momentum is what allows the electron to jump up the energy level; it is also experimentally detectable as a force applied by circularly polarized light. (See also here) Wnt (talk) 06:09, 12 January 2011 (UTC)[reply]
I think it is a lantana variety. I am going by the way the outer flowers are opening first and the shape of the leaves. There are many varieties so a better photograph is required to get a better identification Richard Avery (talk) 18:20, 11 January 2011 (UTC)[reply]
Lantanas are very common around here (I live about 20 miles from Fremont BART), so that's a reasonable suggestion, but although I'm quite familiar with what they look like, that picture is just too fuzzy for me. Looie496 (talk) 19:47, 11 January 2011 (UTC)[reply]
Hmmm, by the way... Is any of the fancy software for sharpening images from ground-based telescopes usable on photos like this, and is it freely available? Wnt (talk) 06:11, 12 January 2011 (UTC)[reply]
You could try Iris, but I think this image is too small and noisy to be deblurred effectively (I may be wrong). For what little it's worth, I'm pretty sure that's a lantana. I know nothing about flowers, but I do live in the Bay Area. -- BenRG (talk) 08:40, 12 January 2011 (UTC)[reply]
No, the air pressure (and thus the density) is equal at all points inside the bubble, in the simplest approximation. Insofar as you can consider a bubble in "equilibrium", the gas pressure is uniform at all points in the bubble, and is equal to the surface-pressure exerted on the interior of the liquid bubble surface (that is, the sum of atmospheric pressure plus the surface pressure of the liquid, related to its surface tension). In a more detailed, dynamic and time-varying analysis, the pressure at each (x,y,z) point in the bubble varies with time and satisfies an acoustic wavewave equation, with boundary conditions defined by the liquid-gas interaction at the surface. The actual bubble surface will "wobble" dynamically, varying in shape around the approximately spherical "steady state" eigensolution (which is only satisfied when the pressure is exactly uniform at all points in the bubble). Other effects you might consider include: whether the bubble is moving as a whole entity (and potentially undergoing force due to net acceleration of the entire unit); the force of gravity, which does set up a vertical pressure gradient in the bubble (mostly insignificant for small bubbles in normal atmospheres); and anything the bubble edge bumps into (such as a liquid surface, another bubble, the ground, and so on). Nimur (talk) 19:23, 11 January 2011 (UTC)[reply]
A soap bubble in air is interesting, because to first approximation it is very simple, but as you point out, the details quickly become complicated. The dynamics seem to be very neutral, and thus the familiar 'wobble'. Do we have any articles that discuss neutral stability (or perhaps more precisely neutrally stable equilibria)? Surprisingly, the word 'neutral' does not occur in stability theory, dynamical system, or even equilibrium. Linear dynamical system does have 'centers' listed on the classification diagram, but no definition or discussion (and this is obviously not a linear system anyway). Is there some terminology I'm missing? SemanticMantis (talk) 19:50, 11 January 2011 (UTC)[reply]
You might be looking for information contained in the perturbation theory article? The "neutral equilibrium" is properly called an eigenfunction - specifically, it is the 0th order, or zero-frequency, solution of the acoustic wave equation with boundary conditions applied. It may also be called the "trivial solution," the "steady state solution", and so forth. The wobbles would be other higher-order harmonic eigenfunctions; it so happens that in this case, these solutions are oscillatory, so the bubble "wobbles" back and forth. I think the message we need to convey to the original poster is that the actual answer depends on how accurately and completely you want to analyze the bubble. Nimur (talk) 20:02, 11 January 2011 (UTC)[reply]
Now that you mention it, as "accurately and completely" as presently possible. I made the mistake of assuming that is how all questions are answered here. —Preceding unsigned comment added by 165.212.189.187 (talk) 21:19, 11 January 2011 (UTC)[reply]
Well, I could dive deeper into a presentation of the wave equation solution, if you are interested in the complete "answer" to this question; but I somewhat hold the opinion that either (a) you already understand techniques for solving partial differential equations, and can easily apply them to analytically or numerically solve for soap dynamic pressures; or (b) you do not already know how to solve those types of equation, and even if I provided a flawless overview of them here, the brief few paragraphs I might write would be insufficient preparation to train you in how to apply those mathematics to this problem. (I'm sure you're capable of learning them, if you're interested to learn; it's just that this is a complicated subject and takes a long time to master). Are you interested in books on soap bubble dynamics? Many prestigious physicists have written extensively on the topic of soap bubble physics; in fact, entire textbooks exist to explore their dynamic solutions. Here are a few Google search results to peruse; those will expose you to some of the techniques you need to analyze the problem "as accurately and completely as presently possible." If you need help finding a more specific resource, I can recommend numerous fantastic textbooks on mathematical methods and/or mechanical dynamics. Nimur (talk) 21:45, 11 January 2011 (UTC)[reply]
Then why don't you just answer every question with, "go look it up yourself here is the link."? To me that is not answering the question asked. I asked, "if the centerpoint of a soap bubble filled with air more dense than any other point in within the bubble?" A logical expectation is a yes or no followed by supporting evidence, not "it depends" that is the most absurd cop-out answer there is. From the way this question is answered I could answer every question on the desk with a bunch of wish wash, say depends a couple of times and then create a link to a site that i google. —Preceding unsigned comment added by 165.212.189.187 (talk) 13:40, 12 January 2011 (UTC)[reply]
It looks like you've received a very thorough answer and discussion from individuals who have a fair bit of expertise. In response, you've mocked and berated these generous volunteers who contributed their time and effort to try to help you. Nimur, I note above, didn't just tell you to 'go away and read the links'; he asked for clarification from you about the degree of assistance (and depth of explanation) that you sought, and was prepared to offer you additional, specific recommendations of references and textbooks that you might find useful depending on your interests and abilities. The Reference Desk is not a magic answer machine, and the volunteers here aren't automatons to be ordered about for your convenience. The correct answer to your question is in the very first answer, and boils down to 'No, to a reasonable first approximation, but for real bubbles it depends." How far you want to take the 'it depends' is up to you. It's not our fault that the laws of physics don't always generate simple and simplistic results. Would you be this rude to a real librarian at a physical library reference desk? TenOfAllTrades(talk) 15:51, 12 January 2011 (UTC)[reply]
Trying hard to assume good faith from the OP, I'll point out that it is not obvious that a soap bubble is an extremely complex system that requires years of advanced study to understand. This may contribute to the OP's frustration, if not excuse hir rudeness. SemanticMantis (talk) 16:13, 12 January 2011 (UTC)[reply]
I think the problem here is that Nimur's initial two sentences are a perfect answer to the question, and everything after that is an unfortunate over-analysis contemplating very rare special cases of acoustic standing waves which would be so transient if they occurred as to be negligible. The answer is no. 71.198.176.22 (talk) 10:58, 13 January 2011 (UTC)[reply]
Ten, that depends. But seriously, Obviously people come to this desk to satisfy their curiosity about odd and mysterious things. And I like it for that, but when questions are not answered as asked, I don't believe that is ordering you around, just answer the question. if the OP wants more they will ask more.
71.198, thanks for the answer. —Preceding unsigned comment added by 165.212.189.187 (talk) 13:52, 13 January 2011 (UTC)[reply]
We have an decent article on the Fuller projection, which has a couple of nice examples of it. What I can't find anywhere on the web (and this would seem like an obvious thing that people would like to produce as a project) is a nice black-and-white outline version, such as you could easily print out and copy, colour in, cut out, and assemble. I'm quite prepared to add the tabs myself, but my graphic design skills fall sadly short of converting the thing to a simple, clean, outline version.
So, does anyone know of such a source, or feel generous enough to make one? I'm sure such a thing would be heavily linked-to and used in all manner of schools and clubs, so you'd be contributing to the global education of at least one generation! 86.163.214.50 (talk) 21:40, 11 January 2011 (UTC)[reply]
Fortunately, this map is an SVG file. You only need remove the 1st, 3rd, and 4th path groups (enclosed in <g> tags) to reveal only the continent outlines. I have uploaded a modified version, File:Fuller projection rotated (land only).svg. You should be able to save this as a PNG or other file; or print it directly. If you need the dashed-lines, or want any color or line-thickness changes, those are easy modifications. Please abide by the license if you reuse this image. (If you aren't sure how to use this file, click here for a version without grids and with grids). Nimur (talk) 22:53, 11 January 2011 (UTC)[reply]
Oh wow, thank you so much! And yes, I'll abide by the license. It will be quite cool to tell them they're using something a volunteer made just so people could see it and use it :) 86.163.214.50 (talk) 00:32, 12 January 2011 (UTC)[reply]
Glad to help. Technically it is the work of many volunteers. The source dataset came from the National Geophysical Data Center (funded by the United States federal government); the original image was created by Eric Gaba, and all I did was remove the colors... It's a collaborative effort to keep information free and free. Nimur (talk) 00:51, 12 January 2011 (UTC)[reply]
January 12
Obesity and diabetes caused by low carb diet?
