Wikipedia:Reference desk/Archives/Science/2008 September 25
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September 25
[edit]Planets, homework for MY 5th grader, can't find in packet, please help!
[edit]This planet has rings and 15 moons.
This planet has 18 moons and 7 rings.
This planet has 8 moons, 2 that can be seen by telescope.
This planet is 93 million miles from the sun. (by ang)
this planet's orbit crosses Pluto every 248 years. —Preceding unsigned comment added by 75.132.46.189 (talk) 00:03, 25 September 2008 (UTC)
- If that planet crosses Pluto's orbit then find information about Pluto's orbit. Our Pluto article would be a good start. Mieciu K (talk) 00:11, 25 September 2008 (UTC)
Uranus, Saturn, Neptune. Earth is 93 millions from sun, what you think? now Jupiter have at least 63 moon,s at least 60 for Saturn, at least 27 for Uranus, at least 13 for Neptune. Your book must be at least 10 years old.--57Freeways 00:14, 25 September 2008 (UTC)
So according to my daughter's book/packet:
( she's with grandma and i'm working)
This planet has rings and 15 moons. JUPITOR
This planet has 18 moons and 7 rings. SATURN
This planet has 8 moons, 2 that can be seen by telescope. NEPTUNE
This planet is 93 million miles from the sun. (by ang) EARTH
this planet's orbit crosses Pluto every 248 years. EARTH
Yes, that was right 10 years ago if you look for a book copyright in 1996. But now scientist keeps finding more moons, and numbers of moons keep multiply. Jupiter, Saturn, Uranus, and neptune is a gas giant when you try to land you can't because there is no place to land. See the article about Jupiter.--57Freeways 00:51, 25 September 2008 (UTC)
Use this table to help.--57Freeways 00:57, 25 September 2008 (UTC)
Earth is definietely 93 million miles away from the sun.--57Freeways 00:58, 25 September 2008 (UTC) this planet's orbit crosses Pluto every 248 years. I'm pretty sure this is Neptune.Avnas Ishtaroth drop me a line 01:20, 25 September 2008 (UTC)
- This is the Science desk - so it important to be 100% clear and scientific about this:
- This planet has rings and 15 moons.
- This planet has 18 moons and 7 rings.
- This planet has 8 moons, 2 that can be seen by telescope.
- There are no planets in the Solar System that fit any of those descriptions. I'm pretty sure none of them did even 10 years ago when this was printed. All three gas giants have uncountable numbers of rings and we'll still be finding more teeny-tiny moons 20 years from now! The number of moons that "can be seen by telescope" is a crazy statement. Where is the telescope? How the heck does the questioner think we found the other six moons if not by staring at them through a telescope?! Stupid, stupid, stupid. All three questions are beyond redemption. Even ten years ago, it was very apparent that we'd be finding more moons all over the place and that the question would likely be incorrect before the ink dried on the page. Worse still - it misses the beauty that is these ring systems. Jupiter has a donut as well as its rings. The hundreds of separate rings around Saturn are sometimes braided together and twist and un-twist as little 'nursemaid' moonlets orbit through the debris. It misses the point that moons and moonlets extend out from these large gas giants in uncountable numbers.
- This planet is 93 million miles from the sun. (by ang)
- I don't know what "by ang" means - but the only planet that is at approximately that distance is the Earth (which varies from 91.4 to 94.5 million miles from the sun - with an AVERAGE of 93 million miles). The "(by ang)" thing...WTF??
![](http://up.wiki.x.io/wikipedia/commons/thumb/d/dc/TheKuiperBelt_Orbits_Pluto_Neptune2.svg/300px-TheKuiperBelt_Orbits_Pluto_Neptune2.svg.png)
- This planet's orbit crosses Pluto every 248 years.
- Well - this is clearly INTENDED to elicit the answer "Neptune" - but it's not remotely correct. Pluto NEVER crosses Neptunes orbit - nor vice-versa! Not even close! It only looks that way on a typical top-down view of the solar system such as a teacher writing a textbook who knew less about the solar system than most of his students would see when struggling to write a quiz! If you look at the system in three dimensions (see picture to the right here) - you see that Pluto's orbit is so tilted that it never comes anywhere near Neptune. In fact, the closest that Pluto and Neptune EVER get to each other is about eleven times the distance from the Earth to the Sun! Pluto actually gets closer to Uranus than it ever gets to Neptune. But even if we're super-generous and we agree to use the classical "top down" textbook view - Neptune has an orbital period of 164 years and it "crosses" Pluto's orbit twice in each loop around the sun...so it crosses it TWICE in every 164 years - not ONCE in every 248. What they are thinking of is that Pluto's orbit is 248 years - but it too "crosses" the orbit of Neptune twice in each orbit - so even if the question asked which body crossed the orbit of Neptune every 248 years - they'd still be wrong. This question is SO far off being right...it's absolutely unbelievable. The orbital mechanics of Pluto and Neptune have been known for at least 60 years - so we can't even accept that the answer is a bit out of date...it's flat out WRONG.
