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June 15

Are Chemical Reactions originally derived from solar energy?

This question came about from my “Horses on Mars” query when one poster opined that horses get their energy from the "solar panels" of the grass they eat, and thus the energy they expend is solar energy converted to kinetic energy. I thought about this, and wondered about the nature of chemical reactions. Take this one: Put some potassium in water. Boom!! Now, is this solar energy? No, it is not. Well, where did all that energy come from?

Perhaps chemical energy of this kind is essentially nuclear energy. And in that case, perhaps it is wrong to say that all our energy, as physical organisms, is derived from solar energy. If we could take in potassium and water in a controlled way, we could be supermen, and the energy we would need would be only that miniscule amount we needed to open a new jar of potassium in the morning and swish it down with a glass of Adam's Ale. Myles325a (talk) 04:01, 15 June 2014 (UTC)[reply]

I'm not sure I follow where you are going? It sounds like you don't really have a good fundamental understanding of what energy is... Energy is simply a way to quantify change. If we have a system in two different states of being, energy is just a measure of how different those two states are from each other. Any of the ways we, as humans, classify energy (potential vs. kinetic... work vs. heat... enthalpy vs. entropy...) are just human created classifications which help us to understand how energy works. How you divide energy into different "forms" is only as important as it is useful. If you start with the "it's all solar energy", you sort of right to a point, except some small fraction is actually energy stored inside the earth from its own formation, some kinds of extremophile life is able to tap into this energy, as do humans when we use Geothermal energy. So if I take a potassium salt, and electrolyze potassium from it using energy from a geothermal power plant, I haven't really used any of the sun's energy. If you really want to harness solar energy for yourself, eat some spinach. Because the energy stored in the chemical bonds in the spinach came from the sun. Just remember, however, as you keep trying to work backwards, that since the sun and earth have not existed since forever, its energy had to come from somewhere first; the only antecedent for all energy is the Big Bang. --Jayron32 05:00, 15 June 2014 (UTC)[reply]

Put another way: where did you get your potassium? The OP incorrectly dismissed his reaction as one that doesn't derive any energy from the sun - because there is no apparent photochemistry going on - but he forgot to account for the energy in the atoms of the reactants that did derive from the sun many billions of years ago.

If we trace the history farther: where did the sun get its energy? Well, that's an easy, well-formed question with a straightforward answer, based on our scientific knowledge about stellar formation. Our sun got its energy for nuclear fusion from the gravitational collapse of its hydrogen gas.

Where did that hydrogen get its energy... - well, the cloud of gas had gravitational potential energy when it was separated; and it got that energy from the kinetic energy it had when it was formed. That kinetic energy came from an earlier time, when the gas was in a different configuration, and its constituent particles were sub-atomic... And if we keep tracing backwards toward the proverbial "dawn of time," we eventually reach a point where the question must be posed in metaphysical terms.

As scientists, we don't think in terms of "first cause." If anything, we're really only concerned with material cause and effect. As Jayron has described, energy is just one of the ways we speak quantitatively about cause and effect. When we are on Earth, talking about terrestrial processes, it is convenient to summarize almost every process as one whose common denominator is the stellar energy emitted by our sun. The original energy didn't "come from" the sun; but there is a clearly defined historical path that lets us trace the time-evolution of almost any terrestrial process back to the sun. Nimur (talk) 05:34, 15 June 2014 (UTC)[reply]

Well, if I must quibble with one thing in that excellent answer, I'm not sure energy really deals well with cause and effect. Energy is either a state function or a process function, and even process (or path) functions can be thought of as a bunch of microstates in succession (i.e. a calculus-sorta-thingy). Energy tells how how much something has changed, rather than what caused something to change... --Jayron32 05:49, 15 June 2014 (UTC)[reply]

It depends on what chemical reactions we are talking about whether they come from the sun. Potassium doesn't come from the sun. Potassium comes only from supernova nucleosynthesis. The energy that was used to electrolyze the potassium from a potassium salt (since potassium is never found as the native metal on Earth) may have come immediately from any of various sources. Many organic chemical compounds on Earth really are generated by plants in photosynthesis, and that is a use of energy that comes from solar fusion. Also, as Jayron32 says, energy is simply a way to quantify change. Robert McClenon (talk) 17:45, 15 June 2014 (UTC)[reply]

With so many competent contributors here I am not sure my ignorance will be helpful. I do believe though that the OP's question is somewhat misunderstood. He is describing this exothermal, extremely volatile reaction: 2K + 2H2O -> 2KOH + H2. What went into this reaction: (1) X-ray energy during supernova explosion, as one person said, that helped to combine protons and electrons to make potassium along with other elements. At this stage the OP is correct: it is all nuclear fusion. (2) during the eons of that particular potassium travel in space and inside the planets the energy could have been subtracted or added when potassium reacted with some anions to make salts (3) Some chemist extracted pure potassium investing some energy in it. (4) the final reaction of potassium with water came (hydrolysis). --AboutFace 22 (talk) 21:24, 15 June 2014 (UTC)[reply]

First, the nuclear fusion that produced the potassium was not in the sun, but in a star that exploded 4.7 billion years ago, the shell of which passed through the protostellar nebula, possibly causing planet and star formation. The sun has never produced any potassium and never will. Red giant nucleosynthesis doesn't produce elements as heavy as potassium. Second, the potassium probably reacted with anions to form a salt in the primitive solar system, not in space. FThird, the energy used to electrolyze the potassium was of solar origin; it probably came from fossil fuel, which is preserved solar energy. Fourth, while the reaction that AboutFace lists is the first reaction, but not the only one in that sequence, because the hydrogen then catches fire, and the remaining potassium often also catches fire. Robert McClenon (talk) 23:19, 15 June 2014 (UTC)[reply]

It might be helpful to break down energy sources to their origin:

SOLAR <- sunlight <- nuclear fusion
WIND <- uneven heating of the atmosphere <- sunlight <- nuclear fusion
WAVE <- wind <- uneven heating of the atmosphere <- sunlight <- nuclear fusion
HYDRO <- precipitation <- evaporation + wind <- sunlight <- nuclear fusion
BIOFUELS <- photosynthesis <- sunlight <- nuclear fusion
FOSSIL FUELS <- organic material <- photosynthesis <- sunlight <- nuclear fusion

Here are a couple that aren't from the nuclear fusion of the Sun:

TIDAL <- rotation of Moon around Earth <- uneven distribution of matter in the universe <- Big Bang
NUCLEAR REACTORS <- nuclear fission <- heavy elements created in supernovae

Geothermal energy actually has multiple sources:

GEOTHERMAL <- tidal heating <- rotation of Moon around Earth <- uneven distribution of matter in the universe <- Big Bang
           <- nuclear decay <- nuclear fission <- heavy elements created in supernovae
           <- residual heat from formation of the solar system <- uneven distribution of matter in the universe <- Big Bang

StuRat (talk) 23:56, 15 June 2014 (UTC)[reply]

Useful. I will note that the second category of geothermal energy has to do with the decay of uranium and thorium in the Earth. Robert McClenon (talk) 00:08, 16 June 2014 (UTC)[reply]

Thanks. Perhaps I should add that supernovae are powered by nuclear fusion, so nuclear fission, either in a nuclear reactor or in the Earth, can also be said to be powered by nuclear fusion, although not in the Sun. So, that leaves us with just 2 energy sources, fusion and the uneven distribution of matter in the universe due to the Big Bang. Of course, if matter had been evenly distributed, then there would be no stars and hence no fusion. StuRat (talk) 04:54, 16 June 2014 (UTC)[reply]

June 16

Chemical leak

What's the safest way to stop a leak of concentrated sulfuric acid from a ruptured tanker truck? Thanks in advance! 24.5.122.13 (talk) 03:05, 16 June 2014 (UTC)[reply]

Although this question isn't specified as one that is not allowed (see top of page), any question that giving the wrong answer could result in dead people should not be answered here! =8^O :71.20.250.51 (talk) 03:27, 16 June 2014 (UTC)[reply]

Ya know, if the emergency responders are looking this up on Wikipedia, I think there is some risk of death in any circumstance. Wnt (talk) 04:41, 16 June 2014 (UTC)[reply]

The problem is people giving their own opinions, there is no problem referring to authorative sources or to a Wikipedia article on the subject is the query is straightforward to interpret. Dmcq (talk) 13:15, 16 June 2014 (UTC)[reply]

Not technical advice -- this is for novel research (see my earlier Q's about hazmat cleanup, avalanche debris, etc.) 24.5.122.13 (talk) 07:42, 16 June 2014 (UTC)[reply]

Perhaps some sort of carbohydrate foam, gel or paste that that can be sprayed or slathered on? The dehydrating ability of concentrated sulfuric acid should carbonize the foam, gel or paste, creating a water-tight, acid-resistant seal that should last long enough for the tank to be emptied. In theory, a very sweet dense meringue could work. Plasmic Physics (talk) 04:02, 16 June 2014 (UTC)[reply]

Maybe epoxy resin would work? I'm thinking either that, or weld the rupture shut. 24.5.122.13 (talk) 07:48, 16 June 2014 (UTC)[reply]

How does epoxy resin behave under the circumstances? Welding temperatures will produce toxic sulfur oxides, not sure that is such a practical idea, considering the precautions necessary. Plasmic Physics (talk) 11:31, 16 June 2014 (UTC)[reply]

I forgot, sulfuric acid vapour is virtually just as toxic as sulfur oxides, so precautions are needed in either case. However, I don't think that welding is a relatively safe option. Plasmic Physics (talk) 13:07, 16 June 2014 (UTC)[reply]

Epoxy will self-polymerize on contact with any sort of acid. As for welding, I agree that it can be dangerous. So epoxy it will be in my scenario. 24.5.122.13 (talk) 22:52, 16 June 2014 (UTC)[reply]

First step is to list some incidents to see if there's a state of the art. Searching "sulfuric acid" "tanker truck" "leak" I see lots of stuff like May 8 in Carson Feb 10 in Tulsa Frederick in 1994 Sullivan in 2011 McCool ... it's clear that anyone with a genuine occupational need can get on the horn and quiz them about their procedures. But there should also be publications... Wnt (talk) 04:48, 16 June 2014 (UTC)[reply]

These are small-scale leaks -- I'm thinking something much bigger. The scenario I have in mind is, the truck gets swept off the road and down an incline by an avalanche, hits an aboveground gas pipeline with its downhill end (thus rupturing and igniting it at once), and comes to rest against the now-blazing pipeline with a rupture at the lowest point of the tank. (This is an UGLY scenario -- you have not only a major acid spill, but a gas fire in immediate proximity, which in turn causes large quantities of acid aerosol to spread downwind.) Also in this scenario, the tank will partly melt from the heat, greatly exacerbating the leak and creating the risk of a BLEVE. First order of business in this case is to shut off the gas; but with the tank partly melted and leaking fast, what can be done to stop the leak? 24.5.122.13 (talk) 07:58, 16 June 2014 (UTC)[reply]

In real life, you would (1) evacuate everybody for several miles around, especially downwind; (2) shut off the pipeline; (3) wait until an airborne tanker can safely fly overhead; (4) dump fire retardant to put out the fire; (5) probably dump a bunch of sodium bicarbonate (baking soda) to neutralize the acid. No human is going to be allowed near that while there is a big fire and a big acid leak. Looie496 (talk) 12:39, 16 June 2014 (UTC)[reply]

Dumping baking soda or any other neutralizing agent will cause an exothermic reaction that will create MORE acid aerosol. An adsorbent (like cat litter) would be a better choice -- once the leak is stopped somehow and the spill contained! 24.5.122.13 (talk) 22:52, 16 June 2014 (UTC)[reply]

Details of some real acid leaks can be seen here at the aptly named sulphuric-acid.com. Alansplodge (talk) 12:43, 16 June 2014 (UTC)[reply]

I don't have the time to read through the entire link, but thus far, I'm yet to find a single example describing the method used to seal a rupture. There is an abundance of examples stating the occurrence of a sealing, but no actual description. Plasmic Physics (talk) 12:59, 16 June 2014 (UTC)[reply]