There are so many more obese people in North America compared to Europe that you can instantly see the difference on the streets. Also, when I'm in the US or Canada, I have difficulties getting my usual high carb, low fat diet. If you order steak with potatoes, what you get is a huge steak and hardly any potatoes. Ham sandwich for lunch? You'll get a lot of ham, hardly any sandwich, like this. Apparently, this is the normal North-American diet, they get most of the calories from fat, proteins, and eat very little carbohydrates. Also, people there seem to think that carbohydrates are bad. After first ordering for more potatoes, I only got what I was served the first time, so I asked for a plate full of potatoes. The (very obese) waiter almost refused to give me that. He said that it is very unhealthy to eat that many potatoes, even though one plate full would still be half of what I normally eat. After finishing that plate I ordered another plate. The waiter almost went crazy...
This leads me to think that a normal high carb diet can prevent obesity and diabetes. Perhaps people in North America are obese because they believe that carbs are to blame for obesity. So, the less carbs they eat, the fatter they become, prompting them to eat even less carbs. This makes sense, because a low carb diet will give you very little energy to be physically active. Energy from fat cannot be released rapidly enough to sustain activities like fast running for long... Count Iblis (talk) 00:54, 12 January 2011 (UTC)[reply]
Wow - I had exactly the opposite observation - that people in the US eat way too many carbs, and not enough fats, and that is causing the obesity. (Since fats make you feel full.) I think you just had a weird waiter. Also Americans eat a lot of cereal (breakfast cereal). Ariel. (talk) 02:10, 12 January 2011 (UTC)[reply]
Not true. How full or empty your stomach is is only one way your body controls Hunger_(motivational_state) (I wish that article were better). People with no or little food often try to fill up with non-nutritious bulk, but such accounts also record how hungry they continued to be. 86.163.214.50 (talk) 09:13, 12 January 2011 (UTC)[reply]
The phrase "Standard American Diet" (a somewhat derogatory term) is sometimes used to refer to a diet that is both high in fats and high in processed sugars (e.g. cola, candy, added sugar). It is correlated with various diseases and obesity. Overall though, the more important predictor of obesity is chronic overeating, i.e. eating more calories than your body actually needs. Some foods, including both fatty foods and high carbohydrate foods, have a high level of Calories per unit volume, which can make them easier to overeat (as compared to most fruits and vegetables, for example). However, that's certainly not the only factor. Cultural factors, such as a preference for snacking and large portions, also contribute to overeating. At the same time there is a lot of contradictory diet advice. For example, the Atkins diet (a rather popular fad diet in American a few years ago) recommended that people would best lose weight on a diet very low in carbs and high in fats. On the other hand, the food guide pyramid and other standard advice tends to recommend a low-fat diet with carbohydrates as the dominant base. Dragons flight (talk) 02:38, 12 January 2011 (UTC)[reply]
The matter is almost certainly too complex to be reduced to a three-way fat/protein/carbohydrate split, let alone to a hypothesis that any of the extremes in that simplified continuum is ideal. Each of the three groups contains wild variability in digestability, metabolism and biologic utilization. For example, there is a huge difference between how a given amount of "carbohydrates" affect the metabolic regulation when eaten as readily-dissolved simple sugars, or as slowly digested long-chain starchy food.
The energy breakdown also says nothing about fiber, or any of a long list of trace nutrients, or even currently-assumed-irrelevant compounds that have yet undiscovered effects on appetite regulation and metabolic signalling. –Henning Makholm (talk) 02:53, 12 January 2011 (UTC)[reply]
http://equalitytrust.org says it's due to income inequality: people who don't know how they will make their next housing or heating payment are more likely to overeat from the abundant subsidized high calorie food sources available in the US. 71.198.176.22 (talk) 06:41, 12 January 2011 (UTC)[reply]
Thanks everyone for their responses. I still think there has to be a simple difference between Europe and the US and Canada, simply because the difference is so huge. One other thing I noticed was that in North America you also have many extremely obese children. Then, I've read that the weight of adults is relatively independent of diet, it depends more strongly on the number of fat cells you have, because the body is programmed to modulate the metabolic rate so as to keep the fat cells filled to some fixed degree. So, if you eat too much as a child and grow up to become an obese adult, you are unlikely to ever get a normal weight. A BBC horizon documentary demonstrated this by putting volunteers on a 5,000 kcal diet for a few weeks. Most participants only gained a modest amount of weight and all returned to their old weight after the experiment withing a few weeks. So, perhaps US parents give their children too much to eat? Count Iblis (talk) 00:15, 14 January 2011 (UTC)[reply]
Something aliens do on TV that I wonder if it's true
I saw a Doctor Who episode where aliens made all the TV channels, radios, and phones broadcast specific message and I'm wondering if this is real or fiction. I've noticed that things like iPhones (especially original ("2G")) causes radio frequency interference when it gets near speakers where the speakers buzz and such. So I'm wondering about the idea of something that causes that kind of interference that you point it at a speaker but instead of just random noise, it'll send out say music and the speaker plays music. I'm not talking about jamming radio signals as on TV/radio as that's been done before, but where any speaker will pick the sound up as long as it's not shielded and has power to it. Geoffry Nathan (talk) 02:54, 12 January 2011 (UTC)[reply]
It is quite possible to get a simple radio to broadcast a message accross a broad range of frequencies. If you've ever been VERY close to a transmitter, you will sometimes find that the station being transmitted will "bleed" through and show up over the entire dial. What basically happens is that a very high powered signal will bypass the tuning circuit and just drive the radio by itself. The principle is actually explained here, which describes how to build a working AM radio receiver without a tuning circuit or even an external power source. --Jayron3203:25, 12 January 2011 (UTC)[reply]
You can broadcast all frequencies at once, but it won't work. AM has one modulation scheme, FM another, cordless phones a couple more (some digital some analog), TV also has video, and cell phones are packet based and you couldn't send to all at once even if you wanted to. And then you have PAL vs NTSC differences for TV, and the same frequencies in different parts of the world is used by different devices, and basically you have to individually target each type of receiver. Ariel. (talk) 04:35, 12 January 2011 (UTC)[reply]
Sure - just being able to travel the galaxy isn't really that hard if you have time to space - photons do it all the time, and they're not very smart. Radio is radio, there is no reason to think aliens have any special abilities with it. If they want to target all receivers they'd need to design for each type. Ariel. (talk) 06:51, 12 January 2011 (UTC)[reply]
Dismas's point aside, it is perfectly possible to broadcast a signal so powerful that you can essentially bypass the tuner of a radio and cause the signal to "appear" to be coming from all frequencies. This works equally well for FM receivers as AM receivers (you'd need to broadcasting both FM and AM signals to be picked up by both). My cheap clock radio which plays the local FM country station at all frequencies (said tower is about 3 miles from my house) will attest to that. Analog TV signals are an order of magnitude more complicated than radio, but in principle if you use the correct standards you should be able to hijack it in much the same method (i.e. broadcasting a powerful enough TV signal, correctly coded, could possibly bypass the tuner circuit as well). With Digital TV, such methods likely wouldn't work, neither with Cable, so we'd have to fall back on "Any species intelligent enough to traverse interstellar space could figure out how to do it" response. --Jayron3204:59, 12 January 2011 (UTC)[reply]