- So, this very, very sad, sorry excuse for a quiz is some how managing to teaching kids at least six or seven incorrect facts in the space of just FIVE questions - and the only one that's remotely right is confusing! Heck, I'm beginning to think one of those Creationist loonies could have done a better job of this! ("Which planet did God name after Donald Duck's dog?")
- When people wonder why standards for science education is declining...this is the reason. Please tell your child's head-teacher that he/she should be ashamed to be pushing lies and half-truths onto the kids. It would be better not to teach them anything on that quiz than to teach them lies and half-truths.
- SteveBaker (talk) 03:33, 25 September 2008 (UTC)
- Steve, how disrespectful to those of faith. Everyone knows that Pluto is not a real planet. On top of which, Pluto was Mickey Mouse's pet!! Have you even read the bible? :) Franamax (talk) 14:44, 25 September 2008 (UTC)
- Yes, I know - I was trying to cleverly cram as much disinformation into a single sentence as possible...kinda like that last question in the quiz. Not only is Pluto not a planet anymore and Pluto is indeed M.Mouse's pet, not D.Duck's. But also: The name came from an 11 year old girl called Venetia Burney, not "God". The "dwarf planet" is named for the Greek version of Hades. It was a full 10 years later that the cartoon dog was named after the planet, not the other way around. Therefore, the only appropriate answer to my question is, of course "Goofy"! (Also - I'm one of a decreasing number of people who actually sat down and read the Bible from beginning to end...it's nearly as funny as Goofy.) :-P SteveBaker (talk) 23:20, 25 September 2008 (UTC)
- Yes, all as told in 2 Disney 4:3-19, you have read it! :) I've read the whole thing too, twice actually. I particularly liked the sequel, "God: The NEW Testament" - it had a lot less sex (no "begat"s) but some really awesome special effects (Revelations). Franamax (talk) 02:54, 26 September 2008 (UTC)
- All of that namby-pamby helping out the poor and needy thoughout the sequel is all very well - but I missed the whole killing off the youngest kids of an entire civilisation, raining blood (that stuff stains!), annihilating the entire ecosystem of the planet, screwing up people's brains so they all speak different languages...all great "vengeful god" stuff! SteveBaker (talk) 04:16, 26 September 2008 (UTC)
- Yes, all as told in 2 Disney 4:3-19, you have read it! :) I've read the whole thing too, twice actually. I particularly liked the sequel, "God: The NEW Testament" - it had a lot less sex (no "begat"s) but some really awesome special effects (Revelations). Franamax (talk) 02:54, 26 September 2008 (UTC)
- Yes, I know - I was trying to cleverly cram as much disinformation into a single sentence as possible...kinda like that last question in the quiz. Not only is Pluto not a planet anymore and Pluto is indeed M.Mouse's pet, not D.Duck's. But also: The name came from an 11 year old girl called Venetia Burney, not "God". The "dwarf planet" is named for the Greek version of Hades. It was a full 10 years later that the cartoon dog was named after the planet, not the other way around. Therefore, the only appropriate answer to my question is, of course "Goofy"! (Also - I'm one of a decreasing number of people who actually sat down and read the Bible from beginning to end...it's nearly as funny as Goofy.) :-P SteveBaker (talk) 23:20, 25 September 2008 (UTC)
- Steve, how disrespectful to those of faith. Everyone knows that Pluto is not a real planet. On top of which, Pluto was Mickey Mouse's pet!! Have you even read the bible? :) Franamax (talk) 14:44, 25 September 2008 (UTC)
- To be fair, Steve, there's at least a reasonable answer to the telescope bit. Many smaller moons were discovered via the Pioneer and Voyager missions, and were (at the time) quite invisible to Earth-bound telescopes. Given the HST and recent developments in adjusting for atmospheric interference, I doubt it holds any longer -- certainly the discovery of minor satellites around Pluto and such cast it into great doubt. But there's absolutely a way to discover a tiny moon without a telescope. — Lomn 15:54, 25 September 2008 (UTC)
- Well, a lot depends on whether you consider the cameras on Pioneer and Voyager to be "cameras" or "telescopes". Wiktionary says "A monocular optical instrument possessing magnification for observing distant objects, especially in astronomy." and Telescope says "A telescope is an instrument designed for the observation of remote objects and the collection of electromagnetic radiation.". The 1500mm lens that Voyager used for it's narrow field camera certainly falls under both definitions. And with that much magnifications, it's definitely what I'd call "a telescope". HST had been in use for 6 years before those questions were printed and it can image even the two tiniest known moons of Pluto - those are only 60 km's or so across and 30 to 50 AU's away. If the supposed answer is "Neptune" then most of it's smaller moons are over 150km across so HST can certainly image them. SteveBaker (talk) 23:20, 25 September 2008 (UTC)
- I read this as an ambiguous distinction also. Can be seen by telescope == depends on the telescope. Ground-based, space-based, set up in your back yard? Presumably the quiz is meant to be answered based on reading of a specific textbook - so the answers don't have to correspond to physical reality, they just have to satisfy the teacher that you've read, integrated and understood the supplied materials. That's really the basis of early education.
