Wikipedia:Reference desk/Archives/Science/2009 July 19

Science desk
< July 18	<< Jun | July | Aug >>	July 20 >

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

July 19

Who was the first man to masturbate in space?

Strange question, I know - but this came up (no pun intended) during a discussion of the mechanics sex in space with some cow-workers today.

Presumably, the guys on long-term space station missions have jerked off in space (probably though boredom as much as anything else) - but is it on record as to who the first guy to 'boldly cum where no man has cummed before' actually was? I'd be very surprised if NASA or the Russians hadn't asked one of their spacemen to try having a wank during a mission to see if it worked up there.

I have a feeling that this has been asked before on here but I can't find anything in the archives. --Kurt Shaped Box (talk) 02:12, 19 July 2009 (UTC)

What moo-ved your "cow-workers" to consider this question? Edison (talk) 02:46, 19 July 2009 (UTC)

FWIW, there was an article about the moon landings in a newspaper that someone was reading. Someone else glanced at it, frowned and asked "I wonder if anyone's ever had sex in space?". Just one of those random things, I guess. Once the talking point had been raised (again, no pun intended), it went on from there... --Kurt Shaped Box (talk) 00:48, 20 July 2009 (UTC)

This is slightly off-topic, but why would ejaculation in weightlessness be any different than on Earth? I mean, the "internal ballistics" should be entirely the same - the neurons fire, the muscle contracts, the cosmonaut comes. There is no "gravity assist" involved :) . As for, erm, who came first - I really don't know. Sorry about that. --Dr Dima (talk) 03:02, 19 July 2009 (UTC)

There is the school of thought, is there not, that it is impossible to get/maintain an erection in zero gravity? --Kurt Shaped Box (talk) 00:49, 20 July 2009 (UTC)

Why would it be impossible? And how would you know -- have you actually tried this in zero gravity? :-D 76.21.37.87 (talk) 01:32, 20 July 2009 (UTC)

I'm not claiming that it's impossible! ;) --Kurt Shaped Box (talk) 02:38, 20 July 2009 (UTC)

These [1] [2] suggest, as I personally expected, if it has happened we don't know who or when. Nil Einne (talk) 03:42, 19 July 2009 (UTC)

Is it too much to ask for a little decorum here? Phrases like 'boldly cum' chafe my sense of decency, and I don't mind telling you. Vranak (talk) 04:41, 19 July 2009 (UTC)

It's a fair enough point. My apologies if you were offended by my choice of words. --Kurt Shaped Box (talk) 00:48, 20 July 2009 (UTC)

While you're at it, I'd like to know who was the first woman to masturbate in space. —Preceding unsigned comment added by 82.43.91.128 (talk) 08:10, 19 July 2009 (UTC)

Mostly likely, anyone who has masturbated in space (and I admit it's not unlikely) did so in a private, unmonitored location and does not discuss it. That said, considering that zero gravity has been simulated for films by using a jet in free fall, it is possible that someone has or could produce public pornography in a zero-gravity environment - but this would be extremely expensive. Dcoetzee 08:16, 19 July 2009 (UTC)

It's been done, albeit on a limited scale. The Uranus Experiment (safe-for-work description) features a brief scene that was filmed aboard a Russian parabolic flight. TenOfAllTrades(talk) 13:24, 19 July 2009 (UTC)

It would take a brave couple to try to perform pornographic acts on the Vomit Comet. However, there are people who have been filmed having sex while skydiving, so I guess anything is possible. Looie496 (talk) 16:50, 19 July 2009 (UTC)

A plaque left on the Moon by the first two Apollo astronauts to spend time there said "We came in peace for all mankind." I never before considered whether it might have been literally true. Edison (talk) 00:08, 20 July 2009 (UTC)

Just to link to it, we do have a sex in space article. Nothing on solitary sex in space, alas. Having seen at the National Air and Space Museum the monstrosities that are space toilets, I can hardly think it would be a very, err, convenient place to do such a thing. --98.217.14.211 (talk) 01:14, 20 July 2009 (UTC)

Bioavailability of calcium

Is it true that calcium in dairy milk is less bioavailable to humans than calcium in leafy greens? NeonMerlin 03:16, 19 July 2009 (UTC)

No, it's the other way round. See Phytic acid. 95.112.134.175 (talk) 07:32, 19 July 2009 (UTC)

Huh? According to our article, at least, phytic acid is found in the hulls of nuts, seeds and grains. And all of the listed sources of phytic acid are grains, legumes, or seeds. And this source referenced by the phytic acid article gives lettuce and spinach as examples of foods that are devoid of phytic acid. The question was about milk vs. leafy greens, and neither one of those contains phytic acid. Red Act (talk) 08:21, 19 July 2009 (UTC)

Sorry I only scanned the article very briefly. I was told by a doctor that phytic acid was found in lettuce. 95.112.134.175 (talk) 08:34, 19 July 2009 (UTC)

This article says “even when it comes to calcium, the complexes [(salts)] found in leafy green vegetables such as bok choy are absorbed more readily than those in dairy foods.” This yogurt manufacturer, not surprisingly, has a contradictory point of view. This looks like it may be one of those questions where it can be difficult to get a clear-cut, unbiased answer. To get a good answer, it will probably be necessary to stick purely to research articles, and even then check to see who’s funding the research, as it apparently is a contentious issue. Red Act (talk) 09:14, 19 July 2009 (UTC)

I don’t want to pay to see the articles I find from Google Scholar, so I’m basing a lot of this post on the little snippets I can see in the search results. But it looks like calcium absorption from most leafy greens (e.g. kale, collards, bok choy, turnip greens, mustard greens, basically anything from the brassica family) is considerably better (40-59%) than calcium absorption from milk (32%). Spinach and watercress, however, are exceptions, since most of the calcium in those is bound up as calcium oxalate. The yogurt manufacturer above, not surprisingly, only lists calcium absorption rates from spinach and watercress, and completely ignores calcium absorption from all those non-oxalate leafy greens. Red Act (talk) 10:01, 19 July 2009 (UTC)

Bizarrely, our calcium in biology article doesn’t list the calcium content of a single leafy green, even though calcium absorption from most leafy greens is better than from milk, and the article lists lots of foods with far less calcium per serving than leafy greens, according to the reference the article cites. E.g., according to the reference, a cup of cooked collards has more calcium than a cup of skim milk (357g vs. 306g)! I guess that article’s editors have an anti-leafy-green bias. Red Act (talk) 11:34, 19 July 2009 (UTC)

The article doesn't list how much calcium there is in milk either (only milk powder, cheese and human milk) so I guess you could say it also has a milk bias Nil Einne (talk) 14:57, 19 July 2009 (UTC)

Yeah, that whole section needs some serious work. Horse meat? I’ve started working a little on a more carefully chosen list, but it’s tempting to just delete that section, since that haphazardly chosen list isn’t a whole lot more valuable than just a link to the very thorough reference. And that list takes up an unpleasantly large fraction of what is otherwise a reasonably well-written article. Red Act (talk) 15:29, 19 July 2009 (UTC)

Not only has that list never even listed regular milk, the list originally contained “vaccine”! Clearly there’s some kind of pro-vaccine, pro-horse-meat bias going on! Red Act (talk) 16:16, 19 July 2009 (UTC)

Horse meat? I think the author must've been a Cossack.  :-) 76.21.37.87 (talk) 00:41, 20 July 2009 (UTC)

I believe the issue with milk and calcium is that there isn't as much magnesium in milk as is required for healthy human functioning. You can absorb all the calcium you want from food but without enough magnesium it doesn't profit you. Vranak (talk) 19:39, 19 July 2009 (UTC)

One obvious consideration is the quantities a person is likely to consume daily. I can easily imagine someone drinking 250g of milk a day, but I suspect far fewer people take in 250g of bok choy (or whatever), even if it may be healthier in a number of ways if they do. In other words, regardless of the concentration and bioavailability, it doesn't mean advocating something else as the best source of calcium in the real world is a good idea. Depending on why you want to know this may or may not be relevant Nil Einne (talk) 20:25, 19 July 2009 (UTC)

My statements above that that list is “biased” were mostly in jest. That list isn’t really “biased”, so much as just being very poorly chosen. However, this statement seriously is showing an unintentional cultural bias.

In most parts of the world, most people don’t generally drink milk as an adult, in large part because they lack the mutation on chromosome 2, that’s present in most people of northern European descent, that makes a person lactose tolerant. For example, in China, despite recent growth in milk consumption due to things like “school milk” plans, the per-capita daily consumption of milk only comes to about 37g. (Take the 17.5 billion liters here, and divide by the 1.3 billion people in China.) Furthermore, that 37 g/day is presumably disproportionately consumed by young children, who have not yet lost their ability to produce lactase. Bok choy, meanwhile, is a popular dish in China. So it’s quite likely that in China (which includes more people than all of Europe and North America combined), more adults consume 250g of bok choy on any given day than drink 250g of milk. Red Act (talk) 01:55, 20 July 2009 (UTC)

I'm not personally convinced that many people consume 250g of bok choy in China. There are a lot of different vegetables in China and while bok choy may be popular it's not the only one (250g would be say 150g for dinner and 100g for lunch which is a fair amount). Although it depends whether you include stuff such as choy sum etc too I guess, I personally don't. They may not consume 250g of milk either but that doesn't mean they consume 250g of bok choy. On the other hand you're right that they probably get a greater percentage of their calcium from sources other then milk, particularly vegetable source and I apologise for neglecting to mention this. Remember however that the 37 g/day if 'disproportionately consumed by young children' is not going to be 37 g/day if the ratios are disproportionate. It could easily be 100 g/day for the the children but 10 g/day or less average for the adults. And remember that adequete calcium is particularly important at that stage of life. But still it's fair to say milk is unlikely to be the primary source of calcium. Ultimately though, my main point it still accurate. The bioavailability issue is somewhat irrelevant when it comes to public health consideration IMHO. If for genetic and cultural reasons milk is a significant source of calcium then the fact that calcium in bok choy is more bioavailable in bok choy (or whatever else) is probably irrelevant. Similarly if milk consumption is low then advocating it as the best source of calcium is not necessarily the best idea and the bioavailability is still largely irrelevant.