I do not believe any intelligent life form (human or otherwise) could decipher, intercept, and then overpower all forms of human telecommunication on Earth, without having significant a priori knowledge of our communication technology. I have played with radio telecommunications as a professional and as a hobbyist, and I will comment that the modern standard telecom systems are really complex - far more complex than the old AM radios that existed a hundred years ago. It's doubtful even a skilled engineer who knew what to look for in an intercepted satellite-TV signal could decipher and reverse engineer the MPEG-2 transport scheme with interleaved codingdigitally modulated on to a phase shift keyedleft-hand polarizedS-band link. And that engineer might have been specifically trained to know what all of those techniques are, what RF and digital parameters are used, and how they are conventionally applied in industry! Imagine trying to reverse-engineer technology invented by another species! Unlike old-fashioned AM radio, having one parameter or one circuit out of sync will mean the difference between perfect signal reconstruction and no signal at all. (Try soldering in one single transistor in the wrong place in a Satellite Television receiver, for example, and see if your signal only "degrades slightly"!) This says nothing of link encryption or other methods that are presently used to actively obfuscate the signal! Sure, an intelligent human can scan the RF spectrum and determine that non-random information is being transferred. And they might even be able to estimate, by bandwidth analysis, that the signal contains video data or audio data. But it's very unlikely they could reverse-engineer / decipher it if they didn't have all the standards, specifications, electronic circuits, digital decoders, and software stacks, that now make up modern telecom systems. When SETI looks for intelligently-created extraterrestrial signals, they really focus their efforts on seeking out alien life that wants their signal to be understood - nice, slow, repetitive broadcasts of simple, low-entropy information that would be encoded in a straightfoward way. Even when we put video signals on the Voyager Golden Record, we used analog encoding, a mechanical transport medium, and included instructions. Yet most SETI experts consider it essentially impossible that an extraterrestrial life form could ever play back that video-phonograph, even if it was neatly packaged and handed to them. (Truthfully, that record is really more of a tongue-in-cheek artistic statement by Sagan et al. on the impossibly unlikely level of technological complexity that 1970s humanity had already achieved, more than it is an effort to communicate with anyone). Most importantly, the Golden Record makes the assumption that an intelligent lifeform will have eyes and thus will care about our encoded video signal. In the reciprocal case, when hypothetical aliens come to Earth and detect all this spurious nitrous oxide in our atmosphere, it is equally likely that they will spend millenia in their advanced universities trying to decipher the complicated ways we periodically chemically modulate our atmosphere in an effort to communicate with us; they very well may not use electromagnetic signaling at all, and never even look for our radio transmissions. Nimur (talk) 19:34, 12 January 2011 (UTC)[reply]
Mere Earthly hackers many times took over TV and radio broadcasts. In one type of piracy, they transmitted their own microwave signal to the transmitter site of 50000 watt clear channel AM stations and sent their own program over it for a while. In another type of hack. A hacker disguised as "Max Headroom" sent his own satellite uplink signal and took over the TV programming being relayed by the satellite, interrupting a football telecast. Then he even interrupted Dr Who!!!!. Hacker "Captain Midnight" pirated the HBO satellite. It should be trivial for technology equivalent to Scottie on the Enterprise if they visited a planet with 21st century Earth technology. If they have the power and technology to travel swiftly across the universe, then they might take the message from Their Leader and transmit it from drone aircraft over each city on all the local AM, FM and TV frequencies at a power level many dB higher than the local transmitters, in a bruit force takeover. Maybe they have amplifiers which work from DC to light and they just send out an overpowering signal. For phones, they could send little robots to all the phone exchanges and celphone repeaters to ring all phones and transmit their message. That leaves voice over internet. They would be thwarted, because their software would run into undocumented features of the internet infrastructure, then they would get stuck on the phone talking to useless drone tech support folks who would step them through ineffective and timewasting scripts. 21:13, 12 January 2011 (UTC)Edison (talk)
On a completely random note, something very interesting happened to me when I was young. I plugged both my TV and Nintendo into the same outlet, but realized I didn't have a cable to connect the two. Oddly, however, the TV nonetheless showed the faint analog signal coming from my Nintendo; evidently, it was traveling through the electrical circuit. As such, I suppose, the aliens might be very good at broadcasting to analog (though not digital) devices, although at such breathtakingly high energy levels that it might blow out the Earth's power grid. Magog the Ogre (talk) 19:17, 13 January 2011 (UTC)[reply]
Or the Sperm whale... Once I was out strolling when I laid myself to rest in a big field of tall grass... Sorry, had an Eric Burdon moment there. Anyhoo, yeah, it looks like the Sperm Whale's brain is bigger than the blue. --Jayron3206:03, 12 January 2011 (UTC)[reply]
The article elastomer has some examples of such substances. Different types of caulk will have different ingredients; is this silicone caulk, acrylic caulk, and what specific brand and type of caulk is it? --Jayron3205:59, 12 January 2011 (UTC)[reply]
viral inactivation in hpv blood
describe the neat skecth of viral inactivation in hv blood?with following flow chart?
describe the neat skecth of viral inactivation in hv blood?with following flow chart? —Preceding unsigned comment added by 202.67.226.236 (talk) 06:15, 12 January 2011 (UTC)[reply]
Welcome to the Wikipedia Reference Desk. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know.--Jayron3206:20, 12 January 2011 (UTC)[reply]
Energy efficiency: bicycle vs. diesel motor
Which one is more efficient: a bicycle or a small modern diesel motor? Normally, beasts of burden are pretty inefficient, and humans are a beast of burden in this case, and diesel motor tend to be very efficient (and their performance is improving). So, if I mind about the environment, what should I choose? Quest09 (talk) 10:25, 12 January 2011 (UTC)[reply]
That depends on what you want to do, of course. For moving around an overfed person, using a bicycle is certainly more efficient, as you use energy that would otherwise just "improve" your waistline. If you go with a small car, you will almost certainly carry around 90% dead weight. If you look at it purely from a thermodynamic point of view (does a human or an engine produce more power per chemical energy input), the Diesel engine will win (it operates at a much higher temperature and hence better thermodynamic efficiency). --Stephan Schulz (talk) 10:46, 12 January 2011 (UTC)[reply]
As far as I'm aware if you discount basal metabolism and just count the extra work you can produce by eating a baked potato your body is about 40% efficient. This is bit better than a diesel car though the diesel engines in a ship can do better at over 50%. This is the major reason exercise is so ineffective at burning off fat and reducing weight, though of course it is much better because it makes people fit. Dmcq (talk) 14:50, 12 January 2011 (UTC)[reply]
Let's make things clear. Ther is absolutely no doubt that driving a bicycle is better for the environment than driving a diesel powered vehicle. Schulz makes the mistake of forgetting that one cannot "turn a person off" while operating the diesel engine so, as Dmcq points out, the person's basal metabolism must be subtracted from the person's total metabolism before comparing the bicycle's efficiency with an engine's efficiency making the bicycle by far the most efficient method of transportation. Dauto (talk) 15:09, 12 January 2011 (UTC)[reply]
It also depends on how you measure efficiency. Bicycles are devices to transport a person from one place to another. However, most devices to transport a person from one point to another with small modern diesel motors are cars. So if you're looking at the efficiency of transporting a person from point A to point B, the bicycle tends to be more efficient, because it's only transporting the person + 50 kg of bicycle, versus the diesel motor, which is transporting person + 1000+ kg of car. If, on the other hand, you're looking at the efficiency of transporting two adults and a table and chairs, the efficiency considerations can change. You need to know what you're really after when you ask about "efficiency". -- 174.21.250.227 (talk) 16:59, 12 January 2011 (UTC)[reply]
I don't know how efficient a plane is but it might be more efficient than a bicycle because it goes so fast. You have to count the cost of the basal metabolism for all that extra time travelling there on a bicycle. Dmcq (talk) 19:02, 12 January 2011 (UTC)[reply]
Is the question about thermodynamic efficiency or the more vague "energy efficiency" in the context of environmental conservationism? "Efficiency" means many different things. I think Quest09 is seeking one of these "embodied energy" analyses on the bicycle and the diesel motor. However, those analyses suffer notoriously from poor definition of boundaries and edge cases. Nimur (talk) 19:41, 12 January 2011 (UTC)[reply]
To bicycle 20 miles takes about 1000 extra calories. This is about 2lb of potatoes, which costs about $1.25. A small car can do maybe 30 miles per gallon? And a gallon costs $3, so it costs $2 to go 20 miles. Ergo the bicycle is more efficient if you eat potatoes. On the other hand you need two Big Macs to get 1000 calories, and they cost $3.57 each, so $7 for two. So if you eat Big Macs, it's more efficient to drive than to bicycle.