- Followup question though: once the various moons and rings were discovered by exploration craft, haven't they been subsequently observed and tracked by ground-based instruments? Franamax (talk) 02:54, 26 September 2008 (UTC)
- Well, a lot depends on whether you consider the cameras on Pioneer and Voyager to be "cameras" or "telescopes". Wiktionary says "A monocular optical instrument possessing magnification for observing distant objects, especially in astronomy." and Telescope says "A telescope is an instrument designed for the observation of remote objects and the collection of electromagnetic radiation.". The 1500mm lens that Voyager used for it's narrow field camera certainly falls under both definitions. And with that much magnifications, it's definitely what I'd call "a telescope". HST had been in use for 6 years before those questions were printed and it can image even the two tiniest known moons of Pluto - those are only 60 km's or so across and 30 to 50 AU's away. If the supposed answer is "Neptune" then most of it's smaller moons are over 150km across so HST can certainly image them. SteveBaker (talk) 23:20, 25 September 2008 (UTC)
- (Read, integrated and understood a lot of irrelevent and incorrect garbage from an outdated textbook...yes)
- Probably, yes. The tricky part of spotting moons is that they are very small and dim and they move quite quickly. You need LONG exposure times to capture a picture of a very dim object. Once you know the moon's orbital parameters, you can program your ground-based telescope to track it for hours accumulating tiny amounts of light and after enough time you'll have a decent picture. But the snag is that you can't FIND a moon that way - if you don't know where it is and how it's moving, you just can't image it. So I think that's probably why the spacecraft-based discoveries were initially important. Another part of it is that accumulating light in ground based telescope like this is great for doing things like spectroscopic and redshift analysis - but it's not so good for seeing craters and interesting surface features - for that, you need a spacecraft nearby. SteveBaker (talk) 04:01, 26 September 2008 (UTC)
- To a certain extent, the precise accuracy of information taught to a 5th-grader is not relevant, although it would be nice. Most people will get through life just fine with only a hazy understanding of the solar system - as long as they know planets orbit the sun, moons orbit planets, the whole thing is really big - knowing Pluto's orbital eccentricity doesn't help butter your toast. Learning how to learn is always the aim, and more precise facts can always wait 'til later schooling. And of course, now there's Wikipedia, where you can check to find out that the current number of known moons of Neptune is "my firend Janey is so awesome".
- You need to also keep in mind the incredible cost of new textbooks and learning materials plied by various consultancies; also the fact that many elementary-school teachers by and large didn't learn any science themselves beyond fifth-grade. Franamax (talk) 06:37, 26 September 2008 (UTC)
- I have to disagree with most of that. Things learned at an early age tend to stick very much. Why do you think oodles of unqualified (and indeed many qualified) people were interested in the status of Pluto? We don't need to teach all the details, of course, but we should make sure that we do not teach things that are plainly wrong. Yes, "learning to learn" is one aim. But such learning is much easier if you manage to get pupils interested in the material - and not disillusioned when they fact-check it somewhere else. And I dispute the "incredible cost of new textbooks and learning materials". For the price of one BGM-109 Tomahawk, we could buy about 10000-20000 elementary school textbooks. And unless my maths is wrong, you could bury each inhabitant (not every pupil!) of the US under 1000 textbooks per year calculating just the direct cost of the Iraq War. Of course, as a society we need to decide where our priorities are, but I would put more into the education of people and less into killing them. --Stephan Schulz (talk) 09:36, 26 September 2008 (UTC)
- You are assuming the textbook is old. I've had the opportunity to review drafts of a middle school science text currently in preparation and it contained some ridiculous inaccuracies (on par with those above) even though it was being written now. The problem, as I see it, is that much of the work in preparing science texts for elementary and middle school education is being done by people whose primary background is either education or writing. Such people seem to assume that if they graduated high school they obviously know enough science to teach it to young people, and that blind faith leads to some ridiculous errors. Thankfully there are some scientifically trained reviewers, but all in all the state of science texts below at least the 9th grade level can be pretty abysmal. It's not uncommon to see old untruths regurgitated because that's what the writer learned when they were in school and they don't have the science background to know when knowledge has evolved. Dragons flight (talk) 09:53, 26 September 2008 (UTC)
- It's instructive to read what Richard Feynman (my personal hero) thought about science textbooks - he took on the job of reviewing science books and was eventually defeated by the sheer frustrating task of fighting the system and trying to fix problems. I've tried (and failed) to get gross errors removed from several math and science textbooks in Texas. Even when the books were revised and reprinted - they ignored my error reports. In one case, a book has had the same error through three reprints despite three long and carefully reasoned/documented letters of complaint to the author, the publisher and the school authorities. I've had better success in getting my kids' grades fixed when he answered a question 100% correctly and was marked down because the official answer was hopelessly wrong. Some of the problems were pretty serious - for example, in geometry, it was exceedingly difficult to get the school authorities to agree that a square is a rectangle and a parallelogram and a rhombus...or that an equilateral triangle is an isosceles triangle and an acute triangle. Those are not small matters - the idea that because something is a member of a specific class, that this somehow removes it from a more general class is a severe academic error that can affect someone's thinking for years to come. Those kinds of problems go well beyond accidentally teaching that Uranus has the wrong number of moons. However, there is no excuse for having ANY errors in a textbook. SteveBaker (talk) 12:58, 26 September 2008 (UTC)
