Wikipedia:Reference desk/Archives/Science/2007 July 22

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July 22

Aliens

What are the chances that extraterrestrial life would live off of oxygen? Is it possible/likely that they would use a different substance to breathe, because the chemical makeup of the atmosphere of wherever they live would most likely be different than that of Earth. —Preceding unsigned comment added by 68.190.122.58 (talk • contribs)

What makes you assume aliens would need to breathe? Dragons flight 04:56, 22 July 2007 (UTC)

There are even organisms on Earth that don't breath oxygen, see Anaerobic organism. Someguy1221 06:03, 22 July 2007 (UTC)

Oxidation is a good way to get lots of energy out of your "food". (If you doubt this, look at all the energy a fire gives off, which is rapid oxidation.) However, there are other processes for releasing chemical energy from food that don't require oxygen, and free oxygen is also rare in the cosmos (we only have it on Earth due to plants), so those points would support aliens possibly using some other method. StuRat 06:05, 22 July 2007 (UTC)

Iy you are looking for life on other planets, looking for oxygen in the atmosphere is a sensible thing to do. That's not because life needs oxygen to breath, but because life makes oxygen gas as a biproduct of photosynthesis. Theresa Knott | The otter sank 09:26, 22 July 2007 (UTC)

Is it possible? Of course. Is it likely? Difficult to say. We don't have too much evidence to the contrary here of anything larger than bacteria which live off of anything but oxygen. It's hard to make odds when you have a sample size of 1 (for the planet as a whole, anyhow). --24.147.86.187 14:35, 22 July 2007 (UTC)

Depends on how you define life, which is not so easy. For their space program, the USSR once built a robot that was designed to look for life. When they tested it here on Earth it found no signs of life. :)

But one aspect of life must certainly be that it has some form of organisation and for that it needs energy. Oxygen is pretty reactive stuff (as StuRat pointed out), but there are other reactive substances. A chemist had better fill that in. But another thing is that that source of energy needs to be replenished or the environment will run out and the life wil perish (which Theresa hinted at). On Earth, one way that is done is through the interaction between animals and plants, with the animals getting energy out of oxidisation of carbon and the plants using energy from the Sun to reverse that. Without the plants, the animals would run out of oxygen and without animals the plants would 'drown in their own shit', so to say (the way yeast does in a brew, which is why you can never get above 12% with a normal brewing process). Actually, they almost did long ago, until animals came to the rescue.

So you'd need an energy-carrier that is somehow replenished by some other process, be it life or a simpler chemical process. And I have understood that there are not many such cycles possible, but again, you'd better ask a chemist. DirkvdM 19:23, 22 July 2007 (UTC)

Part of this is misleading. Most animals can tolerate 100% oxygen atmospheres, and plants can handle nearly pure oxygen provided small amounts of CO2 are there for metabolism. Life actually flourished during past periods with higher O2 levels, as that could accommodate larger animals. So we don't actually drown in high O2. However, we would burn really really well, which is speculated to be one of the feedbacks that limits oxygen levels on geologic timescales. Dragons flight 20:27, 22 July 2007 (UTC)

Dirk is right (except that plants and animals as we know them came later; it was anaerobic and aerobic microorganisms); he's referring to the Oxygen Catastrophe. Dragon is referring to life of a later time. --Anonymous, July 23, 2007, 01:05 (UTC).

The lack of CO₂ would be the problem for plants, though. StuRat 00:08, 23 July 2007 (UTC)

You can look at life on earth to see other ways for organisms to oxidize. Some bactera convert H₂S to sulfur. Others can change Fe²⁺ to Fe³⁺. Other element conversions are possible, such as producing Chlorine, Bromine or may be even Fluorine as an oxidation waste product. If you found a planet with a Fluorine atmosphere you would have to ask how did this come about? GB 02:04, 23 July 2007 (UTC)

I have to add that oxygen is quite a common element, and so it is quite likely to be used by life. Other common elements in stars are carbon and nitrogen, but not so common on the earth. GB 02:08, 23 July 2007 (UTC)

