Wikipedia:Reference desk/Archives/Science/2010 September 27

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September 27

Psychologically why is destroying things so much fun?

A group from out work did volunteer ground clearance in a park. Everyone wanted to chop down trees, even though it was much harder work than litter picking or leaf raking. I have read that demolition work has one of the highest levels of job satisfaction and I can believe it - it looks fun! A lot of people also engage in mindless vandalism. Why is destroying things so much fun? Is there any evolutionary advantage to this? It seems to me that most people would build a building out of necessity but knock one down for fun!. -- Q Chris (talk) 12:10, 27 September 2010 (UTC)

I would add a qualifier to the question. While Q Chris's experience may have involved equal numbers of males and females (can you tell us?), my view as a high school teacher is that his observations would far more accurately describe boys than girls. But overall it's a great question. HiLo48 (talk) 12:18, 27 September 2010 (UTC)

There were about equal numbers, and it appeared that (subjectively) the men and women both enjoyed the chopping down trees, but most of the women would do it for a bit until they were tired and then do some of the less physically demanding tasks. I (and most of the other men) continued chopping down trees until we were covered in sweat and had blisters on our hands - it really was that fun! -- Q Chris (talk) 12:38, 27 September 2010 (UTC)

It acts as a testing of self against nature in order to affirm one's own potency. Insecure youths appear to need to practice pointless destruction more, one such example could be the current UK Prime Minister when he belonged to the Bullingdon Club. --Aspro (talk) 12:39, 27 September 2010 (UTC)

There certainly was an element of competition, especially among the younger men. A couple of young marketing managers went after all the "bigger" trees, and raced to cut them down and drag them to the pile. The older blokes still got a lot of enjoyment out of it even though we were not competing for speed or size of tree. I think that there is some other element, as cooperatively demolishing buildings also seems fun. -- Q Chris (talk) 12:47, 27 September 2010 (UTC)

This is to be expected don't you think. We are a social animal, that cooperate with each other and competitively in a troupe. It appears to be hard-wired into us. Monkey's hunting in a group need to cooperate in order to outsmart their quarry but the chip which actually makes the kill has first pickings (the brain is rich in omega 3 and so is highly prized). It must have been like that for our distant ancestors also. Tearing things down, may have also been necessary to make space, to create more of the environment we needed to exist in. Just saying we evolved on the open savannah may be an over simplification. Our ancestors probably need a mixed and varied bushland which needed to be kept in check. The Australian aborigines are now thought to have slashed and burnt the land into a more hospitable habituate. Talking of which. 'Fire' is another phenomena of nature that fascinates small, and not so small boys. We are today, a product of yesterdays survival techniques. It appears to my mind quite likely, that the more satisfying the activity, the more essential to it was to our ancestors long-term survival as a specie. --Aspro (talk) 13:22, 27 September 2010 (UTC)

I think the Aborigines screwed up. Have you seen 90% of Australia? Googlemeister (talk) 15:37, 27 September 2010 (UTC)

Climate of Australia cites a paper I haven't read that may support that notion to some extent, but surely saying "the Aborigines screwed up the climate of Australia" is hyperbole to the point of easily being taken by some as a bit offensive, don't you think? WikiDao ☯ (talk) 15:51, 27 September 2010 (UTC)

Only if the people of which you speak insist on being offended. Seriously the vast majority of Australia more then 100 miles from the coast is below par in terms of it's ability to support human life. Googlemeister (talk) 15:59, 27 September 2010 (UTC)

Yes. The Aborigines didn't cause that. I'm sure you were joking, and there is actually something to it apparently, but any comments about race or culture are "sensitive" and may easily cause offense in a context such as this is all I'm saying. WikiDao ☯ (talk) 16:05, 27 September 2010 (UTC)

According to the analysis presented in, for example, Tim Flannery's The Future Eaters, the Aborigines did cause that, insomuch as by killing off most of the continent's megafauna during the period ca. 60,000-30,000(?) years BP, they disrupted the ecology so seriously that soils continent-wide were permanently impoverished (the linked article does not well represent the book's arguments, and minimises corroboratory studies that I have encountered elsewhere). Of course, there was no way that those very distant ancestors of present-day Aborigines could possibly know that that was what they were doing, so no blame could sanely be attached to modern individuals for these prehistoric events. 87.81.230.195 (talk) 21:41, 27 September 2010 (UTC)

I just want to point out that I don't think hunting has much to do with it. Lots of species have males who compete aggressively as forms of sexual selection, whether they hunt or not. See Alpha (ethology). However it is worth pointing out that specific expressions of alpha drive are almost certainly highly conditioned by cultural expectations, and not all males of any species strive to be alpha, especially when it does not confer exclusive reproductive success (as it does not with humans). --Mr.98 (talk) 16:28, 27 September 2010 (UTC)