- You are assuming the textbook is old. I've had the opportunity to review drafts of a middle school science text currently in preparation and it contained some ridiculous inaccuracies (on par with those above) even though it was being written now. The problem, as I see it, is that much of the work in preparing science texts for elementary and middle school education is being done by people whose primary background is either education or writing. Such people seem to assume that if they graduated high school they obviously know enough science to teach it to young people, and that blind faith leads to some ridiculous errors. Thankfully there are some scientifically trained reviewers, but all in all the state of science texts below at least the 9th grade level can be pretty abysmal. It's not uncommon to see old untruths regurgitated because that's what the writer learned when they were in school and they don't have the science background to know when knowledge has evolved. Dragons flight (talk) 09:53, 26 September 2008 (UTC)
- I have to disagree with most of that. Things learned at an early age tend to stick very much. Why do you think oodles of unqualified (and indeed many qualified) people were interested in the status of Pluto? We don't need to teach all the details, of course, but we should make sure that we do not teach things that are plainly wrong. Yes, "learning to learn" is one aim. But such learning is much easier if you manage to get pupils interested in the material - and not disillusioned when they fact-check it somewhere else. And I dispute the "incredible cost of new textbooks and learning materials". For the price of one BGM-109 Tomahawk, we could buy about 10000-20000 elementary school textbooks. And unless my maths is wrong, you could bury each inhabitant (not every pupil!) of the US under 1000 textbooks per year calculating just the direct cost of the Iraq War. Of course, as a society we need to decide where our priorities are, but I would put more into the education of people and less into killing them. --Stephan Schulz (talk) 09:36, 26 September 2008 (UTC)
- Probably, yes. The tricky part of spotting moons is that they are very small and dim and they move quite quickly. You need LONG exposure times to capture a picture of a very dim object. Once you know the moon's orbital parameters, you can program your ground-based telescope to track it for hours accumulating tiny amounts of light and after enough time you'll have a decent picture. But the snag is that you can't FIND a moon that way - if you don't know where it is and how it's moving, you just can't image it. So I think that's probably why the spacecraft-based discoveries were initially important. Another part of it is that accumulating light in ground based telescope like this is great for doing things like spectroscopic and redshift analysis - but it's not so good for seeing craters and interesting surface features - for that, you need a spacecraft nearby. SteveBaker (talk) 04:01, 26 September 2008 (UTC)
Btw, can someone tell me what a "packet" is, as used in this question title? Packet makes me think of cereal boxes, not textbooks (unless that is where the incorrect information comes from?) Gwinva (talk) 04:38, 26 September 2008 (UTC)
- Sometimes, especially in grammar schools, teachers hand out material (photocopies of articles, worksheets, selected pages in books, etc.) in bundles or "packets" (often in manilla envelopes) and teach from that material rather than from textbooks. That's what's being alluded to here. Of course, it ought to be easier to keep such material up to date! - Nunh-huh 05:17, 26 September 2008 (UTC)
- Thank you! I suspected that might be the case, but didn't want to assume. But "grammar school"? US usage = elementary school? Gwinva (talk) 07:49, 26 September 2008 (UTC)
- Synonyms in U.S. usage. Probably older folk use "grammar school", younger folk, "elementary". Of course now it's all hopelessly confused, with "middle schools" and such :) - Nunh-huh 07:53, 26 September 2008 (UTC)
- Again, thank you! Where I come from, grammar schools are secondary schools (high schools)... As for packets, they're generally just called "hand outs" or "work sheets". A people divided by a common language, and all that... Gwinva (talk) 07:59, 26 September 2008 (UTC)
- Synonyms in U.S. usage. Probably older folk use "grammar school", younger folk, "elementary". Of course now it's all hopelessly confused, with "middle schools" and such :) - Nunh-huh 07:53, 26 September 2008 (UTC)
- Thank you! I suspected that might be the case, but didn't want to assume. But "grammar school"? US usage = elementary school? Gwinva (talk) 07:49, 26 September 2008 (UTC)
About 2500 words have been written in response to the OP. Maybe some of them could go into Wikijunior:Solar_System? Saintrain (talk) 16:40, 26 September 2008 (UTC)
Does anybody know color of Neptune's sky. To me it looks ocean blue. If Neptune's sky is blue how blue. Is it dark blue?--57Freeways 00:16, 25 September 2008 (UTC)
- I'm not really sure how you define "sky" for a gas giant. There is no real surface to stand on and look up - by the time you reach anything solid it will be dark (well, there will be no sunlight - it's actually white hot at those depths, I believe). The atmosphere above you will most likely look very different at difference altitudes. The Earth's sky is blue due to Rayleigh scattering, Neptune looks blue from the outside due to its absorption spectrum - those are very difference causes. I think the absorption spectrum would still make the sky appear blue from the inside, but I don't know what would happen with scattering, so it could be any colour. --Tango (talk) 01:58, 25 September 2008 (UTC)