BTW, I am using cost as a proxy for energy usage because it correlates extremely well. You can't just look at the energy content of a gallon of gas vs a potato and ignore the energy used in growing, and harvesting the potato, but the cost includes those. Ariel. (talk) 22:54, 12 January 2011 (UTC)[reply]
Yes, but let's not overlook the cost of car insurance, the maintenance cost of a car vs a bike, and the extreme difference in up-front cost of a car vs a bike. Cars are more about comfort, ease, range, and convenience -- on a minimal budget they are not so great. Vranak (talk) 15:08, 13 January 2011 (UTC)[reply]
Googling "converting tv into oscilloscope" throws up a few results[10]. Certainly some people have done this, and you could have a look. This result has lots of links. But beware this warning from one of the pages: "Warning!!! Please note!!! There are high voltages inside tv sets! Use extreme caution! My advice is, never reach into the unit while it is plugged in unless you are real sure of what you are doing"[11]. --Colapeninsula (talk) 17:36, 12 January 2011 (UTC)[reply]
Old ads in electronics magazines told how you could convert a tv into a big screen oscilloscope. One problem is that you do not have available a wide range of sweep frequencies, unless you save only the tube and build all new electronics. It was easier to convert an oscilloscope into a video monitor. Oscilloscopes had electrostatic deflection of the vertical and horizontal trace, while TVs used magnetic coils, much less workable for widely varying horizontal weep frequencies and for high frequency sweep. See [12]. I believe there are kits to get a computer to work as an oscilloscope as well. Edison (talk) 20:55, 12 January 2011 (UTC)[reply]
Pancreatic cancer image
A scan of pancreatic cancerGray's torso
What's pictured in this image: is it the pancreas itself, or something else? The image description isn't in English, and its caption at Pancreatic cancer ("Axial CT image with i.v. contrast. Macrocystic adenocarcinoma of the pancreatic head.") isn't simple enough for me to understand. Nyttend (talk) 15:04, 12 January 2011 (UTC)[reply]
It's a slice of the torso from a CAT scan. The lower-center white structure is a vertebra. The thing just to the right of it might be the heart. The little white streaks are slices of ribs. I'm not sure which thing the pancreas is. --Sean15:31, 12 January 2011 (UTC)[reply]
I suspect the thing in the crosshairs (middle top left) is the pancreas and the cancer. There shouldn't be a heart in that picture — it's too low (note that you can see the formation of the buttocks/lower back). I think what you're labeling as the heart is probably a kidney? The big thing on the left should be the liver. Compare with the Gray's Anatomy photo I've added. The LR axis is flipped. An anatomist I am not, though. --Mr.98 (talk) 16:03, 12 January 2011 (UTC)[reply]
Another way to think of it is that the CT is taken with the person lying down, and you are looking at a slice as though you are standing at their feet, which is the standard convention for radiographs like CT and MRI. The older Gray's Anatomy pic is indeed viewed from "above". Mr.98 is correct that the crosshairs are pointing at a mass (likely pancreatic cancer although you often need a biopsy to know the tissue of origin for certain). IANAR (I am not a radiologist) but I'm pretty sure that the long light-grayish structure that wiggles horizontally and diagonally through the middle of the CT scan is the rest of the body and tail of the pancreas. --- Medical geneticist (talk) 19:35, 12 January 2011 (UTC)[reply]
Heart was a good guess for the pepper-shaped thing, but as Mr. 98 stated, the scan is at a moderate level of the abdomen (there are only ribs in the back and not in the front, and so nothing from the thorax above the xiphoid process should show. The pepper-shaped thing looks like the large intestine. DRosenbach(Talk | Contribs)10:21, 14 January 2011 (UTC)[reply]
Is it not possible to levitate say for instance a cone-shaped object inside another cone when permanent magnets are stuck to the inside of one and outside of the other cone in a polar array formation (all magnets repelling one another), thus producing concentric symmetry? Surely this is dynamic equilibrium in practice?
I think the answer lies in the stability of the levitating configuration. See Magnetic_levitation#Stability. Earnshaw's theorem only precludes stable levitation. In the system you describe, the upper cone may indeed levitate for a short period of time, but it will not return to the levitating state after small perturbations. SemanticMantis (talk) 15:58, 12 January 2011 (UTC)[reply]
Think about the magnetic field lines from just the outer cone (let's say the north poles are facing inward): they emerge from the inner surface, but they have to reach the outer surface somehow. If you have just a few magnets, the field will escape through the gaps; the gaps therefore appear to be south poles (since the field vanishes into the surface there, just like at a south pole) and the inner cone will spin/tip and stick its magnets into those gaps. If you have a perfectly conical field, it must escape out the top of your outer cone, and you will find that the inner cone can't be inserted at all because the whole opening of the cone is a gigantic north pole. --Tardis (talk) 16:29, 12 January 2011 (UTC)[reply]
In the latter case, getting the inner cone into the outer one is just a matter of applying enough force -- say, you could tie it down with weights. However, if the field point inwards everythere on the outer cone, the field must be stronger in the center of the cone than along the walls. Therefore magnets on the inner cone will be attracted to the outer wall, creating instability. (We could reverse the magnets on the inner cone, and then it would be horizontally stable, but we'd also reverse the levitating force that kept it from falling in the first place).
Beware that the idea of magnets "repelling one another" is simplified and inaccurate. A magnet that is oriented against the grain of the field does not really care about where the magnets that generates the field located; it just tries to go in the direction where the field is weaker. If that is closer to the sources of the field (as can happen inside a concave surface covered with magnets) then so be it. –Henning Makholm (talk) 19:37, 12 January 2011 (UTC)[reply]
The surface is always losing heat into space at a rate that depends on its temperature; for any given solar input there will be some temperature where there's a balance, but it isn't reached immediately because there's so much planet to heat/cool. That equilibrium temperature is a function of the solar input (the season) along with surface conditions, but let's ignore those so it's least at the December solstice. Therefore the "target temperature" to which the hemisphere tends is lowest then, but it's still cooling down towards that temperature from the autumn temperatures.
In late January, as it happens, the target temperature (going up) crosses the actual temperature (still dropping) and so the actual temperature doesn't drop any more and begins rising to chase the target. It's exactly the same effect that puts the lowest temperature in a day some time after dawn. --Tardis (talk) 16:20, 12 January 2011 (UTC)[reply]
The simplest answer is that the Earth takes a long time to heat up or cool down, being so huge. Just like a pot doesn't intantly cool down to room temperature the second you take it off of the stove, the Earth does not instantly cool down or heat up with the solstices. While, in the northern hemisphere, the day of shortest insolation is in December, it takes about a month for the Earth to stop cooling off and start heating up again in response to the longer January days. --Jayron3217:56, 12 January 2011 (UTC)[reply]
Thermal inertia is one of many complicated inputs into a model of climate. You might want to read about global climate models to see how scientists attempt to bring observed fact (such as the temperature profile for a region) in line with theoretical expectations (such as a thermodynamic analysis of input and output energies). Nimur (talk) 19:48, 12 January 2011 (UTC)[reply]
Jayron's example above is misleading, because a pot does instantly start cooling down to room temperature the second you take it off the stove. The difference with the Earth is that near the solstice the length of the day is only changing very slowly.
So instead of imagining putting a pot onto the stove or taking it off again, with the burner at a constant setting, imagine a pot (of some dry material that won't boil) left constantly on the stove while you s....l....o....w....l....y turn the burner from 1 up to 10 and then back down to 1 -- moving it the most slowly when it is near the 1 or near the 10. Suppose that if the burner was left at 1 then the temperature in the pot would settle at 60°C; at 2, 70°C; at 3, 80°C; and so on up to 150°C at a setting of 10.
Will it ever reach 150°? No, because you only have it set at 10 briefly. Perhaps it has warmed as far as 125° when you reach a setting of 10. When you lower it to 9, it is still heating because it has not yet reached 140°, the temperature that that setting would produce. Perhaps it reaches 130° by the time you turn it down to 8, and after that it begins cooling. Same thing at the other end of the cycle: when the setting reaches 1, the pot might be at 85°, and it will continue cooling until it reaches 80° at the point when the setting reaches 3 on the way up, after which it will start rising.
Have you read our articles on hypnosis and related topics? Also, the question of "real or not" is heavily dependent on what sort of hypnosis you're talking about and what you mean by "real". For the former, medical uses of hypnosis are vastly different from stage hypnosis. For the latter, stage hypnosis acts undoubtedly occur (stage hypnosis is "real") but may well not be based on traditional hypnotism (stage hypnosis is not "real"). — Lomn17:13, 12 January 2011 (UTC)[reply]
Depends on which part is wobbly. If the door won't stay shut, it is definitly less efficient. Furthermore, its not hard to fix. Jam some folded-up paper under one of the corners. It'll stop wobbling. --Jayron3218:23, 12 January 2011 (UTC)[reply]
Might she be making a thermodynamic argument, that the wobble represents energy lost to mechanical vibration, and eventually dissipated acoustically and as heat? Your girlfriend might be interested to read about how refrigerators work, and refrigeration thermodynamics. Actually, everybody should read about refrigerator thermodynamics. It would be a good thing for the world to know more about thermodynamic efficiency. As we know from the three laws of thermodynamics (which I have interpreted for this specific situation):
After a long enough time, that waste heat is going to be uniformly spread throughout the entire universe, so in the long run it's actually more efficient to just wait for the food to get cold by itself.
