Wikipedia:Reference desk/Archives/Science/2012 April 21

= April 21 =

Is US or UK ahead in commercial transportation fuel synthesis from CO2?
Of http://dotyenergy.com in the US and http://airfuelsynthesis.com in the UK, which company is closest to mass production of carbon neutral transportation fuel from carbon dioxide? Which has the most capitalization? What other companies are working in this field? Is http://rentechinc.com/pdu.php? 71.212.237.20 (talk) 00:46, 21 April 2012 (UTC)


 * Why care? To turn CO2 into fuel, you have to split it: 2CO2 → 2 x CO and O2, or co2 → C and O2.  To do that, you have to add the heat of formation.  That doesn't necesarily mean you have to raise it to a high temperature - but the energy must be supplied in the process somehow. When you burn/consume fuel, you get the heat of formation back.  So, to turn CO2 into fuel, you need an energy source (i.e., fuel to be consumed) equal to the energy you get out of the fuel you make.  That is pointless.  Ratbone60.230.208.219 (talk) 11:41, 21 April 2012 (UTC)


 * It's useless as a source of energy, but quite useful as a kind of battery of energy. 88.9.107.123 (talk) 14:47, 21 April 2012 (UTC)


 * The point is that if the energy comes from wind, hydropower, or solar, then it's carbon neutral. 71.212.237.20 (talk) 17:22, 21 April 2012 (UTC)
 * If wind or hydro, yes, but the ouput is electrical, so just distribute it on the grid. Solar is NOT carbon nuetral if photovoltaic, nothing like it. To make the panels takes considerable energy.  Solar power via heating a fluid that spins a turbine is theoretically better, but it seems that nobody has come up with a reliable maintenance free and efficent device yet.  Ratbone121.215.58.238 (talk) 01:08, 22 April 2012 (UTC)
 * If solar panels (or wind turbines, or hydroelectric stations) did not produce more energy than it takes to manufacture and install them, nobody would purchase them. 71.212.237.20 (talk) 03:22, 22 April 2012 (UTC)
 * Well, until heavy government subsidies, here in Australia at any rate, only nutters and remote area folks who had no alternative, did buy solar panels. The energy required to make the panels is why they are so expensive.  Wind power and hydro is totally different.  Hydro has been mainstrean power in favourable areas since the elctricity industry started. Ratbone121.215.58.238 (talk) 03:42, 22 April 2012 (UTC)
 * Manufacturing solar cells is very energy intensive due to the zone refining that is required. I wonder if you could set up a zone refining solar cell factory in the desert where you have plenty of sand for raw materials and use an array of mirrors to heat the ingot... 203.27.72.5 (talk) 07:21, 22 April 2012 (UTC)
 * There's a hole in the bucket, dear Liza, dear Liza, there's a hole....http://www.youtube.com/watch?v=ElLpKewnxp4&feature=related  Ratbone58.170.172.202 (talk) 09:57, 22 April 2012 (UTC)
 * Solar cells pay for themselves in 4 to 10 years. Wind turbines pay for themselves in 6 to 8 months. I don't know what the figure is for hydroelectric plants. Again, the point is that any renewable source producing transportation fuel will make it carbon neutral. Using the same CO2 feedstock processes for plastic lumber represents an essentially permanent economical means of carbon sequestration which has the advantage of reducing deforestation. 71.212.237.20 (talk) 19:03, 22 April 2012 (UTC)
 * The only way you can get anything like a payback period as low as 4 to 10 years is either a)solar power is subsidised by the Govt, b)it will be used in a remote area, or c)you are in a western country and purchasing cheap Chinese-made solar panels made with their low cost electricity sourced from their coal fired power stations using coal mined with their low cost labour. Having the coal burnt in a counry not your own is NOT environmentally responsible.  Ratbone60.230.215.57 (talk) 01:30, 23 April 2012 (UTC)