Really, do you then suppose that it is acceptable to let the entire tanker empty out naturally, and tend to the resulting mess afterwards? Plasmic Physics (talk) 12:59, 16 June 2014 (UTC)[reply]

That is probably what would be done. Unless the leak is only an inch or so in diameter, it's going to drain in a matter of minutes. Chances are the first responders don't have anything that wouldn't be on a typical fire trucks. Their tools are generally designed to make holes bigger, not smaller. I doubt they would even have a welder on hand. They certainly wouldn't have time to go out and get some epoxy resin or something. They would presumably go by the book. For a gas pipeline incident, the instructions are to not attempt to extinguish the fire, evacuate the area, move upwind, and contact the pipeline operator to shut it off. For fires involving corrosive, water-reactive liquids (like sulfuric acid), recommendations are to consider evacuating a half mile in all directions. Once the pipeline is shut off, if there is still a fire and the acid is still leaking, then large amounts of water would be used to keep the tank cool. Mr.Z-man 15:21, 16 June 2014 (UTC)[reply]

That's a good plan, except for one little thing: In my scenario, there will be people who will need some help evacuating the area -- the trucker, who's been ejected from the cab straight into the pool of acid; a mother and daughter, both badly wounded and trapped in a wrecked car dangerously close to both the pipeline and the truck; and several skiers caught in the avalanche and carried across the road into the acid pool. I believe the rescue team should try to get them away from the area as soon as the gas fire is out, and before dealing with the acid spill, even though it may mean taking their chances with the aerosol? 24.5.122.13 (talk) 23:11, 16 June 2014 (UTC)[reply]

That assumes any of them actually survive the fire. Natural gas can burn really hot. If it's hot enough to partially melt the truck, it's hot enough to cause serious burns to people nearby, in addition to the chemical burns, toxic gases they're inhaling, and physical injuries from the accident itself. The MSDS recommends a water spray to manage vapors. That plus a SCBA system would probably be enough for anyone not lying in a pool of acid. For that they'd need full chemical suits. But those people are probably dead, because lying in a pool of boiling-hot acid is not something people would likely survive. Water over 69 C can cause third-degree burns with 1 second of contact. Mr.Z-man 03:44, 17 June 2014 (UTC)[reply]

With luck, one can survive third-degree burns to even 80% of his/her skin area. But yes, inhalation of acid vapors will significantly worsen prognosis, as will the blunt trauma from the avalanche itself. I'm rethinking the acid immersion -- maybe only the trucker will be immersed (and will die in surgery), but the skiers will be outside the acid spill but inside the toxic vapor cloud? 24.5.122.13 (talk) 07:35, 17 June 2014 (UTC)[reply]

Called to this likely scenario for a 1970s Disaster film the local police chief realizes the only man who can save the little girl trapped in the tanker is Bamro, a Vietnam veteran who has retreated to a Shaolin Monastery in search of absolution as he is haunted by flashbacks to the burning of a village. By the 3rd reel, Bamro is racing to the scene in his Shelby Mustang pursued by black helicopters (firing RPGs inaccurately) sent by agents of the Venusian mafia intent on accelerating acid rain on Earth until its atmosphere matches their own sulphuric acid atmosphere, preparatory to an invasion of Earth by Venus. Bamro arrives at the disaster scene where the police and firemen take cover from the helicopters that continue to fire (inaccurately) on everyone. The police chief has found out that the "accident" was caused deliberately by Venusians but his calls for air force help are ignored because the helicopters are invisible to radar. Bamro alone risks the fire and shooting to climb into the truck. Seeing the little girl provokes a flashback to when he failed to save a girl in the burning village in Vietnam. The truck's fuel tank explodes, trapping them both in the blazing truck. Outside cowering with the police chief we see an Asian lady collapse in tears, she is the girl's mother. Inside the truck, Bamro releases the red-hot parking brake and the truck begins to roll away from the pipeline, gathers speed and plows into a snowdrift at the bottom of the incline. In the closing scene it is evening, the snow is lit by red and blue flashing lights as rescuers dig out badly burned Bamro (he'll live) and the unharmed little girl, both welcomed by the mother whom Bamro recognizes as the girl he thought died in the village. The little girl asks "Are you my daddy?". 84.209.89.214 (talk) 14:07, 16 June 2014 (UTC)[reply]

Hmmm, I saw that movie. (spoiler alert!) I think you skipped over the part where the insurance company lawyer insists (against all advice) that the fire truck try to put out the burning truck with a water hose - and performs a perfect Wilhelm scream as he's dissolved down to a skeleton by the resulting spray of boiling acid. I did like the part in the closing scene where Bamro insists on plunging his scorched hand (a rare case of fifth degree burns!) back into the snowdrift to pull out the little girl's Teddy bear. "Can't leave a man behind!" he manages to croak. (Oddly, that's his only line of dialog in the entire movie.) SteveBaker (talk) 22:47, 16 June 2014 (UTC)[reply]

That's not a bad plot for a movie, by contemporary standards. But as for the OP's question, I don't understand. You're asking how to seal a leak in a "partly melted" tank that has been broadly ruptured by an avalanche? I don't think that's happening. I mean, you're talking about essentially underwater welding, only it's under sulfuric acid, of a huge hole, in an unstable tank. Wnt (talk) 18:55, 16 June 2014 (UTC)[reply]

Not really -- the tanker truck is sitting in a shallow pool of acid, which is flowing downhill (and AWAY from the truck) under its own weight. And on second thought, it won't really be "partly melted" like I thought -- the large volume of acid will act as a heat sink to some extent, keeping the metal temperature down to 300 C or so (but also creating the risk of a catastrophic BLEVE). 24.5.122.13 (talk) 22:56, 16 June 2014 (UTC)[reply]

Well, if sulfuric acid is running through a crack or hole, there's going to be at least a lot of fluid behind it and some pouring through. It still seems like it would be hard to weld it, though I'm no expert. And there's just a huge gap in credulity - why would someone hang out next to this bomb, fooling around trying to plug a hole so acid won't leak out, instead of fleeing and waiting for a remote solution? Sulfuric acid going in a watershed would be bad for the fish, sure, but I don't think many people have that kind of commitment to the ecology. Wnt (talk) 08:04, 17 June 2014 (UTC)[reply]

See above, per the OPs story some people near and/or in the sulfuric acid are trapped but alive so need to be rescued. (That said, I agree with Mr.Z-man that it seems difficult to have a story line where the parties are still alive in a crash with an outcome like this. And further, even if they were alive but trapped, it seems difficult to have a scenario where it's necessary to close the hole to rescue them as opposed to very carefully extracting them, a scenario where anyone is laying in concentrated sulphuric acid but alive seems particularly unplausible. Although from some of their questions particularly last year, I'm not sure if the OP is aiming for hyper-realism anyway.) Nil Einne (talk) 13:31, 17 June 2014 (UTC)[reply]

As a matter of fact, I AM aiming for at least a halfway-plausible scenario -- that's why I'm asking these sorts of questions instead of just writing the first thing that comes to mind. Unlike many of today's writers, I do NOT judge my works by the standards of 1970s disaster films -- I strive to make my work better than those. Which is why I've reconsidered the part about the acid immersion: upon reading your responses, I've decided that any casualties actually immersed in the pool of acid will die, and only those plucked from its path in time will survive. Also note that I did not specify that the hole must be closed in order to save the trapped casualties -- on the contrary, the casualties will be extricated first, and then the hole will be closed with epoxy (NOT welding -- that would be too dangerous, as Plasmic pointed out) to prevent the acid from spreading and endangering other people in the vicinity. 24.5.122.13 (talk) 00:31, 18 June 2014 (UTC)[reply]

Seems like a crane or a helicopter would be the easiest way to extricate the victims from the acid flood. But the conditions necessary for this to happen are pretty seriously contrived. Mending the hole in the tanker isn't going to get rid of the flood of acid that has them trapped anyway. Basically, any hole thats big enough to create a flood of acid that you couldn't easily run away from would be much too big to fix - and in any case, the tanker would be empty long before anyone could figure out a way to fix it and get the necessary equipment in there. Personally, I'd bet you could back a pickup truck through the acid, have the victims hop aboard and then drive slowly out again before the tires were destroyed sufficiently to prevent the truck from moving. Even if it's down to the rims, it would move well enough to get out. SteveBaker (talk) 15:13, 17 June 2014 (UTC)[reply]

Note as mentioned above, the acid is supposed to be pouring down a hill so possibly shouldn't be too pooled if there is way to stop the leak. (That said, I do agree as I mentioned that there are problems with the scenario in addition to whether it makes any sense to save some one that way even in the scenario.) Nil Einne (talk) 15:22, 17 June 2014 (UTC)[reply]

A helicopter is precisely what I plan to use to extricate the casualties (in any case, the avalanche has blocked the only road, so only a helicopter or a bulldozer can get there anyway). And the hole is pretty small, so the acid is coming out slowly -- but the casualties CAN'T run away because they're too badly hurt (concussions, broken bones, shock, that kind of thing). 24.5.122.13 (talk) 00:31, 18 June 2014 (UTC)[reply]

(un-indent) OK, let's see if I got the main points right: (1) Epoxy is a fairly safe and effective way to seal the hole in the tanker truck, whereas welding is dangerous; (2) The victims will have to be extricated first, before dealing with the leaking acid (but not until the gas fire is out); and (3) Those casualties which were immersed in acid will almost certainly die. Is that correct? 24.5.122.13 (talk) 23:52, 18 June 2014 (UTC)[reply]

Well, that's not very plausible. So you mix up your epoxy, which you happen to have lying around someplace nearby. Then you smear a big goop of it over this hole - while the acid is still pouring out...but won't the pressure of all that liquid just force the not-yet-set epoxy away from the hole? What holds the epoxy in place against all that pressure for the five or so minutes it takes to set? A liquid-carrying tanker probable has a tank that's a couple of meters tall - so the pressure at the bottom (where, I suppose the leak is at) will be pretty high. Conc. sulphuric acid has a density close to twice that of water - so at the bottom of the tank, the pressure will be really quite high. It might be like trying to fill the end of a garden hose with epoxy while the water is turned on. Added to which, if you don't cover the hole just right, you're going to have the stuff squirt out in all directions - which is bad news for the person applying the epoxy.

Honestly, this story has BOGUS written all over it. SteveBaker (talk) 05:11, 19 June 2014 (UTC)[reply]

OK, what then? Should the rescue crew try to offload the acid from the leaking tanker truck into, say, a portable storage tank of some kind, and just hope that not too much acid leaks out in the meantime? (That would also take care of the BLEVE hazard.) Or maybe they could try to jack up the leaking end so that the rupture is above the level of the acid (is that even possible?) 24.5.122.13 (talk) 05:35, 19 June 2014 (UTC)[reply]

If the goal is simply to get some people out alive without a BLEVE going off in the meanwhile, couldn't you just open whatever normal valve or relief valve is available and let the stuff pour out? Why do you need to stop the leak at all, when you're worried the whole thing is going to blow up from the pressure??? (But if there's pressure, how big a hole can it really be?) Or empty your service revolver into the furthest end of the truck? (not sure it will penetrate) In general, if you can't stop the heat from building up, you don't want to stopper the bottle better. I think you should reevaluate the scenario from first principles...

Oh, and please consider carefully before aiming your fire hose into the truck... what was that rhyme, water to acid keeps things placid... :) Wnt (talk) 16:37, 19 June 2014 (UTC)[reply]

OK, I've made up my mind -- they'll offload the acid from the leaking tanker truck into another, intact, tanker, and thus contain the leak. (Not sure where they'll find the other tanker, though, or how they'll get it to the site, given that the avalanche has cut the only road; they might have to sling it all the way from Edmonton.) As for the BLEVE hazard, simply putting out the gas fire (and the forest fires which it had ignited) will prevent it by removing the source of heat. (On second thought, I think they'll first try the epoxy trick as a desperate measure, only to have it promptly blow out due to the hydrostatic pressure -- as Steve Baker pointed out will happen in real life.) 24.5.122.13 (talk) 00:03, 20 June 2014 (UTC)[reply]

Why can't people bring dead people back to life?