Herms

Are human Hermaphrodites real? Or are all of those pictures just photoshopped? --59.180.4.84 06:12, 22 July 2007 (UTC)

Yes, there are hermaphroditic people. Many of the pictures you see could be faked, though. Try searching on medical websites for real pictures. A Very Noisy Lolcat 07:27, 22 July 2007 (UTC)

I think the better question is, is there an actual documented case of a human succesfully reproducing (or at least getting an embryo out of it) with him/herself, to which the answer is no (to my knowledge, though I imagine this would be kind of a big thing, so I'll presume no). Alternatively, is there a documented case of a human siring two children, once as a father, and once as a mother, to which, again, the answer would be no. In all cases of human hermaphroditism that I have read of, many of which are heavily documented, only one set of genitalia is functional, or neither is. The problem with human hermaphroditism is that the testicles and ovaries are produced from the same base organ in developing embryos, so unless there is something truly bizarre going on, you can't get both. However, it is possible for a human to have both male and female external genitalia (this has been documented to varying degrees of development thereof), but at least one will be useless in all cases. On there other hand, this paper describes something truly bizarre going on, cases in which children have developed ovaries and testicles. It mentions, however, that such patients are prone to a great manner of abnormalities in these organs, and removal of one is usually performed. It further does not give a positive answer to either of my above rephrasings of the question. It does discuss some of the children reaching puberty and completing development of only one set of genitalia, not both. Someguy1221 20:42, 22 July 2007 (UTC)

Savage Love [1] has a letter from a woman who just discovered that she has two vaginas. It is thought to be “didelphic uterus” in which there are two complete female reproductive systems. Just seemed worth mentioning. She had only had one lover, so apparently was still a virgin in the less used vagina. Edison 21:44, 22 July 2007 (UTC)

172" or 17.2" pipe @ 3,740 psi

One might be surprised how gruesome a totally professional report can be without going into much detail:NIOSH FACE case titled:

Maintenance Man Dies After Being Drawn Into 172-Inch-Diameter Positive Pressure Intake Pipe--Virginia

I'm having a hard time picturing the events described occurring in a pipe 14.3 feet in diameter. Did they forget a decimal point or do they really use pipes that huge at paper processing plants? Anynobody 07:29, 22 July 2007 (UTC)

While I can't speak to paper plants, one way to create high pressure is to have a very large fan directed at a small pipe. So it could be that this opening is specific to the fan drive segment creating the large overpressure. Dragons flight 09:51, 22 July 2007 (UTC)

Yes, I believe you're right, it's likely 17.2 inches inner diameter. The "smoking gun" for me is that it said "the vacuum suction pulled his chest against it" and that "the victim was doubled over backwards and pulled 38 feet through the pipe by the vacuum". This means the pipe would need to be about the size of a man's chest. They apparently repeated the error everywhere they mentioned the pipe, which seems odd based on the level of detail in the rest of the article. I suspect that a spellchecker is to blame, which probably said "Did you mean 172 inch" when it found "17.2 inch". The editor then likely picked "Replace All" when they meant to pick "Skip All". Since the spellchecking was the last process in the checking process, they likely never read it after running the spellcheck, or would have spotted this obvious error. (Interesting that we a have serious human error in an article about a deadly human error.) StuRat 14:38, 22 July 2007 (UTC)

172 inches isn't the only number I'm suspicious of; I don't think I believe that "3,740 psi" figure, either. If the pipe is 17.2" in diameter, that's 400 tons of force on the end of it, or if (somehow) the pipe is 172", it's 40,000. With 400 tons on a 17" pipe, I don't think the poor guy would have been "stuck" long enough for his buddies to try to pull him off; I think he would have been sucked completely in in an instant.