I mention potency (to be taken in its widest sense) in my first post. Hunting was just giving a further example which does not include chopping down trees. Also, I'm restricting comments to primates in general not unrelated critters. The OP's question is about phenomena that clearly appears to cut across cultures, so with respect, I think this is just tangential.--Aspro (talk) 17:01, 27 September 2010 (UTC)

Destroying things, as such, is not necessarily fun; if your job is to destroy big buildings it may well be satisfying, but if your job is operating a trash compactor, satisfaction is hard to attain, even though you destroy a far greater number of things per week. I see no need to embark on a great fantasy of evolutionary psychology to explain this. Surely it's fun to affect things, for the sense of empowerment, regardless of whether you are destroying, creating, or just altering them. Chopping down a tree is a rare opportunity to have a big effect on a big object. Destroying a building feels significant, viscerally. (The greatest changes I routinely make to the world are microscopic and affect only bytes on hard drives.) One advantage of destruction over creation is that you don't have to think too hard or be too careful to get it right; there is nothing delicate in the process that you mustn't break, because breaking things is the whole objective. This is less true in the case of demolishing buildings, which must often be done with high precision; I imagine being told off for making an error that caused a demolition to be unsafe would reduce the job satisfaction. 81.131.61.27 (talk) 16:40, 27 September 2010 (UTC)

The question is "are there any evolutionary advantages to destructive behavior" right? And then a very specific example is given, in which it appears that men (mostly) are doing physically demanding labor in the proximity of women. As worded, the answer seems to me to be "yes, and there's a lot more going on in that example, and why all that is gets complicated." Evolutionary psychology gives an overview. WikiDao ☯ (talk) 17:33, 27 September 2010 (UTC)

I do not agree that destroying things is fun. To me trees are precious, I would hate to destroy any. Building something would be better. However chopping trees down has far more drama and variety than leaf-picking, and may be preferred for those reasons. 92.15.25.79 (talk) 18:43, 27 September 2010 (UTC)

In modern life, destroying things is usually prohibited. The fun comes from transgressing that rule. By the way, I dispute the claim that it's hard to obtain satisfaction as a trash compactor. I had a weekend job at a supermarket when I was a kid, and that was my favourite task. I never got tired of it. If you ever get the chance, I recommend crushing a pallet of expired yoghurt cartons. --Heron (talk) 19:21, 28 September 2010 (UTC)

Light from just after the Big Bang. Why is it reaching us now, since the matter from which earth was created also began with the Big Bang? Light travels much faster than matter.

Surely if light and matter were created simultaneously at the time of the Big Bang, such light would have passed us by immediately and be billions of light years ahead of us rather than behind? Or are we looking at that light "from behind" as it accelerates away from us into the future?

Many thanks indeed for any explanation.

—Preceding unsigned comment added by 222.123.128.194 (talk) 15:32, 27 September 2010 (UTC)

To prevent spamming, I removed your email address --KägeTorä - (影虎) (TALK) 15:34, 27 September 2010 (UTC)

I assume you are referring to cosmic background radiation? It's not quite "light from the Big Bang" so much as "weakened radiation from the Big Bang which has been bouncing around for quite a long time," if that makes sense. I'm not sure "from behind" or "ahead of us" are the right metaphors for thinking about an event which created space and time itself. It is not that the Big Bang exploded into a space (and then created us); it's more than the Big Bang was the creation of space. I think it makes more sense to think of it less as an explosion than as a big, hot, ball that expands and then cools down, and we're currently still inside the ball. --Mr.98 (talk) 15:57, 27 September 2010 (UTC)

As Mr.98 says, what we can detect in the cosmic microwave background radiation isn't light - it is microwave radiation that used to have a shorter wavelength but has been stretched as the universe has expanded. This radiation was emitted at an early stage in the development of the universe, at approximately 380,000 years after the Big Bang - we don't see any radiation from earlier than this because the universe was not transparent to radiation before this time. So this radiation has been travelling towards us for over 13 billion years. The reason it has taken so long to reach us is that it was emitted from a very long way away (exactly how far away gets complicated because space has expanded by over 1,000-fold while the radiation was travelling). Radiation that was emitted from nearby has already gone past us and we have missed it. Gandalf61 (talk) 16:16, 27 September 2010 (UTC)

I'd like to take a different stab at this. First, the OP is exactly right in pointing out the paradox -- the space that became "us" and the space that became "the CMB" were once right on top of each other, and on the surface it makes no sense that light-speed EM radiation (arguing the nuance of "light" based on wavelength is rather silly; it's fundamentally the same stuff) that was emitted relatively close by is only now reaching us billions of years later. "Radiation that has been bouncing around" isn't quite right; what is there for the radiation to reflect off? No, the answer is briefly mentioned in the posts above without really being linked: while matter doesn't move faster than light, space itself can expand faster than light. The early universe (prior to the formation of the CMB) underwent the inflationary epoch, and to this day the universe is subject to the metric expansion of space. This bit of physics (collectively known as inflation) explains how newly-visible parts of the universe (that is, the CMB) which should have no causal connection to us instead fit the cosmological principle. Everything was once very close together and causally connected but then expanded faster than light itself could propagate. — Lomn 17:45, 27 September 2010 (UTC)