- I meant by above the cloud-tops, I thouhgt neptune looks rich blue on the sky above clouds.--57Freeways 03:27, 25 September 2008 (UTC)
- I think Tango's caveats still apply. "Above the cloud tops" is a fairly vague definition for a gas giant. Neptune's Great Dark Spot, for instance, is thought to be a gap in cloud cover rather than a cloud itself. Additionally, "true color" is a very tricky concept when it comes to photography. Note NASA's photo gallery of Neptune, where Voyager's near-true-color image is darker and less saturated than the HST's. Images at SolarViews show the same contrast. — Lomn 15:38, 25 September 2008 (UTC)
But the article said neptune's sky is blue. Uranus is too. neptune I thought has a haze layers which would put the sky color to be ocean blue. It wouldnot be black because it have an atmosphere. Uranus have a haze layers so it's sky is thought to be light blue, just like Earth's same as Saturn's.--57Freeways 22:36, 26 September 2008 (UTC)
- How you explain this? jupiter, Saturn, Uranus's sky is blue above the clouds, and they must have some haze layers so does Neptune.--57Freeways 22:52, 26 September 2008 (UTC)
- Those are photos taken from the outside. "Sky" is what you would see looking up from inside the atmosphere, that's not necessarily the same colour as the atmosphere from the outside. --Tango (talk) 23:03, 26 September 2008 (UTC)
Global Warming Counterargument
[edit]I was debating this subject with someone, and he said that the temperature will not continue to rise indefinitely as proposed by "An Inconvenient Truth" (I'm not sure that Al Gore was making that point; it's what my opponent said) and that if one examines the history of Earth's climate, we are in a relatively stable period; essentially, stability is abnormal. Is there any truth to these claims?CalamusFortis 04:29, 25 September 2008 (UTC)
- Scientists have been arguing over this topic for years, so unfortunately we can't provide THE answer. For starters, you might enjoy "The Great Global Warming Hoax?", which predicts global cooling. Also New Zealand Climate Science Coalition, which offers links to many interesting research articles. Gwinva (talk) 04:49, 25 September 2008 (UTC)
- I don't think anyone claims the temperature will rise indefinitely. If they do, they are clearly wrong. There is only so much heat coming from the sun, so the planet will have to reach equilibrium eventually, whatever happens. --Tango (talk) 14:46, 25 September 2008 (UTC)
You should also know that many of the scientists who were quoted on the great global warming hoax consequently sued C4 for taking their remarks out of context...82.22.4.63 (talk) 17:39, 25 September 2008 (UTC)
- Did they? Nice to know. I was merely offering links which might provide some of the "counterarguments" requested by the OP, but since I've not read either of them, I'm certainly not in a position to judge their academic rigour. Gwinva (talk) 02:41, 26 September 2008 (UTC)
- Indeed. And neither Al Gore nor any scientist worth the appellation claims or claimed that temperature will rise "indefinitely". As a first, very rough approximation, it cannot become hotter than the maximum of its current core temperature and the surface of the sun without violating the second law of thermodynamics. More realistically, the current predictions center around about 3° Celsius temperature increase per doubling of atmospheric CO2. The normal difference between icehouse and hothouse modes of Earth's climate are about 10° degrees Celsius (globally - much more in high latitudes), so I would not consider a very much higher rise due to anthropogenic greenhouse gases likely. Note, however, that even that would have devastating effect - including complete meltdown of the ice caps, sea level rise of 60-70m (enough to flood most costal plains and cities), and corresponding social and political unrest (to put it mildly). On the plus side, all that will take a long while - IPCC projections for 2100 are "only" 9-88cm, and while thy are conservative, they are not outrageously so. And yes, while civilization will suffer and may even break down, life will almost certainly go on for several million years more. --Stephan Schulz (talk) 18:10, 25 September 2008 (UTC)
Certainly an "indefinite" rise is right out of the question...however, it seems technically possible that we could conceivably drive the planet to the point where it looks like Venus...a surface temperature of 460 degrees C. (Well, actually, the earth is further from the sun - so it would be a bit lower than that - but not by much). To get to that point, we'd have to initially drive the temperatures up to the point where deep ocean methane-hydrides would melt and dump methane (a nasty greenhouse gas) into the atmosphere and the oceans. That would cause plants and algae to die off on vast numbers - that would start to shut off CO2 absorption - CO2 from rotting vegetation, forest fires and volcanoes would build up in the atmosphere causing still higher temperatures - more plant die-off - less CO2 absorption - more heat...with nothing to stop it. Gradually, the increasing acidity of the atmosphere combined with higher temperatures would cause carbonate rocks to start to boil off CO2 - yet more greenhouse gasses - eventually, we'd hit 100 degC and then the oceans would boil - and the resulting enormous quantities of water vapor (which is an even bigger greenhouse gas than CO2) would drive things even further off the rails. As these additional gasses enter the atmosphere, it gets denser and denser - and that too pushes the heat up and promotes other chemical reactions to acidify the atmosphere. Eventually, thermodynamics demands that things level off - but by then, Earth is Venus-2.0! So I think if we ever let things get so bad that large scale plant die-offs started to happen then we'd be unable to prevent runaway heating of the planet...reaching maybe 200 to 300 degC (Venus is at 460degC...so it's not impossible).