3,740 psi is huge. You'd need special, small-diameter, thick-walled, high-pressure piping for it; there's no way you could sustain that kind of pressure in a 17" diameter pipe, unless it were constructed and machined like a submarine hull. —Steve Summit (talk) 15:22, 22 July 2007 (UTC)

Clearly the victim of this industrial accident was in the atmosphere on the outside of the building before he was pulled into the pipe, whatever its diameter. Therefore there could only have been 14.2 psi of "vacuum pressure" even if the other end of the pipe were connected to perfect vacuum. Air pressure pushed him into the pipe, rather than "vacuum pressure" pulling him into the pipe. It scares me that either a government or an industry would issue such an addled report. A 17.2 inch pipe is believable. The area is such that atmospheric pressure could apply 2200 pounds of force. The same phenomenon would apply as when a window of an airplane blows out at high altitude and a passenger gets sucked out (this happens less often than movies would imply). Why would they have attempted to replace the blower without shutting down the flow of air through the pipe? The whole story is senseless. Edison 21:20, 22 July 2007 (UTC)

Argh! You're right, of course. I was worried about the report's use of the perplexing term "positive-pressure vacuum pipe" also, but I didn't think it through far enough to remember that you can't have more than 14.2 psi of suction.

(I'm not sure I believe "17.2 inch", either -- would they really use that much precision? Wouldn't they just say "17 inch"?)

Addled and senseless, indeed. —Steve Summit (talk) 22:29, 22 July 2007 (UTC)

For 14.2 above, read 14.7. --Anon, July 23, 2007, 01:18 (UTC).

I've explored other case reports on the page, and get the impression that at some point in the late 1990's they finally started submitting these electronically. Which made me theorize earlier reports were transcribed. Would 374 psi be more reasonable for the pressure? Anynobody 23:25, 22 July 2007 (UTC)

No, it's still way too much. Most steam locomotives had boiler pressures less than that, and besides, as noted, 14.7 psi is the greatest possible suction. I wonder if they had something in mind with pounds? Let's see, the cross-section of a 17.2" pipe is pi*8.6^2 = 232.35 square inches... so it would take over 16 psi for the total pressure on one end to be 3,740 pounds. So that's not it.

Another thought: maybe the comma should be a decimal point. 3.74 psi. That still seems a lot for the stated purpose, but at least it's physically plausible and enough to suck someone in. But why would it be stated to such a high precision, if that was it?

--Anonymous, July 23, 01:18 (UTC).

People make dumb mistakes all the time, myself included if you've seen my user page. Reading not only this one, but several more senseless reports, this is simply what happens when people make dumb mistakes in a hazardous environment. I don't just mean the guy who got sucked to his death but whoever should have shut down the other blowers and appointed a safety manager. (I had no idea how dangerous it is to be a farmer, or the horribly disgusting fates possible.) Anynobody 23:41, 22 July 2007 (UTC)

Rather than attribute the death to a "dumb mistake" I would review the whole process for possible failures to follow standard OSHA safety procedures. The job as described was a literal deathtrap. There would normally be a job briefing, reviewing the possible dangers to avoid, with appropriate barriers, tagout procedures, safety harnesses, barriers, etc. I still do not understand why the intake of air through the 17 something pipe wasn't stopped while they were trying to mount a new blower over the opening. How did they get the old blower off the opening with that much pressure pulling it in? I just don;t see the need for all the alleged vacuum pressure to move wood chips into a machine, when a backyard leaf blower or vacuum cleaner would be adequate to move them, as soon as the air was moving at 3o miles per hour or so. Edison 15:07, 23 July 2007 (UTC)

Well, I contacted the NIOSH via the form on their web site, and got a prompt reply from the senior investigator in the case.

There was some sort of character-set problem: the pipe diameter was not 172 or 17.2 inches, but 17.5 inches, i.e. 17½. The report on the web site has now been corrected.

As for the huge pressure, that is correct, but it is the pressure on the output side of the blower. (I think this means some of the report's wording is misleading.)

--Anonymous, July 24, 2007, 14:42 (UTC).

Well done! (I've got a barnstar here for ya, but alas, you've got no user page to put it on.) --Steve Summit (talk) 23:54, 24 July 2007 (UTC)

[Still scratching my head over that pressure, though -- that ain't no "blower"; that is a compressor!]

Common knowledge in 2007 that would be insanely valuable in 1807.