 * It's not quite what you're asking, but essentially it is the US: corn ethanol. We in the UK don't have anything like that scale of a biofuel industry. SmartSE (talk) 12:30, 21 April 2012 (UTC)
 * Fuel which raises the cost of food is bad news, and isn't really carbon neutral because of agricultural fuel use. 71.212.237.20 (talk) 17:22, 21 April 2012 (UTC)
 * But it is carbon neutral if the fuel used for agriculture is sourced from the very agriculture it's performing. 203.27.72.5 (talk) 07:16, 22 April 2012 (UTC)
 * For a couple of crops, maybe. Then you need fertiliser, which takes energy to produce.  Biofuel is like solar panels - the energy consumed is so high it only works commercially if governments prop it up with laws and subsidies.  Ratbone58.170.172.202 (talk) 09:57, 22 April 2012 (UTC)
 * See compost, sir. Whoop whoop pull up Bitching Betty 18:14, 22 April 2012 (UTC)
 * Where does the material to make compost come from? The point is, if you expect to get energy out of an area of land for an indefinite period, without bringing in fertiliser from somewhere else, you are basically expecting to make just another form of perpetual motion machine.  Ratbone60.230.215.57 (talk) 01:30, 23 April 2012 (UTC)


 * See Energy returned on energy invested and (the source cited for the ERoEI graph).  Corn ethanol has an ERoEI of, at best, 1.6 -- any inefficiency in production, and you'll be losing energy on every gallon of fuel you make.  Biodiesel is even worse, at an ERoEI of 1.3.  For comparison, photovoltaic energy has an ERoEI of 6.8 or so, wind is 18, and hydroelectric is somewhere upwards of 100. --Carnildo (talk) 02:16, 24 April 2012 (UTC)

ban all plastic bags ... and then?
Crude oils and natural gases around the world are very complex mixtures of organic materials. We get all kinds of fuels and raw materials from these non-renewable natural resources.

I can certainly reduce my plastic bag consumption. However, I still consume much gasoline. If I don't reduce my use of fuel oils (driving cars, use electricity directly and indirectly ...), then the oil industry still has to pump up so much crude oil to produce so much fuel for me and also so much organic byproducts that will be used to manufacture plastic bags, forks, cup lids, styrofoam peanuts, lousy key-ring toys, all these miserable disposable things that will never be disposed .......

You can kill a fat cow to get two hundred lbs of meat. In the mean time, you get bones, fats, horns, hoofs, hair, .... I think crude oils contain much less waste because many "cow ingredients" are more difficult to use. They may be useful to some people, but the market demand much less of these low-end "cow ingredients".

Without the plastic bag industry, how do we make good use of all these chemical soups that will become LDPE and many other low-end plastics? I think it may be a good idea to store billion tons of low-end plastic pellets somewhere for future generations. The costs can be added to fuel prices. However, these low-end plastics may still degrade in storage.

The best way is to reduce oil consumption so we don't need to pump up so much crude oil. But what will happen if we just ban plastic bags? -- Toytoy (talk) 05:49, 21 April 2012 (UTC)
 * Amongst other things, we will have fewer discarded (because trivially cheap) plastic bags littering the streets and countryside, and being washed via drains and rivers into the sea where they contribute (along with other discarded plastic items) significantly to harming marine life (which ingests them or their fragments both involuntarily and through mistaking them as food items: rubber bands resemble marine worms, plastic bags jellyfish, etc). {The poster formerly known as 87.81.230.195} 90.197.66.64 (talk) 08:47, 21 April 2012 (UTC)