On the more general point of lactose intolerance, it's actually an interesting issue. For example our article says "Some studies have found that most Japanese can consume 200 ml (8 fl oz) of milk without severe symptoms (Swagerty et al., 2002)" and "Lactase persistence, allowing lactose digestion to continue into adulthood, is a dominant allele, making lactose intolerance a recessive genetic trait." and "For healthy individuals with secondary lactose intolerance, it may be possible to train bacteria in the large intestine to break down lactose more effectively[57] by consuming small quantities of dairy products several times a day over a couple of weeks" and "Some studies indicate that environmental factors (more specifically, the consumption of lactose) may "play a more important role than genetic factors in the etio-pathogenesis of milk intolerance",[11] but some other publications suggest that lactase production does not seem to be induced by dairy/lactose consumption.[58]". In other words, it's a lot more complicated then something like '90% of Chinese can't drink any milk'. I don't know about in China (although I believe there is great growth in dairy consumption, e.g. [3] and [4] albeit this has probably been very negatively affected by the melamine scandal), but while growing up in Malaysia I found there wasn't actually much discussion about lactose intolerance despite the fact it's obviously must be fairly prelevant (and proven by [5]). Milk consumption is rather low compared to many Western countries but there is advertising and an increasing consumption, and milk is sold in most supermarkets and many convenience stores and also sometimes in secondary schools. Most doctors will I presume quickly diagnose any lactose intolerance related problems and there is likely general awareness but it's not actually some that gets great consideration. However cultured milk drinks are very common and probably one of the key reasons for an increase in milk consumption and these would I presume generally have significantly lower lactase.

Nil Einne (talk) 05:49, 20 July 2009 (UTC)

I’m surprised you think that there wouldn’t be too many people in China who would eat 250g of bok choy in one day. 250g doesn’t seem like all that much bok choy to me. I happen to have some baby bok choy in my fridge right now. It’s just 4 of those little heads, they weigh 278g, and I will almost certainly eat them all in one meal. In fact, pretty much every day I eat a bowl of vegetables more than twice that mass (567g) in one sitting. I guess it’s a matter of perspective; I’m 193cm tall, and I have a different idea of what a “lot” of food is than a smaller person would.

Just to clarify something, it looks like you might possibly be thinking that I thought that there would be a lot of people in China who eat an average of 250g of bok choy per day. Clearly, Chinese cuisine is so wonderfully broad that it’s hard to imagine too many people choosing to narrow their diet to bok choy to that extent. My point was just about the events on any given day, not about an average daily bok choy consumption rate. E.g., my presumption is that the number of people in China who eat 250g of bok choy on July 20, 2009 will be greater than the number of people in China who drink 250g of milk on July 20, 2009. Red Act (talk) 08:09, 20 July 2009 (UTC)

"However cultured milk drinks are very common and probably one of the key reasons for an increase in milk consumption and these would I presume generally have significantly lower lactase." -- Another factor to consider is that they contain bacteria that digest lactose and so, once consumed, will actually help the person digest lactose and thus overcome lactose intolerance. FWiW 76.21.37.87 (talk) 03:57, 21 July 2009 (UTC)

250g of bok choy does sound like a fair amount to me. I don't know that much about Chinese diets in China, but from my experience with Chinese diets in Malaysia, it expect them to generally be significantly more carbohydrate laden then many Western diets. (The amount of rice you get in most Western Chinese meals is miserly.) Of course they are also likely to contain a much greater proportion of vegetables to meat then many Western diets. Although I have to say 576 g of vegetables seems quite high to me unless you're thinking of a salad and I'm not sure how common that is in China (I don't think it's likely to be common for Han Chinese, but not sure about others). And one thing I think we'll both definitely agree on, they'll generally be a lot smaller then Western diets. And while perhaps I didn't explain this very well, I think a key point is what percentage of their vegetables are bok choy? I would presume many will contain a greater variety of vegetables then bok choy (and as I've said it also depends on what you mean by bok choy). So while undoubtedly there will be people who consume 250g or more per day, the number of people is very difficult to even guess IMHO. I.E. in terms of the second issue you raised (or your original point which you're right I didn't really understand), I think it's extremely difficult to guess. It depends a lot on how milk consumption is distributed. I looked for a median consumption figure but couldn't find any. My guess is there are a large number of people who don't drink any milk (which is still I believe a relatively high value product) significantly lowering the average. Therefore the number of people who do drink 250g/day would be higher then the figures may imply. Let's not forget 250g/day isn't much. A (largeish) glass of milk, a small carton or bottle, perhaps 2 cultured milk drinks (well depending on the size although I couldn't find what percentage milk an average cultured drink is, I would presume it's fairly high). There may also be a seasonal factor to the vegetables (and perhaps to the meal sizes). Given the great uncertainty in both areas, I do think it's rather hard to say which will be higher. You could easily be right, indeed perhaps it's fair to say you're likely to be right but I don't think we can say that with any degree of certainty. In the long term I do expect that the number drinking 250g/day will exceed eating 250g/Bok Choy both because of the current trend of increasing milk consumption and because I would expect Bok Choy consumption to decrease (as consumption of meats increases and also more 'exotic' vegetables). P.S. Of course this concentration of Bok Choy is a bit arbitrary since the original quote was a lot more then bok choy but bok choy was all I mentioned so :-P P.P.S. In light of the Drew Smith thing, I've resolved to try and say this sort of thing more You're right about one thing, it was silly of me to mention the 250g thing without thinking properly since it is likely as you've suggested that in a number of places people's consumption of high calcium non milk sources (including bok choy but also a lot of others) greatly exceeds their consumption of milk. Nil Einne (talk) 17:43, 27 August 2009 (UTC)

Reflecting light vs color

I'm shining a green laser onto flat surfaces. I know from experience that the light that reflects back into the eye is a lot dimmer on a black or dark surface. What color would reflect the green laser the best? White seems like a likely answer but what about a green surface of the same hue of the laser? -- penubag  (talk) 04:50, 19 July 2009 (UTC)

If you want a very non-quantitative, crude, rule-of-thumb answer, then white would be your best bet. White reflects all or most of the visible spectrum quite well, so you have little (however, still nonzero) chance to hit an absorption spectral line with your laser wavelength. You are right assuming that green surface reflects green light better than red or blue surface; but "better" does not mean "well", and green is not a single wavelength. So I'd choose white over green if I were you. Quantitatively, on the other hand, your question is unanswerable as posed. The problem is, we only have three types of color receptors (cones) in our eye, but infinitely many distinct wavelengths in the visible part of EM spectrum. Thus, infinitely many different combination of wavelengths produce the exact same color percept in a normal healthy human. In other words, many different surfaces with different absorption spectra will look the same shade of green under the same light source. And this tells you very little about the reflection coefficient at the precise wavelengths that your laser emits. Hope this helps. --Dr Dima (talk) 05:17, 19 July 2009 (UTC)

IMPORTANT: please NEVER experiment with reflecting a laser into your eye. A reflected laser light can still damage the retina very efficiently and permanently, and some of the damage does not become apparent until much later. Just don't do it. --Dr Dima (talk) 05:23, 19 July 2009 (UTC)

Thank you very much for that answer, you explained it very thoroughly.

Is reflected light from a laser onto sheet of paper dangerous? My particular laser is a Class 3B. From the Laser_safety article, it says, "A Class 3B laser is hazardous if the eye is exposed directly, but diffuse reflections such as from paper or other matte surfaces are not harmful." My friend's laser is 10x more powerful and can pop balloons and burn skin under exposure but I never thought anything of it. -- penubag  (talk) 05:48, 19 July 2009 (UTC)

You are welcome. And, regarding laser safety, Class 3B can definitely cause permanent eye damage. Reflection from a surface is not necessarily much less dangerous than the direct exposure, for two reasons. First, even when the surface looks matte, it is hard to judge by eye how much light is reflected into any direction; a significant portion of the beam may still undergo specular reflection, depending on the local surface conditions. Second, it is impossible to control all reflections; not even in the lab, and definitely not at home. In any home there always are reflective surfaces around (mirrors, windows, cups, jars, polished metal handles, your wrist-watch, etc.) and, inevitably, laser will be reflected off those surfaces and into your eyes every once in a while. So doing this kind of home experiments with a Class 3B laser is not recommended to say the least. However, it may be a very good idea for a science project, provided (1) a proper eye protection is used whenever required, (2) laser beam travels in a horizontal plane that is substantially lower than the eye-level of the shortest of the participants, and (3) no-one EVER lowers his head to the level of that plane when the power is or may be on. The reflected light level can - and should - be measured with a photodiode or a similar device, and NEVER with an eye! By the way, using a photodiode you can perform the measurements with and without an Integrating sphere to measure total reflection and specular reflection, respectively. --Dr Dima (talk) 07:18, 19 July 2009 (UTC)

Maybe the laser saftey article should be written -- penubag  (talk) 21:18, 21 July 2009 (UTC)

It exists! Laser safety (note spelling). 70.90.174.101 (talk) 05:57, 22 July 2009 (UTC)

The color of a surface is a direct indication of the colors it will reflect best. A leaf is green because it's absorbing the other colors. Your light would be best-reflected by a material that's exactly the same color as the laser. Of course there are other factors, such as the smoothness of the surface (a rough surface would scatter light in many directions). IIRC, few materials will reflect 100%. It's not an easy question to answer, and it can't be answered completely without intense quantum calculations, if at all. Twang (talk) 22:39, 19 July 2009 (UTC)

White is probably better than a surface the same color as the laser - mainly because it's exceedingly difficult to make a material that has that exact color - where there are plenty of naturally occurring materials that are very bright white. The best answer is a surface that's a really good mirror - which has no "color" (in the conventional sense) at all...but it somewhat depends on what you need the answer for. SteveBaker (talk) 23:14, 19 July 2009 (UTC)

I know, but I said what if the exact color could be attained. -- penubag  (talk) 21:18, 21 July 2009 (UTC)

firefly

Recently while walking by a graveyard a friend noted that the fireflys looked like souls rising from the graves. It did look like they moved in a generally upwards direction. Tonight I observed the flight paths of fireflys around dusk at a cook out in northern Virginia. As I watched I noticed that in general they would light up as they moved upward at least nine out of ten times. It seemed that their flight paths would involve an intentional drop in elevation so that they could rise from a near standard elevation at each lighting. To be more exact they would hover fly laterally to a point in space dip at an angle, hover, than light as they moved up ending well above their flash point and sometimes hovering before moving laterally to a new location. I don't remember fireflys doing this when I was a child in Maine; in fact I remember many fireflys lighting up as they moved in lateral directions looking like zig zags. But that was a few years back and my memory may be bad. I was wondering if anyone knew anything about firefly behavior and could explain the correlation between moving up and lighting up?--OMCV (talk) 04:57, 19 July 2009 (UTC)