If I -- a moderately-educated Australian adult of average intelligence -- woke up tomorrow to find I'd been warped to the year 1807, what knowledge of mine would be most valuable to the doctors, scholars, etc of the time? My first thoughts were of bacteria, psychotherapy and Franz Ferdinand's assassination. A Very Noisy Lolcat 07:35, 22 July 2007 (UTC)

Ones that spring to mind for me are advanced methods for producing steel, controlled steam locomotion (it was in its early stages in 1804-1810), internal combustion using stuff like diesel, electrical currents, vaccination methods, and the concept of the elevator. Inventing high grade steel for building materials, bio diesel, and an electrical generator would see the railways and business jump significantly ahead if started that early.  ALKIVAR™ ☢ 09:13, 22 July 2007 (UTC)

Ones that jump to my mind are the principles of electricity generation and that bacteria causes disease. Somewhat more esoteric, but highly practical would be dynamite, antibiotics and pasteurization. Dragons flight 09:33, 22 July 2007 (UTC)

This is a question I have thought about too and realised that unfortunately

• some things, I know can be done, but can't do them myself (e.g. making steel)
• some things I can do are useless without some other knowledge, that I lack (I could use transistors in a circuit, but I couldn't make them).

—Bromskloss 10:21, 22 July 2007 (UTC)

I'm not sure the 1807ers would be impressed by word of an event you claim will occur 107 years in the future. Algebraist 11:35, 22 July 2007 (UTC)

Photography and phonography would be pretty valuable, and at heart are both relatively simple - plus, bring them together and you've got talking cinema 120 years early! Laïka 12:22, 22 July 2007 (UTC)

Convincing them to look for Brownian Motion earlier, and experimentation with Uranium salts, in order to discover radioactivity, would have allowed remarkable advances in physics to have happened a hundred years earlier. Similarly, pretty much everything that became encapsulated in the Maxwell Equations could have been discovered and published in 1807. But in terms of common-place stuff, really simple things like hygiene - convincing people to wash their hands, boil their food and chlorinate their water - would have been hugely beneficial. Batmanand | Talk 13:56, 22 July 2007 (UTC)

Convincing people to be better stewards of the earth would be insanely valuable from 1807 to 2007.--138.29.51.251 14:00, 22 July 2007 (UTC)

When I consider this "time traveller problem" I realize that the main challenge would be to convince anyone to try your ideas. Hygiene for example was rejected by the experts time and again, and only tested and accepted after a long bitter battle. Remember that Semmelweis ended up in an insane asylum after a lifetime of failure at convincing doctors to wash hands. So, the most valuable tidbits in 1807 would be those things which would imediately make you fantastically wealthy. Having gotten rich, you could then fund all sorts of research and manufacturing based on 2007 knowledge, and those many who try to stop you would fail. In other words, you don't want to be a Ignaz Semmelweis who knows that surgeons should wash pus off their hands before the next surgery... and you don't want to be a Nikola Tesla whose amazing advances are sometimes accepted but usually ignored. Instead you want to be a Tom Edison who uses his income from ticker-tape machine sales to rapidly achieve any damn revolutionary idea he wants. --Wjbeaty 14:36, 22 July 2007 (UTC)

A knowledge of the Geology of Australia, particularly its gold deposits, would enable you to become insanely rich and thus fund your good works. DuncanHill 14:49, 22 July 2007 (UTC)

Or you could come up with some inventions that were expected in the 1810's. Inventions farther in the future likely wouldn't work due to lack of infrastructure. Airplanes, for example, wouldn't work in 1807 due to the lack of lightweight, powerful engines. StuRat 14:55, 22 July 2007 (UTC)

Makes sense, but then by definition, these inventions were about to come out anyway, so how valuable would introducing them a few years earlier (best case scenario) be? (Worst case scenario is getting attacked by irate 19th c. inventor for stealing their idea.) TresÁrboles 04:22, 24 July 2007 (UTC)