 * The thing about the crude oil 'cow' is that you don't have to settle for what comes in from the field; if you need more 'meat' (or 'hoof', or 'eyeball', for that matter) there are catalytic refining processes that can get it for you. A modern oil refinery uses quite a few different techniques to separate the different components of crude oil, and then to manipulate the different fractions to produce the mix of products required at market.  Taking your specific question about polyethylene, steam cracking is a high-temperature process used to break longer-chain, saturated hydrocarbons into the smaller, unsaturated compounds (like ethylene) used to make plastics.  Ethylene isn't a naturally-occurring component of crude oil; it's deliberately manufactured in order to feed downstream industrial users.  If there were a reduced demand for ethylene, then the hydrocarbons used to make it would be used to generate a different end product instead.  TenOfAllTrades(talk) 13:39, 21 April 2012 (UTC)
 * Both cow slaughter and oil rerfining are highly efficient. There is little waste in either process. You may not eat those low value parts (or may not realize what exactly is in your hot dog or gelatin dessert) but your dog or garden plants may eat them. Some end up as industrial feedstocks too. Rmhermen (talk) 14:06, 21 April 2012 (UTC)
 * It's not even just those parts. Some people find those parts of the animal to be very desirable, e.g. Menudo, headcheese, black pudding, chitterlings, lengua, etc. etc.  -- Jayron  32  23:55, 21 April 2012 (UTC)
 * If we develop advanced virtual reality worlds that jack directly into our minds then limited physical resources become an irrelevant concern. All society would need then is the power to operate the simulated reality and a little extra nutrition to keep our bodies ticking along until we replace our minds with digital simulations. I don't think we'll need plastic bags at that point. Sky Machine   ( ++ ) 21:56, 21 April 2012 (UTC)
 * Touché. 203.27.72.5 (talk) 01:49, 22 April 2012 (UTC)

Insect ID
Can anyone identify either of these two pretty critters, both from southern Vietnam? The moth was somewhere in the order of 15cm across; the other (weevil?) perhaps 6-8. I'd particularly like to know if the hook shapes on the weevil's antennae serve a specific purpose. Thanks, HenryFlower 10:19, 21 April 2012 (UTC)
 * The black and yellow chap looks like the longhorn beetle, Pachyteria dimidiata  Sean.hoyland  - talk 10:38, 21 April 2012 (UTC)


 * Thanks--one down! The moth resembles the Emperor Gum Moth (Opodiphthera_eucalypti); not quite the same though (that one's Australian and lacks the transparent 'windows' in the eyes). HenryFlower 12:19, 21 April 2012 (UTC)
 * I have no particular knowledge of this species (being UK/European based), but I believe some lepidoptera can lose patches of specialised (scent-bearing?) scales from their wings as they get older, so yours might simply be an older specimen; alternatively, it might be a sexual dimorphism. On balance, however, I think it's a different but closely related species. {The poster formerly known as 87.81.230.195} 90.197.66.219 (talk) 02:17, 22 April 2012 (UTC)
 * (ec)It appears to be a Tussah moth, Genus Antheraea perhaps it is the Antheraea pernyi since it is similar in appearance to those pictured here. --Modocc (talk) 02:22, 22 April 2012 (UTC)
 * Thanks! HenryFlower 05:41, 22 April 2012 (UTC)

~ Health-Related Questions: For Only Knowledge & Experienced People of Excellence Only ~
Thingstofollow (talk) 10:57, 21 April 2012 (UTC)
 * what is the median cost of birth on state, and usa level. possibly include UK, AUS, etc. if you know.
 * what is the most reputable rankings for Maternity Hospitals?
 * what are the 1-2 most reputable ranking for each section on mastersinhospitaladministration.com/2011/hospital-rankings-in-the-usa-the-ultimate-list/ -- include one sentence as to why
 * what is the average hip size, or average range of hip sizes?
 * will ask on ehealthforum.com or SOMEWHERE if nobody knows

Odd tree growth
Can anybody give me any information on this phenomenon? The dense portion within the tree really seems to branches and twigs of the tree, not a parasite or epiphyte. There are at least three trees with this appearance at Nostell Priory, but I've never noticed the phenomenon anywhere else. Is it natural to this particular species, or the result of disease? Or has it been pollarded in some odd way? I haven't managed to identify the species, or even the genus of the tree: only a few leaf-buds are open yet, so I can't tell the size or final shape of the leaves, but from the young leaves I've seen I think it might be a lime, or perhaps an elm. --ColinFine (talk) 11:34, 21 April 2012 (UTC)


 * It's called a witch's broom (for obvious reasons). It is a symptom of many different diseases and can occur on many different species. EB also have an article which is a bit different to ours, and there are many scientific publications about it to be found. SmartSE (talk) 12:27, 21 April 2012 (UTC)


 * From the branches that looks like a lime tree, and I've seen this phenomenon in a number of places in southern UK usually, on lime trees. I would say it is unusual but not rare. Richard Avery (talk) 13:27, 21 April 2012 (UTC)