But it's pretty academic because we'd all be dead LONG before that happened.
It seems very unlikely to me that things could possibly get that bad - but there are a lot of 'runaway' situations here and when you get "positive feedback" in a system, it can be impossible to stop. It's hard to know for sure though because some things (such as increased evaporation of the oceans) can both help and hinder the process. More evaporation means more greenhouse-gasses (water vapor) - but it also means more fluffy white clouds which reflect sunlight back out into space again. In those cases, it's incredibly hard to predict when the point comes where the increase in cloud cover balances the increase in greenhouse gasses.
But I certainly wouldn't want to exclude the possibility of Venus-like conditions arising from this situation.
SteveBaker (talk) 22:43, 25 September 2008 (UTC)
- Hi. Although stability is rare, on a human history scale we have been enjoying this stability for a very long time. So, if a sudden change occured, it would seriously disrupt civilization, becuase all of modern civilization has developed during this stability. Quoting another Wikipedian, such a drastic temperature rise like the one predicted "would be seen as nothing short of apocalyptic". Thanks. ~AH1(TCU) 01:39, 26 September 2008 (UTC)
- Although we can only hope that SteveBaker's apocalyptic scenario won't arise, there is a potential trigger to release those oceanic clathrates. Permafrost areas in the Arctic have unusually large stores of unprocessed carbon, i.e. plant matter that has not yet been processed by microbes. Warming could potentially release this carbon, most unpleasantly as methane. I can't find the disturbing reading on the "budgets" involved (the potential releases would dwarf total anthropogenic emissions), but I did find a few papers [1] [2]. Of course, like everything GW-related, there is intense controversy on this. However, if we do get caught in a feedback loop (and considering that GW is manifesting strongly in the Arctic, it's not impossible), that little bit of extra warming could be enough to release methane hydrates from the ocean on a large scale. Then we would have a problem! Franamax (talk) 03:18, 26 September 2008 (UTC)
- What makes the "runaway to Venus" unlikely is that the temperature of Earth was quite a bit higher at some times in the past (due, among others, to changes in orbital cycles, continental drift, and tectonic processes affecting the atmosphere), and that we quite possibly already survived at least one Methane hydrate gasification - well, the lucky 10% or so of species did. Of course, this may well be a stochastic process, and we got lucky. We may or may not get lucky the next time (if any), especially considering that the sun is (very slowly) warming up... --Stephan Schulz (talk) 19:26, 26 September 2008 (UTC)
Chemistry
[edit]What is the basic Difference between Radical and Ion.I Think that Radical is the Group of charge molecule. EG NH2+ please satisfy me.i will be very thankful to u. —Preceding unsigned comment added by 119.152.246.120 (talk) 05:24, 25 September 2008 (UTC)
- A radical is a molecule, atom, or ion with an unpaired electron. An ion is a molecule or atom with a different number of protons than electrons. An ion may be a radical, but there are ions that are not radicals, and radicals that are not ions. Someguy1221 (talk) 05:39, 25 September 2008 (UTC)
Histogram of distribution of skin color
[edit]I had an odd thought last night: what would an accurate histogram showing the distribution of skin color in the world look like? Anybody have a guess, or the data needed to put one together? --98.217.8.46 (talk) 12:28, 25 September 2008 (UTC)
- Von Luschan's chromatic scale has a map showing global distribution according to his classification, however it doesn't deal with respective populations of the area. -- MacAddct1984 (talk • contribs) 14:02, 25 September 2008 (UTC)
- Right, I'm interested in populations. But I'm not interested in imagined "native populations", either, I'm interested in the current population. --98.217.8.46 (talk) 14:48, 25 September 2008 (UTC)
2D PAGE not sensitive to low-abundance proteins
[edit]I'm reading a journal article about a 2D PAGE which did not show some of the proteins expected "possibly due to their low abundance". They then say "more comprehensive analyses will be performed to identify the altered low-abundance cellular factors by using large-size gel slabs, depletion high-abundance proteins, enrichment of the samples by pre-fractionation and by using silver staining coupled with LC-MS/MS analysis". How do you suppose they might deplete high-abundance proteins, leaving the low abundance ones unaffected? What do they mean by pre-fractionation? Is silver-staining more sensitive or does it just enable the LC-MS? --Seans Potato Business 13:21, 25 September 2008 (UTC)