Psychotherapy would not be that valuable at that time. Most people would not believe it. It was an uphill struggle for Freud even a few decades later. You'd have a similarly difficult time convincing people about bacteria. Basically, in Kuhnian terms, you are talking about showing up with knowledge specific to a particular paradigm and trying to force it onto people who are not in any way prepared for accepting such a paradigm. What you want is someting that will easily assimilate into existing understanding; something that does not require extensive belief in certain abstract modes of thought (anything relating to things people cannot see is pretty tough to sell to people, even today, if they have not been taught to have faith in that matter of thinking); engineering advances would be the easiest in this respect, far easier than theoretical advances. Personally, I think the suggestion of dynamite was particular good (hell of a lot safer than traditional explosives at the time, requires no paradigm that people would find inaccessible in the early 19th century). The internal combustion engine could potentially work out as well — you'd need to develop an infrastructure which could take advantage of it but again the engineering and chemistry is not beyond their comprehension, just skill. With an effective knowledge of airplane design you could easily be quite valuable to any government, but you'd have to demonstrate it first. --24.147.86.187 16:48, 22 July 2007 (UTC)

Weaponry is another obvious one, for a man concerned only with getting rich. AK-47s, pump-action shotguns, semiautomatic pistols, napalm, plastic explosives, mustard gas, etc. --Kurt Shaped Box 17:23, 22 July 2007 (UTC)

While all of the above would be usefull, keep in mind that they're no immunity from sharpers or proficient confidence men and/or embezzlers. That said, Do you know anyone who was assassinated? The two dudes who saved that German Emperor from an anarchist got a dukedom each out of it (I think). If you happen to remember certain political trends, you could ride the waves and stay in office for years on end. 68.39.174.238 18:34, 22 July 2007 (UTC)

Copper wire was widely available in 1807, and the innovation of insulating it with cotton, then building telegraphs, electric generators and electric motors would be immediately feasible in 1807, if one had a high school physics understanding of these devices. A blacksmith or machinist of that era such as a gunmaker coud make the iron parts needed if you could describe them and provide drawings. A big 19th century electrical breakthrough was cutting the cost of a kilowatt hour of electricity by an order of magnitude or more by making it with a generator powered by a steam engine rather than zinc and copper plates in a battery. Next step: arc lighting. Then telephones. Then incandescent light bulbs (harder to get working with commercially useful lifetime and brightness than the aforementioned devices). Electric railways. Transformers and AC for long distance transmission of electricity. Household appliances. Then X-ray tubes and vacuum tubes, as soon as the light bulb technology is working, and the whole world of early 20th century electronics, up through radio. television and computers, but over a century earlier. Certainly a machine shop in 1807 could have built you phonographs and movie cameras and projectors if you could draw plans. I think you would have to be quite a specialist to know how to make transistors in 1807, much less integrated circuits, with the micro-etching and clean room crystal growing required.but knowing transistors are possible and the basic principles of doping semiconductors and biasing junctions should make it possible to kick start semiconductos solid state electronics if you developed a few hundred thousand dollars profit from the earlier ventures and could hire a research team. On the dark, side, certainly machine guns would be hugely valuable, as would land mines. A very high degree of specialized knowledge would be needed to get avation working. Even by the 1880's very silly things were written in the leading scientific journals about how airplanes of the future might work. Edison 20:57, 22 July 2007 (UTC)

Ah, any links regarding those silly airplane things? —Bromskloss 22:01, 22 July 2007 (UTC)

I could not find the articles I saw in Science in the 1880's issues. Indexing sometimes leaves much to be desired. But I found the steel balloon "aeroplane" with a vacuum inside, 1887 [2] , Aeropaedia from the Dublin Review [3](p 95) describes aeroplanes with screw propellors, proposed steam airplanes, and interesting acounts of balloon ascensions (1890). Steam airplanes are discussed (p302) in The Gentleman's Magazine (1888)[4] . If a time travellor built a working airplane in the 1880's or perhaps a few decades earlier, the notion would not have been novel to the educated person of that age. They would just have seen it as the culmination of research then in progress. Edison 14:52, 23 July 2007 (UTC)

If I could, I would bring a copy of Wikipedia! :-) —Bromskloss 22:01, 22 July 2007 (UTC)