In Frankenstein, the titular science nerd makes a monster out of dead body parts. It's unclear how he did it, but he did it. Although his scientific methods aren't the main point of the story, what is the difference between life and non-life? 140.254.226.242 (talk) 17:30, 16 June 2014 (UTC)[reply]

It isn't clear how he did it because he didn't do it. Remember that that story is fiction. Mary Shelley didn't have to specify how he did it. The genre that we call science fiction hadn't yet been defined (being invented decades later by Jules Verne and H. G. Wells), but she followed the rules of science fiction in not specifying things that she didn't have to specify. Robert McClenon (talk) 18:09, 16 June 2014 (UTC)[reply]

Our article on life points to one definition in the opening paragraph: "Life is a characteristic distinguishing objects having signalling and self-sustaining processes from those that do not, either because such functions have ceased (death), or because they lack such functions and are classified as inanimate". Several other definitions of what constitute "life" are listed under definitions in the same article. WegianWarrior (talk) 17:40, 16 June 2014 (UTC)[reply]

In general, necrosis involves a loss of cell membrane integrity, i.e. the cells physically break down in a way that makes it very difficult to restart them. For example, a neuron with even a small hole in it is not going to be sending any signals, because those are charges on opposite sides of the membrane. Now tissue death does occur over a period of time, and some people are hopeful that current practices in resuscitation can be improved on, but no bolt of lightning is going to unscramble an egg. This leaves the remaining hope that somehow you can "forensically" resurrect a person by some kind of brain scan that tracks every neuron and figures out (somehow) what synapses and long-term potentiation they had, and makes a reasonably accurate duplicate. But whether such a duplicate would be that person, or whether anything but a true tissue printer generated flesh and blood duplicate even could be any person, is philosophically very debatable. Wnt (talk) 18:32, 16 June 2014 (UTC)[reply]

if you take the time backword and change the corse , it call " the next world " thanks water nosfim — Preceding unsigned comment added by 192.116.142.154 (talk) 19:09, 16 June 2014 (UTC)[reply]

Frankenstein doesn't hold together for any number of reasons that were not understood when it was written (how about organ rejection in a body sewn together from 30 different cadavers!) - so let's just discount that.

One major problem is the cause of death in the first place. In order for someone to have died, something fairly bad must have happened to their body systems - and repairing that would obviously have to take place before one could even consider reviving them. That said, there has been a recent application for human trials of a technique where severe trauma patients would have all of their blood replaced with chilled saline - stopping all of their life signs completely - and then reviving them after an hour or so once the trauma team have patched up whatever needed fixing. Since the lack of all clinical signs of life means "death", they will (technically) be reviving the recently dead. SteveBaker (talk) 19:20, 16 June 2014 (UTC)[reply]

Imagine a volume like a cubic foot filled with water. Then imagine that somehow at the start of the process the water had small areas with higher temperature. Another point is that this volume is absolutely isolated from the outside world. What would happen after a while? The water's heat, thermal energy from areas with higher temperature will flow to the areas with lower energy and soon the whole volume will assume equal temperature. Can this system go back in time and internally recreate the difference in energy across the volume without outside intervention? No, it contradicts the Second Law of Thermodynamics. The same is with the human/animal body. Any animal body contains billions of cells with membranes with electrical gradient across them. It is maintained by ion pumps that pump sodium out of the cells into the inter-cellar medium and potassium the other way around. Aside from those two ions dozens of other substances are moved across the membranes all the time. When a person dies the pumps stop and the gradients get equalized. Restarting them contradicts the Second Law of Thermodynamics therefore bringing dead people back to life will never happen. --AboutFace 22 (talk) 21:49, 16 June 2014 (UTC)[reply]

you can take back only information , change the corse of the dead one ,it statistic ocar in flaktation , and you can stabilize on the write superposition . thanks water nosfim — Preceding unsigned comment added by 192.116.142.154 (talk) 04:30, 17 June 2014 (UTC)[reply]

Mary Shelley wrote Frankenstein in 1818 when the mainstream vitalist notion was that a living organism differs from the non-living in that it posesses a unique "vital spark", associated in Western medicine with Hippocrates' Four temperaments and humours, and called its Élan vital by Bergson in 1901. The pre-Christian Stoic philosopher Posidonius postulated that such a "vital force" emanates from the sun to all living creatures. Shelley built her story on this thinking (that could not be seriously challenged in the scientific world until synthesis in 1828 of Urea C O(N H₂)₂ previously thought to be only a by-product of life) and on the effects of electricity on dissected animals reported by Galvani. While she makes no direct mention of electrical reanimation in the novel Frankenstein, film adaptations typically show electrical laboratory equipment and the monster's awakening is brought about by an electrical storm. The OP is correct that Victor Frankenstein's scientific methods aren't the main point of Shelley's seminal "soft" science fiction story. Its subtitle The Modern Prometheus refers to a Latin myth of Prometheus who makes man from clay and water, like Victor rebelling against the laws of nature (how life is naturally made) and as a result is punished by his creation. 84.209.89.214 (talk) 22:07, 16 June 2014 (UTC)[reply]

The description of temperature equalizing in a volume of water is a great statement about the laws of thermodynamics - but the analogy is seriously flawed.

We can easily heat up the water again and restore the original patchy variations of temperature using appropriate heat sources brought in from outside. All that tells us is that a "sufficiently dead" body cannot simply come back to life by itself (although there are energy stores in fat deposits in a dead body - so even that limited interpretation is not prohibited by thermodynamics). The "rules of the game" here are that we can use any reasonable amount of external input in re-animating the dead. (For example: A handy lightning storm - to follow the OP's line of thinking). So the laws of thermodynamics (which apply only to closed systems) are simply inapplicable here. SteveBaker (talk) 22:26, 16 June 2014 (UTC)[reply]

SteveBaker, I did not expect you to fight for the lost cause. Had a living body had just 10 cells (compartments with temperature and concentration gradients) it would have been one thing, but a human body has billions of such compartments just in the brain. No lightning will ever help you and no energy stored in fat either. --AboutFace 22 (talk) 01:02, 17 June 2014 (UTC)[reply]

I'm not saying that lightning or fat deposits will do the job - what I *AM* saying is that an argument that the second law of thermodynamics is proof that resuscitation is impossible is nonsense. The second law only covers closed systems and that's not what we're talking about here...and even as a closed system, the body has considerable energy reserves - so a thermodynamic argument simply cannot be employed here. Your bucket of water can return to it's former state if there are heating coils and a fully charged battery.

Don't get me wrong though - I agree that there are hard-to-reverse problems with a dead body that would make it insanely difficult to "fix" it. My only beef is that your "proof" of that by reference to the 2nd law is nonsense - and therefore subtracts from the argument instead of adding to it - which is why I feel the need to correct you. SteveBaker (talk) 05:23, 17 June 2014 (UTC)[reply]

Ms. Shelley may have been familiar with the 1803 experiment by Professor Giovanni Aldini, Galvani's nephew, who used a powerful battery to produce movements in the dead body of executed murderer George Forster, whose spinal cord had been severed and whose blood had been drained after his hanging. A contemporary account said "On the first application of the process to the face, the jaws of the deceased criminal began to quiver, and the adjoining muscles were horribly contorted, and one eye was actually opened. In the subsequent part of the process the right hand was raised and clenched, and the legs and thighs were set in motion." Edison (talk) 02:05, 17 June 2014 (UTC)[reply]

OMFG "one man, Mr Pass, the beadle of the Surgeons' Company, was so shocked that he died shortly after leaving." The salad days of science! But nonetheless, this only works with a fresh corpse where many of the cells are still alive.

As for the thermodynamic argument: it is true that you can unscramble an egg with excess energy input, and some really sophisticated nanotech. I mentioned an approach with a tissue printer, but I suppose there are other ways to try to reform every cell as it was. But if you don't do it precisely as it was, is it the same person? For believers in atman this is an easier question for others, but even then, you have to ask how good it has to be to be a person at all. Which requires understanding of consciousness, which is a paranormal phenomenon. There is no known experiment to show that an arbitrary computational device "really feels something" as opposed to "being programmed to exclaim its discomfort". It is, therefore, necessary to develop a theory of the paranormal in order to answer the question in that case. I've made some comments on this regard in the past here but I fear I may try on the audience's patience to do so again, especially considering it's a Science desk. Wnt (talk) 04:00, 17 June 2014 (UTC)[reply]

People have been bringing people back to life for eons, by burying them in soil. They sprout or hatch, they grow, they eat, they breed and age and die again. Return to life isn't what the bereaved in Pet Sematary, "The Monkey's Paw" or Game of Thrones really want. They want to go back in time, and enjoy the same face/personality they remember. That's the hard part, even within one lifespan.

Frankenstein couldn't have convinced the family of the man he got the monster's heart from that its beating meant he was alive again. Neither the brain donor's, even if the monster remembered private moments. Stitching a face onto a complete living stranger and giving him the backstory would be far more likely to fool us (though hopefully still rather unlikely). InedibleHulk (talk) 05:11, June 17, 2014 (UTC)

Blood alcohol content

If water doesn't reduce BAC, why is it that downing a glass of water between drinks or even diluting strong alcoholic drinks with water, reduces the effects of alcohol? — Preceding unsigned comment added by 2.221.70.208 (talk) 20:14, 16 June 2014 (UTC)[reply]

Alternating alcoholic drinks with water can reduce your overall intake of alcohol if you take your time drinking the water, so that would indirectly reduce your blood alcohol content (BAC). But otherwise you're right, just very quickly drinking a glass of water between alcoholic drinks won't affect BAC and intoxication (reduced motor skill, slurred speech, etc.). However, alcohol has other effects besides intoxication. Alcohol consumption causes body dehydration, which produces headache, tiredness, etc., usually several hours later. Drinking water between alcoholic drinks helps prevent dehydration and may reduce some of those effects.--Dreamahighway (talk) 21:16, 16 June 2014 (UTC)[reply]

However, drinking a glass of water before using a breathalyser does reduce the reading sometimes. Presumably it flushes some of the alcohol off the surface of the mouth and gullet. Greglocock (talk) 22:43, 16 June 2014 (UTC)[reply]

If someone has had enough alcohol to potentially fail a breathalyzer test, they ought not be driving. Tricking the cops into thinking the driver is sober could have fatal consequences. ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:36, 17 June 2014 (UTC)[reply]

Thank you for the lesson in morals, wrong forum. The instructions for my breathalyser tell you to do that. 23:20, 18 June 2014 (UTC)

This use of water is not a trick. Technically blood alcohol is best measured by blood, yielding a value for what the brain actually experiences. The breathalyzer is merely a surrogate test. Flushing alcohol out of the mouth will, if anything, increase the blood alcohol level; it only removes the spurious contribution of recently consumed alcohol. Now sure you could say that really the cops in a jurisdiction with a .08 ought to run in people who blow .07, .06, .05 just for the principle of the thing - that's how Wikipedia admins tend to act, after all - but that is typically regarded as a matter for politics. I see on reading the article that some states have actually made the BrAC levels legally binding ... which must be interesting when someone has only used mouthwash (as the article details) and can prove it with a negative blood test result.

Followup question: what determines the 2100:1 partition ratio the article says is programmed into the machines? I'm seeing a value of 2300 in the literature and a statement that it is acceptable for use in individuals with "normal pulmonary function" [1]. There must be some people getting badly screwed by the testing procedure, but I'm not sure at this point who. Wnt (talk) 20:19, 17 June 2014 (UTC)[reply]

Unless I missed something, there's nothing in our article suggesting mouth wash will cause a significantly false reading in an evidentary breath test 15 minutes after consumption which as per our article, is evidentally the norm before testing.