- Using high performance liquid chromatography and liquid chromatography-mass spectrometry, i.e. LC-MS. See this reference. Silver staining assists PAGE. See this reference. Axl ¤ [Talk] 16:15, 25 September 2008 (UTC)
- I have an article on my desk I've intended to read for months now. "Recent Developments in High-Abundance Protein Removal Techniques" in LCGC North America vol 26 no 3 p 278 by Tim Wehr. My quick skim of the article suggests it is exactly what you are asking about. I think that articles from this non-peer review mag are available on line for free. ike9898 (talk) 16:42, 26 September 2008 (UTC)
- Hey, thanks for the tip. A quote from the arrticle: Using "split-couple-recombine" combinatorial systhesis, a library of hexapeptides bound to macroporous 65-μm-diameter polymethacrylate microbeads is produced, with each bead carrying a unique peptide sequence. The sequential coupling of the 20 protein amino acids results in a library of 206 unique beads. These are packed in spin columns with a 100-μL bed volume. In contrast to antibody-based immunodepletion products, which typically have a capacity of 100 μL or less, sample volumes of 1 mL and more can be applied to the ProteoMiner beads. Because there are a limited number of binding sites for each protein, HAPs quickly reach the bead capacity, and excess HAPs are passed through the column. After sample introduction and washing, bound proteins are eluted from the column with a small volume (≤300 μL) of elution buffer (5% acetic acid, 8 M urea, 2% CHAPS). The net result is depletion of HAPs accompanied by at least a threefold increase in the concentration of LAPs - is this not a ridiculous idea? Surely some LAPs (low abundance proteins) simply wont bind to a hexapeptides and be flushed staight through? I see no reason to assume all or even most LAPs would recognise any hexapeptide. --Seans Potato Business 22:42, 27 September 2008 (UTC)
physical draw backs of jogging
[edit]1.does jogging makes a man slim quickly but as we leave the routine ,fatness reverses fast again. 2.does it have any drawbacks for jogging after some eating. 116.71.188.65 (talk) 14:26, 25 September 2008 (UTC)
- Moved poster's sig to proper spot. Franamax (talk) 14:34, 25 September 2008 (UTC)
- We can't give medical advice. Ask a doctor/nutritionist/personal trainer. --Tango (talk) 14:42, 25 September 2008 (UTC)
- This isn't medical advice...1) Jogging, like any physical activity, will help to burn calories - that's not guaranteed to cause weight-loss but increased exercise is reasonably well correlated with becoming 'healthy' (so if you are overweight it may burn off fat). Obviously if you stop jogging then your calorie-burning will reduce (unless you replace the activity). To combat this you could take in less calories, or burn calories through other activities. 2) Jogging after eating might be uncomfortable if you feel 'full up' so aren't as flexible. Similarly running on an empty stomach could cause discomfort too. 194.221.133.226 (talk) 14:52, 25 September 2008 (UTC)
- The first question might not be, but the second is. If we say there are no drawbacks and then the OP goes jogging after eating and falls down ill because of it, we could end up in a lot of trouble. --Tango (talk) 15:00, 25 September 2008 (UTC)
- No, we wouldn't end up in trouble. The no medical advice bit is not a legal requirement. In general, there's no reason not to jog after eating, it is up to your own preference. Some people are fine with it, others feel uncomfortable. This is not medical advice tailored to your situation, this is just a general statement of pretty commonly known information. --98.217.8.46 (talk) 22:59, 25 September 2008 (UTC)
- I believe the Wikipedia:Medical disclaimer prevents us from getting into legal trouble. We don't give medical advice here to protect OPs from harm. Zain Ebrahim (talk) 12:42, 27 September 2008 (UTC)
- No, we wouldn't end up in trouble. The no medical advice bit is not a legal requirement. In general, there's no reason not to jog after eating, it is up to your own preference. Some people are fine with it, others feel uncomfortable. This is not medical advice tailored to your situation, this is just a general statement of pretty commonly known information. --98.217.8.46 (talk) 22:59, 25 September 2008 (UTC)
- I agree with anonymous editor 194.221.133.226. This is not "medical advice". A doctor or nutritionist would be no better informed than anyone else (although a personal trainer might be). As 98.217.8.46 states, the answer to question 2 is derived from common sense and general knowledge. Axl ¤ [Talk] 07:39, 26 September 2008 (UTC)
How is water taken up by the body?