That could be challenging without at least a computer and power. As I recall, we would fill something like 300 volumes. Dragons flight 22:28, 22 July 2007 (UTC)

If I found myself in the situation you describe I think I would keep very quiet about my ideas and knowledge. People of all ages seem to be very superstitious of people who have a great deal of strange information. The last thing I would want to do would be to give people the idea that I’m a sorcerer or demon. --S.dedalus 00:11, 23 July 2007 (UTC)

So, how was 1807? —Bromskloss 08:48, 23 July 2007 (UTC)

Lovely, thank you! Although having Bonaparte charging all over the place was slightly disconcerting. --S.dedalus 02:03, 24 July 2007 (UTC)

I suspect that most of these suggestions fail because most people from 2007 don't actually know how how most of the wonders we have work. To take the first few suggestion - how many of us could actually describe how these things work?

• advanced methods for producing steel - I have no clue.
• controlled steam locomotion - I have some approximate ideas, but I don't know the details.
• internal combustion using stuff like diesel - I understand the principles - but how to make the fuel?
• electrical currents - This is probably the one I could help most with - but even so, to make anything beyond an fascinating toy...tricky.
• vaccination methods - How the heck do you make a vaccine? No clue.
• the concept of the elevator - emergency fallback braking systems - and I'm not 100% sure how those work.

Sure we all have a vague idea - but outside of our own specialities, could we really offer much help? SteveBaker 01:27, 23 July 2007 (UTC)

You should read up on smallpox, anyone with access to dairy farms can make a crude version of that vaccine (though it was invented before 1807). As a physicist, I might fail metallurgy, but I bet I could get the others to work given enough time and period materials. Dragons flight 02:22, 23 July 2007 (UTC)

But if you wait a few more years, you could bring back the recipe for transparent aluminum. "Computer? Hello computer..."

Atlant 16:27, 23 July 2007 (UTC)

If you knew your history well, you could possibly turn the tide in the Naopleonic War to which side you chose if you could convince the right people.

You might be interested in this (fake) game show: "Phone Call to the 14th Century". You get 60 seconds to impart as much knowledge as you can. --TotoBaggins 18:48, 23 July 2007 (UTC)

Almost zero. The question isn't what you know is possible, but what can you build? Can you build an internal combustion engine and make the iron and steel necessary? Can you produce the kerosene? I can speculate about what might happen in 2107 but without the ability to actually build any of it, you might not be any different than anyone else. da Vinci proposed all sorts of things that he lacked the ability to build. But perhaps there is one thing you may know: boil your water. You may even be able to build a toilet as it is a simple mechanical device. --Tbeatty 20:12, 23 July 2007 (UTC)

Of course simply knowing that a given technology is possible is often all that is needed to spur innovation in the field. --S.dedalus 02:07, 24 July 2007 (UTC)

But see above the response by Wjbeaty, i.e. you will not be believed especially if you haven't the foggiest on how a particular technology actually works in any useful way. Remember, we are talking about the average person. TresÁrboles 04:22, 24 July 2007 (UTC)

It's a more interesting problem to consider the what the average person knows in detail and can demonstrate convincingly -- not much I'm afraid! (I include myself in this!)

Specifically for 1807 in the U.S. ... just brainstorming...

I know in the U.S., there's supposed to be a war with the U.K. in a few years. I don't know how that simple knowledge can help anything.

I know there's gold in California... yeah! Although... I'm not sure where to look (was it near Sacramento? Maybe an average Californian would fare better here). Likewise for the future gold rushes of the Yukon and Australia. For the Yukon, at least I know you can go from Skagway up across some insanely steep hill.. and then what?

I know about the airfoil, but I don't know that I could make anything other than a toy (if even that), and I'm sure they would already have flying toys.

Photography? Put some kind of chemicals on paper somehow and expose it to light just so, and ... never mind.

It's starting to look like there would be zero effect!