I'm not sure the paradox is as strong as you're making out -- surely the key point here is that looking out into space is looking backwards in time and therefore the light we are seeing from 13.7ish bn years ago is also from 13.7 bn light years away (modulo the complexities of all that stuff about integrating a(t) along the line of sight that I've mercifully forgotten the details of). Inflation is required to explain why the temperature is so uniform in widely separated parts of the sky which should never have been causally connected with each other, but not the simple fact that we do see something there.--81.153.109.200 (talk) 19:46, 27 September 2010 (UTC)

I have to disagree with this. If you assumed flat space-time and all that, it would definitely be impossible to see any light from the big bang unless it was reflected off something. EM radiation doesn't just hang around. It travels in a line at the speed of light. Without accounting for metric expansion, any light from near the big bang would be at the edge of the universe and traveling outward, where we would never be able to observe it. To put it another way, in flat space-time, a photon and anything massive can't cross paths more than once unless the photon gets reflected. Rckrone (talk) 23:11, 27 September 2010 (UTC)

No, sorry, this doesn't make sense to me. Surely the directions the photons are heading in are isotropically distributed in all directions at the point of last scattering, so that some of them are heading in the right direction. It's not like they "know" they're at the "edge of the universe", the universe was filled with them at that point (and still is, just redshifted down to microwaves). Some of them were bound to be heading in the direction that we'd be able to pick them up. The whole universe is expanding, so I'm not sure what you mean by "outward". --81.153.109.200 (talk) 17:21, 28 September 2010 (UTC)

The Big Bang.

Maybe a more intuitive way to explain this (for myself as well as the OP) is with reference to a more visual approach. The graphic at right, for the point of simplification, shows the universe as a 2-D sheet. Big Bang at bottom, later (more current stage) at top. What's important is that in the very early period, space is very close together and light saturates it pretty homogeneously. As space itself accelerates faster than light in an initial inflationary period, the light itself is still imbedded in that space. So let's imagine a single photon, going from the bottom-left to the top-right. In the blobby phase, it is just starting out on the far bottom-left. In frame 2, it has just hit the edge of that red galaxy. In frame 3, it is just beyond the red galaxy. In frame 4, it hits the blue galaxy. So it would take it just about the time of traversing the universe to hit that blue galaxy, assuming that the amount of space has increased faster than the speed of light. Now I think the point of confusion here is seeing the initial Big Bang as an "outward" movement of photons (e.g. center to the edge) rather than a huge amount of energy/mass in a really exceptionally tiny amount of (very saturated) space. So you would have things like a photon on the lower-left edge facing to the upper right edge, not just an idealized "center" going outward. This is my admittedly qualitative and potentially wrong understanding, and what I was trying to convey in my first response (which is not as good as some of the others), and perhaps others can correct me on this or clarify it. --Mr.98 (talk) 21:53, 27 September 2010 (UTC)

Here's a diagram I just made that may or may not be helpful. Unlike the other time I made diagrams for a thread like this, this picture isn't numerically accurate, nor is it to scale. It's hard to draw the CMBR to scale for the same reason it's hard to draw the solar system to scale. What this shows is an Ω = 0 universe (the real universe has Ω ≈ 1) in which the early glowing plasma phase lasts for a much longer time (relative to the current age) than in the real universe. The nice thing about Ω = 0 is that spacetime is the flat spacetime of special relativity, and what I've plotted to the right is just an ordinary SR spacetime diagram in which light always travels along 45° lines, the SR redshift formula is valid, and so on. The CMBR that we see is the boundary of the plasma region; we can't see into the interior because the plasma is opaque. It's similar to looking at the Sun. The boundary is horizontal (spacelike) instead of vertical (timelike), but that doesn't make much difference. The surface temperatures are even similar: ~6000K for the Sun, ~3000K for the CMBR (but the CMBR is hugely redshifted). The temperature of the interior is much higher.

You can think of the shape of the last scattering surface as due to time dilation—particles near the edges of the diagram are moving faster, so they take longer to do anything, including cooling down. Likewise, you can think of the increasing density of the Hubble flow lines near the edge as due to length contraction. A nicer way to think of both of them, though, is in terms of Lorentz transformations; this whole universe is invariant under Lorentz transformations that leave the vertex at the bottom fixed, and everything else follows from that. You can use a Lorentz transformation to center the here-and-now horizontally, so it looks like we're at the center of the universe, but of course we're not; every location is the same as every other.