Actually the time between consumption and testing is likely to be higher, I presume the evidentary breath test machines in the US are like the ones here and are big enough (our article mentions some portable evidentary units but doesn't elaborate they are used and the info would suggest not much if at all) that they are only generally stored in the police station (plus observing the suspect out in the field seems problematic) so unless the suspect is very stupid and secretly drinks mouth wash in the police car on the way to the station, it's probably 25+ minutes (even if the police station is only 5 minutes away it's likely to take 5 minutes at least for processing etc before the suspect is put under observation for the test) before the testing in the mose cases. (There are sometimes mobile units stored in a bus but I don't know what percentage of suspects they process and whether they even follow the same procedure or have extended waiting times.)

Of course this may not help in other cases like belching, but you only mentioned mouth wash.

P.S. Our article suggests most/all? states in the US with evidentary breath tests make it rebutable. In other words if the suspect has a reliable blood alcohol test from the time of the test, it's likely a simple matter of presenting that evidence. It doesn't specifically mention, but I'm presuming in most of the US as in NZ, the blood test is up to the suspect. They can either choose to take the blood test instead of the evidentary breath test or can choose to take the blood test if they fail the evidentary breath test [2], at the financial expense of the government as with the other tests. This doesn't of course help those who have an extreme fear of needles or whatever that will prevent a blood test. But for the rest, it's probably not even normally a case of needing to present the evidence. If you don't trust the breath test, just choose the blood test, it seems unlikely you'll even be charged if you pass regardless of what happened with the evidentary breath test.

Nil Einne (talk) 00:04, 18 June 2014 (UTC)[reply]

Today's breathalyzers are sophisticated enough to exclude mouth alcohol or any alcohol other than the blood-gas exchange of the lungs. It's the reason why continuous blowing is required. The machine is looking for a curve that matches lung alcohol. Once that curve is detected, the reading is made. Anything but that curve is invalid. --DHeyward (talk) 05:31, 18 June 2014 (UTC)[reply]

Thanks! - I did not have any inkling of that. Wnt (talk) 17:39, 18 June 2014 (UTC)[reply]

June 17

free convection of heat transfer fluids

I have designed heat transfer engines using free convection. I have tried commercially available heat transfer fluids and none of those I have tried so far are as good as water in free convection.

I have suggested to manufacturers of these fluids that they grade their fluids according to their free convection properties compared with water. This would be quite easy to do using a vertical cylinder of the fluid with a heat source at the base. They could then rate the efficiency of their heat transfer fluid according to how fast the fluid higher up in the cylinder heats up using water as a standard for comparison.

Does anyone know if this grading of fluids according to the test described above has ever been done? And if it has what would it be called? If this has been done already I would not have to waste a lot of time trying different types of heat transfer fluids and finding in the end they are not as good as water for free convection heat transfer. — Preceding unsigned comment added by Petercl14 (talk • contribs) 02:33, 17 June 2014 (UTC)[reply]

Sure! There's a ton of money in mud engineering! It's a really empirical science; those guys have parameters for everything - fluid density, fluid thermal conductivity; electrostatic characteristics, chemical behavior ... variations of all of the above, with respect to temperature and pressure... you name it! From the Schlumberger Oilfield Glossary entry on temperature gradient , I found a link to High-Pressure, High-Temperature Technologies, a review article of common technologies used to characterize borehole fluids. That paper has an entire reference section, "For more on laboratory testing of fluids, see..." the dozens of references they cite. You might also find references on a variety of downhole heaters.

You can bet that if water was better for the job than commercial mud, production companies couldn't charge as much as they do for all their special chemical formulations! Nimur (talk) 02:46, 17 June 2014 (UTC)[reply]

Note that the test you devised is not testing thermal convection alone, but also conduction, radiation (unless you add dye to the fluid to make it opaque), and thermal capacity. Depending on the parameters of the test (height and diameter of the cylinder, temperature difference, elapsed time), different factors will play more or less or a role in the outcome. So, while water may be the best fluid given your parameters, it may not be for all such parameters. StuRat (talk) 05:29, 17 June 2014 (UTC)[reply]

A Heat pipe is a passive device that offers high thermal conductivity between points whose temperatures correspond respectively to liquid and vapour states of the internal fluid. The vast majority of heat pipes for room temperature applications use ammonia (213–373 K), alcohol (methanol (283–403 K) or ethanol (273–403 K)) or water (298–573 K) as the working fluid and have much higher thermal conductivity than is possible by convection or conduction in a single-phase substance. 84.209.89.214 (talk) 21:23, 17 June 2014 (UTC)[reply]

What gene (or genes) produces DHA?

Thx. Ben-Natan (talk) 06:45, 17 June 2014 (UTC)[reply]

To do this one, I first went to NCBI and chose the "Gene" database option, but the list was all eukaryotes for some reason. There ought to be a way to get the data out (i.e. go to PubMed and look up the papers the right way) but not having the patience I went to KEGG, which fortunately for the moment seems to have risen out of the water again, but is making some plea for funding. Anyway, it sent me straight to [3] which gives the immediate reaction upstream of DHA. This gives me an EC number [4] which represents the reaction catalyzed, which potentially could be more than one homologous gene, but often was evolved just once. Regrettably... that's a red herring; it's palmitoyl hydrolase, present in humans and many other organisms. But clicking on the precursor gets us quickly to [5] (well, at least, in not many clicks... the site is kind of slow) which is a diagram of the biosynthesis of many unsaturated fatty acids. Unfortunately, it turns out it's not providing the details on the precise enzymes doing the desaturation, though it does give an indication of the order in which the bonds are processed. [6] provides no EC number for example. So... looking for the last step, delta-6, quickly turns up in PubMed a paper that says that rats do it [7]. Now I remember that it's actually linolenic acid that is more special as a precursor. So I go back to scratch at PubMed and search "docosahexaenoic acid" "essential" "precursor" (spelling the first one is the challenge of this assignment) and find [8] which says the alpha-linolenic acid is the one that is essential. Looking back at the KEGG figure, this is on it; the linolenic acid is downstream of the delta-15 desaturation. After some flailing around I search "delta15" "docosahexaenoic acid" and get [9] which is one of those too sensible to work ideas of genetically engineering the benefits of omega 3 directly into an animal to improve its health. (This is one of those GMOs I dread, because it sounds like such a great idea, but messing with lipid metabolism has a thousand trickle-down effects that could be unpredictable) Anyway, this paper identifies some of the key genes they used to make the difference. I could go on, but have to pause for now... Wnt (talk) 08:46, 17 June 2014 (UTC)[reply]

Going on, they mention a delta-4 desaturase (just upstream of the delta-15 but also important, and an easier lead because they use the delta-15 from C. elegans) and one of the sources is "marine microalgae Pavlova lutheria" which our disambiguation link names as a chromalveolate. (As I recall this is your special interest) Unfortunately they don't give an accession number but they do reference [10] which is, somewhat surprisingly, "Elsevier open access" (honest) and so the audience can follow along here. I really ought to read that article, but for now I ^F'd "accession" and clicked [11]. It is tempting to hit "Run BLAST" from this but don't -- the link is for a blastn search of the mRNA, which will probably get you nothing that is not pretty closely related. Instead hit on the hyperlink for protein-id = [12] which gets you just the amino acid data. Now you can hit Run BLAST if you want, and if you're doing this for a serious purpose you would in a variety of ways trying to scrape every last homologue, but for now, I find the precompiled results at BLink lower down on the right sidebar to be sufficient. [13]. Sho'nuff, there are other chromalveolates in the list -- Rebecca from Pavlovaceae, the heterokont Aureococcus -- but after that the list takes a turn toward the multicellular, with choanoflagellates and a few outright animals, then on to trypanosomes and euglenoids... which leaves us with a need for a more careful search. The thing to remember, after all, is that BLink highlights the very best matches, which means that if you have an incomplete sequence, a few errors in your sequence, etc., or even just a turn in evolution that added a little loop somewhere in the catalytic site, then those hits are going to tumble down the rankings. Now if you can just look at the species names and tell which are chromalveolates you can get more out, but so far about all I recognize is Thalassiosira from further down the list. So now it's time to finally hit that Run BLAST link [14]. Going into the search parameters I'll turn the E-value down to 0.1 because I don't want a bunch of crap I'd have to confirm experimentally to convince anyone it's a real match, which should shorten the output a little. However, there's a bit of a snag ... turns out the taxonomy input won't take Chromalveolata - doesn't recognize it because when browsing taxonomy Alveolata is right under Eukaryota. So you'll have to assemble your own Chromalveolata according to taste. For now, I'll just run with Alveolata as an example. This yields [15] <--- TEMPORARY link, will expire June 20. This reveals one clear "hypothetical" delta4 for Paramecium, which is more than you had, but the others come up as delta5 or 6. There's some comment even in the first paper about the various bonds and how the enzymes work - I'm afraid you actually need to look very carefully at this point and figure out if the "delta5/6" activity delivers what you want. You can also BLink back from any of these proteins and see if they match a different protein as top link (subject to the caveats above) for organisms where you know you have a true ortholog. You may well end up drawing up multiple sequence alignments and trees before it is through. And of course you also have the other chromalveolate groups to do. At this point I can't go on much without having a better understanding of the underlying reasons behind your question and what you're really hoping to find, but I hope this gets you primed up to get started. Wnt (talk) 17:36, 18 June 2014 (UTC) @Ben-Natan:[reply]

Normal behavior by a headless cat?

The Jerome Lettvin article states that the neurologist found that a headless cat could walk on a treadmill, scratch an itch, and maintain its balance to avoid falling over. It cites a textbook as a reference, "Neurons and Networks Second Edition, John Dowling, Belknap Press of Harvard University Press 2001, page 307, Figure 13.5" as a ref but the relevant page is not viewable online. Presumably the body was connected to a source of oxygenated blood. I removed as vandalism the last sentence, added long after the rest, which stated that the cat later made a full recovery and led a happy life. The article says that unidentified Russian scientists replicated the experiment. There has long been a supposed film of Russian scientists having a disembodied but responsive dog's head connected to a source of oxygenated blood, which some have said is crude trick photography. I have certainly seen decapitated chickens run around flapping their wings for perhaps a minute, but I question whether higher vertebrates such as cats (or humans for that matter) have the decentralized nerve centers needed for walking, for instance, or maintaining balance even for a minute after decapitation. Does anyone have access to the book in question to confirm what it states about Lettvin's work? Edison (talk) 21:46, 17 June 2014 (UTC)[reply]

I don't have access to the source either, but I think there might be a misunderstanding here. Very few scientific studies have used cats that were actually headless, but there were quite a number of studies (in the "old days") that used cats that were spinalized -- in other words, the spinal cord was cut in a way that disconnected the head from the rest of the body. It's possible to get spinalized cats to walk on a treadmill by holding the body in place over a running treadmill -- see for example PMID 2357538. Looie496 (talk) 22:24, 17 June 2014 (UTC)[reply]

(EC)I found the page in question online [16] but it has a cat with surgical transection of the brain stem and electrical stimulation causes walking apparently due to spinal reflexes. However it lists several scientists as doing an original 1911 experiment and a Russian/Swedish team as doing a followup, with no apparent mention of Lettvin. Thus it was not quite a "headless cat" and Lettvin does not appear to be involved, but i would still appreciate confirmation that he is not referenced anywhere else in the book cited, before removing mention of the cat studies from his bio article. Would a human with a severed spinal cord be able to walk on a moving treadmill, or would carefully timed electrical stimulation at the spine suffice? Or would electrodes have to be on the limbs which were to move? Edison (talk) 22:56, 17 June 2014 (UTC)[reply]

Paralyzed humans don't walk reflexively in the way cats and some other quadrupeds do. It's pretty clear that eliciting walking with spinal cord stimulation is feasible in principle, but the technology isn't yet mature enough for use with humans -- PMID 24549394 is the closest thing I know about. I'd be surprised if devices to do that don't exist 10 years from now. Looie496 (talk) 01:31, 18 June 2014 (UTC)[reply]

Mike the Headless Chicken lived for 24 months after most of his head had been cut off. 84.209.89.214 (talk) 23:08, 18 June 2014 (UTC)[reply]