I 'm not sure if it would be different for a 2007 Australian person going back to 1807 Australia either. Maybe the average Australian knows where all the gold was? TresÁrboles 04:22, 24 July 2007 (UTC)

I would suggest sleeping from now on clutching a scientific encyclopedia, just incase of such an eventuality. (And hope that whatever transports you transports the encyclopedia with you). Capuchin 08:12, 24 July 2007 (UTC)

'You can't take it with you.'

Spider identification

Hi, I took this shot of a spider in my appartment : [5] and I would have liked to identify its species so as to be able to upload it to commons and include it in relevant wikipedias. The size was about 2mm and it weaved a pretty impressive web of about 30cm diameter. I am living in Sweden. Any help is welcome. --Nattfodd 11:39, 22 July 2007 (UTC)

After looking at some galleries, it seems to be of the "long-jawed" kind, but I couldn't find the exact family. --Nattfodd 11:34, 22 July 2007 (UTC)

To summarize: 2mm long, north-european, brown colouring, probably long-jawed, weaves ~30cm webs. --Nattfodd 11:39, 22 July 2007 (UTC)

Turned out to be Uloborus walckenaerius. I found the answer on [6]. --Nattfodd 13:17, 22 July 2007 (UTC)

Wow that thing looks evil. Are there any better pictures of it? That one you found is in a strange posture. Or is it really like that? Capuchin 14:33, 23 July 2007 (UTC)

Tree rain

Is there a formal name for this phenomenon ? After a brief rain storm (during which time there may have been no rain under a large tree), the rain drops, which have been slowly falling from leaf to leaf, start to fall to the ground from under the tree, leading to a time when it is raining under large trees and nowhere else. This could also happen from dew after a wind gust. StuRat 16:10, 22 July 2007 (UTC)

yes, but I've forgotten what.

—Preceding unsigned comment added by 172.207.154.122 (talk • contribs) 20:24, 22 July 2007

I can't find this anywhere, the only word I can think of is "dripping". Sorry if this doesnt help. Maybe it would do better on the language desk. Capuchin 11:28, 23 July 2007 (UTC)

On the funnier side, we used to call this the "capacitor effect", imagining that the tree stores the "charges" and releases them later -- WikiCheng | Talk 05:16, 24 July 2007 (UTC)

Isn't it more like an inductor...? :p --antilived^{T | C | G} 06:08, 24 July 2007 (UTC)

I would suggest that it is more like lots of little capacitors (leaves) forming a bucket brigade delay line. The buckets empty when they get too full. So the term for this could be: Leaf delay.--SpectrumAnalyser 14:55, 24 July 2007 (UTC)

Visible Insect With Large(st) Population

I am looking for a source on the worldwide population of an insect species which is very populous. I prefer an insect that is at least 2-3 mm long and is not eusocial. Really anything with a population higher than 10 billion would do.

I would also like to know the length of one generation of that insect.

The point of this is to provide an example of a species that would, on average, mutate every base pair in its genetic sequence in a relatively short period of time, given a mutation rate of 10^-10 to 10^-12. If you could find the population of an insect that has been observed to evolve either in nature or experimentally, that would be even better.

Thank you

I humbly suspect that most insect species have a population far greater than 10 billion. I know nothing of mutation rates and so on, but a classic example of an insect evolution observed "on-the-fly" is the Peppered moth. See Peppered moth evolution. Unfortunately it's much bigger (in it's adult phase) than the 2-3mm you specify, but it is a fascinating example. I'm sorry I can't give you a more specific answer - anyone else? Best regards, TreeKittens 02:04, 23 July 2007 (UTC)

A classic insect species for evolutionary and genetic studies is Drosophila melanogaster. It is usually 2-3mm in length, and I guess it's population to be utterly vast, but I have no evidence for this. It's generation time is about 2 weeks, depending on temperature etc. Hope this helps a little. Best regards TreeKittens 02:39, 23 July 2007 (UTC)

You could go for the plague locust. GB 02:44, 23 July 2007 (UTC)

I didn't figure finding a species with a very large population would be hard. But I can't find any references to even estimates of insect populations.