This universe doesn't have a horizon problem. Everything is in the causal future of a single point (the vertex at the bottom), even though the surface of last scattering is infinite in size! This diagram shows that you don't need anything to move faster than light to solve the horizon problem. It also shows the difficulty of talking about "faster-than-light expansion" in general relativity. I could plot this diagram in different coordinates where the expansion "looks" superluminal, but it's the same physics either way.

I haven't linked Ned Wright's cosmology tutorial in a while. It has a lot of diagrams similar to this one, illustrating changes of coordinates, the horizon problem, and inflation, among other things. -- BenRG (talk) 06:36, 28 September 2010 (UTC)

That's a nice graph and clarification, thanks. --Mr.98 (talk) 15:41, 28 September 2010 (UTC)

UK Fuel Sources

Are there any more up-to-date numbers on the UK sources of fuel than these from the 1990s?

• gas – 39.93% (0.05% in 1990)
• coal – 33.08% (67.22% in 1990)
• nuclear – 19.26% (18.97% in 1990)
• renewables – 3.55% (0% in 1990)
• hydroelectric – 1.10% (2.55% in 1990)
• imports – 1.96% (3.85% in 1990)
• oil – 1.12% (6.82% in 1990)

--CGPGrey (talk) 17:03, 27 September 2010 (UTC)

It used to be easy to go to the local library and look these things up in the many volumes of UK National Statistics. However, now that they tell you to find it online, it always seems to me that the information that I want they charge for. Still, that said here's a link to their site : [1]--Aspro (talk) 17:16, 27 September 2010 (UTC)

This seems to have key data, with this providing more links. - Jarry1250 ^{[Who? Discuss.]} 18:39, 27 September 2010 (UTC)

The information here is live. --Heron (talk) 19:11, 28 September 2010 (UTC)

That is amazing -Thanks. Wonder if we should link to it in the article?--Aspro (talk) 20:32, 28 September 2010 (UTC)

If you're using it as a source, then that would be a good idea. --Heron (talk) 18:04, 29 September 2010 (UTC)

Why do Paper Clips work better than Copper wire in an electrical stimulation experiment?

Preparing for a Physiology class later this week, I've put together a square-wave stimulator, some electrodes, and tested them by shocking myself on the forearm (slightly dampened with some salt water.) One thing I discovered after comparing electrodes borrowed from another college nearby, made with paper clips (aluminum?), with the ones I made (copper wire) is that the shock is more detectable and dramatic with the paper clip electrodes.

I have no idea why this is, but would love to have an explanation before some student asks me.

Any ideas? Wevets (talk) 18:18, 27 September 2010 (UTC)

The response of the nerves in the skin to electric shock depends on the path taken by the electricity. You might like to put a milliammeter in the circuit to determine whether the current is actually larger with copper, but is flowing more evenly through the skin, thus causing less pain. I've found that a small current is more detectable if the cut ends of a finely stranded wire are gently stroked over the skin. Your paper clip is probably having a similar effect by restricting the main current flow to particular concentrated points. I trust that you have limited the current in your circuit to less than 3 milliamps for safety reasons. Dbfirs 18:33, 27 September 2010 (UTC)

The dominant factor here should be skin resistance. The composition of the electrode shouldn't make any noticeable difference. However, as Dbfirs says, the shape of the electrodes (you are using two, right?) could easily make a difference, and physiological factors that affect your GSR could also matter, if they aren't controlled. Looie496 (talk) 20:06, 27 September 2010 (UTC)

The skin resistance should be the same between the two tests, so I would suggest that the copper wire isn't as clean as you think it is... The "paper-clip" electrodes are probably made out of coated mild steel, not aluminium (too expensive and too brittle), and any coating that prevents surface oxidation will promote the passage of electric current to your suffering skin! Physchim62 (talk) 00:59, 28 September 2010 (UTC)

Aha - so the thickness of the wire rather than its composition is the important factor here? The copper is thicker than the paper clips. Perhaps I should also try with some thinner copper wire.

Don't worry - I'm not about to shock myself into oblivion. I'm being very cautious, and the equipment has built-in safety limitations I won't be tinkering with. Wevets (talk) 01:01, 28 September 2010 (UTC)

Copper is actually a much better conductor than aluminum (see Electrical conductivity)174.131.80.53 (talk) 18:35, 30 September 2010 (UTC)

synchronized reflected vacuum energy waves fluctuations as the origin of Gravity: a case study: the black hole: a suggested mechanism of how gravity interacts with light waves, electromagnetic waves