Keep it in mind that a short term (acute) experiment with electrical stimulation of the nervous tissue is one thing but a chronic functioning is another. Electrical stimulation of the visual cortex (area 17) was performed by Bradley (in the UK) if I am not mistaken in blind humans and caused some phosphenes but soon glial degeneration took place. In short, the neurons died out but glia proliferated at the stimulation site. --AboutFace 22 (talk) 14:54, 18 June 2014 (UTC)[reply]

Death. μηδείς (talk) 20:27, 18 June 2014 (UTC)[reply]

The "walking headless cat" story made me think of an 1842 grammar book saying "Charles the First walked and talked a half hour after his head was cut off" just needed a semicolon and a dash added to be correct. Edison (talk) 00:02, 19 June 2014 (UTC)[reply]

Detleff Neumann-Neurode

Why is the article about Detleff Neuman-Neurode still in question ??? Why does it say in the beginning: NEEDS ADDITIONAL CITATION FOR VERIFICATION ??? Dr.Reinhard Ganz wrote his dissertation about D. N-N. and Mrs. Dehn opened a D. N-N Clinic in London, England. What more verification is needed??? I am D.Neumann-Neurode's granddaughter and wrote my memoirs about my childhood which I have spent at my grandparents home with my two sisters and my mother. (Title of the book: ONE LIFE MANY CHAPTERS) I am Margrit von Kleist. Please remove the note at the beginning of my grandfather's article. Thank you — Preceding unsigned comment added by 99.251.181.93 (talk) 23:32, 17 June 2014 (UTC)[reply]

This belongs at Talk:Detleff Neumann-Neurode, but anyway: The problem is not that anyone doubts your grandfather's existence (though Wikipedia has had some remarkable hoaxes over the years), but that the typical reader has no idea where most of the information in the article came from – and thus of its reliability. —Tamfang (talk) 01:14, 18 June 2014 (UTC)[reply]

June 18

Contacting Google

Hi, so I have an idea that I would be interested in contacting Google (the corporate entity) with regards to. Obviously, everyone immediately thinks "crackpot inventor" who has some terrible invention that they think is amazing. Google obviously receives contact from people like this in the hundreds every day. What would be the best way to make someone with some semblance of decision making power aware of my idea? Email or post may not be an option as Google are famously un-contactable, however a social media campaign might work? Or contacting press to get notoriety? No legal advice please! 195.27.53.211 (talk) 10:01, 18 June 2014 (UTC)[reply]

Have you even tried? Obviously it has to be possible for people to contact them. There is a contact link here. I suggest you try that first.--Shantavira|^{feed me} 12:03, 18 June 2014 (UTC)[reply]

What is the idea? If you're considering using social media, then surely you could also tell us? My point is, if it matches up with some topic already being studied in Google's research labs, you might be able to contact that group directly. SemanticMantis (talk) 15:09, 18 June 2014 (UTC)[reply]

Many (perhaps most) tech companies go to some lengths to avoid even reading your suggestions! The reason for this is that they may be working on the same idea already - and if they talk to you about it - or even convey your message to those who create things - then you might be in a position to sue them for stealing your idea when it was really a case of parallel invention. In one company I worked for (a video game company), mail that came from unsolicited sources went to one specific staff member who would open it and dispose of anything that looked remotely like a suggestion for a new game or an improvement to an existing one. She never spoke to our engineers and other developers. We actively worked to AVOID taking suggestions from the public. I'm betting that Google are the same - they don't want your suggestions - they are just a pain in the butt to have to deal with!

So, if you have a world-beating idea, then work on it yourself - then run a Kickstarter project to raise some money to achieve it. SteveBaker (talk) 20:10, 18 June 2014 (UTC)[reply]

You may be right; I don't work at Google, or for a "tech" company (whatever that means :) But when I see people from e.g. Google Research or Microsoft Research at conferences, they are happy to present their work to us, and get feedback from their colleagues, etc. Of course, some of these people are more like academic research scientists than "normal" employees, so there is an expectation of sharing work via publishing, collaborating on projects across institutions, etc. SemanticMantis (talk) 20:54, 18 June 2014 (UTC)[reply]

Silicon and the human body

This source says that there is no silicon in the human body. Is that accurate, or does it refer to the "living" parts only?

I.e. do the bones and/or teeth contain silicon? (The source doesn't look terribly reliable to me anyway. Lots of stupid little errors: "1026 watts" when it should read "10²⁶ watts" here, and even worse, H₂ when it should be H₂O here.) - ¡Ouch! (^{hurt me} / _{more pain}) 10:03, 18 June 2014 (UTC)[reply]

Composition of the human body does list a small amount of silicon. It has the unsourced claim that silicon is "probably needed by mammals also". -- Finlay McWalterᚠTalk 11:23, 18 June 2014 (UTC)[reply]

Well, there certainly will be some silicon in the digestive tract, although scientists consider this to be technically "outside" the body. Silicon dioxide is a common food additive: Silicon dioxide#Food and pharmaceutical applications. That's powdered quartz, BTW. StuRat (talk) 11:26, 18 June 2014 (UTC)[reply]

"Bartender, two quartz for Stu and me!" *COUGH*

Wow, thanks. I'd count that as outside, too. (Less than iron, too – I wouldn't have guessed that either!)

One more flaw of the source I was reading, I guess, not to mention the lines "Dimethyl borine (...) Soluble in organic solvents (ethanol, other[sic], etc.)" - ¡Ouch! (^{hurt me} / _{more pain}) 12:23, 18 June 2014 (UTC)[reply]

The answer is kind of hand-wavey. As near as I can tell, in humans it seems that silicon in various forms has some sort of beneficial effects on collagen and keratin(?) synthesis, but it's not clear that it is necessary. There is definitely evidence that it is present in the body, but it's not known if it is required. (See the footnotes for Silicon#Biological role, and Silicic acid#Silicic acid in health.) TenOfAllTrades(talk) 12:21, 18 June 2014 (UTC)[reply]

Disputed Identification

File:Artocarpus.odoratissimus1we.jpg

Tree with Disputed identification.

Any comments from the experts here? Sfan00 IMG (talk) 10:23, 18 June 2014 (UTC)[reply]

Any chance you know where in the world it was taken, or have any other photos of the leaves/flowers? I see the file is used at Artocarpus_odoratissimus, but the resolution is too low to even make out if the leaf margins are entire... SemanticMantis (talk) 15:07, 18 June 2014 (UTC)[reply]

It's sourced to a USGS image... I don't have much other information. :( Sfan00 IMG (talk) 18:03, 18 June 2014 (UTC)[reply]

Ok, who's disputing the ID, and where/why? I see a note on the file, but nothing on Talk:Artocarpus_odoratissimus. The source link on the file is broken, but I was able to re-find it here: [17]. Looks like these people are professional biologists, and have a ton of specific IDs for plants in Hawaii. The specific picture is tagged "Keanae Arboretum, Maui, August 07, 2003". Also, at the link above, we see there is a lot of variety in leaf shape of this species. So, together with the low resolution and the lack of specific reason to doubt, I'm inclined to use this as an expert ID and forget about it. SemanticMantis (talk) 19:48, 18 June 2014 (UTC)[reply]

What causes a radio to go off channel ?

I adjust a radio so the radio station comes in clearly, don't touch it after, yet the next day it is off station and needs to be readjusted. What causes this ? Is it temperature or humidity changes ? StuRat (talk) 11:19, 18 June 2014 (UTC)[reply]

Is it a digital, or analog control? IE, do you turn a knob to change the station, or press a button?Zzubnik (talk) 12:23, 18 June 2014 (UTC)[reply]

ObPersonal: having occasionally opened up old radios and radiograms to clean out decades of fluff accumulation, lubricate the parts, etc, I've noticed that some tuning mechanisms involve a length of cord between the tuner control wheel and the actual tuner. I assume that this might undergo slight changes of length due to both the factors you mention: tuning is often so sensitive that only a tiny change would have a noticeable effect, and my bathroom radio seems to require more retuning than most. {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 13:52, 18 June 2014 (UTC)[reply]

(Not sure why you smalled your text, as this seems to be a direct answer.) Yes, it's an old analog clock radio. So, other than storing it in a hermetically sealed, temperature controlled vault, it sounds like there's no way to keep it on station. StuRat (talk) 17:49, 18 June 2014 (UTC)[reply]

That would have been a really cool magic trick back in the 50s or so. Have a cord with a good coefficient of thermal expansion near an ornamental hole where you could aim your breath into the radio. Ask the spirits to tune it in for you... if you could have done that without laying a hand on it, while your observers fail over and over again, even failing to see a reason after taking the radio apart... Wnt (talk) 16:54, 18 June 2014 (UTC)[reply]

OR It heats up, the dial expands, and moves off channel. μηδείς (talk) 20:23, 18 June 2014 (UTC)[reply]

Most good FM radios have AFC (Automatic frequency control) with sufficient range to compensate for temperature or humidity changes to tuning. AFC can however allow a strong signal to pull the tuning away from a weak signal when the signal frequencies are close. For this reason some receivers have an AFC on/off switch. 84.209.89.214 (talk) 22:40, 18 June 2014 (UTC)[reply]

Interesting, thanks. Would e.g. a late 1970s radio have AFC? Our article seems to indicate that similar functionality can be had via a Frequency_synthesizer, and that sometime in the 1970s consumer radio devices might have switched over. As far as other signals, that reminds me of an idea I had on the topic (for I have very similar experience to Stu): could changes in other signals cause a radio to fall out of tune? In a city, there are any number of sources of interference. Of course devices are supposed to both not produce interfering signals, and to accept incoming interference without malfunction, but I always took that to mean an ideal, which doesn't always happen in the real world. So, if my radio stays tuned to one station for weeks, but on a certain day I have to re-tune, and sometimes find that same station very difficult to receive. Could changes in other broadcasts explain this? SemanticMantis (talk) 22:54, 18 June 2014 (UTC)[reply]

All FM (but not AM) receivers are subject to Capture effect which is a kind of AFC, not a welcome one when interfering signals are strong. 84.209.89.214 (talk) 23:30, 18 June 2014 (UTC)[reply]

Natural units

Look up Planck length and Planck time. If my knowledge about these terms is correct, these are units that we can't have a fraction of; every measurement of length/time is these units times a whole number. This is clearly very wrong, however, for Planck temperature. What property does the Planck temperature have here?? Georgia guy (talk) 16:01, 18 June 2014 (UTC)[reply]

I think your conceptual understanding about the quantization of time and distance is a bit incorrect: there's nothing that forbids a distance or length or duration whose magnitude is smaller than one Planck unit. We simply don't know of any physical entity or process in which that distance is meaningful.

On the whole, when a physical system is quantized it means that whenever we observe it, we will find integer multiples of some fundamental unit. There are lots of systems that are quantized, including macroscopic systems: for example, a theoretically perfect, tightly stretched guitar string will only resonate at integer multiples of its fundamental frequency. In practice, we know this is untrue: we hear musical timbre because of the interplay of all the complex harmonics and non-harmonic motions of the string and its soundboard.

In microscopic physics, we have the same problem! Electron orbitals are quantized, and when we look at an atomic emission spectrum, we find perfectly harmonic integer multiples of a base energy level. ...Except when we don't. Just like the guitar string, the major components of the system follow a simple, quantized theoretical model; but as we zoom in closer and closer to the details, we sometimes find perturbations and other effects. When we zoom in really closely, we usually find that those other perturbations are also quantized, but with different parameters. (In fact, we can say the same about the guitar - its continuous acoustic spectrum can be decomposed into a Fourier series of individual vibrations - and by definition, a series is made of discrete (quantized) elements).

One of the ongoing quests in theoretical physics is to find the most fundamental particles - and therefore, the most fundamental scale of quantization. A century ago, we split the atom into its subatomic particles; and we developed a rigorous theory for how the energies of those particles were quantized. Decades later, we split the subatomic particles into even smaller particles - quarks - and we found that they too have certain properties that are quantized. To my knowledge, we have not yet found any physical entity whose energy scales are quantized in smaller increments than these subatomic particles. That is why, in common parlance, we say that we have found the fundamental particles.