The most common firefly species in eastern North America is the Big Dipper (Photinus pyralis) [6], which flies in a J-shaped trajectory, lighting on the upswing, making it look like they're all flying upwards. Acroterion _(talk) 15:27, 19 July 2009 (UTC)

Link to the Washington Post article on why this is a good year for fireflies (lightning bugs in the mid-Atlantic) [7] and a graphic that describes several species' patterns [8]. Presumably, the Big Dipper wasn't common in Maine and a species with a different pattern prevailed. Acroterion _(talk) 15:42, 19 July 2009 (UTC)

Sorry I don't have a scientific explanation, but this reminds me of Manichaeism#Cosmogony. In some other article that I can't find now I have read that (according to this believe) the light is collected by the moon and transfered to the sun. A more darwinistic explanation (well, it's a guess) is that when trying to find a mating partner many kinds of animals try to show vitality by doing costly things like buying a luxury car (on credit) of flying steeply upwards. It's only natural that they shine a light on the ups and not on the downs. 95.112.134.175 (talk) 15:29, 19 July 2009 (UTC)

Each species exhibits both distinct flight patterns as well as blinking patterns. Only the males fly -- the female climb stalks and trees and blink to the males to attract them for mating, or lunch. It has been documented (from a Tuesday Science section, that's all I can remember) that females sometimes blink the wrong way to catch males from other species for lunch. DRosenbach ^{(Talk | Contribs)} 19:54, 19 July 2009 (UTC)

How do you know they "looked like souls" - you know what a "soul" looks like? SteveBaker (talk) 23:09, 19 July 2009 (UTC)

I'll have to ask my friends how she knows what souls look like Steve. Until then thanks for all the info and links every one, much appreciated.--OMCV (talk) 01:52, 20 July 2009 (UTC)

In his magisterial Introduction to the History of Science, George Sarton, in the course of recording his amazement that Dante appears to have been the first imaginative writer in European history to mention fireflies (Vol. 3, Part 1, pp. 487–88), remarks that "one would expect them to impress any poetical and imaginative mind". He goes on to recount an exchange he had with D'Arcy Wentworth Thompson on the subject, in which the latter suggested that there may have been, in ancient times, a superstitious aversion to mentioning both butterflies and fireflies, they both having been viewed as dead men's souls. (A butterfly was ψυχή, psyche, in ancient Greek.)

One of my own favorite "poetical and imaginative" lightning-bug passages is in Vladimir Nabokov's Ada:

The males of the firefly, a small luminous beetle, more like a wandering star than a winged insect, appeared on the first warm black nights of Ardis, one by one, here and there, then in a ghostly multitude, dwindling again to a few individuals as their quest came to its natural end. Van watched them with the same pleasurable awe he had experienced as a child, when, lost in the purple crepuscule of an Italian hotel garden, in an alley of cypresses, he supposed they were golden ghouls or the passing fancies of the garden.

—Deor (talk) 03:23, 20 July 2009 (UTC)

Needles on the skin

What is the effect of sticking a needle on my skin? Will I release any hormone? --Mr.K. (talk) 10:58, 19 July 2009 (UTC)

Possibly Endorphins. -- Aeluwas (talk) 12:20, 19 July 2009 (UTC)

Depending upon the damage you do, you may also trigger Hemostasis (including Coagulation) and the release of the chemicals involved. Shower of Jagged Steel (talk) 14:32, 19 July 2009 (UTC)

Well, one possible effect is that unless you are very careful about sterility you can get a really nasty infection -- puncture wounds are the worst kind. Looie496 (talk) 16:54, 19 July 2009 (UTC)

They are? Why? Vimescarrot (talk) 22:07, 19 July 2009 (UTC)

For superficial wounds, even if they look nasty, bacteria usually don't thrive all that well, and it is relatively easy for the body to flush any contaminants to the surface. Puncture wounds, if they get infected, tend to form abcesses. If an abcess gets large, the immune system has difficulty keeping bacteria in it from growing, which can ultimately result in sepsis, which is generally fatal if not very aggressively treated. Looie496 (talk) 22:28, 19 July 2009 (UTC)

As an aside, is it the same with gunshot / shrapnel wounds? (I'm pretty sure that those tend to get infected too.) 76.21.37.87 (talk) 00:34, 20 July 2009 (UTC)

Bullets and shrapnel tend to be pretty clean, so the only bacteria that get into a wound tend to come from the clothing or body surface, but even so, yes, those sorts of wounds can easily produce life-threatening infections. Looie496 (talk) 00:44, 20 July 2009 (UTC)

The above is why animals which fight with domestic cats (other cats, mostly) get a lot of abscesses: the cat's teeth are like needles. --Sean 14:58, 20 July 2009 (UTC)

What's the resolution of our eyes?

Is there anyway to measure the resolution of the human eye in the same way we do for a TV? --Cameron Scott (talk) 11:33, 19 July 2009 (UTC)

Eye#Acuity has information relevant to your question. Dauto (talk) 12:06, 19 July 2009 (UTC)

Better to compare the resolution of the human eye to some camera or eyesight of other animals than to a display. Edison (talk) 15:21, 19 July 2009 (UTC)

The reason it's hard to find numbers for this is because there really isn't any region with constant resolution for the eye. The highest resolution occurs at a point at the center of the fovea, and the resolution drops off pretty sharply as you move away from that point. Looie496 (talk) 16:38, 19 July 2009 (UTC)

Also, there is a trade between speed of aquisition and resolution. When we stare at something, our eyes vibrate in order to sample the image at positions between the "pixels" produced by the rods and cones of our eyes. We also see monochrome information (brightness) at about four times the linear resolution at which we can see colors. Hence you hear numbers in the 2000 to 8000 pixel region - with 4000 probably being about right. SteveBaker (talk) 23:06, 19 July 2009 (UTC)

The foveal resolutiojn is the relevant number. We automatically look at and area of interest or saliency.I seriously doubt the assertion of "eyes vibrating to sample positions between pixels." Edison (talk) 00:06, 20 July 2009 (UTC)

Hmm. The two facts Steve mentioned are correct, but it's unclear whether they're causally related. It is definitely true that our eyes vibrate, or at least jiggle, constantly, in what are called microsaccades. It's also a fact that there are numerous tasks where we are capable of detecting spatial structure considerably finer than our smallest receptive fields -- this phenomenon is called hyperacuity. But as far as I know it hasn't been established that microsaccades are involved in hyperacuity -- unless I've missed something, which is always possible. Looie496 (talk) 05:46, 20 July 2009 (UTC)

Well, correlation isn't causation - but I'm sure of one part of this: if the muscles that perform the microsaccades are slowed down (eg because your eyes are tired or because you've recently been aneasthetised or something) then your vision is blurry. Also, it's hard to imagine any other means by which we could have visual acuity that's better than the underlying resolution of the rod/cone cells - and it's exceptionally difficult to imagine any other reason why we'd perform these microsaccades. FWIW: I've actually built a high-resolution camera by taking many pictures with a rapidly vibrating still-frame digital camera and over-sampling and averaging the in-jittered pictures together - the results can be pretty impressive. SteveBaker (talk) 02:33, 21 July 2009 (UTC)

Super-resolution is a common image processing technique. Vibrations, or dithering, are a class of methods that assist in sub-sample resolution. This is a way to "beat the Nyquist rate" - but what is actually happening is that time-domain signal is being transformed into spatial-domain signal (no physical laws are violated, of course). I would not be surprised at all if there were physiological, biological/psychological versions of these techniques. They are certainly very common in software and hardware signal processing. Nimur (talk) 00:52, 22 July 2009 (UTC)

Long-term storage of water

If one was to fill a 20 litre container with water for long-term storage for use in an emergency which rendered tap water unavailable or unsuitable, would there be a noteworthy risk of something growing in it? Would it be advisable to change the water contained periodically? Would it be advisable to add anything to the water prior to storage and/or immediately before use? ----Seans Potato Business 19:02, 19 July 2009 (UTC)

Try it. Experiment. Smell the water. Taste the water. The ultimate arbiter of whether something is good for you or not is your own body. Vranak (talk) 19:37, 19 July 2009 (UTC)

Well it's a bit problematic if there's a major disaster and you find then the water is not "good for you". Anyway without trying to provide a definite answer, I would consider boiling the water before use, if that's practical. In most cases, energy may be limited so it may not be a good idea to use what you have for boiling water when you can avoid it. You may want to keep some water sterilisation/purification tablets in your emergencies supplies if you can't boil the water. If your household water is chlorinated then if you get fresh water and close and keep the lid tight that may help. Don't use water that has been sitting exposed to the air. Chlorinating the water further may help, but you'd need further research to find an appropriate level so you don't end up with such a high level that if you need it in 1 year you'll have to wait 1 week before you can drink it. P.S. I came across this [9] which may be of interest but I'd look thorough the sources thoroughly before I trust it Nil Einne (talk) 20:13, 19 July 2009 (UTC)

Why a 20 liter container? I find that many juices come in smaller plastic bottles. They are probably good for storage of water for drinking purposes. They might prove more easily transportable. Storage space taken up might be comparable. If some get spoiled for some reason, others might be still potable (and not to mention portable). Bus stop (talk) 20:23, 19 July 2009 (UTC)

If you're concerned about something like a hurricane or earthquake, I think filling a few 5-gallon (= 20 liters) containers with water is a very reasonable idea. As long as they're tightly sealed, I don't see why you would have to change the water more than once a year or so -- nothing is going to grow in an airtight container of pure water. Looie496 (talk) 20:48, 19 July 2009 (UTC)

A google search for "emergency water storage" yields several sites with some good information. I would tend to trust official sites more than the various ask-me sites, since the latter may have been written by non-experts. The FEMA site for example may be a good starting point. Key points include periodic rotation or replacement of your emergency water supply and proper preparation of water storage containers (such as sanitizing containers with bleach). If you are reusing containers, soda bottles are recommended over fruit juice or milk containers because of difficult-to-remove residual milk protein and fruit sugars in the latter. -- Tcncv (talk) 21:01, 19 July 2009 (UTC)