The reference desk is a place for asking for information, not for lengthy presentations of original ideas -- collapsing due to length. Looie496 (talk) 20:00, 27 September 2010 (UTC)
The following discussion has been closed. Please do not modify it.
Hello Wikipedia, I have recently found your name (Wikipedia) as a reference on a book. So, I am going to ask the following question: could it be that: Gravity is, in my opinion, originally generated from the medium i.e. the Vacuum and Vacuum energy, on masses. the vacuum energy 10^107 joules per cubic centimeter creates a force (a repulsive in nature, since energy of vacuum is different from energy of mass and mass surface) on the mass surface, similar to surface tension force. The body of the mass provides a surface where vacuum energy fluctuations (waves?)could reflects off. these reflections of the vacuum energy would then become "synchronized" when reflected off the mass surface into high and low energy waves sinusoidal mathematical functions (orbits) mixed with other geometrical representing motion mathematical functions pending on Vacuum and Vacuum energy medium surrounding the mass. The density of the mass would be a deciding factor of the frequency of the vacuum energy synchronized reflection, in such a way that shorter wave reflected will form from a denser body (black hole). When two masses are within the fields of each others synchronized reflected vacuum energy waves(gravitational forces filed), they "shadow" each other from the non reflected vacuum and vacuum energy waves fluctuations; therefore falling into a lesser, a weaker repulsive medium, resulting in the observed attraction of the two masses to each other.--e:Y,?:G 06:37, 15 September 2010 (UTC) —Preceding unsigned comment added by E:Y,?:G (talk • contribs) The Black Hole event horizon support's the above suggested mechanism for Vacuum energy synchronized wave reflection off mass's bodies, in a way that the mass of the black hole is so dense that the vacuum energy waves reflected have wave length that does not support to carry the light waves or the electromagnetic waves as a lesser density mass bodies do. Or the unreflectiveness of light off the Black Hole mass body, is may be because these vacuum energy synchronized wave reflection off the mass's bodies, must reflects off a body not of the dimensions of the Black Hole mass i.e. less than 5 solar masses. The form these vacuum energy waves reflected off the mass must meet a certain geometrical dimensions. gravitational lensing is another example supporting the above suggested mechanism in a way that the reflected vacuum energy waves off dense bodies are not synchronized in the same way the lesser denser mass bodies do. Another conclulsion form the above suggested mechanism for vacuum energy synchronized wave reflection off mass's boies, is it must be in a certien formate for it to "carry" light and electromagnatic waves. and could be that, Taking into considerations E = M C^2, different type of matters with respect of their density's, differently reflects, i.e. in a different patterns, the Vacuum energy fluctuations (Casimir effect). In my opinion, the synchronized reflections of vacuum energy fluctuations off of a mass constitute the gravitational forces for that mass. In compression to a lesser density mass such as the earth, the matter in the black hole within the event horizon (equation of state), (UC Berkeley, September 24, 2010, high pressure experiments reproduce mineral structure 1,800 miles deep in the earth: where seismic waves have different patterns when run through post-pervoskite's zone of Magnesium silicate perovskite (MgSiO3) above the earth core). In my opinion, The Matter of a lesser density such as the earth matter, would react differently than the matter of the Black Hole to Vacuum waves, vacuum fluctuations, vacuum energy, which (the vacuum energy fluctuation ) when reflected off of these two different matters (equation of state) creates different synchronized reflected vacuum energy waves i.e. different gravitational forces; Where synchronized reflected vacuum energy waves is a gravitational force for a set, a defined system that has a specific equation of state. Also, The matter of the Black Hole (within the event horizon) may not reflects electromagnetic waves, since light have two components vectors: electric and magnetic, as it (the light) does reflects off of a lesser denser mass's such as the earth; therefore no light reflects off of a black hole matter, as observed. (UC Berkeley, September 24, 2010, high pressure experiments reproduce mineral structure 1,800 miles deep in the earth: where seismic waves have different patterns when run through post-pervoskite's zone of Magnesium silicate perovskite (MgSiO3) above the earth core). Or/and, the vacuum, vacuum energy of the atmosphere of a black hole will not support to carry light waves (or, most electromagnitic waves within the "atomspher" of the mass of the black hole. and light speedThat constitute that If we defined the atmosphere of a black hole to be the space between it's event horizon and it's mass surface, and if the rules of equation of state where to apply within the event horizon of a black hole atmosphere's with consideration to light travel; then E = M C^2 as an equation of state, could not probably be applied or used within the atmosphere of a black hole. E = M C^2 is does not apply in the black hole as a Equation of state for the absence of most electromagnetic waves spectrum (Hawking radiation existence?).--e:Y,?:G 19:58, 25 September 2010 (UTC)--e:Y,?:G 19:58, 25 September 2010 (UTC) —Preceding unsigned comment added by E:Y,?:G (talk • contribs The reflection of the vacuum waves off a mass's body could work as "sonar" in way or light reflection in way to evaluate a mass density.--e:Y,?:G 08:44, 15 September 2010 (UTC) —Preceding unsigned comment added by E:Y,?:G (talk • contribs) --e:Y,?:G 21:55, 17 September 2010 (UTC) --e:Y,?:G 18:24, 27 September 2010 (UTC) —Preceding unsigned comment added by E:Y,?:G (talk • contribs) thank you --e:Y,?:G 18:27, 27 September 2010 (UTC)

We can't really help you with things like this, but your "shadow" suggestion would imply that gravity varies by the surface area of an object, rather than its mass. You will also need to do the math and calculate these waves and show that the math works perfectly before anyone will take an interest in this. Ariel. (talk) 23:26, 27 September 2010 (UTC)

Electro-conductive body paint?