But we should make it abundantly clear: it is a physical system whose properties follow quantization rules: it is not actually the units themselves which are quantized. We can easily define half a Planck length - or a whole 1.0 Planck lengths, for that matter - even if we can't find any physical system for which that length is important.

Nimur (talk) 16:14, 18 June 2014 (UTC)[reply]

Atomic energy levels are nowhere close to integer multiples of a base energy level. Protons have three valence quarks, but they don't divide into three discrete pieces, one per valence quark. The notion of the quest for the most fundamental scale of quantization sounds more like Greek atoms than modern physics to me. -- BenRG (talk) 21:10, 18 June 2014 (UTC)[reply]

Fascinating analogy about Greek atomic theory! So fascinating that CERN, arguably the world's preeminent research institution in the field of modern particle physics, uses the exact same analogy when describing their quest to break apart sub-sub-atomic particles! Nimur (talk) 01:38, 19 June 2014 (UTC)[reply]

The sound of a guitar string can be quantified by a Fourier series whose infinite series of terms can be truncated not due to any property of the string vibration but because listeners are oblivious to harmonic and non-harmonic energies above the upper limit of human hearing. The quantisation step between Fourier terms is dictated by the frequency resolution obtainable from a given observation time, which is chosen arbitrarily. It is that arbitrary choice that changes the true continuous acoustic spectrum to an approximate discrete series. 84.209.89.214 (talk) 22:19, 18 June 2014 (UTC)[reply]

...and why do you think that's any different for atomic scale systems? I think you've just restated the uncertainty principle, which expresses the relation between the maximum achievable resolution in one variable, and extent of measurement in a second non-commuting variable. In this case, your variables are bandwidth, Δf, and duration-of-measurement, Δt. Fascinating how that applies in a classical problem, and we didn't even need to resort to literary gimmickry! Nimur (talk) 01:33, 19 June 2014 (UTC)[reply]

I think there is a big difference between Fourier's classical world view where math would allow no limit to the frequency resolution Δf obtainable by extending the duration-of-measurement T (using my symbol) and Heisenberg's discovery of a real-world impossibility of simultaneously knowing exact values of both position and momentum of a particle. That uncertainty cannot be overcome by making the observation longer, nor somehow less intrusive (as was thought) but has the reality of a physical constant. Having to accept tradeoffs between precisions of different quantities is routine to engineers in many fields but the quantum mechanical notion that the Universe itself cannot be entirely accurate is the Paradigm shift that unseated Lord Kelvin's famous assurance in 1900 "There is nothing new to be discovered in physics now. All that remains is more and more precise measurement." 84.209.89.214 (talk) 12:15, 19 June 2014 (UTC)[reply]

According to the article, the Planck temperature is a maximum possible temperature. So it seems as if the inverse temperature were more fundamental somehow. But is there a quantization of temperature into fractions of the Planck temperature? I know in general I've read some strange things about negative temperature that is hotter than any positive temperature, etc. ... but nothing gets colder than absolute zero. Is this system telling us that we're looking at the inverse of the quantity that really matters? And if so... what does it mean? Wnt (talk) 17:49, 18 June 2014 (UTC)[reply]

The Planck units are the unique unit system in which c = ħ = G = 1. That's literally all that we know about them. Naively you would expect important quantities in a theory of quantum gravity to have values close to 1 in those units (this is called naturalness, or just dimensional analysis). That doesn't mean the values would be exactly 1, or would be constrained to integers. If, by some other argument, you could show that quantum gravity implied quantization of, say, inverse temperature, then the quantum of inverse temperature would probably be small in Planck units. The Planck units by themselves don't tell you anything about minimum or maximum values or quantization. -- BenRG (talk) 20:24, 18 June 2014 (UTC)[reply]

Unless something has changed since I took math in high school, presuming that these units are numbers, they can be divided by any other number [except 0] or multiplied by any other number. ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:55, 18 June 2014 (UTC)[reply]

Well, to quote the article directly then, As for most of Planck units, a Planck temperature of 1 (unity) is a fundamental limit of quantum theory, in combination with gravitation, as presently understood. In other words, the wavelength of an object can be calculated by its temperature. If an object was to reach the temperature of 1.41 x 1032 Kelvin (TP), the radiation it would emit would have a wavelength of 1.616 x 10-26 nanometers (Planck length), past which quantum gravitational effects are irrelevant. At temperatures greater than or equal to TP, current physical theory breaks down because we lack a theory of quantum gravity.[2] Now my understanding, I should add, is that a photon with a wavelength around the Planck length has a mass around the Planck mass and is, in short, a black hole. There's something really weird about this math... Wnt (talk) 21:09, 18 June 2014 (UTC)[reply]

Abuse of ignition interlock device

Sometimes a person convicted of a DWI will be required to install an ignition interlock device in their vehicle. From what I understand, the idea is to make the person blow into the machine, which then calculates their blood alcohol content (BAC). If they have an acceptable BAC, the vehicle will start. If their BAC is unacceptable, the ignition of the vehicle will not start. The objective is to prevent the individual from driving drunk or driving while impaired. So, my question is this. If an impaired person wants to drive – and wants to beat the system – they can just have some other individual, such as a non-impaired friend, blow into the machine. Is there some way that the machine itself or law enforcement prevents this from happening? In other words, how do "they" (the machine, the law enforcement and criminal justice system, etc.) know that it is the correct person who is actually blowing into the machine? Thanks. Joseph A. Spadaro (talk) 21:20, 18 June 2014 (UTC)[reply]

The answer is in the second paragraph of the BAC article: It requires an additional sample at some random point in time. Meanwhile, if a sober passenger not only allows a drunken driver to take the wheel, but also helps him try to evade the test, that passenger sounds like a candidate for a Darwin Award. ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:41, 18 June 2014 (UTC)[reply]

The answer is in the second paragraph of the ignition interlock device article. 84.209.89.214 (talk) 22:26, 18 June 2014 (UTC)[reply]

Oops! Too bad I don't have a designated typer. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:40, 18 June 2014 (UTC)[reply]

As described by the article this device sounds rather rudimentary, though I suppose someone very drunk might have difficulties. It doesn't even describe a CO2 sensor, just a need for air to be pushed in. People on this forum seemed to think that any source of minorly compressed air would work. Wnt (talk) 23:37, 18 June 2014 (UTC)[reply]

Thanks. Not sure how I missed that. I skipped over the lead and went directly into the article, where I found nothing. Nonetheless, that is their method of trying to prevent the wrong person from breathing into the machine? Wow. The article says that the machine will require a second sample at some random time, later on down the road. That doesn't seem like that would be particularly effective. I would think that, oftentimes, drunk people are relatively close to home, not that far away in distance (i.e., at the local bar). Plus, I am sure most drunks are not thinking rationally. So, it seems to me that the drunk would easily convince himself that "Oh, I will just drive for a few minutes until I get home; the machine won't ask for a sample so soon; I'm sure I will be home by then". No? Or, not to mention, when the machine is asking for a second sample, just ask a new "clean" person who happens to be in the vicinity. No? Joseph A. Spadaro (talk) 01:26, 19 June 2014 (UTC)[reply]

Like a padlock, even though it's basic and easy to "beat" by force, it's effective in "discouraging" the behaviour and making it impossible to deny the "intention" to commit the crime of drunk driving. That second person would be responsible and perhaps held liable in a criminal and civil courts, not to mention endangering their own lives. The devices themselves are generally low-tech and can be defeated even without the aid of a second person. Virtually all ignition interlock devices and breathalyzers for that matter can be fooled with a baloon filled by the person before drinking. Some basic devices also lack a carbon dioxide sensor and can be beaten by forced air from any source. — Preceding unsigned comment added by 24.100.220.34 (talk) 04:49, 19 June 2014 (UTC)[reply]

The "second person" does not necessarily have to get in the car and go for a ride as a passenger (thus, foolishly risking his own life by being driven by a drunk). The "second person" can just blow into the machine, exit the car, and his job is done. I expect that would happen a lot with "friends" trying to "help each other out". Joseph A. Spadaro (talk) 18:17, 19 June 2014 (UTC)[reply]

I'm sure there are plenty of ways to evade the device - but consider that doing so results in a crime of far greater magnitude than DWI being committed - so if this hypothetical person were to get stopped (eg for driving erratically) then it would be clear that the device had been tampered with or misused - and I would expect them to incur a considerably greater punishment as a result. Remember, the purpose of the device is to allow them the privilege of driving (when sober) for the purposes of going to work or something. Without that device, they'd be barred from driving completely.

Yes, but all of that is based on the premise of the driver thinking and acting rationally (i.e., weighing the cost/benefit and the consequences). A drunk who just wants to get in the car and go home is probably not thinking so rationally. He is probably convincing himself that "I only live just a few miles down the road; I am sure I can get there just fine". Joseph A. Spadaro (talk) 18:12, 19 June 2014 (UTC)[reply]

OK, so the corollary to the popular saying would be, "Friends DO let friends drive drunk, as long as they won't be in the car." ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:56, 19 June 2014 (UTC)[reply]

These days, I'm rather surprised that the devices aren't equipped with a camera. It would be easy to capture a short video of the driver taking the test - and if they were required to present that for inspection (say once a month) that would be an almost certain way to ensure that they aren't cheating the machine. SteveBaker (talk) 04:58, 19 June 2014 (UTC)[reply]

Maybe someday. Technologies evolve. Think of the evolution of the seat belt and the air bag, for example. ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:52, 19 June 2014 (UTC)[reply]

I had the same thought, although a snapshot should be sufficient. A flash might be needed, though, as presumably many of these drunks get in their cars at closing time at the bar, when it will be dark out. The car dome light might be disabled by the drunk to hide the identity of the person taking the breathalyzer test. Disabling the camera flash or covering the lens would be more obvious tampering. You could also refuse to start the ignition unless a certain level of light is detected by the camera. StuRat (talk) 15:50, 20 June 2014 (UTC)[reply]

It's worth remembering that while wikipedia may have an article on anything, they aren't always that good. This FAQ from a manufacturer of such devices suggests that

1) Some do have cameras.

2) They do have anti circumvention measures which try and stop you using any random source of compressed air (I don't know how well they work obviously).

3) The random retest is apparently at least partially to discourage getting someone else to provide a breath sample. This is what the LEDE says and wasn't disputed above but if you look at the talk page, someone claims the "official reason" is to prevent a driver drinking while driving. (Perhaps also a driver who drunk very recently, but long enough that mouth alcohol has largely dissipated.)

4) Several minutes are provided to take the retest so you can pull over if necessary. I guess this will nominally allow someone to attempt to cheat again (theoretically there could be a much smaller time frame once the car has pulled over but this require the device to have access to data it probably doesn't). But I was thinking there must be such an allowance otherwise you may end up with a hazardous situation if a person has to try and take the test ASAP in unsuitable driving conditions. That said, per that source and [18] it sounds like the devices are designed so you can take the test while driving rather than having to pull over or wait until you stop naturally at an intersection or whatever.

I didn't see any mention of a flash there but if you mean an ordinary one, it seems a bad idea, at least for the tests while driving (and the source did suggest the retests are also recorded). A better proposition would be to use an infrared light or flash. You just need enough details that the person is recognisable after all. (You could probably find out what they use with more searching.)

