Science desk
< January 19	<< Dec \| January \| Feb >>	Current desk >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

January 20

Phenomenal eggs

What explains the following phenomenon:

Fill a basket about halfway with straw, add a few eggs, fill the rest of the way with straw such that the eggs are approximately in the center of a basket of straw. Now, shake the basket. One would expect the eggs, being much heavier (denser) than the straw would "gravitate" to the bottom of the basket; however, they rise to the top instead.

I came across this in a real-life experience and remembered the above phenomenon from one of my prehistoric science classes, but forgot the explanation. —2606:A000:1126:28D:20D1:2886:5F71:22E5 (talk) 15:45, 20 January 2019 (UTC)[reply]

This is probably a size-based packing, more than density. If the density difference is fairly small (try it again with stone eggs), then what happens instead is that small perturbations from shaking allow the smaller particles to drop, but not the big ones (they're always supported by something). There's a similar effect for why fields continue to "grow rocks", even after farmers have taken all the rocks out. Andy Dingley (talk) 16:03, 20 January 2019 (UTC)[reply]

We have an article about this. catslash (talk) 17:15, 20 January 2019 (UTC)[reply]

Thank you "Granular convection" is the term I was looking for (is straw 'granular'?). BTW, the "real-life experience" was an effort to get grapes to stay at the bottom of a container of tobacco (they magically keep rising). —[OP]:107.15.157.44 (talk) 19:13, 20 January 2019 (UTC)[reply]

The phenomenom of the heavy eggs rising appears to represent extraction of energy from a field of particles in random motion, something which is argued by Feynman to be impossible in a Brownian ratchet. DroneB (talk) 19:51, 20 January 2019 (UTC)[reply]

You have to put energy into the container to get the eggs to rise. Greglocock (talk) 21:00, 20 January 2019 (UTC)[reply]

OK. I just have to ask. Why would anyone want grapes to stay at the bottom of a container of tobacco? --Guy Macon (talk) 22:29, 20 January 2019 (UTC)[reply]

Grapes have a natural means of maintaining an even humidity (absorbs moisture if above a certain level; emit moisture if below a certain level). They also add a bit of aroma, since the tobacco absorbs aroma. The tobacco has anti-fungal properties so the grapes will not rot; instead, they'll eventually turn into raisins —if— they stay covered (not directly on top; ie: not exposed to ambient air). ^{[sorry, no citation]} —2606:A000:1126:28D:20D1:2886:5F71:22E5 (talk) 23:05, 20 January 2019 (UTC) —P.s: raisins soaked in cognac turn into yummy grapes.^[1][2][reply]

The failure of the Brownian ratchet does not imply the failure of all ratchets. It does mean that the pawl must be damped - it must be able to lose the energy given to it be the teeth rather than return it to them. Although the motion of the granules is random, it is damped by friction, and in this it differs from the motion of the atomic particles in the Brownian ratchet. This is a corollary Greglocock's observation that you must put energy into the system. The ratchet mechanism may or may not be the true explanation of the Brazil nut effect, but it is at least a possibility. catslash (talk) 23:52, 20 January 2019 (UTC)[reply]

Emotions with a cognitive component

Certain emotions e.g. joy, sadness do not seem to necessitate a "cognitive", or "propositional" (I think that's right) component to them: they don't have to be "about" anything. However, others, such as anger or surprise, seem to.

What does this say about the status of anger and/or surprise as emotions? Are they not basic emotions, or are they?
Presumably both emotions have moderately distinctive involuntary physiological effects that can be altered with drugs. How do these drugs affects other aspects of anger and/or surprise?--Leon (talk) 16:39, 20 January 2019 (UTC)[reply]

OR, but I have experienced lingering annoyance without being able to recollect what I was annoyed about - suggesting that this emotion can exist separately from cognition. catslash (talk) 23:15, 20 January 2019 (UTC)[reply]

As a counter example to "anger needs cognition" consider the Hatfield–McCoy feud and Von Hippel–Lindau disease#Notable cases. Imagine living nextdoor to people who suddenly get angry for no reason. --Digrpat (talk) 22:36, 21 January 2019 (UTC)[reply]

I'm not sure the premise to the question is itself sound. I don't see why anger, for example, needs an antecedent. Some times, people just are "angry" in the same way people are just "sad", without necessarily having "cause" to me about. Yes, some things make people "angry" or "sad", but I can't think of any emotion, like anger, sadness, joy, etc. that requires a cause. I've certainly known people to be angry for no good reason. --Jayron 32 00:51, 24 January 2019 (UTC)[reply]

I wasn't speaking of causes, but associated thoughts. I can be sad without thinking about what's making me sad. But anger has an object.--Leon (talk) 16:40, 24 January 2019 (UTC)[reply]

Looking for something about Isolation Experiments on people

I didn't see anything about this on the solitary confinement page. I just want to know if there's any data about individuals being isolated and how long they lasted before they experienced any mental issues. Sensory deprivation studies would be the extreme version of what I see.. I'm just looking for data in regards to solitary confinement with little sensory input. 50.27.72.253 (talk) 18:05, 20 January 2019 (UTC)[reply]

Besides the article Solitary confinement, Wikipedia has articles about Solitary confinement of women and of the mentally ill in USA. There is also an article about Sensory deprivation. The Ganzfeld effect of perceptual deprivation or the use of sensory deprivation in the Ganzfeld experiment in ESP may be of interest. The cited articles contain many references. There is also a report on hallucinations in sensory deprivation that follows a study in 2009. In the '50s Donald Hebb at Montreal's McGill University studied how sensory isolation affects human cognition. DroneB (talk) 19:26, 20 January 2019 (UTC)[reply]

Has anyone ever done scientific experiments on the effects of human isolation over long periods, months or even years?.

BBC - Future - How extreme isolation warps the mind

NASA - Behavioral Issues Associated with isolation and Confinement: Review and Analysis of Astronaut Journals (Journals) - 01.10.19

Alansplodge (talk) 22:45, 20 January 2019 (UTC)[reply]

Brown wax

Why does my ear wax come out brown but then go yellow after rolling it? 80.2.22.165 (talk) 21:49, 20 January 2019 (UTC)[reply]

Moisture content and crystal structure. This is typical behaviour for waxes. It's naturally brown and it doesn't go "yellow" (i.e. changes hue), it just becomes a paler brown; it loses transparency as what was previously a homogeneous and translucent material is disrupted.

There's a similar effect if you take coloured candle, cool the wax down (you won't see this effect with warm wax) and bend it - it'll turn white. Andy Dingley (talk) 22:13, 20 January 2019 (UTC)[reply]