Intuitively, from just a rotational dynamics consideration, I'm convinced that she is correct, but I can't find any published research to confirm this. I also suspect that the effect will be small compared with other inefficiencies in the system unless the wobble is large. Dbfirs11:40, 13 January 2011 (UTC)[reply]
Why was it easier to unify the weak nuclear force with electromagnetism rather than the strong nuclear force? Aren't the two nuclear forces more closely related to one another? --J4\/4 <talk> 18:36, 12 January 2011 (UTC)[reply]
No, evidently not. Their only similarity (compared to electromagnetism) is that they have limited range, and therefore both show up only in nuclear phenomena. But the short range arises, as far as I understand, for entirely different reasons. –Henning Makholm (talk) 19:09, 12 January 2011 (UTC)[reply]
Worth pointing out that electroweak theory really isn't a unifyed theory anyways in the sense that within the electroweak theory there are still to completely independent interactions (that is non-unified interactions) refered to as weak isospin and weak hypercharge (not to be confused with the flavor isospin and flavor hypercharge which are not gauge interactions.)Dauto (talk) 05:09, 13 January 2011 (UTC)[reply]
Flower identification/information needed
Hello folks, can anyone tell me what to make of this flower blossom? To give a bit of background, this is a blossom on an anthurium plant belonging to my gran. The plant has had normal blossoms (the kind you'd expect on this sort of flower) for at least five years; it has a couple right now, too, but recently developed this blossom (which almost looks double-flowered). I've never seen anything like it before, and neither did the employees at various flower stores and the local botanical garden.
Looks like an aberrant flower form; this may happen sometimes. I do not know if this is caused by injury, age, genetic makeup of this particular hybrid, or a combination of those factors. Googling for "anthurium double spathe" returns quite a few hits. Also, I've seen aberrant orchid flowers on quite a few occasions with an extra labellum or two, usually where the petals should have been, co-occurring with normal flowers. This may be a result of selective (in)breeding. There's no reason why this couldn't happen to anthurium as well. Hope this helps. --Dr Dima (talk) 21:39, 12 January 2011 (UTC)[reply]
Yes there are many factors that could cause such a thing. I doubt selective inbreeding is the main cause, because all other blooms on the plant have been 'normal'. On the genetic front, it could be mutation in the progenitor stem cells from which the bloom developed. Also certain plant pathogenviruses can manipulate host DNA. These and other epigenetic processes seem likely culprits to me. You can propagate the cluster holding the aberrant bloom via stem cutting as described here [13]. If that plant continues to produce the same type of bloom, that would be evidence toward mutation in the stem cells. Any other ideas? SemanticMantis (talk) 15:13, 13 January 2011 (UTC)[reply]
(Edit Conflict) Yes. Cats (Family Felidae) and dogs (Family Canidae), along with various other Families, are both members of the Order Carnivora, all of whose member families are by definition descended from a single progenitor species. This would have been a member of the older (and now entirely extinct) miacid Family Miacidae, probably a member of the Genus Miacis, and probably lived around 4250 million years ago.
However, although we know of at least one species of Genus Miacis, Miacis cognitus, we cannot be sure if this particular species was the Most Recent Common Ancestor of the carnivores, or whether it was a (probably similar) sister species, of which fossils may not have yet been (and may never be) found - only a small fraction of all extinct species, with or without descendents, have been found as fossils, as fossilisation is a very rare event. In short, we are certain that there was such a common ancestor species of all Carnivora, and know roughly when it lived and what it it was like, but can't point to a particular fossil and say "This was one of them."
Within the Order Carnivora, the lines that gave rise to the Felidae and Canidae (and which also included what subsequently became civets and mongooses, and bears and seals, respectively) probably diverged only a few million years after the Order's origin, but the details of this are not yet well understood. Considering the major differences between some of their respective closer relatives, it's interesting that the skeletons of cats and dogs themselves have remained so similar. To summarise, although cats and dogs as we now recognise them did not spring directly from a common ancestor, the cat-like and dog-like Sub-Orders, Feliformia and Caniformia, to which they belong did do so.
What vehicle is indestructible in any typical commuter's crash?
As a kid, I dreamed of owning a vehicle that couldn't crumple or get disabled in any way through a crash. I wonder what vehicles are indestructible and can put up with such egregious abuse?
Depends what type of vehicle you're talking: do you just mean road-worthy vehicles, or any kind? If you mean the latter, you should consider tanks; pretty much the only way to stop them is explosives or preventing them from getting fuel. Nyttend (talk) 03:41, 13 January 2011 (UTC)[reply]
I want a normal commuter's vehicle, so that rules out an Abrams. Besides, I'll probably need a military driving license to drive one anyway. (Moreover, don't they only get 1 MPG?) If 95 is too unreasonable, then 85-MPH bumpers will suffice, because I suppose then, that beyond 85, I'm no longer commuting; I'm racing for recreation. If a schoolbus will give me at least 20 MPG, then I might be up for it. I'd like to rule out the Hummer as well because not only did their division bite the dust, owning and/or driving one could make me look like a douchebag, especially in this environmentally-inclined societal climate!
It's not just your own speed that matters; you also have to consider the speed of the guy you're planning to have a head-on collision with. --Anon, 07:26 UTC, January 13, 2010.
Have you considered taking a train? a Solid Diesel locomotive could hit just about any passenger car at 95 mph (if you can get it to go that fast) and only scratch the paint job. If you have to contend with another locomotive, or a heavily loaded truck, then you are going to not be quite so Unstoppable. Googlemeister (talk) 19:26, 13 January 2011 (UTC)[reply]
This is a fantastically bad idea; a vehicle designed to retain its shape perfectly in the event of a crash would be VERY unsafe. When a vehicle crashes, your body is decelerated very rapidly; the effects of this deceleration can be ameliorated if the energy of the crash is dissipated in some way; modern cars are literally designed to crumple in the event of a crash because it is safer for you, the driver, if they do. If they did not crumple, the full energy of the crash would be felt by the driver and passangers, and could cause much more damage. To put it in simpler terms: When you crash, something is going to be destroyed: it can either be you or your car. Which do you choose? --Jayron3204:54, 13 January 2011 (UTC)[reply]
There are other options. You can have non-destructive impact absorbers - something as simple as a large spring with a latch/ratchet (the latch to keep the spring from recoiling). Ariel. (talk) 05:54, 13 January 2011 (UTC)[reply]
The OP seems to be looking for a commercially availible vehicle. A 1970's era Buick would fit the bill; those things were basically as indestructable as a car could get, and much less safe (for the reasons I cite above) than modern cars with crumple zones. Anyone, I suppose, could invent any number of highly impractical impact absorber which would meet the technical requirements of preserving the car and driver both unscathed; that has to be coupled with the notion of it being a drivable car! --Jayron3206:00, 13 January 2011 (UTC)[reply]
In practical terms, a large, heavy, modern, vehicle that meets Europena crash with 5 stars. I'd have a preference for a unitary body, and a smaller preference for a longitudinal engine. I'd fit a 5 point harness, and do it up tight. Not too sure about wearing a helmet. Greglocock (talk) 06:02, 13 January 2011 (UTC)[reply]
That protects the driver, but not the vehicle. Every vehicle that passes the Euro NCAP with high marks will have very extensive crumble zones, some of which will even be designed to crumble under fairly low impact forces to protect pedestrians in a collision. What the OP wants is not practically feasible. Kinetic energy grows with the square of the speed. Potential energy of of an elastic medium (as exchanged in a collision) typically is roughly linear with deformation. The energy involved in a 95 mph crash is about 400 times of that in a 5 mph crash. So a bumper that gives only one centimeter on a 5 mph crash would have to give nearly 4 meters to store the energy in a 95 mph collision - that's about the length of a good-size car. And I'm fairly sure that bumpers deform more than a centimeter ("about half an inch" ;-) in a 5 mph collision to begin with. --Stephan Schulz (talk) 09:35, 13 January 2011 (UTC)[reply]
You're essentially looking for some sort of action hero vehicle that can smash through anything and keep on ticking, right?
That's going to be a tall order. An HMMWV (A real one. Not an H2 or something) with some of the 'upgrade kits' might be your best street-legal option, but it's not the batmobile. It was really just designed as a jeep replacement.