 * These growths are associated with burrs (or "burls" if you're American). The Common Lime Tilia × europaea is noted for them and they distinguish it from the many other lime species and cultivars. The Field Guide to the Trees of Britain and Northern Europe by Alan Mitchell says; "Bark... burred and densely sprout-infested especially at the base". The poet Robert Browning noted the same feature in the English Elm Ulmus procera, in Home Thoughts from Abroad;
 * ''And whoever wakes in England
 * ''Sees, some morning, unaware,
 * ''That the lowest boughs and the brushwood sheaf
 * ''Round the elm-tree bole are in tiny leaf
 * ''While the chaffinch sings on the orchard bough
 * In England—now! Alansplodge (talk) 17:04, 21 April 2012 (UTC)


 * Are we entirely uncertain this isn't mistletoe? See File:Mistletoe Abundance Wye Valley.jpg.  -- Jayron  32  19:31, 21 April 2012 (UTC)
 * Well, I'm entirely certain it isn't mistletoe. Or ivy. I went and looked. --ColinFine (talk) 17:36, 24 April 2012 (UTC)
 * It's possible, but every part of mistletoe is light green. We seem to be seeing a mass of dark twigs in this instance. Alansplodge (talk) 21:03, 21 April 2012 (UTC)
 * Mistletoe has an easily recognizable geometry, too. It doesn't have straight, parallel branches like the twigs on this tree. And it has leaves on it all year round. When I first say the picture, I thought it was ivy. But then I noticed that the bottom portion of the trunk is bare. Looking closely, I have to agree that it is some type of hyper-proliferation of the tree itself rather than an epiphyte. Dominus Vobisdu (talk) 23:19, 21 April 2012 (UTC)
 * Let's not let mistletoe off so easily. It does indeed steal resources from its host, making it parasite. ;) 96.233.247.233 (talk) 01:43, 22 April 2012 (UTC)

Thanks, Smartse and Alansplodge. --ColinFine (talk) 17:38, 24 April 2012 (UTC)

alternative explanation
I heard about the book fingerprints of the gods which offered a different explanation for some archaeological discoveries, i understand that this is farfetch explanation but the idea is fascinating, can you guys give me a list of this kinds of things?

explanations of phenomenons that is not particularly accepted by mainstream science but is interesting to know. thanks 203.112.82.129 (talk) 16:30, 21 April 2012 (UTC)


 * I'm not kidding or being sarcastic when I say try using Youtube for this sort of thing. Start with your topic and browse the related links on the right.. eg http://www.youtube.com/watch?v=o52zJEGqkhI etc.Oranjblud (talk) 18:25, 21 April 2012 (UTC)


 * The idea is interesting, but resolving it is like nailing Jello to a tree. The hypothetical First Race Of Man was at once so thoroughly careful about covering up its tracks that we find no highways or monuments or garbage dumps or plastic baby dolls from their era.  Yet they were sorry enough for their poor sorry brethren that they let slip a few key ideas in mathematics or architecture or something.  Because no evidence can exist for the idea it is not falsifiable, which means it's not really science, except maybe as hypothesis.  Of course, we still have no real idea whether our planet is just an ornament in the highway median of some ultimate galactic civilization, protected from the truth by a few low-grade holograms.  And so forth - it leads smoothly to solipsism and related philosophical black holes.
 * That said, of course, there is doubtless much that our ancestors were capable of that we don't know. Shorelines from the Ice Ages are under water and only beginning to be explored.  But the key here is, you don't need to be able to build spaceships to know how to do calculus.  The ancients could have developed lots of clever math and lost it without leaving much of a trace.
 * I fear that too often such arguments are meant, consciously or otherwise, to denigrate the achievements of certain races. When people say that the native Central Americans couldn't have built pyramids without contact from Egyptians, or aliens, or gods, or predecessors, what they're saying is that they are what?  Too stupid to pile rocks together?  It reflects a lack of awareness of how extensively the New World was populated before smallpox and other diseases decimated their civilization.  The reason why such races in such early times could do things like modern man can, is that despite economic and educational disadvantages they were our equals in intellect and character. Wnt (talk) 19:31, 21 April 2012 (UTC)