Ignore the "taste it" guy, above; you can't taste cryptosporidium or any number of other waterbourne pathogens, and getting that wrong will kill you. If you must store the water in a large vessel, then you should count on using purification tablets to make sure it's safe. Even if the water is good when you open the vessel, over the days and weeks following that, when you're returning to it (with hands you haven't washed properly) you'll inevitably contaminate it long before it's finished. Don't boil water - what little fuel you have should be used to keep you warm and warming food; boiling every drop you drink will multiply your fuel needs greatly. Rather than a home-filled demijohn, I'd seriously consider stockpiling smaller supermarket-bought bottled water (the cheapest kind, obviously; here in the UK 2 litres costs 13p) which guarantees it's safe and uncontaminated (and being in smaller containers means you don't have all your eggs in one basket). Plus those modest-sized empty bottles have a bunch of re-uses, from storing captured rainwater to being a kind of primitive fuel. -- 87.113.21.118 (talk) 22:11, 19 July 2009 (UTC)

Are you familiar with how rats eat? I imagine not. They take a little bite to eat, wait a while, and if they don't feel bad they go back for more. This approach works well enough for humans as well. Vranak (talk) 01:48, 21 July 2009 (UTC)

Rats are rats. If they die they die. If you're a human you'd rather not die. You are also capable of rational thought, reading, preparation, and a whole load of other stuff a rat can't do. It therefore makes a lot more sense to prepare for a disaster and do things properly both before and after the disaster as a result, rather then hope your water stays fine and rely on your 'taste' and 'not feeling bad' to get you thorough. (Your approach doesn't really explain what you do if you find out your water is bad BTW. Throw it away and squeeze the juice from rats?) Particularly since in a disaster you're not likely to be able to have medical care and as we're discussing here you're likely to have limited fluids and food, and may even need to be able to move quickly, so getting yourself sick isn't exactly a great idea particularly when it's avoidable Nil Einne (talk) 18:16, 27 August 2009 (UTC)

Yes, it's a good idea to change it now and then (say, yearly). And you *might* want to add something to it to discourage anything that might grow in it. You can use tincture of iodine or household bleach for that. Some more advice here and here. Twang (talk) 22:45, 19 July 2009 (UTC)

Original research: If you fill clean glass jugs with tapwater, in a few months they may have green things growing in them. This is not to say either that you might not drink it is thirsty enough, or that you would not get ill if you did. Bottled purified water would go far longer and still not have visible things growing in it. I expect that half gallons of water could be "canned" as could fruit juice, by canning processes in the Ball Blue Book or per recommendations of State Departments of Agriculture in the U.S., and be consumed long afterwards. So: ordinary tap water? Very short shelf life, measured in days or weeks at most. Supermarket bottled water in large containers is pretty cheap, and storing a supply for a week or two drinking needs will not bankrupt most people. Shelf life should be a year or so. If you turn off the main water intake, to prevent introduction of contaminated water if the water plant goes off line, and turn off the gas to the water heater, to avoid explosion if the water level drops too low, you have an emergency water supply of 40 gallons (160 liters or so) in many homes. You should be able to drink this and survive for quite a long time, acknowledging that the little green fuzzies will grow in it as well eventually. Edison (talk) 00:02, 20 July 2009 (UTC)

Why would you trust "Supermarket bottled water" but not tap water? Most cheap brands (and some expensive ones) of bottled water are literally tap water, often not even filtered. APL (talk) 02:39, 20 July 2009 (UTC)

Personal OR here. I've stored tap water for extended periods in large plastic containers Malaysia and New Zealand and haven't gotten green stuff growing in it. I also tend to end up with a lot of water bottles in my room and if I happen to drink one after several months the water tastes odd but I haven't yet gotten sick (not that it's a good indicator). However this is not fresh water but rather water that I've been drinking so is probably fairly contaminated. However the water doesn't tend to have green stuff growing in it. So I'm not really sure what's up with Edison's water supply. (The water supply in Malaysia is sometimes a bit dirty, probably due to poor piping but is usually chlorinated.) Also I suspect the problem is partially as a result of unclean bottles as the bottles tend to keep the taste after you wash them. And you tend to get the same problem if you keep reusing a bottle for several months. As someone mentioned above, this is a big issue if you reuse fruit juice containers, cleaning them out properly. In more general terms, again complete OR here, re-filling a 20L bottle is likely to be a lot easier then ~7 3 L fruit juice bottles. If the refilling difficult causes issues then this is an important considering. If you keep more then 20L, e.g. 40L - 60L then ~13 or 20 of these 3 L containers it likely becomes an even bigger issue. If you would refill a 20L container every 6 months but the 3 L every 2 years, I would suspect the 20L is better. Indeed I would stay the same about pre-bottled water. In terms of durability etc, while you do have redundancy I would expect there's a good chance most of the bottles will go off so I don't see it as necessarily a big benefit. Also as anyone who's ever used one of those large containers would know, and as may be obvious, they are quite strong things. I would expect them to be much more puncture resistant, and also resistant to things falling on them. If you store the 3L containers in durable box this may make up for that of course. This may be significant since if it's e.g. an earthquake it's easy to imagine things falling on the water bottles. On the other hand, you could store the smaller bottles in different locations. I'm not sure about resistance when dropped, the large containers obviously are stronger but also a lot heavier when full. You could try dropping them both from a defined height when full (it may be easier to fill up the 20L after you've taken up to this height) but please take very careful care about where you do this, you could easily kill someone or cause major property damage. However this may not be such a big issue, you shouldn't be storing your bottles that high up anyway. One final issue, if a water tanker is sent during this emergency, it'll be a lot harder to fill up the 3 L bottles then the 20 L bottles on the other hand, it'll be harder to fill up the 20L bottles from say a stream (but you could use a small bottle or something to help). Personally I would suggest something like e.g. one 20L and perhaps a few smaller bottles intended for the storage of water may be best Nil Einne (talk) 06:25, 20 July 2009 (UTC)

How long is this 20L going to last you? for how many people? how long do you expect the emergency to continue? in total breakdown of piped supplies but with civil order (eg pumping station failure), they'd start bringing in tankers in under a day (and shops would be open to buy bottled water). With disorder (eg natural or nuclear disaster) 20 litres won't last you long enough to get out of there, nor will you find clean supplies in a reasonable distance. For some unspecified short-term (2 or 3 day) shortage, the contents of the hot water heater would be the best, though it might not taste very good because of deposits in the tank. - KoolerStill (talk) 09:47, 20 July 2009 (UTC)

OR here, but I used to live in an area where the water was technically safe to drink, but was a dark gray from mineral deposits so we would bring in drinking water in 1 gal milk jugs from someone we knew who had a well (water was not chlorinated). This water never grew any green things although we would only store it for 1-2 months at a time. Googlemeister (talk) 13:36, 20 July 2009 (UTC)

The recommended daily intake of water for an adult male is 3.7 liters...more than that in a hot climate. So if all you do is drink the stuff, 20l will last you about a week if you're alone - much less time if you are a family. You may be able to economise a little in an emergency - but it's not going to last a month no matter what. Of course a typical water consumption rate in the USA is 50l per person per day! However, this fact points the way to maintaining your 20l emergency supply. Simply install a 20l tank between the water main and your home let your household water flow in at the top and out at the bottom - so it's continually replenished. The water in that tank will be replaced 'automatically' in just a few hours of typical domestic use - so it won't have time to turn nasty until after whatever catastropy you are worried about comes to pass. At that point, you'll have 20l of completely fresh water in your tank. It's not going to turn bad in a week - and that's probably about as long as it's going to last you. SteveBaker (talk) 02:24, 21 July 2009 (UTC)

How is the proposed tank better than my present water heater, which holds about 40 gallons or 150 liters, which should have a longer "shelf life" since it has been previously heated to 130 degrees F or 54 C? In a pinch the toilet tank is a good short term source of pure water. Older ones hold about 4 gallons, newer ones considerably less. Just remember not to flush! Edison (talk) 03:44, 21 July 2009 (UTC)

If you have foreknowledge of the coming disaster (say a hurricane) people will fill their bathtubs to have a short term supply of available water. Seems to me like it would not be easy to keep it from getting contaminated though. Googlemeister (talk) 13:40, 21 July 2009 (UTC)

I agree that in an emergency, the hot water tank, toilet cisterns, swimming pools and (when possible) pre-filled sinks and bathtubs are a better source of drinking water...which is why most people don't go putting 20 liter tanks out in their backyards. I guess it all depends on how long this hypothetical disaster lasts. If it's a planetary scale problem - you'd better find a nice lake or have a decent well. But if help is likely to arrive in a week - you should be OK with the hot water tank contents and the toilet cysterns. I'll confess to having 50 one liter bottles of mineral water stashed away for emergencies. I bought them several years ago - and the water is still crystal clear...I presume that means it's still OK to drink. SteveBaker (talk) 15:10, 21 July 2009 (UTC)

OR again but speaking of tanks, it's fairly common to have a cold water storage tanks in Malaysia (well at least Kuala Lumpur). These are large things, depending on the house e.g. my house I think it was 500 litres (half a cubic metre). (Usually stored on the roof, so that if the water supply goes off you can still use it I believe.) In my house we didn't actually use this for drinking but I think it's quite common it is used. Obviously in regular use it's likely replaced at a reasonably high rate. I didn't mention this before but we had major water problems in 1998 where I lived (problems with the pipes and other things I think) which lasted more then a month. We didn't obviously expect it to last that long so didn't conserve the water in the tank that well but it definitely never developed any problems that I recall. Water tankers did come around and while their water was sometimes oddly smelling (not a chlorine smell, there was some suggestion some of them were old petrol tankers) it was fine stored for quite a few days. As mentioned, you do need a lot more then 20L, we had quite a number of large buckets (with lids) and bottles (possibly 10L or 20L) and the tankers would come every 3 days or so IIRC (although you obviously want more just in case). In my school, they brought in a very large (circular) water tank (my guess is at least 1000L, perhaps more) I don't know how frequently they replenish this and don't think I used it to drink that much but it never developed any problems that I noticed. Of course, this water may have been extra chlorinated so it lasted well but I doubt it. Nil Einne (talk) 18:06, 27 August 2009 (UTC)

The usual advice is to change out the water every 6 months, and put in a drop or so of household bleach per gallon of water to kill bacteria. equipped.org and its forums have a lot of info on water storage. 70.90.174.101 (talk) 06:00, 22 July 2009 (UTC)

Coal liquefaction economical at how many dollars per barrel?