What you really want is some sort of front-line combat vehicle. A MRAP or a M1117. I don't think these are available to civilians, and I doubt you'd be able to get them registered for street use anyway. But if you live the sort of super-hero life where you have to smash through walls in your morning commute, perhaps you don't care if you can get a registration sticker. APL (talk) 17:20, 13 January 2011 (UTC)[reply]
Indestructibility is a matter of degrees, a school bus would survive most commuter car impacts, but a train would ruin its day severely. Even with military vehicles, they're not designed to be indestructible, they're usually designed to survive a hit from their own main gun, and to survive hits from expected common battlefield dangers (IE the most common weapons of the most probable opponent). You can buy some British surplus military armor as a civilian, but it is US policy not to sell to civilians but instead sell surplus and replaced armor to allied nations. You could also buy a used armored car, not the military kind but the kind used by bank cash collection services and retail cash delivery services, there's even a website for it, google turned up a few (would linking a commercial sales list site for what the OP wants be allowed here?) 65.29.47.55 (talk) 22:37, 13 January 2011 (UTC)[reply]
I'm looking to find a hybrid motorcycle someday. Even though the 85-MPG Peirspeed Delivery 150cc is promising as a fuel miser, that might not be enough one day, due to tightening emissions standards and whatever else, that only hybrid powertrains could meet.
Therefore, when will Harley get one on theirs?
And are there other motorcycle manufacturers that already make hybrids?
The Piaggio HyS is probably the first. Harley will get one a few days after hell freezes over- like BMW and Ducati motorcycles, they are wed to a certain look and a certain engine design. Can-Am was next. I think we'll see more production-ready ebikes before hybrids- it's a packaging issue. tedder (talk) 05:17, 13 January 2011 (UTC)[reply]
Hellalready has. When the EPA keeps tightening their emissions and fuel economy regulations, don't you think Harley will have to comply eventually? Harleys may be wed to a certain look & design, but they have all sorts of new features that they're able to hide under the antiquated-looking chassis. Therefore, they could hide a hybrid drivetrain too, could they? --70.179.178.5 (talk) 05:38, 13 January 2011 (UTC)[reply]
Eh, they will eventually, or they'll bypass hybrid and go for the electric. Again, it's a packaging issue. BTW, their integration of modern (Bosch) ABS into the current chassis is positively brilliant; research what they did with the wheel position/rotation sensor so they didn't need a toothed hub if you are curious. tedder (talk) 06:06, 13 January 2011 (UTC)[reply]
Imprinting (biology)
Imprinting is a psychological instance where a sight or a sound is immediately stored into the long-term memory center of an organism either indefinitely or temporarily.
Imprinting is a common occurence in the newborns of many animal species.
Avians
Ducks: A Duckling, when it's about to hatch, will visually imprint itself upon the first being that they see and follow it around thereafter as its mother.
--Arima (talk) 03:32, 13 January 2011 (UTC)[reply]
Well, it depends. If hydrogen has a significantly higher joules/gram ratio than an equivalent amount of airplane fuel would, for systems of comparable efficiency, you could generate the same range and speed on lower mass. Likewise, if a fuel cell had a significantly higher efficiency, at a comparable joules/gram ratio, the same would be true. I have no idea about the actual numbers on these things, but even ignoring the faulty buoyancy arguement, its within the realm of possibility that a hydrogen fuels aircraft would weigh less. --Jayron3206:11, 13 January 2011 (UTC)[reply]
If joules/gram is better (which it is for the raw fuel, but may not be once you include the storage system), then simply burning it would work better, and would be just as clean. Unlike cars airplanes don't benefit from the typical advantages of electric motors (high torque, variable speed, regeneration). Ariel. (talk) 07:06, 13 January 2011 (UTC)[reply]
Conventional jet fuel is almost 10,000 times as dense as hydrogen gas. On a modern airliner, roughly speaking the fuel tanks are the inside of the wings. To store an equivalent mass of hydrogen gas without pressurization, you would need tanks 10,000 times that size, which would be a little difficult to fit into the airplane. And if you stored it in highly compressed form, then you would need heavy tanks to withstand the high pressures. Today's gas cylinders may support a pressurization of several hundred times normal air pressure, but not several thousand, and they're already pretty heavy. (An alternative is to use liquid hydrogen as was done on the Saturn V rocket, but that requires cryogenic temperatures to be maintained at all times when there is fuel on board; also not very practical today.)
The hydrogen fuel article claims that at pressures typically used, hydrogen occupies 4 times the volume of an amount of gasoline of corresponding energy content, and is 1/3 the weight. But there is a whiff of advocacy about that article and I do not entirely trust it; for one thing, it doesn't even mention the weight of the tanks. --Anonymous, 07:46 UTC, January 13, 2010.
A few weeks ago some colleagues and I were discussing Six Sigma, Green Belts, and all the trappings of that methodology. Eventually we got around to discussing the applicability of Six Sigma to non-manufacturing areas. The one that stumped us was HR. HR is necessarily quality-focused, but in a far more subjective way. Also, few HR operations approach the scale necessary for Six Sigma statistical analysis. Someone ventured that a theoretically massive company (Walmart? US Federal Government?) could apply Six Sigma methodology to their global training or recruiting programs, assuming they had globally equivalent programs, which is a massive assumption to make. I've been idly considering this for the past 2 weeks and haven't been able to come up with anything any more practical. Can the RefDesk? The Masked Booby (talk) 08:41, 13 January 2011 (UTC)[reply]
Almost all HR data is subjective, but the six sigma and similar processes need objective measurements to provide useful information. Call center employees' performance is probably measured using objective scales of time, accuracy and/or possibly customer feedback survey scores, so it might work in that context. 71.198.176.22 (talk) 10:51, 13 January 2011 (UTC)[reply]
skipped lines in raw Cassini images
In raw Cassini images, such as this one, every other line is typically incomplete on the right side. What causes this? Is it a transmission bandwidth problem, and will the missing data be filled in over time? Or is it a recording bandwidth problem, and is the data lost? — kwami (talk) 09:55, 13 January 2011 (UTC)[reply]
I'm not sure, but I think it might be an artifact of an automatic contrast adjustment system designed to get the maximum dynamic range out of an image by dynamically stepping the CCD contrast ratio when particularly bright areas unsuitable for the current setting are encountered. The information to adjust for those artifacts is probably sent out of band apart from the raw image data, and they need to be recombined to make a coherent contrast image. 71.198.176.22 (talk) 10:46, 13 January 2011 (UTC)[reply]
It does seem to occur most often in bright areas when there are also substantial dark areas in the image. But not always: [14] Well, as long as the data hasn't been lost, I suppose it doesn't matter too much. — kwami (talk) 11:13, 13 January 2011 (UTC)[reply]
The raw image pages on the Cassini site all contain a link to the Raw Images FAQ, which seems to describe both of the problems seen in the linked images. The first image, with truncation of alternating rows of pixels, shows an artefact of the image compression algorithm. When an image is captured in lossless compression mode, the algorithm looks at two rows of the image at a time, and seeks to compress the data down to at most one half of its original size. If that compression cannot be achieved, the line of pixels is truncated until the desired compression ratio is reached. This works brilliantly for low-contrast or low-detail subjects (for images containing mostly empty space, for instance, or uniform cloud cover) but gets into trouble with complicated, high-detail subjects filling the full width of the frame (like the densely cratered surface of the moon in the picture). On the other hand, while the right-hand edge of the image becomes 'tattered', the remainder of the image contains the full detail captured, and won't have any artefacts of lossy compression.
The second image looks like it's missing several consecutive rows of data in the upper part of the frame; I would be surprised if it were anything more complicated than a temporary loss of signal. (The ragged edge in the lower-right part of the image is the same lossless compression artefact we saw before.) The FAQ notes that – due to onboard storage limitations – Cassini only sends most images once; they aren't retained on board, and if part or all of the picture is lost, there's no way to get it back. Particularly 'important' images are recorded and replayed to ensure successful transmission, but scientists have to select those 'important' exposures in advance.
While the speculation about automated contrast adjustment is interesting, the FAQ doesn't mention such a system, and indeed notes that exposure times for images are set by scientists on the ground in advance (which can and does lead to under- and over-exposure, particularly when novel targets are photographed for the first time.) TenOfAllTrades(talk) 13:47, 13 January 2011 (UTC)[reply]
The Cassini imaging artefacts are all described here. The raw images can be improved by filling the omitted (black) pieces of alternate lines with an average of the complete lines above and below, effectively halving the vertical resolution in these areas. Cuddlyable3 (talk) 00:20, 14 January 2011 (UTC)[reply]
Is vacuum really vacuum or not
Is a vacuum really vacuum or not?
It is impossible to construct a really vacuum space. We all know that electro-magnetic waves can travel through a vacuum. But an electro-magnetic wave is a kind of progressive wave (more specifically transverse wave). As we all know that a wave is caused due to the disturbance of the particles in a medium. So,there must exist some kind of particle in the vacuum which has no mass and charge. The particles are photons. That means a photon does not travel from a place to another to transfer energy. Rather we could say it transfers energy from one point to another point just by transferring the energy to the adjacent photon. That means if we can create a really vacuum space, even the electro-magnetic radiation can not pass it. If this theory could be right then I can assure you that it can be proven that string does not exist. Even the Theory Of Everything can be proven.