 * I am also not kidding when I say that Youtube is a haven for nutjobs and conspiracy theorists. You are more likely to get a good scientific treatment by asking random people on the street.
 * The problem with theories like this is that they seem plausible if you look at them in isolation, and only take the evidence presented. This theory will conveniently omit all the evidence that their theory is physically impossible. The idea that a pole shift could have made Antarctica habitable as recently as 10000 years ago is absurd and scientifically impossible (I suggest you read the articles True polar wander and geomagnetic reversal, because many people don't actually understand what a pole shift really is). Additionally, the Antarctic ice caps are demonstrably millions of years old. If you're interested in a balanced treatment of this theory, I'd read the articles I linked (especially true polar wander). If you're interested in wild speculation or downright foolishness, I'd try Youtube. Don't think I'm being condescending: the people in the linked interview make their prejudices apparent right off the bat. They feel oppressed because the scientific community takes their theories for what they are: wildly speculative, based on thread-bare evidence, and based on near-impossible to impossible assumptions. All this when their "evidence" is easily explained away by coincidence and human nature. "Suppression of knowledge" is a phrase only used by people who don't care about scientific proof. - Running On Brains (talk) 19:41, 21 April 2012 (UTC)


 * See also Crackpot index; Graham Hancock's books (of which I have actually read several) all rank fairly high. What makes Hancock so engaging is that he saves his crazy for the last fifth of the book or so.  He does a good case of gathering a bunch of seemingly innocuous evidence without letting you know what he's gonna do with it.  Once you've bought into his evidence, he throws in the "The aliens did it" bit at the end (or whatever crackpot theory he's proposing).  Since the first part of the book is usually so artfully crafted and well written, it makes it easy to get trapped in it, and then fall for his wacko conclusions.  Of course, Hancock's Fingerprints of the Gods is basically a rehash of Erik von Daniken's Chariots of the Gods, which pretty much established the genre of this type of work.  -- Jayron  32  20:13, 21 April 2012 (UTC)


 * I can tell you're not kidding because youtube is where i heard about the book, in fact its from Joe Rogan, and thats what amaze me. I just asked this on ref desk because i already know about ancient aliens and other similar stuff, i just know that some, if not most of you guys can tell me what other interesting things to look for. — Preceding unsigned comment added by 203.112.82.128 (talk) 21:12, 21 April 2012 (UTC)


 * One alternate theory was proposed in response to a contest to come up with valid theories in violation of Occams's Razor. In it, the Earth is inside-out (a hollowed out sphere), with us living on the inside, and as we approach the center of the sphere (our sky), atoms become steadily smaller, until infinitely small.  The theory didn't explain why this happens.  However, the effect apparently would cause a visual distortion making it appear the Earth is how we think of it.  StuRat (talk) 14:08, 22 April 2012 (UTC)

See my userpage. Count Iblis (talk) 01:36, 23 April 2012 (UTC)

Vactrain effects
What effects, if any, would a Vactrain have on the human body? And how exactly would passengers be let off the train? 64.229.204.143 (talk) 19:57, 21 April 2012 (UTC)


 * As long as the train was kept pressurised, it would have no effect on the body. When you fly in a modern airliner, the air pressure around the plane is very low indeed, but because planes are reasonably airtight, and air pressure is maintained by air pumps on board, all most passengers experience is ear popping. Indeed, the Vactrain should be safer than a plane in this respect, since in an emergency you can simply flood the tunnels with air. The way the passengers get off is that once the pipes operate on an airlock type system - when the train is in the station (or on the approach to it, since there's no need for vacuum tunnels on the low-speed tracks in stations) the ends of the tunnel simply open to let the train out, and close behind it. There are also more advanced ideas for how to seal the end of the tunnel - the StarTram concept for instance uses what's called a "plasma window" - electrically charged gas controlled with a magnetic field to form a "curtain" that seals the tunnel to air but lets the train can pass out. Smurrayinchester 21:10, 21 April 2012 (UTC)


 * I can see a few problems:


 * 1) Air exchange with the environment is normally used in a train to keep the indoor air fresh. This can't be done while in a vacuum.  They may not even want to vent air from the train because that would steadily lessen the vacuum in the tunnel.  So, they would then need to recycle the air in some way.  Since this is rather expensive, I bet they would do the minimum required, resulting in stale air (low oxygen, high in carbon dioxide and pollutants).