Nil Einne (talk) 17:38, 20 June 2014 (UTC)[reply]

June 19

Hair growth by weight

How many miligrams of hair (on the head, not including facial hair) does an average man with a full haid of hair grow in a month? Has this ever been measured empircally, rather than calculated? — Preceding unsigned comment added by 24.100.220.34 (talk) 04:39, 19 June 2014 (UTC)[reply]

L'Oreal did a calculation here that comes out to about .2 grams of hair per day or 6 grams per month. uhhlive (talk) 21:46, 19 June 2014 (UTC)[reply]

Geese and the transmission of information

Every spring (starting late May and early June) we get 100's of geese, mainly Canada goose, that congregate on both sides of the airport road (69°06′44″N 105°05′15″W / 69.11222°N 105.08750°W / 69.11222; -105.08750) where it is illegal to shoot them. At the same time there are thousands out of town. After a short period they move out onto the tundra to lay eggs and raise their young. Once the gosling's are born there might be one or two families that return to the sides of the road. You can drive by them with a truck or ATV and walk, even with a dog, by them and they don't move. The only way to get them to move is to walk towards them or bend over. However, the geese on the land (this is before the eggs are laid), where you can shoot them, will fly off well before you get into shotgun range. So the question is how do the geese know that being on the side of the road is safe? How do they transmit this information between one another? CBWeather, Talk, Seal meat for supper? 08:08, 19 June 2014 (UTC)[reply]

Good question. It's kind of the same question as "How do crows know to take off when the farmer walks out the door with his shotgun?" Perhaps it's experience - or lack thereof. ←Baseball Bugs ^{What's up, Doc?} carrots→ 09:43, 19 June 2014 (UTC)[reply]

I don't think it is possible to give any sort of precise answer, but there's little doubt that observational learning plays an important role. There are lots of well-studied examples of it in birds. See for example Observational learning#Social Learning in Crows. Looie496 (talk) 12:53, 19 June 2014 (UTC)[reply]

Crows do seem to be quite intelligent, and do seem to be able to communicate threats to each other. There was a study done where a person wearing a given mask harassed some crows, then later walked by a different group of crows, and they were frightened of him, too. So, somehow the first group communicated that he was a threat to the second group. There's also inter-species communication of threats. Of course a baking dog can communicate a threat to it's owner, but many other species cooperate and share intel like this. In some cases, the communication even describes the type of threat, like "snake". StuRat (talk) 15:59, 20 June 2014 (UTC)[reply]

Wait, isn't there a Canadian equivalent of the migratory bird act? I only ask because in USA it is illegal to ~~ever~~ shoot them in many circumstances... Our article says that UK acted "on behalf" of Canada in signing the treaty. Anyway, it's a little unclear from your description, but isn't there a timing difference as well? E.g. parents of young that cannot fly yet will be much less likely to take flight when threatened. Birds in general and fowl in particular behave very differently at different times of the breeding cycle (sorry, that article is terrible). Otherwise I agree with Looie's general comments and links. Finally, if you're interested in controlling them on your property, a pair of mute swans or a border collie usually does the trick. There are even service businesses in the US that come out with dogs and swans to keep geese away from golf courses [19]. SemanticMantis (talk) 14:42, 19 June 2014 (UTC)[reply]

Canada's version appears to be Migratory Birds Convention Act. According to [20], Canada geese are considered game birds and may be hunted in Canada under certain circumstances as game birds. Per various links like [21] and [22] it sounds like migratory Canada geese can generally be hunted in the US during certain seasons that are made on a year by year basis, and resident ones at additional times (when migratory ones are not really present and depending on the area). Nil Einne (talk) 16:10, 19 June 2014 (UTC)[reply]

Oops, thanks! SemanticMantis (talk) 16:57, 19 June 2014 (UTC)[reply]

Thanks for the replies. It looks as if Looie's links provide the answer. The parents molt at nesting time so they can't fly until the young are ready. That's why very few return to the road area before migration. They prefer lakes and large ponds where they can escape from foxes. The only problem we have with them is that besides the road they occupy the ponds at both ends of the runway. Thanks. CBWeather, Talk, Seal meat for supper? 09:43, 20 June 2014 (UTC)[reply]

For your specific example, here are some ways they could know the difference between areas where they might be shot and areas where they won't be:

1) Their own experience. If somebody shot at them or another bird in sight in one area, they will tend to think of that area as dangerous. This may not apply to other areas. Being migratory birds, they would need to understand that threats vary by location. For example, bears might be malnourished in one area and try to catch them, but may be well fed in another location and leave them alone for easier prey. Knowing this would be important to their survival. Also, they may remember a threat from previous years.

2) Another bird could communicate the threat level to them simply by flying away, or not, for a given stimulus. If all other birds fly away, they may do so too, even if they aren't directly aware of a threat. This can include birds of other species and non-birds that run away. A forest fire is a good example of this, when all species of animals can be seen flying and running away. I don't think they all directly detect the fire, but many just "go with the crowd" and follow where they are going. (Of course, this type of group behavior can lead to problems, too, like when one whale beaches itself and all the other whales follow it and beach themselves, too.)

3) Birds may also make warning calls telling others of the threat. This can include birds of other species and non-birds, too.

And a note on evolution here. While it wouldn't do a bird much good to understand the Theory of Relativity, knowing what is and isn't a threat is critical to their survival and thus passing down their genes, so a large portion of their rather limited brain capacity is devoted to this task. Therefore, they seem to be able to figure out threats in ways that require more intelligence than we credit them with possessing. StuRat (talk) 16:14, 20 June 2014 (UTC)[reply]

Synthesis of HgH
₂

What solvent would be useful for the titular synthesis, using dichloridomercury and lithium tetrahydridogallate, the temperature must be kept below 149 K (−124 °C; −191 °F)? Plasmic Physics (talk) 11:42, 19 June 2014 (UTC)[reply]

Ethereal solvents are commonly used for metal-hydride reactions, but I don't know specifically about gallates. Diethyl ether melts at 157 °C, so having some reactants/products dissolved it it (or adding a small amount of some other cosolvent) would probably drop the mp 8 K or or more, enough to keep it liquid at your target temperature. Dimethyl ether would be a liquid at that temperature range, but you'd have to condense it to use it...a practical annoyance. If you don't need an ether, alkanes C5 and smaller have low enough mp. DMacks (talk) 18:08, 19 June 2014 (UTC)[reply]

Erm, you mean 157 K! Wnt (talk) 22:32, 19 June 2014 (UTC)[reply]

I don't think that alkanes are good solvents for salts (lithium tetrahydridogallanate), or is this particular salt an exception to rule? Plasmic Physics (talk) 03:25, 20 June 2014 (UTC)[reply]

Why in God's name would you want to make mercury(II) hydride in the first place? TenOfAllTrades(talk) 18:04, 19 June 2014 (UTC)[reply]

As the article states, it has no economic uses, and is made only as an academic curiosity. Like all mercury compounds, it is toxic. If you aren't a chemistry professor planning to publish a paper for research, it is best avoided. (If you were a chemistry professor, you probably wouldn't ask here because you would have done a literature search.) Robert McClenon (talk) 18:09, 19 June 2014 (UTC)[reply]

As a starting point, one would have found a ref for using lithium gallanate in this type of reaction it and start with that solvent. DMacks (talk) 18:18, 19 June 2014 (UTC)[reply]

No need for him to apologize for curiosity - it is indeed interesting to find out about solvents that are good for crazy cryogenic reactions! Wnt (talk) 22:32, 19 June 2014 (UTC)[reply]

It is probably toxic, but since it rapidly decomposes above 149 K, the only likely hazard is by contact, and even then, cryogenic burns are the biggest issue. Plasmic Physics (talk) 00:19, 20 June 2014 (UTC)[reply]

Well, I thought since this compound has been identified for a while, it is about time that it is isolated also. So, I'm just working through a method to see how it could be done. Plasmic Physics (talk) 00:02, 20 June 2014 (UTC)[reply]

One of the refs in the article (the one that discusses the magic temperature of decomposition) mentions making it and isolating it on a cold plate. Heck, they make it at what, 4 K, and then warm it enough to remove the unreacted reactants, matrix, etc. DMacks (talk) 02:23, 20 June 2014 (UTC)[reply]

That is not what I meant. I meant a reaction which is not photocatalytic. Plasmic Physics (talk) 03:25, 20 June 2014 (UTC)[reply]

How well can temperature be controlled in cryogenic syntheses? Plasmic Physics (talk) 00:02, 20 June 2014 (UTC)[reply]

Very well on small scale. Baths can easily be controlled to a degree or tenth or even better at some ranges. But getting that equilibrated throughout a reaction medium becomes harder as scale increases as the reaction becomes more exothermic. Endothermic often less of a problem because "a bit too cold" for an already very cold reaction just means the reaction slows down until the temperature re-rises to match bath (negative feedback that does not usually damage the product, etc.) See Cryocooler and Cooling bath (I remember being surprised at first how predictable those were once I managed to avoid freezing them outright). Or can just use a liquid+solid bath of some material whose melting point is the temp you want. DMacks (talk) 02:20, 20 June 2014 (UTC)[reply]

Parallel plate transmission line

I looked in the transmission line article but it does not describe this version. I want to know if parallel plate transmission lines are always balanced, or can they be operated unbalanced?--86.180.143.223 (talk) 17:33, 19 June 2014 (UTC)[reply]

A Microstrip line consisting of a thin flat conductor which is parallel to a ground plane is an example of an unbalanced parallel plate transmission line. One can model a balanced parallel plate transmission line as two microstrip lines back-to-back with a common ground plane that can be removed since, by symmetry, it carries no current. 84.209.89.214 (talk) 19:55, 19 June 2014 (UTC)[reply]

I should have made it clear that what I meant by a parallel plate transmission line is one where the conductors each have the same width. This is therefore different from the microstrip arrangement which is operated in unbalaced mode. Is there any advantage to a symmetrical parallel plate line being operated balanced or unbalanced? --86.180.143.223 (talk) 11:11, 20 June 2014 (UTC)[reply]

The unbalanced parallel plate line is not as well isolated from the surroundings as when balanced, since its fields do not cancel at a distance. Therefore unbalanced lines are more susceptible to interference or to causing interference...unless you wrap the ground plane around to change the line to a Coaxial cable. Balanced lines are easy to set up for a desired impedance, such as when matching to a Dipole antenna. See Dipole antenna#Feeding a dipole antenna. 84.209.89.214 (talk) 19:14, 20 June 2014 (UTC)[reply]

Wheat in Stilton

Our article on Stilton cheese makes no mention of its wheat content, but it's an allegation -- for want of a better term -- that's consistently made online. Could anyone point me in the direction of a WP:RS that states that Stilton contains wheat so that I can add it to the article (or not, as the case may be)? I don't eat wheat but used to be damned fond of a tasty piece of Stilton and would like to be sure one way or another. Thanks, Ericoides (talk) 18:25, 19 June 2014 (UTC)[reply]

Hope this article and the links contained therein helps you make your mind up. --TammyMoet (talk) 18:32, 19 June 2014 (UTC)[reply]

Islands with largest highest-point-to-area ratio

I'm interested making relief maps of islands with large highest points relative to their area, so that they look more interesting. Taking islands over 10000 km² in area from List of islands by area and over 2000 m high from List of islands by highest point, I compiled this list:

Island	Highest point (m)	Area (km²)	Ratio (m/km²)
Hawaii	4205	10434	0.403
Mindoro	2582	10572	0.244
Jamaica	2256	11190	0.202
Sumbawa	2722	14386	0.189
Negros	2435	13074	0.186
Panay	2117	12011	0.176
Seram	3027	17454	0.173
Palawan Island	2085	12189	0.171
Flores	2370	14154	0.167
Sicily	3326	25662	0.130
Taiwan	3952	35883	0.110
Timor	2963	28418	0.104
Vancouver Island	2195	31285	0.070
New Britain	2334	35145	0.066
Alexander Island	2987	49070	0.061
Axel Heiberg Island	2210	43178	0.051
Hispaniola	3098	76480	0.041
Sri Lanka	2524	65268	0.039
Mindanao	2954	97530	0.030
Hokkaido	2290	78719	0.029
Luzon	2922	109965	0.027
Java	3676	138794	0.026
South Island	3724	145836	0.026
North Island	2797	111583	0.025
Iceland	2110	101826	0.021
Sulawesi	3478	180681	0.019
Honshu	3776	225800	0.017
Ellesmere Island	2616	196236	0.013
Sumatra	3805	473481	0.008
New Guinea	4884	785753	0.006
Borneo	4095	748168	0.005
Madagascar	2876	587713	0.005
Baffin Island	2147	507451	0.004
Greenland	3694	2130800	0.002

However, Penang Island, at 833 km² and 295 m has a ratio of 2.824, much larger than any of the above.