(I,being an inhabitant of a third world country could not get the proper opportunity to check it practically due to deficiency of instruments. I could not contact to anyone to verify my thinking as I could not meet to someone who can really guide me to this thing. So,I'm heartily requested to the respectable volunteers of the Wikipedia to help me to find out what is going on actually. Sorry to write this on your page as it is prohibited to write this kind of things. But I could not find any alternative way. Hope that you would be kind enough to help me.) — Preceding unsigned comment added by 61.11.120.66 (talk • contribs) 04:58, January 13, 2011
This: "As we all know that a wave is caused due to the disturbance of the particles in a medium." is not correct. And because it's not correct all the rest of what you wrote is based on a false premise. The links the other editors provided you will explain why it's not correct, but basically photons require no medium in which to travel. Ariel. (talk) 10:48, 13 January 2011 (UTC)[reply]
Perhaps the OP was thinking of sound waves that do require a medium, but yes, the premise seems to be wrong for E-M radiation. There is also the problem of whether a vacuum is really observed as a vacuum depends on the reference frame (see Unruh effect). Dbfirs11:33, 13 January 2011 (UTC)[reply]
Don't feel bad, of course, This question puzzled great minds for hundreds of years, until Einstein (among others) solved it. APL (talk) 17:03, 13 January 2011 (UTC)[reply]
I'd attribute the discovery of the ability of electromagnetic waves to propagate in a vacuum to James Clerk Maxwell or maybe to Heinrich Hertz. Einstein studied photons and electromagnetic waves, but I don't think his triumphant works were related to discovering that electromagnetic wave propagation can occur in free space. Nimur (talk) 19:44, 13 January 2011 (UTC)[reply]
The "vacuum" is basically what's left when we remove everything that we know how to remove. It is possible that what we think of as the vacuum has additional structure that can be removed in some way unknown to us. That would be what's called a false vacuum. If it is possible, though, it's ridiculously far beyond our current capabilities as a species, because we know from astronomy that events far more energetic than anything we can create have failed to make a dent in the vacuum. -- BenRG (talk) 01:44, 14 January 2011 (UTC)[reply]
Also, with respect to the original poster: Satyendra Nath Bose was a native of Kolkata, yet he managed to not only rise through the local education system, but to eventually develop some of the most earth-shattering theories of our century about the behavior of matter in unusual circumstances. I can't know what opportunities or challenges you may face, but "being an inhabitant of a third world country" is not, in and of itself, necessarily a barrier to becoming a physicist. It may be much more difficult, but it is still possible. Nimur (talk) 19:52, 13 January 2011 (UTC)[reply]
Snow glow
On the night of a snowstorm, the entire sky remains bright overnight with an orangish glow: it seems to occur even in rural areas. I surmise this is the town's lights reflecting off the snow and back into the atmosphere. However, even one night later, this glow disappears. It's a pattern that's remained consistent (in my observation) throughout my lifetime. The only explanations I can think of:
The cloud cover dissipates, diminishing the reflection.
The structure of the snow crystallizes after sublimating in the sun.
The snow disappears out of the trees via wind and sublimation.
None of these explanations immediately strikes me as the main culprit. Respectively:
I note that streets are most likely located in the same location as street lights. However, snowplowing still only covers a minor part of the surface area of a town, and the diminishment of light strikes me as disproportional.
Even with cloud covers on subsequent nights, the light is less clear.
Does sublimation really change the reflective properties of the top of the snow so much that it reflects less?
This immediately strikes me as a stretch, unless we maintain that only a little snow can stay in the trees overnight (the rest falls off), all of which sublimates/blows off by the next night.
The streets are by far the brightest part of a city. Small towns too!
Assuming your observation is accurate, the only possibility that comes quickly to mind for me is that during the interval the surfaces of the snow deposits change, lowering their albedo. The hypothesis would thus be that newly-fallen snow arranges in such a way that the reflectivity is maximized, and environmental factors (temperature, wind, vibration, physical contact) degrade this reflectivity over time. I look forward to reading other answers! The Masked Booby (talk) 12:24, 13 January 2011 (UTC)[reply]
Maybe the falling snow intercepts and scatters the light before it reaches the ground? Or perhaps the worst light pollution in the area isn't actually from streetlights but a commercial or industrial parking lot that is normally kept clean from end to end? Wnt (talk) 13:55, 13 January 2011 (UTC)[reply]
Just to chime in — though two anecdotes are not data — I have noticed the exact same thing, and in fact noticed it against last night and thought about posting a question about it on here myself. --Mr.98 (talk) 14:44, 13 January 2011 (UTC)[reply]
I'll bet that #1 is a much bigger part of it than you think. The yellow glow comes from those sodium vapor lights that are pointing almost exclusively at the road. (And at parking lots!) Sure, this is a small fraction of the town's total area, but no one is shining floodlights on empty fields. APL (talk) 16:45, 13 January 2011 (UTC)[reply]
... and, of course, it doesn't happen in truly rural areas that are far from street lighting. We don't see "tangerine trees and marmalade skies" here. Dbfirs18:01, 13 January 2011 (UTC)[reply]
It sounds like we're informally agreeing that #1 plays a large part. As baffling as this sounds, it may be the reason - as huge a difference as the lighting makes. I can tell you two things about where I've lived: 1) never a huge city (which would render it moot), and 2) I've lived fairly rural, but I don't remember what happened there to be honest. Magog the Ogre (talk) 18:52, 13 January 2011 (UTC)[reply]
If you're talking about the night during the snow, then of course the air is full of scatterers (snowflakes) and you would expect the city glow to be much enhanced. Even if it's not appreciably snowing at the ground, I would guess it possible for many snowflakes to stay suspended in moving air beneath the clouds for some time. --Tardis (talk) 01:22, 14 January 2011 (UTC)[reply]
Vagina dimensions correlate no more to a woman's height than a man's penis length or, say, the size of one's earlobes or nose. They are indepedent genes (French and Jewish noses aside... OK bad joke... take whatever potshot you'd like at me, I'm American and we take our fair share). Mind you I'm not a medical expert (and neither have I slept with tons of women so as to get a scientific sample size... a number that would need to be quite large anyway), but this is what I've heard. Magog the Ogre (talk) 18:47, 13 January 2011 (UTC)[reply]
Only female humans have vaginas. Obviously there is a correlation between vaginal dimension and the height of the female because the vagina of a child is smaller than an adult. The vagina is very flexible and able to expand to pass a baby. Tall slim women are not known (OR) to have larger vaginas than short women, hence there is no obvious correlation among adults. Vaginismus is the condition where a vagina is abnormally restricted due to a muscle reflex. Episiotomy is an operation to enlarge the vagina to ease childbirth. After giving birth vaginally, it's normal for the vagina to be larger than it was before[15]. Whether one recovers the pre-birth size is uncertain but may be helped by doing Kegel exercise. Cuddlyable3 (talk) 00:03, 14 January 2011 (UTC)[reply]
I agree with Edison; I don't have any idea why you've said that Cuddlyable. Also, puberty can change all sorts of characteristics which have nothing to do with height. Magog the Ogre (talk) 06:25, 14 January 2011 (UTC)[reply]
I'm guessing Cuddlyable3 meant pedantically to say that among humans, only females have a vagina – presumably because the OP refers to "a human's vagina" instead of either "the human vagina" or else "a woman's vagina". WikiDao☯07:09, 14 January 2011 (UTC)[reply]
I'm guessing Cuddlyable3 subscribes to a particularly binary view of gender, which is dependent entirely and only on the genitals. This would classify all those with vaginas and without penises as female, and all those without vaginas and with penises as male. Quite how Cuddlyable3 would then classify those with ambiguous genitalia I don't know, but this classification would certainly imply classifying all transgender people as being whatever Cuddlyable3 thought their genitalia looked like, rather than what they say they are. All in all, an odd thing to say. 86.164.67.42 (talk) 12:45, 14 January 2011 (UTC)[reply]
Note the use of indent. The set "human" was established by the OP. A subset of that set is "female human". Another subset is "nervous american who weighs quantities of women in tons". Gender is a classification like that of a lens "concave or convex is what defines sex" and a penis is a vagina that got made inside out. We are not so ogreish as to assume that everyone has found out what should happen at Puberty. Those still in doubt need the WP:DUCK test. Cuddlyable3 (talk) 13:20, 14 January 2011 (UTC)[reply]
Based on a recent question about the most-recent common ancestor of cats and dogs [16], I'd like to see some candidates for the most primitive living Carnivoran. By primitive I mean possessing a smaller number of derived characteristics. It may be hard to compare primitiveness between felids and canids, so perhaps finding a primitive member of each would be enlightening. Thanks, SemanticMantis (talk) 15:06, 13 January 2011 (UTC)[reply]
There do not seem to be definitive answers to this question, perhaps because the Order underwent a good deal of rapid evolution soon after its appearance. Googling "Basal living carnivore" finds a good many sites discussing matters surrounding the topic: one, a Powerpoint presentation appearing under the heading "Fissipedia and Pinnipedia_Pailinrut - Slide 1" (which I lack the interweb-fu to link directly) has some particularly relevant slides. My impression is that, of extant Carnivora, the African palm civet is a good candidate for the most basal of the Feliformia, but I'm unsure whether this is borne out by genetic analyses. 87.81.230.195 (talk) 17:16, 13 January 2011 (UTC)[reply]
Hi, I was thinking that if we take a dead body, and instead of burying it under the ground, we put it in some place hard to penetrate, what will it become after a long time? will it turn into soil? or petroleum?