Hmmm, neither can I offhand. I suspect this is because the total world population of a particular insect would not be a very useful figure for ecologists and biologists as they would normally be interested in the population within a particular ecosystem. One way to derive an estimate may be to use any biomass figures you can find, and simply divide them by the mean mass of the organism. I think that may be your best bet. Sorry I can't help you with the specific figures. Best regards TreeKittens 21:34, 24 July 2007 (UTC)

You are aware I hope, that it is rather unlikely that a mutation in every base pair would be seen given that certain single point mutations will result in a change too critical for the resulting organism to survive? Nil Einne 12:40, 23 July 2007 (UTC)

I am not suggesting that all the mutations survive. Just that for these types of species, it is not unreasonable for random mutation to find the changes that lead to adaptive changes fairly quickly if there are any.

Castor oil on eyelashes

Hi, I apply castor oil daily on my eyeleashes in order to make them thick. Is there any harm in doing that daily?? Thank you

If you are looking for medical advice, we can't answer you, as Wikipedia does not give medical advice. As for beauty tips, I have no idea, but perhaps someone else will. Dragons flight 20:36, 22 July 2007 (UTC)

Whether or not this is a request for medical advice, it can be answered without giving any! Our own article on castor oil discusses it's many uses in medical treatments and folk treatments. It was even commonly believed long ago to treat burns. The only adverse effect from castor oil, it appears, would come from consuming very large quantities of it (I have no idea what a large quantity would be for castor oil), but consuming anything in large enough quantities will kill you. Further, considering that castor oil is an ingredient in some foods, perfumes and even some modern medical treatments, I think you can make your own judgement on this. Someguy1221 21:42, 22 July 2007 (UTC)

Be aware that anything liquid applied to the eyelashes may regularly end up on the eyes and most perfumes, foods and medical treatments don't tend to end up on the eyes regularly. Nil Einne 12:34, 23 July 2007 (UTC)

I doubt that it hurts anything - but I'd be very surprised if it helped. Once a hair has sprouted from the follicle, it's dead material - more hair is added at the root - but the part of the hair you can see is just a dead thing. All of these shampoo adverts that talk about feeding and nourishing your hair are more 'sham' than shampoo. So the only things the olive oil could possibly be doing to 'thicken' your eyelashes would be to somehow cause the Keratin to swell up and thereby gain thickness (which sounds possible, I suppose) - or perhaps it might cause the follicle to grow a thicker hair (seems very unlikely to me). What I think you should do (for the good of all mankind) is to do a careful experiment. Put castor oil on your left eye lashes - and don't put any more on your right eyelashes. It takes 4 to 8 weeks for an eyelash to grow and then fall out - so if the oil is making a difference, it should be obvious within two months. If you can tell the difference between your left and right eyes after that amount of time then it works! Otherwise - not. To be really sure, you should ask other people (preferably those who don't know you) whether they can tell the difference - because you are bound to be a bit biassed. Please tell us what happens! SteveBaker 20:52, 23 July 2007 (UTC)

In some parts of south India, there is a practice of applying castor oil on the eyelids to get a 'cooling effect' (whatever it means). They also apply it on the eyelids if there is irritation in the eyes, as a home remedy. I am not sure if this really helps. I personally have felt that it makes you slightly drowsy, may be because you tend to close your eyes to get over that funny feeling after it is applied. I also agree with SteveBaker (to make the hair look thicker), because castor oil is also applied on the head -- WikiCheng | Talk 05:08, 24 July 2007 (UTC)

Binturongs

I was unable to track down the original reference that contains the information regarding the reproduction parameters in binturongs in the article. Could you please post those or direct me to the person that posted it? Thank you, Amoresco 21:05, 22 July 2007 (UTC)AMoresco

This information was in the original version of the article, as created by 64.63.221.115 (which IP has not edited for three years). The original article cited [7] and [8]. These source more-or-less corroborate the information given, though neither seems to give the estrus period. None of the currently listed references appear to give this information. Algebraist 14:14, 23 July 2007 (UTC)

Google gives this article on JSTOR: [9]. The abstract is kind enough to give all the facts. Algebraist 14:21, 23 July 2007 (UTC)