I saw a mention about electro-conductive body paint in an episode of C.S.I. Miami. Does such a thing really exist? Isn't it a pretty stupid idea? What prevents the current from entering the wearer's body, potentially electrocuting him/her? JIP | Talk 18:36, 27 September 2010 (UTC)

I don't know if this paint really exists, but if it does it would have a low resistance, while the body (the skin) has a higher resistance, so most of the current flows in the paint and not in the body. Skin effect has some info on a different mechanism that probably does not occur here, but might. Ariel. (talk) 19:30, 27 September 2010 (UTC)

It really exists. Check here. APL (talk) 19:34, 27 September 2010 (UTC)

The principle might be better appreciated by viewing this video, which shows things at the extreme end of sensible.[2]. Its about 60 seconds in that you start to see it in action.--Aspro (talk) 20:46, 27 September 2010 (UTC)

My neighbours wonder why I walk around with a tin foil hat on my head. This is the best reason I can give (and please don't try this at home as it it frightens the folks across the yard). It further demonstrates electricity (and mind controlling rays) taking the easiest route to ground. [3] --Aspro (talk) 21:05, 27 September 2010 (UTC)

Paramecium, communication, electromagnetic signals

At our article on Paramecium there is a paragraph in dispute. It is alleged that an experiment has shown that Paramecium may be able to communicate with other Paramecium over short distances with the use of electromagnetic signals. The dispute is over whether this is an April Fools' Day joke. Bus stop (talk) 20:33, 27 September 2010 (UTC)

We are discussing it on the Paramecium Talk page. Bus stop (talk) 21:07, 27 September 2010 (UTC)

It doesn't have to be a an April Fools joke to be wrong. It sounds wrong to me, and unless you can find more research that confirmed/reproduced it I would either remove it, or at least disclaim it with words such as "appeared", "one experiment", "unconfirmed", etc. Plenty of published papers turn out to be wrong. Ariel. (talk) 22:28, 27 September 2010 (UTC)

That is tantamount to original research. This phenomena is sourced to PLoS ONE and Scientific American. Bus stop (talk) 22:45, 27 September 2010 (UTC)

PLoS ONE is a reputable journal. So is Scientific American where it comes to articles, although it is equivalent to a news magazine where it comes to brief reports. Looie496 (talk) 22:57, 27 September 2010 (UTC)

You're right, it is OR. That's simply my sense after looking through it. The gold standard for science is reproducibility, and this study has not been (as far as I know anyway). So when you take that, plus other factors (single author, small sample size, etc) this doesn't seem good enough to me. But I accept that that is not the wikipedia policy. Ariel. (talk) 23:07, 27 September 2010 (UTC)

I emailed the author and asked him. Ariel. (talk) 23:17, 27 September 2010 (UTC)

Thanks for the forthcoming reply and for emailing the author. Bus stop (talk) 00:50, 28 September 2010 (UTC)

He replied:

Dear Ariel

Thanks for your interest.
Here my answers.

1) It is not a fools joke.

2) For the time being I am the only one who does this type of experiments with Paramecia but by far not the only one who does this type of experiment.

3) Actually, you can see my paper also as a repetition of previous studies but with another organism.

4) I apologize for not contributing on your blog.

A remark after reading your discussion.
        Single author does not mean bad work.
        Experiment 1 was 14 times repeated.
                This is a big sample size.

Please, do not talk in such a sloppy way about other people's work.
It took about 700 working hours to do all experiments, read into the literature, permanently hand out my paper to my critical collegues checking for errors, making it waterproof, double-check the statistics and so on ...
Note, the field is old (1923) but only few people work on it. These people have to convince the Scientific community about the reality of so-called bio-photons.
Join in in a construcitve way.

Yours friendly
Daniel Fels

PS: Maybe you and your friends have a (long) glance at this recent review.

Attached was a pdf titled: "Electromagnetic cellular interactions" by "Michal Cifra, Jeremy Z. Fields, Ashkan Farhadi". doi:10.1016/j.pbiomolbio.2010.07.003 Ariel. (talk) 09:56, 29 September 2010 (UTC)

I believe that restores seriousness to the premise that Paramecium may be able to communicate by electromagnetic radiation over short distances, with one another. This does not mean they own their own personal BlackBerry, but rather that they have perfected long before man did, the ability to project oneself wirelessly. Bus stop (talk) 16:14, 29 September 2010 (UTC)

Burning alcohol without a flame

Do metal oxides catalyze the oxidation of isopropanol by sodium hypochlorite? --Chemicalinterest (talk) 23:18, 27 September 2010 (UTC)