I already asked on Talk:Coal liquefaction but I am in a hurry, I need to calculate economic projections, and I really need to know. Please answer wherever is more appropriate and I will make sure a summary appears in the other place. 99.60.2.8 (talk) 21:45, 19 July 2009 (UTC)

According to this article from China (2006??) "International indicators show that if the cost of liquefied-coal oil ranges from US$22 to US$28, the process is still profitable.... Presently, it costs around US$25 per barrel to produce one ton of coal-liquefied oil with three to five tons of coal used in the production." (Does that cost include the environment and transportation?) Here's another, 2007, Bloomberg article (ref'd in the WP Synfuel article). Twang (talk) 23:09, 19 July 2009 (UTC)

Well, if it's only $25/barrel and oil is $40/barrel, then WHY THE BLOODY HELL AIN'T WE DOING IT?! This technology could EASILY gain us energy independence and stop our money from going to the Arab terrorist savages and oil sheikhs, so why not start liquefying coal and start doing it TODAY?! 76.21.37.87 (talk) 00:31, 20 July 2009 (UTC)

According to those articles (which are a bit incoherent), those prices are based on a coal price of under $10 per ton. In the U.S. right now, high-quality coal gets $40-$50 per ton, and the price was much higher before the economic downturn. Looie496 (talk) 02:44, 20 July 2009 (UTC)

Oh, I see, it's the [regional] price of coal driving up the production costs. On the other hand, coal liquefaction don't need high-quality coal -- it works just fine with low-quality subbituminous coal, lignite and even peat if need be. The total efficiency is lower of course, but it'll still work. 76.21.37.87 (talk) 03:08, 20 July 2009 (UTC)

BTW, I've also read (in some research paper, don't remember the name off the top of my head) that they found a way to liquefy solid waste along with coal. The way that it works is they mix the coal with some waste tar (from steel foundries) or plastic or old tires or even garbage and then liquefy it in the same way as if it was just coal Coal liquefaction. If that's true, it can also greatly reduce the raw material cost (cause only half the raw material is coal, the other half garbage), and also have a big benefit for the environment (whatever...) by getting rid of all that garbage and old tires. FWiW 76.21.37.87 (talk) 03:16, 20 July 2009 (UTC)

Coal liquefaction also has large capital costs, and it becomes economical only at quite large volumes. (building that plant would cost a lot, take several years, during which price of crude oil might change almost several times) -Yyy (talk) 18:50, 20 July 2009 (UTC)

The price of crude will be going mostly up during those several years. 76.21.37.87 (talk) 04:50, 21 July 2009 (UTC)

@76.21.37.87 Similar things have been suggested and tried with other "waste materials". (turkey waste, cooking oil etc.) The problem is economics. Once you find a use for waste it becomes a commodity instead of useless trash. All of a sudden you'll get market dynamics driving up the price. 71.236.26.74 (talk) 19:42, 20 July 2009 (UTC)

So if you are smart and have invented a way to turn turkey poo into barrels of oil, the first thing you should do is go to all the turkey farms and offer them a very long term contract to buy the stuff for next to nothing. Googlemeister (talk) 20:02, 20 July 2009 (UTC)

It's usually turkey carcasses - and the real big turkey producers have their own plants...83.100.250.79 (talk) 22:21, 20 July 2009 (UTC)

No one has mentioned it, but coal to liquids is also dreadful from a global warming perspective. You release far more CO2 per barrel than if you were just working with petroleum. Dragons flight (talk) 20:05, 20 July 2009 (UTC)

Yes, indeed. More to the point, the idea that this will be a great technology once the oil runs out neglects the problem that we can't possibly use all of the oil we've got without flooding the planet to a depth of 20 to 30 feet of ocean. We don't need to swap one kind of hydrocarbon for another kind - anything with carbon in it is pretty soon going to have to be off-limits as a fuel source. Coal, natural gas and oil are all going to have to be strictly off-limits. Worse still, because it takes a lot of energy to turn coal into oil - the destruction of the environment caused by doing that will be worse than either burning coal or burning oil! Hopefully, the world will realise this pretty soon (the USA is MAYBE doing something halfway useful) and tax the shit out of fossil fuels of all kinds. At that point, coal liquifaction will be just about the most useless technology imaginable. SteveBaker (talk) 02:11, 21 July 2009 (UTC)

And then how the hell are we gonna get around, how the hell are we gonna get raw materials and finished products where they're needed most?! For that matter, how the hell are we gonna trade with other nations if we ain't got no ships (that run on fossil fuels)?! Your idea to "tax the shit out of fossil fuels of all kinds" is tantamount to throwing away almost 200 years of technological progress (and our American birthright of prosperity and economic leadership) for some crazy environmentalist agenda of limiting global warming, and it's recklessly irresponsible to say the least!!! Well, now that you've exposed your real agenda of having the civilized nations go back to a pre-industrial level of development (which you've disguised up to this point with all that crooked talk about "environmental issues"), maybe we can have a straight, honest conversation about whether such a course of action is good or bad for the USA... 76.21.37.87 (talk) 04:10, 21 July 2009 (UTC)

For the benefit of all others who want to weigh in on this: Note that SteveBaker wrote that "hopefully the WORLD will tax the shit out of fossil fuels", not "the USA will tax the shit out of fossil fuels". I wonder if he's also secretly advocating some supranational system of world governance (either under the auspices of the UN, or as a single "world government")... 76.21.37.87 (talk) 04:16, 21 July 2009 (UTC)

Cargo ships can be run on nuclear power. Railroad trains can be run on electricity. Airplanes and cars will not work without fossil fuels, though. Nuclear ships currently are more expensive than fosil fuel powered ones. Railroad electrification is also more expensive than using diesl power. -Yyy (talk) 05:15, 21 July 2009 (UTC)

Yeah, what about airplanes and cars, SteveBaker? Are you proposing that we all walk to work (oh so many miles in my case, and also in many other people's cases) instead of driving, and that we travel coast-to-coast by train (3 days at the very least) instead of by plane (a few hours)?! And also remember that "cars" also include the delivery trucks that transport merchandise from the regional warehouse (harbor, airport, train station, whatever) to nearby stores; what do you propose as a replacement, horse-drawn buggies?! Obviously no purely electrically-powered vehicle can offer us the same flexibility as a diesel lorry. Plus, keep in mind that electrifying every single railroad line in our country, and replacing all of the steam-powered / diesel-powered ships with nuclear-powered ships will cost hundreds of billions if not trillions of dollars, while creating only a marginal economic improvement (if any). This kind of expenditure with hardly any return on investment could literally sink our economy!!! Now you're getting some idea of what it would mean for our prosperity if fossil fuels are outlawed!!! And also, last but not least, nuclear-powered ships (or indeed any kind of nuclear-powered transport) have their own environmental / safety problems (like, what could happen in case of a shipwreck)... 76.21.37.87 (talk) 05:44, 21 July 2009 (UTC)

I'd say it is a pretty safe bet that by mid century ground transportation will be mostly electric. We already have a proliferation of consumer hybrids. The logical jump to plug-in hybrids will almost certainly be popular in the next decade, which reduces fuel consumption by ~80% for typical commuter use. From there I'd expect to also see a proliferation of light duty all electrics and some form of fuel cell vehicle for heavy duty uses (e.g. replacing diesel trucks). Hybrids are close to economical already, so it wouldn't take much of a refinement in technology or an increase in gas prices to make them a natural replacement for traditional cars. I suspect that similar concerns will also make the other technologies economical in time (especially with either a large carbon tax of a supply driven spike in oil prices). Once it becomes cheaper to go electric than not, it would just be a matter of waiting for electric vehicles to replace traditional ones as cars and trucks naturally get replaced due to old age. However, I am skeptical of nuclear ships, and planes will probably run on hydrocarbons for a long time. That said, we don't need to reduce emissions to zero. If one can remove most of the transportation problem and replace most power stations with renewables and/or nuclear, then we'd buy ourselves many more decades to come up with other solutions. Dragons flight (talk) 06:23, 21 July 2009 (UTC)

And how do you propose to "remove most of the transportation problem", eh?! Besides, you just admitted that the other technologies are supposed to become "economical with a large carbon tax" -- how do you think a "large carbon tax" will impact our economy and our industrial development?! It'll just raise transportation (i.e. gasoline, airfare, freight S&H, etc.) costs to unthinkable levels without making it any cheaper to "go electric"; as matters stand, it's the next-worst alternative to mandating electrification! And speaking of airfare, I repeat my question: WHAT ABOUT AIR TRAVEL?! Do we limit air travel (an indispensable part of our national economy)?! Cause that's what'll happen if a "large carbon tax" is put in place! 76.21.37.87 (talk) 06:43, 21 July 2009 (UTC)

Even for ground transportation, it's probably gonna be cheaper to liquefy coal than to go electric -- all it'll take is to build some coal liquefication plants (those could even be co-located with existing oil refineries and use those to refine the syncrude), which is a lot cheaper than replacing all of the energy-transportation infrastructure, trading in every car and truck in the country, and putting every railroad line under the wires. 76.21.37.87 (talk) 06:51, 21 July 2009 (UTC)

And as for hybrids, remember that they still use gasoline -- just a lot less of it. 76.21.37.87 (talk) 06:57, 21 July 2009 (UTC)

A good plug in hybrid, if regularly charged, is not going to use petrol for commuter transport which is what probably 90%+ of car travel is. Nil Einne (talk) 09:14, 21 July 2009 (UTC)

So how is the progress going to make a plug in tractor trailer with cross country range? Googlemeister (talk) 13:38, 21 July 2009 (UTC)

We call those "trains". They do require some initial investment in infrastructure, but are otherwise entirely possible and reasonably efficient. APL (talk) 20:03, 21 July 2009 (UTC)

They also run on rails, which limits the places they can go (to say the least). For cross-country freight transport, trains are useful, no doubt; for delivery to local retail stores, not so much. 76.21.37.87 (talk) 23:32, 21 July 2009 (UTC)

AEB

Well, we have a pretty clear choice - allow most of the major cities of the world to wind up under 20 feet of water, have most fertile land in the world covered by ocean, massive species die-off, etc...but still be able to drive to work in gasoline powered cars...or we fix it. Fixing it isn't going to be either cheap or easy - but it certainly doesn't mean that we have to revert to a pre-industrial society. (I sure as hell hope not - I make computer games for a living - I don't think I'm well-suited to an agrarian life-style!).