i'm asking this because I see some creationist say that "we are made of soil, because we will turn into soil after being buried."
the soil itself isn't mainly made up of organic compounds and is mostly made up of mineral ones, so where doall the organic compounds in our body go? — Preceding unsigned comment added by Sina-chemo (talk • contribs) 18:33, 13 January 2011 (UTC)[reply]
In the short term, it will blow up. In the long term it will dry out and turn to dust as long as there is air to wick off moisture. Anything that can sublimate/evaporate will. I'm sure there will be folks who provide more accurate answers. (!) PЄTЄRS J VЄСRUМВА ►TALK18:39, 13 January 2011 (UTC)[reply]
Assuming the container is sealed, even from water, most likely you'd end up with a damp sludge containing the mineral and organic compounds that the gut flora couldn't digest along with their waste. I wouldn't call it soil, although it'd probably be something that'd be good on your rosebed. Check out the Decomposition article. -- JSBillings18:50, 13 January 2011 (UTC)[reply]
And about Sina-chemo comment about soil, it depends which soil you are talking about. O horizon soil is almost all organic matter, whereas the B-horizon is mostly mineral matter. --T H F S W (T·C·E)18:59, 13 January 2011 (UTC)[reply]
Actually Judaism doesn't believe in a Judgment day. Rather the resurrection of the dead is a reward - basically heaven on earth. Ariel. (talk) 01:35, 14 January 2011 (UTC)[reply]
You might be interested in reading about bog people, who are essentially preserved in an almost pristine state for thousands of years, due to the presence of tannins in their environment. It's almost a natural mummification. The exact outcome in the long-term is highly dependent on environmental conditions - in very hot, dry areas, bodies will dessicate; in very cold areas, they will freeze and preserve. In a temperate area, they will engorge (bloat) and then proceed to rot. If bacteria, fungi, insects, and large predators have access, the soft tissues are stripped. And given a long enough time and proper geological and environmental conditions, the bones and some other parts can fossilize, meaning that certain minerals will be chemically replaced by more permanent minerals - petrification. Nimur (talk) 01:06, 14 January 2011 (UTC)[reply]
I find that somewhat surprising, as a spritsail is normally a fore-and-aft sail. The rectangular sail under the bowsprit is called a Blinde (literally "blind one") in German, and German sailing terminology shares low German roots with English. Does this ring a bell? --Stephan Schulz (talk) 01:02, 14 January 2011 (UTC)[reply]
Our overly-thorough sailboat diagram doesn't show any sail projected below the bowsprit. (I have never seen anything there on any ship either, but I haven't spent much time on tall ships). Our carrack article names six sails: "bowsprit, foresail, mizzen, spritsail, and two topsails" - so we can rule out a few of those. Our spritsail article illustrates what I would call a gaff rig; so let's call the square forwardmost sail on Santa María the "bowsprit sail" until something more authoritative comes along. Nimur (talk) 01:44, 14 January 2011 (UTC)[reply]
Here is another web source that also calls it a "spritsail": "An additional sail, the spritsail was bended to a yard under the bowsprit. The sail was called "blinda" in Germanic languages, which reflected the fact that the sail effectively prevented visibility forward." –Henning Makholm (talk) 02:21, 14 January 2011 (UTC)[reply]
The articles on positron emission and such don't really explain this well. My understanding is that a proton absorbs a W+ boson and it then turns into a neutron while releasing a positron and an electron neutrino. Is this correct? ScienceApe (talk) 04:57, 14 January 2011 (UTC)[reply]
I would put it slightly different. The proton EMITS a W+ WHILE turning into a neutron AND THEN the w+ turns into a positron plus electron neutrino. Dauto (talk) 05:08, 14 January 2011 (UTC)[reply]
That's a diagram of a negative beta decay. Granted the diagram for a positive beta decay would be very similar to that one. Dauto (talk) 05:29, 14 January 2011 (UTC)[reply]
Kindly help me find some good used solar panels for the K-State Wesley
Even though I don't tithe regularly, I don't like to let God down by depriving His churches this way. While reflecting on this, I decided that a better, 21st-century way to tithe would be to give a gift that will keep on giving long after the initial offering.
Such a gift would be in the form of residential wind turbines or solar panels. An energy-generating wind-turbine of any form could be well out of my budget range (I'm looking for no more than a $400 investment) so I've decided to find our campus ministry center a solar panel to donate.
Froogle.com won't be too useful when I search for "used solar panel," so that's why I seek your suggestions. I prefer used for the cost savings, but I hope they're still quite useful despite no longer being new. I also hope for a substantial power output from the said panel. The more watts-per-dollar, the better.
I believe that when item donations to churches/ministry centers keep generating them money (or saving them costs), the donor would keep tithing to God even when not actively giving. Therefore, I would call this a form of "passive tithing," a term most of you have never heard of, but would be possible thanks to these environmentally-inclined power generators. —Preceding unsigned comment added by 70.179.178.5 (talk) 09:14, 14 January 2011 (UTC) --70.179.178.5 (talk) 09:14, 14 January 2011 (UTC)[reply]
Sorry to throw cold water on your idea, but $400 doesn't come remotely close. Just the inverter and grid hookup will cost you thousands (including installation). Almost no one sells used solar panels, so used are not much cheaper than new. And $400 in solar panels will get you maybe 150 to 300 watts (and remember practically you'll get 1/3 of that because of night), which is almost nothing for a large building, and that doesn't even include installation. On top of that solar panels have a payback period of around 5 to 15 years - meaning it will take that long for them to save $400. Ariel. (talk) 10:33, 14 January 2011 (UTC)[reply]
Um shouldn't you get a job before you worry about tithing [18]? Also have you considered donating a bidet? Considering how wonderful they are perhaps the church will find more members come because of the bidet? This would seem to be the greatest gift of all at least for most churches. From your POV you'll get converts both ways! Nil Einne (talk) 11:05, 14 January 2011 (UTC)[reply]
That's an interesting suggestion. A Bidet is a low-mounted plumbing fixture or type of sink intended for washing the genitalia, inner buttocks, and anus. As a church fixture a bidet could additionally serve as a novel Baptismal font. Cuddlyable3 (talk) 15:06, 14 January 2011 (UTC)[reply]
A practical suggestion is to use $200 to buy a solar panel and a small motor attached to a Prayer wheel. You will thereby make a pious gesture towards a religion that does not encourage propitiation to a bloodthirsty deity. You can give the remaining $200 to the poor if you are not preoccupied with self interest. Cuddlyable3 (talk) 12:43, 14 January 2011 (UTC)[reply]
Hiroshima/Nagasaki and radiation
Do we have an article/s that deal/s with persisting levels of radiation in these cities? I couldn't find the information during a quick flick through some likely articles. --Dweller (talk) 10:43, 14 January 2011 (UTC)[reply]
A couple of weeks ago I ran across something, probably off-wiki, that stated that neither city had much residual radiation even in the days immediately after the attacks because the explosions were airbursts and thus relatively clean. "Clean" in this context would mean that the fission products and unfissioned material fell elsewhere, and that the main radiation exposures to humans were neutron exposures from the moment of actual explosion. I can't remember where I saw it, though. Acroterion(talk)13:35, 14 January 2011 (UTC)[reply]
The Rhine: an eco-biography appears to mention the flora nad fauna of the Rhine, but it also refers to Robert Lauterborn, saying that by the time he died in 1952, he had published over 100 articles on Rhine Flora and Fauna - He might be a good person to search for. Searching for him on google scholar does turn up a number of articles but the almost all appear to be in German. Obviously though, being dead, he won't have published any articles recently - A you searching specifically for recently published information?
Please do your own homework.
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