 * 2) Getting out in an emergency would have to be slower. Even if they were willing to flood the tunnel with air, this would take a long time, if not done with explosive force.  So, if there's an emergency requiring immediate evacuation, like a fire, many could die.  The alternative of supplying space suits for all would be prohibitively expensive.  Perhaps they could evacuate everyone to one car, and disconnect from the burning car, though.


 * 3) If there's a hole blown in the train, say by a terrorist, this could lead to explosive decompression.


 * 4) A slow leak could result in low air pressure, causing people to pass out and eventually die. This occasionally happens on planes.


 * 5) The higher speeds allowed by such a train pose their own increased risks. A collision, for example, would become more deadly.


 * So, such a train would be more dangerous than a train in normal air. StuRat (talk) 13:56, 22 April 2012 (UTC)
 * You wouldn't need to disconnect the burning car. Once it is evacuated and sealed off, you can just vent the air, which would put the fire out instantly. --Tango (talk) 17:25, 22 April 2012 (UTC)


 * That would fill the tunnel with smoke and deposit soot everywhere, but I suppose that's OK. StuRat (talk) 01:54, 23 April 2012 (UTC)


 * Also, if you're flooding the tunnel with exterior air, it could be done with explosive force—you're doing it very infrequently, so that would become a possibility. Whoop whoop pull up Bitching Betty 17:57, 22 April 2012 (UTC)


 * When the shock wave hit the cars it would blow them apart, or at very least bounce the passengers around inside. A 10 PSI difference hitting the end of the car, let's say 10 feet by 10 feet, or 14400 square inches, would exert an instantaneous 144,000 pound force on the end of the car.  StuRat (talk) 01:54, 23 April 2012 (UTC)


 * Just 10 PSI? That is easy to withstand! Whoop whoop pull up Bitching Betty 18:38, 23 April 2012 (UTC)

Biomorph-producing fractal formulas
I need some biomorph producing fractal formulas... does any one know any? except the mandelbrot, and I don't want it to be just interesting, but really look like biomorphs....--Irrational number (talk) 20:25, 21 April 2012 (UTC)
 * This is a very vague question. Who judges how biomorphic a certain image is ?! Nevertheless, you may be interested in L-systems, which can broadly generate life-like patterns. Also note that "fractal" formulae are not necessary for the generation of "biomorph" patterns. See e.g. reaction-diffusion systems. In particular, If you are interested in some of the mathematical properties of biological pattern formation, I highly recommend "The Chemical Basis of Morphogenesis", (Turing, 1952) . SemanticMantis (talk) 01:52, 22 April 2012 (UTC)
 * Turing's patterns are not fractal (they are spots and things like that), but the L-system reference is a good one. Mandelbrot's book contains a bunch of examples.  Our article on fractal broccoli might also have a helpful pointer or two. Looie496 (talk) 02:01, 22 April 2012 (UTC)
 * Indeed, Turing patterns are not fractals. That is why I said ""fractal" formulae are not necessary for the generation of "biomorph" patterns." before I suggested the other links. I suppose I should have made the distinction more clear. SemanticMantis (talk) 03:20, 22 April 2012 (UTC)
 * I didn't say that fractals necessarily make biomorphs, I'm looking for formulas that do make such things. I've been doing some "experiments" in "ultra fractal" program seeing different formulas and looking for those that resemble biomorphs, which, although interesting, was not very successful. I also found an article in the references of the pickover stalk article, which seemed to have some biomorph producing Iteration formulas, but I tried them and they were all blank.So, I wanted to try finding some here...--Irrational number (talk) 10:10, 22 April 2012 (UTC)

Any thoughts?--81.31.188.28 (talk) 10:41, 23 April 2012 (UTC)