We have to wind up with an electric/hydrogen economy. We need all the windmills, tidal, geothermal, solar and (regrettably - but of necessity) nuclear and hydro power we can scrape together - and fill the inevitable gaps with plant-based (but preferably not corn-based) ethanol and other 'renewables'. We need to agressively pursue energy saving measures where we can. We need to work harder on fusion reactors and consider space-based solar energy plants.

Cars will (by preference) be smaller than they are now and probably plug-in electric - but where longer range is required, hydrogen or perhaps plant-ethanol driven. Not many people need to drive more than 100 miles per day - so commuter cars can be electric - and we can either rent or own hydrogen/ethanol cars for the occasional road-trip. Airline travel needs to be drastically scaled back - we can cut out almost all business travel using the Internet. We need to re-vamp the rail network (which is easy to electrify) and use it to replace trucks and planes where-ever we can. Long distance shipping will become much more expensive - so "cheap" goods from overseas won't be anything like as cheap - but hey - the flip side of that is that outsourcing becomes a lot less attractive when shipping costs more than labor.

Houses, offices and factories need to be better insulated and tools and appliances should be carefully designed to save energy.

I don't think our lifestyle has to change as much as the scaremongers think - and many of the changes are for the better. But the sooner we do it - the less painful it's going to be. When our crops start failing and our cities start to be deluged - it's going to be a LOT harder to fix.

The tricky part right now is to get the whole world to pull together. Europeans are definitely sold on this. There are promising signs that China and the USA are beginning to get active about it - but India is still a major problem.

SteveBaker (talk) 14:09, 21 July 2009 (UTC)

While it would be optimal from a high altitude perspective to do all the things you suggest above - and many of them are or will be done - there are significant difficulties fitting it into the US government budget without a serious carbon tax, which both parties seem to have decided is unacceptable. Instead they have decided to go with a "cap and trade" system in which they give away 75% of the emission credits, completely defeating the purpose and handing the ball to lobbyists and otherwise politically connected companies.

Barring some direct value placed on not emitting CO2, it seems green energy will have to compete in the free market based on economics alone and unfortunately at the moment it does not fare well against established technology - largely coal and oil (wind advocates will tell you different, but they often use selective mathematics). The real impetus to act in this non-carbon tax scenario would be a sustained high oil price. It is perhaps ironic that the companies most hurt by oil's collapse are the green energy startups.

I would also urge you to consider carbon capture. I know it's an unproven technology and it has some real flaws. But there is also potential there to allow us to use the world's massive coal reserves, without irresponsible emissions, for decades if not centuries to come. I'd say it is at least as promising as some of the more outlandish green energy proposals (including a complete "hydrogen economy"). TastyCakes (talk) 14:31, 21 July 2009 (UTC)

The trouble is that we can't bank on carbon-dioxide sequestration to actually work. We also can't bank on fusion power or space-based solar working either. It's also really too late to bet the farm (literally!) on a completely theoretical possibility like that. We MUST proceed on the basis that neither fusion nor carbon sequestration will work - and if either or both DO happen to come through with the goods - then we'll be a much happier planet.

However, let's consider what you say. Suppose for one moment that CO2 sequestration on an industrial scale were to work (not even the most crazed advocates claim you could do it on a small scale). You can't run cars on coal - and even if you could, you couldn't sequester the CO2 on that scale - you can't run airplanes or trucks on coal either. You MIGHT (maybe) be able to do it for very large ships - but not for trains or individual homes.

So even if we HAVE CO2 sequestration at some time in the future - we STILL have to have: Electric cars, all-electric homes and factories, etc, etc. You can't dig up coal, turn it into oil (as our OP suggests) put that into a car and THEN sequester the CO2! So every single one of the things I describe above has to happen at the exact same pace of development and at the exact same rate of funding and commitment whether CO2 sequestrated "clean coal" eventually works or not. So - by all means lets invest in the research - but that cannot, MUST NOT stop us from switching over to an electric/hydrogen/plant-ethanol economy.

FWIW, I think CO2 sequestration is a ridiculous concept - where on earth we put all of the CO2 even if we could sequester it is a completely un-thought-out problem! SteveBaker (talk) 21:14, 21 July 2009 (UTC)

(ec)You just finished advocating electric cars and trains that essentially could run on coal! Further, power plants comprise about 40% of CO2 emissions in the United States (and probably significantly more in places like China). This number would only increase in your proposed electric future. If the goal is to get off of oil, that's one thing, but if the goal is to reduce emissions that's quite another. I hold no illusions over the former, but carbon sequestration could certainly address the latter. Further, I think you misunderstand the problems with CO2 sequestration. There are massive depleted natural gas reservoirs in the United States, indeed throughout the world, which formerly held hundreds of TCFs of natural gas. Huge amounts of CO2 could be injected into them without going anywhere near the fracture pressure which would allow it to escape, and it could be monitored very easily with conventional oilfield equipment. Gas has been in these geological formations at pressure for millions of years, I see no reason to expect it won't stay there long enough for human purposes. The problem is you'd need a massive CO2 collection system since the powerplants are for the most part nowhere near these reservoirs. Perhaps worse, you have to process the gas to separate out other problematic things before you can inject it, and then when you inject it your compression requirements are not insignificant. CO2 is already injected in many oil fields as a type of Enhanced Oil Recovery to maintain reservoir pressure and reduce viscosity. But barring that motivation there is no financial incentive for companies to do it - unless someone (ie the government) is willing to pay them to do it, or to punish them for not doing it.

I am not saying that we shouldn't do all the things you have said. But personally, I'd bank on geological sequestration long before I bet on nuclear fusion or Space Based Solar. And this isn't a game of absolutes - no one is going to click their fingers one day and have us all driving fuel cell cars. Even if only a portion of emissions can be sequestered, it is still more breathing room with regards to the problem as a whole. The question is whether that is the most economically effective way it can be done. TastyCakes (talk) 21:43, 21 July 2009 (UTC)

I'm actually an optimist about carbon sequestration eventually working (though it still needs to be demonstrated). As a society we currently remove 100 trillion cubic feet of natural gas from the Earth each year. Most of that gas has been safely sequestered in the Earth for millions of years. For comparison, we need to be able to store 600 trillion cubic feet per year of CO2 in the ground to totally eliminate all current emissions. That's only 6 times larger than the flux of gas we currently take out. The comparison to natural gas shows that it is possible for the Earth to store massive quantities of gas for geologically relevant intervals. Figuring out how to take advantage of that on a practical level is a massive undertaking, but I don't think it is an impossible problem. Most of the estimates of the potential storage capacity of deep reservoirs suggest that we'd run out of usable fossil fuels before we run out of places to store CO2, though without large scale demonstrations it is hard to know how accurate those estimates are. And of course, potential reservoirs may not exist at all the locations where one might want to have them. Dragons flight (talk) 21:32, 21 July 2009 (UTC)

PS. I realized my comment might be misinterpreted. Steve is right about needing to pursue various options to address the various sources, etc. My comment is meant to focus just on the feasibility of large scale carbon capture and storage when you have point sources to work from. Dragons flight (talk) 21:45, 21 July 2009 (UTC)

My point is that even if CO2 sequestration does eventually work and is 100% effective - all that buys us is 'green' electricity. We STILL have to make the transition to electric cars, hydrogen fuelled ships, trains, airplanes, etc. It makes absolutely ZERO difference to the strategy we should be pursuing right now - at this very minute. If we don't start phasing out gasoline-powered cars/trucks/ships now - then there will still be an alarming number of them still on the roads in 10 to 15 years time. But the risk that this technology doesn't pan out is just too high. We can't rely on it - the stakes are just too high. So by all means let's spend some money to research it - and let's spend some money on fusion and other possibilities too...but we can't let the idea of "Clean Coal" be the answer to all of the problems. Even if it's 100% effective and does everything the enthusiasts claim for it - we still have to overturn the entire fossil-fuel based economy into something based around electricity/hydrogen. SteveBaker (talk) 23:20, 21 July 2009 (UTC)

Electricity won't run cars / trucks / planes, as Yyy correctly pointed out. And as for hydrogen, remember, it don't happen naturally -- it's made using fossil fuels (either natural gas, or in some cases coal gasification. 76.21.37.87 (talk) 23:49, 21 July 2009 (UTC)

Assuming that global warming is actually happening, is actually cause by humans, and can actually be prevented it might make sense to spend the trillions of $ to do something about it, if you can get everyone on board. Change will not be from carbon taxing, it will happen from high oil prices caused by supply shortage. Saw that last summer when the total number of miles driven by Americans dropped off a good bit. Googlemeister (talk) 16:37, 21 July 2009 (UTC)

I agree with your skepticism, I too am not entirely convinced of the global warming story. My supporting a carbon tax is based on the assumption that it is true and is as pressing an issue as presented by its proponents. If it is, a simple flat percentage carbon tax seems the most fair, transparent way to make energy users and producers value any process that prevents CO2 emissions. It gives them the latitude to do whatever is most effective at reducing those emissions, whether that be building a nuclear plant or a wind farm, building more transmission lines to hydro dams or sequestering carbon in some way. Under such a system, the market would determine the most effective means of avoiding emissions. I would take such a market over a group of politicians deciding where to apply subsidies and other market manipulations any day, and it would have avoided throwing huge amounts of money into things like corn-based ethanol, in my view a technology that is utterly pointless except as a tool of political pandering. TastyCakes (talk) 17:09, 21 July 2009 (UTC)

I really think that at this point, if you're still skeptical, it can only be because you haven't read or understood enough about it. There is massive evidence for global mean temperature rise, melting ice - and worse...melting methane clathrates, migration of plants and animals further north than they've ever been, vanishing glaciers...how can those NOT be due to a general warming of the planet?

Even if you don't believe humans are at fault - the consequences will still be cruelly felt by everyone - and it behooves us to try to prevent it if we want anything approximating our present civilisation to survive. I don't care about pointing the blame at nature or at humans. If some theory about the end of a mini-ice-age or the sun producing more energy or a bizarre coincidence of volcanic activity makes you feel happier about yourself - then fine. But even if it IS one of those things - we still need to cool the planet or all of the consequences will still happen. The only safe way we know to do that is to cut down the amount of greenhouse gasses. So - OK - maybe I buy your viewpoint...but we still need to do something about it - that doesn't change a thing!