Hey, that's one of the simpler questions you ask! ;) Probably, but I don't know of any studies that have proved it. Metal oxides are usually good catalysts for any sort of oxidation reaction – exactly how good depends on a lot of other factors, of course. Physchim62 (talk) 00:49, 28 September 2010 (UTC)

I think the appropriate catalyst would be a redox or Lewis acid catalyst that is soluble but doesn't complex water too much. That is, Fe(III) is out of the question. Does Cu(II) decompose bleach? John Riemann Soong (talk) 03:52, 28 September 2010 (UTC)

Umm, I've used it in the lab -- hypochlorite just did its simple work and converted it into acetone without a catalyst. Of course, we waited an hour or so. As I recall, there are two steps in the bleach oxidation: (CH3)2CH--OH + OCl- ----> (CH3)2CH--OCl + OH- ----> (CH3)2(C=O) + Cl- + H2O. If you could convert that into a cyclic, concerted reaction maybe it would be faster. Of course, the alcohol isn't completely oxidised here.

Once you have acetone of course, you can start to go along the haloform reaction until you get a carboxylic acid (acetic acid) and chloroform. Lewis acid metal ions might stabilise the acetate (a negative anion -- not susceptible to another deprotonation) allowing hypochlorite to react further to yield another chloroform molecule and carbonate.

Chloroform isn't quite thoroughly oxidised though. It has one C-H bond left. And C-Cl bonds aren't the strongest thing ever. Did you want it to be oxidised by chlorine or oxygen? Well the reaction doesn't have to stop here either. Chloroform has an acidic C-H bond cuz of those three electron-withdrawing chlorines, so it can form dichlorocarbene in strongly basic solutions (I don't know if bleach is strongly basic enough -- usually I think people use potassium hydroxide) which can participate in all sorts of radical and electrophilic/nucleophilic reactions. But in water it's likely to form formic acid (via an acyl chloride intermediate).

Complete and orderly oxidation of hydrocarbons (and their alcohols) tend to be done by industrial-scale catalysts as opposed to done in the lab. John Riemann Soong (talk) 03:28, 28 September 2010 (UTC)

That is organic chemistry. I do inorganic chemistry! :) --Chemicalinterest (talk) 11:03, 28 September 2010 (UTC)

Here is my story. I mix bleach and rubbing alcohol. Nothing happens. I add CuO. It starts bubbling moderately rapidly. (I have yet to test whether the gas is CO₂) To a new solution of bleach and rubbing alcohol, I add Fe₂O₃. It starts bubbling a little more rapidly than CuO. To a new solution of rubbing alcohol, I add MnO₂. It is bubbling too. Is it the oxidation of alcohol to CO₂ and H₂O that makes the bubbling? --Chemicalinterest (talk) 11:01, 28 September 2010 (UTC)

Ahh, but isopropanol is an organic compound. You're sure you're not merely decomposing the hypochlorite? Also do you have any pH paper or way to evaluate how much the pH changes as you do this? The only obvious ways to evolve gas from isopropanol is you're dehydrating it (making isobutylene, a gas) or thru the haloform reaction to produce carbonate (which should take a while!). Do you have any glass apparatus through which you can capture the gas? John Riemann Soong (talk) 12:54, 28 September 2010 (UTC)

Intriguing if you're causing bleach to attack unactivated C-H bonds. The production of methanol via the orderly oxidation of methane is a major industrial problem, that if you solve, would earn you lots of money ;-). Your solution doesn't change colour? Hmm. Maybe somehow you're producing O2 + chloride. Also, bleach activated with some semi-fancy catalysts attacks unactivated C-H bonds, but doesn't completely oxidise the hydrocarbon. John Riemann Soong (talk) 13:02, 28 September 2010 (UTC)

I'm assuming it's not chlorine (otherwise you'd tell us, lol). Light a match and then snuff it until its glowing -- does it glow brighter near the evolved gas? (This would be really effective if you had some sort of glassware by which the gas could by channeled.) John Riemann Soong (talk) 13:27, 28 September 2010 (UTC)

I was thinking of this reaction: C₃H₇OH + 9 NaClO → 3 CO₂ + 4 H₂O + 9 NaCl Would that reaction be likely to occur? --Chemicalinterest (talk) 13:37, 28 September 2010 (UTC)

Just because you can balance the equation doesn't mean it occurs readily. ;-) Welcome to organic chemistry lol. Unlike bonds between say, metal ions (or other reducing agents) and inorganic compounds, C-C bonds and C-H bonds are strong -- on the order of 250-400 kJ/mol. For one -- isopropanol is a secondary alcohol. It's not likely to form a carboxylic acid (the precursor to CO2 being given off -- at least when there's no combustion involved) without the haloform reaction. I'm still intrigued where the gas came from though. Once you convert isopropanol to acetone, the carbons next to the C=O bond become "activated" and more susceptible to alpha-oxidation -- hence, haloform reaction. Have you tried the same thing with hydrogen peroxide?