Is there a quick way of get a list of islands with the largest ratios?

Thanks! cmɢʟee⎆τaʟκ 19:25, 19 June 2014 (UTC)[reply]

Can't help with a general list, but I bet Ball's_Pyramid has a high ratio. It made some news recently when this critter Dryococelus_australis was recently re-discovered there. Stack_(geology) will have some other very tall "islands" with small areas. Also, your ratio is effectively getting at rugosity, though that ratio is unitless, while yours comes out to the slightly-weird 1/m. SemanticMantis (talk) 20:18, 19 June 2014 (UTC)[reply]

The smaller the islands in your list are, the bigger the numbers you will get, so for a 1 km² island peaking at 1m you will get 1.0, but really that is not very impressive at all. You should use something more like a height to width ratio. Graeme Bartlett (talk) 21:13, 19 June 2014 (UTC)[reply]

Good point. Rugosity is similarly not biased by area. But computing rugosity for an island probably can't be done without very good topographic maps or lidar imaging (and some decent effort on top of that). SemanticMantis (talk) 21:29, 19 June 2014 (UTC)[reply]

Try height divided by the square root of area. It's dimensionless and doesn't depend on the island being round or long. Oh, and do compute it for SemanticMantis' example, and for the Old Man of Hoy. AlexTiefling (talk) 21:35, 19 June 2014 (UTC)[reply]

(ec) Exactly. To some approximation, you will have the steepest average slope from shoreline to peak on the island with the greatest ratio of highest point to 'width'. Of course, since islands aren't necessarily square or circular, that concept of 'width' is a bit fuzzy. For a 'scale' term, you could just use the square root of area, and take the ratio of height to that scale length to get a 'steepness' score. (Incidentally, Hawaii tops that list too. Penang Island, meanwhile, ends up around the middle of the new list.) TenOfAllTrades(talk) 21:39, 19 June 2014 (UTC)[reply]

Many thanks, SemanticMantis, Graeme, Alex and TenOfAllTrades. You're right, this gives prominence (mind the pun!) to small islands. Perhaps even more extreme than Ball's Pyramid is Ko Tapu, assuming its area is a circle of 4m diameter at sea level. I couldn't find the area of Old Man of Hoy, but estimate a width of 35 m from photos. Dividing by square root of area gave:

Island	Highest point (m)	Area (km²)	m/√km²
Ko Tapu	20	0.000016	5000
Old Man of Hoy	137	0.01	1370
Penang Island	833	295	48
Hawaii	4205	10434	41
Mindoro	2582	10572	25
Seram	3027	17454	23
Sumbawa	2722	14386	23
Jamaica	2256	11190	21
Negros	2435	13074	21
Taiwan	3952	35883	21
Sicily	3326	25662	21
Flores	2370	14154	20
Panay	2117	12011	19
Palawan Island	2085	12189	19
Timor	2963	28418	18
Alexander Island	2987	49070	13
New Britain	2334	35145	12
Vancouver Island	2195	31285	12
Hispaniola	3098	76480	11
Axel Heiberg Island	2210	43178	11
Sri Lanka	2524	65268	10
Java	3676	138794	10
South Island	3724	145836	10
Mindanao	2954	97530	9
Luzon	2922	109965	9
North Island	2797	111583	8
Sulawesi	3478	180681	8
Hokkaido	2290	78719	8
Honshu	3776	225800	8
Iceland	2110	101826	7
Ellesmere Island	2616	196236	6
Sumatra	3805	473481	6
New Guinea	4884	785753	6
Borneo	4095	748168	5
Madagascar	2876	587713	4
Baffin Island	2147	507451	3
Greenland	3694	2130800	3

(For comparison, Burj Khalifa at 830 m and 0.008 km² has a value of 9300 and the Dushanbe Flagpole at 165 m and 0.00002 km² (estimate) has a value of 37000!)

Guess the problem now becomes subjective, as to how small an island to accept while it still being relatively well-known. Thanks for all your help! cmɢʟee⎆τaʟκ 13:15, 20 June 2014 (UTC)[reply]

If anyone's curious, approximating the basal area of Ball's Pyramid by an ellipse, we get an area of ~1.036 km^2. This gives the ratio as 563m/√(1.036)km² ~= 552, making it third on the list above. Also I think the arithmetic on Ko Tapu is wrong. For a 4m diameter I get area= 4pi m2=1.25664e-5 km^2. Then 20m/√(1.25664e-5)km² ~= 5642. Using the top diameter of 8m I get a ratio of ~2821. So barring any other arithmetic errors, Ko Tapu is the clear 'winner'! SemanticMantis (talk) 15:37, 20 June 2014 (UTC)[reply]

Carbonatite magma phase separation

Carbonatite lavas are very unusual in appearance and composition, and apparently result from the separation of phases in magma. See [23] for some video well worth watching. A question they raise in my mind, though: does the separation of phases here have anything to do with the hydrophilic aqueous phase and hydrophobic organic phase that typically dominate a smaller and cooler separatory funnel than the ones here delivering different flavors of magma to the Earth's surface over spans of (only) thousands of years? Does the partition of various minerals to these phases align with an analysis of how polar they are expected to be in a magma setting? Can you say that a carbonatite or silicate phase mixes with X mixes with Y mixes with... until you have a series that relates it in hypothetical miscibility directly to oil or water? If not, can you find a direct analogy from liquids at STP for this kind of phase separation? Wnt (talk) 22:40, 19 June 2014 (UTC)[reply]

In magma, hydrophilic/hydrophobic properties are irrelevant because the system does not include liquid water (only water vapor, if any); a more relevant classification is into lithophile, chalcophile and siderophile minerals (which has more to do with electronegativity and ~~polarisibility~~ polarisability, not dipole moment). That said, since the elements found in carbonatites are extreme lithophiles, this kind of differentiation may indeed take place (although there are other hypotheses as well). Bottom line is, we don't know enough yet to tell for sure. 24.5.122.13 (talk) 00:40, 20 June 2014 (UTC)[reply]

Perhaps there should be a redirect: polarisibility → Polarizability 71.20.250.51 (talk) 03:19, 20 June 2014 (UTC)[reply]

polarisability?

In any case, how can things be separated based on electronegativity? I thought things with different electronegativity tend to like each other, like sodium and chloride?

As for polarisability, is that more important in magma because so many ions are present in that environment, or some other reason? Is there any example of phase separation on this basis at STP?

Oh, also: under Goldschmidt classification all the rare earths are listed as "lithophiles". But the article I linked at top says that the only rare earth mines are in these abnormal carbonatite deposits... Wnt (talk) 05:43, 20 June 2014 (UTC)[reply]

OK, one thing at a time:

(1) Thanks for correcting my spelling -- that's precisely what I meant.

(2) In magma, precisely such a separation is believed to take place: siderophile (electronegative) cations remain in their reduced (metallic) state, chalcophile (electropositive, polarizable) cations combine with sulfur anions (one of the two major anions in magma) to form sulfides, and lithophile (electropositive, non-polarizable) cations combine with oxygen anions (the other major anion) to form oxides (which may react further to form hydroxides or carbonates).

(3) In magma, polarisability is important because oxygen and sulfur are the major anions, and polarisability determines a cation's affinity to each -- high polarisability will favor combining with sulfur (which is also polarizable), and low polarisability will favor combining with oxygen (which is also nearly non-polarizable).

(4) The carbonatite deposits preferentially include lithophilic minerals, and exclude siderophilic and chalcophilic minerals -- so there's no contradiction re. rare earths. 24.5.122.13 (talk) 07:50, 20 June 2014 (UTC)[reply]

Thanks! You're being very helpful. I hope you'll consider starting an account and contributing to our articles.

Come to think of it, would a mixture of metallic mercury and carbon tetrachloride provide an example of this sort of phase separation? Wnt (talk) 14:03, 20 June 2014 (UTC)[reply]

June 20

Attraction between charged object and stream of water - does it really show that water molecules are polar?

I have seen in several places (such as on this webpage: [24] ) that the deflection of a stream of water towards a charged object shows that water molecules are polar. Does it really show this? I have managed to find an example of a stream of liquid NOT being attracted to a charged rod ("Nonpolar tetrachloromethane molecules are not attracted to either charged rod." [25] ). This still does really show the reason why water IS attracted (and is not due to something like charges on surface, or conductivity of water, for example). FrankSier (talk) 15:26, 20 June 2014 (UTC)[reply]

I don't know the answer to your question - but the business of attracting (or not) flows towards nearby objects doesn't necessarily indicate polarization - it can also happen due to the Coandă effect and also to Bernoulli's principle...so it's not always easy to determine which effect is in play. SteveBaker (talk) 19:14, 20 June 2014 (UTC)[reply]

I think the OP is asking about a situation where the stream of liquid isn't actually touching the charged object, so fluid dynamics effects aren't really an important part of the problem. Red Act (talk) 20:26, 20 June 2014 (UTC)[reply]

You are correct, the deflection of a stream of liquid towards a nearby charged object is not a sufficient condition to conclude that the liquid is composed of polar molecules. For example, a stream of mercury will be deflected towards a nearby charged object because it conducts and hence can develop a nonzero free charge density, not because it develops a nonzero bound surface charge density due to the alignment of electric dipoles as in the case of a stream of pure water. Red Act (talk) 20:13, 20 June 2014 (UTC)[reply]

The gray circle for microwave toasting

Things like microwaveable pot pies that have a gray circle on the interior of the packaging that help to toast the product- what is that material? It must not be very metallic, otherwise sparks would fly. What is it?20.137.2.50 (talk) 16:22, 20 June 2014 (UTC)[reply]

I think it is metallic, but the metal bits are small and disconnected, so they don't get a chance to build up enough of a charge to arc. StuRat (talk) 16:24, 20 June 2014 (UTC)[reply]

Our article on susceptors have a bit more details - in short it's a material able to absorb electromagnetic energy and convert it to heat. WegianWarrior (talk) 16:43, 20 June 2014 (UTC)[reply]

Name of foot ailment.

(This isn't a request for diagnosis, prognosis or treatment advice for any medical condition)

I'm trying to find the name - and prevalence in the USA - of a medical condition whereby standing for too long (possibly for occupational reasons) can cause nerve damage - which in turn can result in some kind of postural problem - which goes unnoticed because of the nerve damage - ultimately result in a foot condition so bad that it may require amputation. That's basically all I know about it - I'm really just trying to find some hooks for information so I can go read up about it myself.

(There are days when I'm actually glad that I have a desk job!)

TIA SteveBaker (talk) 19:22, 20 June 2014 (UTC)[reply]

I don't think there is a separate foot related disease like this. What you are describing vaguely resembles peripheral neuropathy typically as a consequence of diabetes type II. Being overweight helps also. Vasculitis also may be a contributing factor. --AboutFace 22 (talk) 20:02, 20 June 2014 (UTC)[reply]

BTW, what nerve damage do you have in mind? Afferent, sensory nerves or efferent, motor nerves? --AboutFace 22 (talk) 20:07, 20 June 2014 (UTC)[reply]

I don't know! That's what I'm trying to find out. I'm guessing that because (I'm told) the nerve damage causes sufferers not to notice that they're somehow making matters worse - that it's probably sensor nerves that are the problem here. But I honestly don't know. SteveBaker (talk) 21:15, 20 June 2014 (UTC)[reply]

The context here is that someone wants to have me work on a gadget to help these people - and before I first go to talk to the guy, I'd like to try to appear at least a little fluent with the science - maybe know some of the words. SteveBaker (talk) 21:15, 20 June 2014 (UTC)[reply]

Steve, we have a (terribly sourced) article Long-term complications of standing, but it doesn't mention anything about nerve damage. Deor (talk) 20:43, 20 June 2014 (UTC)[reply]

Hmmm - didn't seem to illuminate much...thanks for trying. SteveBaker (talk) 21:15, 20 June 2014 (UTC)[reply]