Worse still - if you think an oil shortage will save us - you really need to crunch the numbers (I've done it right here on this very Ref Desk on several occasions). What those numbers say is that by the time we've burned enough oil to start pushing the prices up to the level where burning the stuff becomes uneconomic - it's already FAR too late. The amount of CO2 produced by burning (say) 50% of the world's present reserves would be more than enough to bring about the worst of the predicted catastrophies. Worse still - if you are completely honest - you'll have to admit that we won't simply burn all of the easy-to-get oil and then stop and switch to something better - because it'll then become economic to mine currently uneconomic oil-shales - and to use that fancy new BP technology that makes liquid fuels from natural gas - or (as our OP suggests) from the liquifaction of coal. So the price of producing CO2 won't get really prohibitive until all of the oil, coal AND natural gas gets used up - and the world's coal reserves are simply massive - so that's death to most of the life on the planet - it's so much CO2 that we'd die of CO2 poisoning, let alone global warming!!

The entire problem with stopping this catastrophy is that simple market forces won't help us at all if the amount of CO2 required to wreck the planet is less than what we'd produce by burning the remaining oil stocks...and it is...MUCH less! So the approach you suggest simply won't work.

If unmodified market forces won't do it - we're left with simply banning the stuff - or taxing it into extinction - or artificially limiting it's use via stuff like cap & trade or some other clever fiscal trick. I'm neither a politico nor an economist - and I honestly don't know (or particularly care) which of those we do...so long as we pick one that works. No matter which it is, the consequences are the same. If we're not going to force people to stop using fossil fuels by simple rule of law - we can artificially push the prices up to the point where other alternatives are cheaper - or we can limit the output of CO2 with a cap and let the market decide who gets to economize. For sure the level of the presently proposed cap won't help much - but a gradual ratchetting down of the size of the cap (how much each CO2-production "credit" represents) is a possible solution. Cap and trade (done right) would entice the open market to spend money on researching and constructing alternative energy sources and ways to cut energy usage. A flat out carbon tax would give the government enough funding to do that research and construction. If you are on the right wing of the political spectrum then you should advocate cap & trade and keep the government out of the business of making green products - if you are on the left then a carbon tax makes sense because it guarantees that the money to do the work will appear and be directed in one coherent direction. As I said - that's a political choice, I don't much care which it is...but we need one or the other and we need it yesterday. SteveBaker (talk) 23:00, 21 July 2009 (UTC)

You may be right about global warming. But there lies the rub: I'm not an expert on the matter and haven't studied it academically, but I consider myself an educated person, and I have read a reasonable amount on the subject, yet I've never seen the argument broken down to the point where I buy it hook line and sinker. I think it is clear that the climate is changing - I have been to the Athabasca ice fields where there's a little sign where the glacier was 50 years ago, and it's a long way from where it is now. And I've been to Joshua Tree National Park, where areas that ranchers used to graze their cattle on are now far too barren to consider that. But as you point out I am not convinced that humans have been the dominant factor with this, and even less so that it's carbon dioxide emissions that have done the most harm. But perhaps where I diverge from you the most is that I'm not convinced that we can do anything to stop the rise in temperatures even if we really tried, although it seems quite clear we could beggar ourselves in the process (or to be more precise, force the third world to remain beggared rather than develop their societies). We know the Earth's climate is not a constant and that it has been far warmer in the past. We know we're in an interglacial period of gradual warming. I won't dispute that temperature rise could have devastating consequences. But I am not convinced that this hasn't been in the cards all along or that our puny efforts to curb it aren't the height of arrogance. I hope I'm wrong and that humans really are masters of our own domain and that our domain now constitutes the entire planet, able to control its climate to our liking. I suppose time will tell. Like I said before, I believe measures should be taken, including a carbon tax (which I do not believe is the "left option", and I'm not sure I follow the logic that leads you to that conclusion), but only because, as you point out, perhaps we can halt the temperature increase and the damage it entails. But at this time I do not see it in the same all or nothing, do or die light as yourself, mainly because I think there is reasonable possibility that we can't do anything to stop it no matter how hard we try. TastyCakes (talk) 03:18, 22 July 2009 (UTC)

And how are we gonna make sure we do this without destroying our economy (which is what'll happen if we start artificially raising the price of fossil fuels)?! Remember, our American way of life is our birthright and is NOT to be thrown away for some notion of "saving the environment"! 76.21.37.87 (talk) 23:54, 21 July 2009 (UTC)

Why would it destroy "our" economy? We can do a gradual, predictable shift from other taxes (especially sales taxes) to carbon emission taxes, keeping the overall tax quota constant. It's a simple system that fully leverages the ability of the market to provide cost-effective solutions. Last years oil crunch has done more for green energy in the US than any number of direct subsidies, and we are all still alive. Keep the oil price at 150 US$/barrel for a few years, with other fossil fuels taxed correspondingly, and we will see a massive shift towards less energy-intensive technologies and carbon-neutral energy sources. --Stephan Schulz (talk) 11:43, 22 July 2009 (UTC)

How many times do I have to keep repeating myself: Artificially raising the cost of transportation WILL CAUSE GREAT DAMAGE TO THE AMERICAN ECONOMY. If you can't see the reason why, then you seriously need to brush up on your economics. 98.234.126.251 (talk) 23:13, 22 July 2009 (UTC)

Maybe it would help to stop repeating this as a mantra (even with capital letters) and explain why you think that a predictable controlled raise of the cost of transportation (with the money being returned via some other mechanism) would cause great damage to the American (what happened to "our"?) economy? As e.g. opposed to the great damage caused by unpredictable and extreme fluctuations in the cost of transportation and the unavoidable steep rise in price as we get into a permanent oil squeeze in the not-to-far future, and no to mention the potential cost of non-market based conflicts about fossil fuel resources? --Stephan Schulz (talk) 23:32, 22 July 2009 (UTC)

Well, I'm a petroleum chemist, not an economist, but it's pretty clear to me that artificially raising the cost of transportation OVER AND ABOVE the increased fuel costs caused by diminishing fuel supply will compound any damage caused by such a cost increase (remember, the cost increase due to the carbon tax will be IN ADDITION TO the market-based increase in fuel costs, not INSTEAD OF these). And even if the money is "returned via some other mechanism" (which you haven't really talked about how it'll be done), such a selective pressure on the transportation industry will have nationwide economic effects far beyond higher fares and freight costs and the loss of jobs in the transportation industry. Keep in mind that the transportation industry's function is to link distant places together, help the supply access demand, and facilitate commerce in general. Now with the DRASTIC increase in carbon taxation that you and SteveBaker are advocating, all of a sudden you'll increase the cost of transportation so much that it's no longer affordable for most purposes! This will mean no air transportation in particular (as SteveBaker admitted in an earlier post), and HUGE cost increases for all other sectors (no matter whether they choose to keep the current technology and pay the extortionist tax, or avoid it by spending HUGE amounts of capital on expensive new (and so far inferior in performance) "green" technologies). So say farewell to overnight shipping -- all freight will have to go by train, which will take 3 days or more -- and forget any kind of air travel, whether for business or for pleasure (as a matter of fact, it's questionable whether railroad transportation would remain affordable, what with the mandatory electrification and the inevitable demand-based increase in prices). Just-in-time shipping will (inevitably) go out the window too -- all businesses will have to keep at least three days' worth of inventory to avoid the risk of running out -- and that will just do wonders for the cash flow! Checks will now take a week or more to process, which will hurt cash flow as well. In addition, it's not just the air transportation that will disappear -- ALL trucking operations, even local ones, will be decimated by your carbon tax (remember, there are currently NO practical all-electric / fuel-cell trucks, and none are likely to be on the market in the near future). That will GREATLY IMPEDE local retail shipments from the local warehouse to the market, and the enormous costs / limited availability of such shipments could very well drive most rural / suburban retail stores out of business, leaving only those that are really close to the railroad station. And that would, in turn, result in an exodus from small towns back into the inner cities, worsening the already bad enough overcrowding and all its related problems. Farmers (especially small farmers) will be negatively affected by the loss of their small-town market base, and they'll be hurt even more by the increase in shipping costs to the big-city markets. International trade will suffer, too (the shipping lines will either have to pay the carbon tax up their noses, or replace ALL their ships with extremely costly nuclear-powered ones), and THAT will hurt ALL businesses that rely on foreign trade, which will thus hurt us ALL. That's the long answer; the shorthand for all of this, I think, is "domino effect". I'm sorry that you had to take the effort to read all this, but with your level of ignorance in economic matters, no shorter answer would have been possible. 98.234.126.251 (talk) 00:40, 23 July 2009 (UTC)

Why would there be an inevitable increase in cost of rail transport if the demand goes up? I'm not an economist, but this seems to fly in the face of normal economics. As far as I'm aware the normal idea is that when demand goes up for something in which production can be easily increased, cost goes does. Economies of scale and all that. It's not as if you can't build more rails when you need them. So does this mean the cost of car transport has also gone up since the early 20th century because of the massive increase in demand? Wow I never knew that Nil Einne (talk) 11:50, 23 July 2009 (UTC)

You really should take Econ 101 before you post any further nonsense here. It's a basic law of economics: when demand goes up (assuming a constant supply, which it always is in the short term), prices go up too. Anything to the contrary is just BS. Yeah, I'm not an economist either, but this much I know very well. Besides, it takes many years to build a railroad line (not to mention that it costs $1 MILLION per mile of track). 146.74.230.113 (talk) 23:56, 23 July 2009 (UTC)

Who is talking about the short term? And if you think that increased cost of (some forms of long-distance) transportation is bad for local farmers, I would suggest you need some econ course. Increasing the cost of fossil fuels gradually and in a controlled manner will certainly be less disruptive than prices running into a non-elastic squeeze in a few years. We need to get free of oil dependence anyways, as oil will be in short supply fairly soon. "Continue as now" is not an option. --Stephan Schulz (talk) 14:07, 24 July 2009 (UTC)

I really suggest that you re-read what I said earlier about the effects of a carbon tax, cause you got it all bassackwards. For the record, I made it clear that it won't be just "long-distance transportation" that will be hurt by the carbon tax -- local trucking operations will be crippled too, and THAT'S THE ONE FORM OF TRANSPORTAION THAT LOCAL FARMERS CRITICALLY DEPEND UPON. Furthermore, while a non-elastic oil squeeze sure would be disruptive to the economy, a carbon tax at the level that you and SteveBaker are proposing ($150+ per barrel) will be even more disruptive for obvious reasons. It's not the type of price increase, but the amount of price increase that will cripple the transportation industry. And furthermore, a "carbon tax" (i.e. a tax on ALL fossil fuels), as opposed to a "gasoline tax" (i.e. a tax on just petroleum imports) will actually HURT the transportation industry's getting off of petroleum by raising the cost not only of petroleum fuels, but also of promising alternative technologies such as oil shale or coal liquefaction. Remember -- oil is scarce, but coal (and oil shale) is plentiful, while biofuels are just a scam as you're probably well aware without me telling you, and electric / nuclear powered transport is prohibitively expensive and impractical for many purposes, as I've already shown. 98.234.126.251 (talk) 22:48, 24 July 2009 (UTC)

Too late, Steve. Now that 76.21 has skillfully exposed your hidden agenda to create a One World Government with the goal of reverting us to a pre-industrial society we'll never believe your 'crooked talk' of so called Global Warming again!