Think about this first. What would the bleach attack? (Or maybe what would the catalyst help attack?) The weakest point, naturally. (In an environment full of strong bonds, the weakest bonds go first.) The C-H bond next to the oxygen is weakest (for various reasons you may or may not be interested in). So that would be oxidised first, and donated to Cl+ -- hence, OH- + HCl + acetone. The remaining C-C bonds and the C-H bonds are slightly actually stronger as a result of this (they are more polarised) -- the C-H bond becomes a little acidic. So the most obvious route would be haloform reaction, that takes advantage of the "activated" C-H bond. But do metal catalysts really catalyse the haloform reaction that fast? Wow. John Riemann Soong (talk) 18:18, 28 September 2010 (UTC)

That sounds unlike any mechanism I've seen published evidence for for the bleach oxidation of alcohols. To steal from someone up-thread, Just because you can draw a mechanism in which the bond you think is weakest breaks doesn't mean that's how the reaction happens. The most active/donatable electrons in isopropanol are lone-pair on oxygen, not a C-H covalent bond (otherwise reacting IPA with H+ would potentially oxidize it also rather than forming oxonium -> carbocation!). There's evidence for an alkyl hypochlorite intermediate, that then undergoes loss of your H as H+ in an E2-like reaction to give C=O. DMacks (talk) 20:58, 28 September 2010 (UTC)

I was simplifying it for him since he probably didn't need to know all that. Yes, AFAIK you get (CH3)2-CH-O- + HOCl, then alkoxide attacks the chloride side of hypochlorous acid, yielding (CH3)2-CH-OCl + OH-. (The alkyl hypochlorite is better able to stabilise the O-Cl bond than the hydrogen is.) The overall picture is that the C-H bond is weakest so that's the bond that gets "attacked" overall. AFAIK the rate-determining step is getting the deprotonated alcohol to attack the hypochlorous acid. A metal catalyst may turn it into a smoother, more concerted reaction. John Riemann Soong (talk) 21:06, 28 September 2010 (UTC)

Simplifing or omitting details that don't matter is good. Making statements that contradict basic science and known facts is very bad. It's simple to say the moon is made of cheese, but it's bullshit, and it's harmful to say it when you're trying to explain something about either cheeses or moons. You proposed the complete opposite of how the electrons move! DMacks (talk) 21:13, 28 September 2010 (UTC)

It's possible you're producing chloroform (which in turn reacts to produce all sorts of byproducts). Now I would expect it (unless you had an immensely selective catalyst) that little bubbles of gas (from like carbon monoxide + H2O, or carbon dioxide and hydrogen) would be produced though. Also, do you have a thermometer you could probe the reaction with? John Riemann Soong (talk) 18:29, 28 September 2010 (UTC)

Hydrogen peroxide would catalytically decompose with the metal oxide catalysts. I was thinking of oxidation by bleach in a similar way to burning. The bubbles were not insignificant, though. Enough to make some foam. Why does alcohol burn then and not produce chloroform or acetone or some other product? Oxygen is a weaker oxidizing agent than hypochlorite. The test tube does get quite warm, giving the title of this section. --Chemicalinterest (talk) 20:35, 28 September 2010 (UTC)

Bleach tends to oxidise by nucleophilic/electrophilic attack (depending on pH and the reductant and which side of the hypochlorite reacts first). That is, bleach tends to react via two-electron transfer.

During straight-up combustion, unreactive triplet oxygen more easily interconverts into reactive singlet oxygen -- which attacks via free radical mechanisms -- that is, one-electron transfer. Radicals abstract C-H bonds and C-C bonds like *that*. Bleach AFAIK isn't an oxidant via radicals. You can use hydrogen peroxide with metal catalysts btw -- I suppose you've tried -- but according to some papers I've read the H2O2 can survive long enough to induce significant reactions. John Riemann Soong (talk) 20:47, 28 September 2010 (UTC)

One more thing I did. I added household vinegar (5% acetic acid) to the reaction mixture and it did not significantly increase the reaction rate. See this for an argument whether that reaction made chlorine --Chemicalinterest (talk) 11:03, 29 September 2010 (UTC)

To all the mixtures? Fe(III) is a moderately strong Lewis acid but Cu(II) -- quite weaker (it's oxidising properties are stronger). John Riemann Soong (talk) 14:47, 29 September 2010 (UTC)

Cu(II)'s oxidizing ability (electrode potential +0.34) is weaker if Fe(III) is reduced to Fe (electrode potential +0.77). If Fe(III) is reduced to Fe then yes, Cu(II) is the stronger oxidant.

Oh well, this discussion does not seem to be producing a satisfactory explanation. I plan to test the gas to see whether it is CO₂. --Chemicalinterest (talk) 17:38, 29 September 2010 (UTC)