Also, besides relying on video games for your livelihood, iirc you're also an advocate of space exploration. You clearly haven't thought this pre-industrial business through. You would do well to learn from 76.21's logical and rational thought process. APL (talk) 20:15, 21 July 2009 (UTC)

I'm humbled by the razor sharp edge of his/her crazed ramblings cogent arguments. SteveBaker (talk) 21:14, 21 July 2009 (UTC)

So, let me get this straight here. On the one hand, SteveBaker is advocating space exploration; on the other hand, he advocates an outright ban on fossil fuels?! Doesn't he understand that all spacecraft require fossil fuels to get into space in the first place?! Clearly he needs a refresher course in logical thinking. 76.21.37.87 (talk) 23:44, 21 July 2009 (UTC)

This is nonsense. Ariane 5 has purely cryogenic (H2/O2) main stages. I don't know what's in the propellant for the SRBs, but this can certainly be synthesized without use of fossil fuels. Anyways, you are committing the frequent fallacy of argumentum ad consequentiam. The effect global warming will have on the world or the economy or our life style or Steve's ability to fly to Titan has not the least effect on the degree of correctness of the theory. --Stephan Schulz (talk) 23:58, 21 July 2009 (UTC)

For the record, hydrogen is made from natural gas or from coal, so fossil fuels are used in its manufacture. I'm not sure what the SRBs are made of (have to look it up), but I'm pretty sure that fossil fuels are used at some point during their manufacture. As for your statement about "appeal to consequences" -- for the record, I'm not disputing the correctness of global warming here (although I'm not convinced of it), only stating that the course of action SteveBaker advocates will lead to unacceptable consequences for the American economy and way of life. So don't try to go putting words in my mouth cause that's not gonna work. 76.21.37.87 (talk) 00:51, 22 July 2009 (UTC)

One day I want to get a job working in a Liquid Oxygen mine, digging up fossil rocket fuels. APL (talk) 00:43, 22 July 2009 (UTC)

That's not even funny. 76.21.37.87 (talk) 00:56, 22 July 2009 (UTC)

Just looked up Space Shuttle Solid Rocket Booster: it uses ammonium perchlorate as an oxidizer (which requires hydrogen for its manufacture, the hydrogen being derived from natural gas or from coal, as I've mentioned two or three times already), and also requires butadiene and epoxy resin, which are both made from natural gas or petroleum. Stephan Schulz, your assertion that SRBs can be made without fossil fuels is completely wrong. 76.21.37.87 (talk) 01:25, 22 July 2009 (UTC)

The Space Shuttle does use ammonium perchlorate. So? Many space craft launch on substances that could theoretically be synthesized in an entirely green way. In fact, I don't see any reason Ammonium Perchlorate couldn't. Just because they aren't currently doesn't imply a logical contradiction between supporting both space travel and a fossil-free world. In fact Space-based solar power could, in theory, be one of the technologies that allows us to reduce our reliance on fossil fuels. (Though closer to home technologies like renewable energy sources and nuclear are far more likely in the near future.) APL (talk) 02:59, 22 July 2009 (UTC)

"Many space craft launch on substances that could theoretically be synthesized in an entirely green way." -- I challenge you to give an example of a spacecraft that does not require any fossil fuels for fuel, and then maybe I'll believe what you said. And as for the synthesis of ammonium perchlorate, I already told you that it absolutely requires hydrogen, which in turn must be made either from natural gas by autothermal reforming, or from coal by the water-gas reaction. (I'm a petroleum chemist, I know how these things are made.) And regarding "space-based solar power": it's absolute BS, it'll cost trillions of dollars in capital cost while still being more expensive in terms of operating cost than coal / natural gas / hydroelectric / nuclear power. You might as well take ten billion benjamins and launch'em into space instead! Renewables might be better in terms of economics than space-based solar, but there won't be enough of'em to meet all our energy needs, so nuclear is the way to go (as far as electricity production is concerned). As for transportation, we'll still have to use hydrocarbons for that for the foreseeable future (which is why a carbon tax is a bad idea, it'll cripple our transportation system that our economy depends on). 76.21.37.87 (talk) 03:36, 22 July 2009 (UTC)

It's technically trivial to make hydrogen by electrical hydrolysis of water. It takes more energy than using coal/natural gas as a source, but if you have clean electricity (from whatever source) you can certainly make hydrogen without fossil fuels. Dragons flight (talk) 03:59, 22 July 2009 (UTC)

You're certainly right about electrical hydrolysis taking (much) more energy than autothermal reforming. This also means that it'll cost much more to make hydrogen in this way than by reforming; in fact, this process is hopelessly uneconomic compared to natural gas reforming or coal gasification. And higher price of hydrogen will mean a much higher price for launching stuff into space, which will greatly hinder any kind of space exploration. 76.21.37.87 (talk) 04:09, 22 July 2009 (UTC)

I'll take reasonable bets the that price of the (raw) fuels are a negligible part of the the overall cost of a space mission. Apparently, hydrogen prices are less then US$1/kg for large quantities. The Shuttle uses about 100000kg. The marginal cost of a Shuttle launch is about US$ 60 million, the total program cost is about US 1.3 billion per launch. At the moment, making H2 by electrolysis is about 3 times more expensive than via methane reformulation. So that's US$ 200000, about 0.3% of the marginal cost, and 0.015% of real cost. --Stephan Schulz (talk) 10:03, 22 July 2009 (UTC)

And how much more would it cost to send people to the Moon and to Mars (which is what space exploration is all about)? I'm sure that it'll use much more fuel per launch than the space shuttle. And if we're serious about space exploration, then we can't just go around in circles (pun intended) in low Earth orbit, which is all that the shuttle can do. 98.234.126.251 (talk) 02:48, 23 July 2009 (UTC)

It'll use more fuel sure. But it seems to me fuel will remain only a small proportion of the total cost. Nil Einne (talk) 11:44, 23 July 2009 (UTC)

Comment Don't really want to take part in this debate, except to point out that as a non American, I consider it, as with I think much of the rest of the world, the birth right of all humans to actually have a future, even if it means Americans aren't entitled to their birthright to destroy the world, or whatever 76 thinks is the American birthright. You also don't need to 'world government' for concented action. You just need individual national governments agreeing to do what's best for all rather then doing what's best for them and screwing everyone else (including their own future). It's been done before, e.g. with CFCs P.S. One thing I agree with is that it's definitely right to presume people who've spent their live studying something must be wrong because we're incapable of understanding what they're studying. For example, this quantum physics stuff must be wrong. I've never understood it nor do I suspect much of the rest of the world. Schrödinger's cat is a good example of how it's nonsense. And when you combine it with the nonsense that is General relativity... And then there's all this crap about quarks. And how can you claim the Poincaré conjecture is solved when I can't understand the solution? The same with Fermat's Last Theorem and its alleged proof (if Fermat had a remarkable proof, may be his one actually made sense, aye?). Nil Einne (talk) 11:44, 23 July 2009 (UTC)

Wow, what a bunch of incredible BS here. So basically, just because you're not American, you think you have a right to tell us Americans to give up our prosperity for all the rest of the world as if it mattered?! For the record, the US Constitution clearly states that the American government is ACCOUNTABLE TO THE AMERICAN PEOPLE and to NO ONE ELSE! And by saying that "people who spent their lives studying something must be wrong because we're incapable of understanding what they're studying", you've just exposed yourself as a complete idiot who knows nothing about science and doesn't even believe in it. 146.74.230.113 (talk) 23:56, 23 July 2009 (UTC)

As an American, I'll comment that the Constitution does not override morality. If an action by Washington harms people, even mere foreigners, only an ass would say "The Constitution says it's okay, so shut up." — Nil Einne's cracks about science are either crazy or satirical and I'm not going to bother deciding which. —Tamfang (talk) 16:26, 30 July 2009 (UTC)

Well actually I think most Americans do care about the rest of the world, it's only a few like 76 and apparently 146 who think they shouldn't care about the rest of the world. So an American government bound to the American people is by definition bound to care about the rest of the world. And besides that, I don't see how destroying their own future benefits Americans, even if they bring the rest of the world along with them. If however Americans really believe they should destroy the world because it's their right, then I think the rest of the world has to consider their future and they may have no choice but to try and stop the Americans somehow and so ultimately Americans will have to consider that even if they are really intent on destroying the world and thinks none of the rest of the world matters, the rest of the world is not going to agree. In other words, even if 76's and 146's POV is indicative of all Americans (which I doubt) Americans do have to consider the rest of the world, since the rest of the world do actually care about themselves, and many do in fact care about Americans too regardless of who Americans do and don't care about. But as I've already said, I don't think this will be necessary, since most Americans don't actually believe they should destroy the world because it's their birthright. Other then Tamfang and 146, no one else has commented so I can't be sure but I think my comments on science were self obvious. There are plenty of things I don't understand that well, as with a lot of people. If I had enough time to study them, I hope I would. Some of the comments above appeared to suggest that because the person making the comment couldn't understand the science behind global warming, it must be wrong. My comments on science (and mathematics) were to indicate how dumb this sentiment is. Just because someone doesn't understand something doesn't mean it's wrong. Usually the people who have spent their lives studying something are more likely to be right then someone who spent a few days, couldn't understand it and so claim it is wrong because they can't understand it. This doesn't mean we should always trust authority but rather we should recognise there is a reason why people have authority and in most case our inability to understand something doesn't mean it's wrong. It just means it's difficult to understand Nil Einne (talk) 16:47, 27 August 2009 (UTC)