[edit]I feel silly for asking, but I seriously can't find any good info. I guess my search terms are pretty bad. When drinking water, where in the body is it taken up? Does stomach acid matter at all? Does having a full/empty stomach matter? And, perhaps most importantly, how long does it take to clear out of the stomach? Thanks in advance. -- Aeluwas (talk) 14:39, 25 September 2008 (UTC)
- It's absorbed in the intestines, both small and large, according to those articles. I don't know about the rest of your questions. --Tango (talk) 14:58, 25 September 2008 (UTC)
- From Guyton's Textbook of Medical Physiology, 11th edition, chapter 65. Very little water is absorbed in the stomach. This is because the internal lining (epithelium) lacks villi, which are abundant in the small intestine. Between six and eight litres of water are absorbed from the small intestine each day. A further one and a half litres are absorbed in the colon. [Most people drink between one and three litres each day. The "extra" water absorbed comes from secretions into the gastrointestinal tract.] Stomach acid makes no difference. Axl ¤ [Talk] 16:50, 25 September 2008 (UTC)
- Thanks guys. I also found these links: gastric emptying and the effect of omeprazole on water gastric emptying. It looks like ~15 minutes would be a normal time to get rid of 50% of the water. -- Aeluwas (talk) 19:55, 25 September 2008 (UTC)
Hair Growth in Mammals
[edit]in many cows ,dogs etc the hair cant grow from certain point but coats ,man etc it grows continously .can some explain me this fact. —Preceding unsigned comment added by 119.154.2.133 (talk) 16:20, 25 September 2008 (UTC)
- Hair follicle goes through cycles. At the end of the cycle the hair is shed. Some animals (cows) have shorter cycles so the hair stays short. Others (people) have longer cycles. A person's eyebrow's follicles have shorter cycles (a few months) than head hair follicles ( a few years) so head hair can grow much longer before it sheds but eyebrows stay short. Saintrain (talk) 19:23, 25 September 2008 (UTC)
- But then why would human head hair have such long cycles? --Kjoonlee 23:46, 26 September 2008 (UTC)
Are cows immune to CS gas?
[edit]Just heard someone on a radio phone-in quote the factoid that cows are supposedly immune to the effects of CS gas. Anyone able to confirm/deny? It doesn't sound to me like something that anyone would even bother to test... --Kurt Shaped Box (talk) 16:57, 25 September 2008 (UTC)
- CS gas does not address cows specifically, but says Notably, CS has a limited effect on animals due to "under-developed tear-ducts and protection by fur". -- Coneslayer (talk) 17:03, 25 September 2008 (UTC)
- I'm sure they would bother to test it, since virtually all chemical weapons (even mild ones like this) are tested extensively on animals. --Sean 18:57, 25 September 2008 (UTC)
- But I don't know if cows are a common test subject Nil Einne (talk) 20:33, 25 September 2008 (UTC)
- I've been pondering this on-and-off since I posted the question. Perhaps a herd of cows was used at some point as an experimental substitute for a crowd of hostile rioters when testing CS gas grenades in the open air? Only thing I can think of (though it doesn't really sound plausible)... --Kurt Shaped Box (talk) 22:11, 25 September 2008 (UTC)
- Is there a plausible situation in which the use of CS gas against protesters also affected a herd of cows? It could have been an incidental observation. Plasticup T/C 22:31, 25 September 2008 (UTC)
- These sorts of factoids are often over-specific to make them seem more obscure. (ie : "It's illegal to hitch a pet [exotic animal] to a fire hydrant.") Perhaps someone took the fact that animals are resistant to CS gas and decide to restate it as "cows are resistant". It wouldn't take too many retelling for that to become "cows are immune". APL (talk) 01:07, 26 September 2008 (UTC)
- Cows have big eyes as well as noses with mucous membranes, neither protected by fur. I doubt that a cow in a cloud of CS would be immune to its effects. As soon as the irritant contacts the eye, the interior of the nose, the mouth and the lungs it has its effect. Having fur might protect somewhat against direct skin contact, which is the least of your worries. Edison (talk)
Why do people prefer creamy skin lotions compared to solid or liquid formulas?
[edit]I got addicted watching skin cream ads on YouTube and wondered why every lotion and cream for the skin is a whipped white concoction? Is there something humans like about white creamy lotions as opposed to colored oily or watery formulas? Do any wild animals put anything on their skin to soothe dryness? --70.167.58.6 (talk) 22:19, 25 September 2008 (UTC)
- Any coloring agent in the lotion is likely to stain skin and clothing. --Sean 22:54, 25 September 2008 (UTC)
- Pigs roll in the mud to cool themselves off... I don't know if they get any moisturizing effect out of it to (or get one intentionally, anyway). --98.217.8.46 (talk) 23:03, 25 September 2008 (UTC)
With a creamy lotion, it's easier to control where you're applying it than if it's more watery. --Anonymous, 03:03 UTC, September 25, 2008.
- What about it was gelatinous or paste? --70.167.58.6 (talk) 16:30, 26 September 2008 (UTC)
- Well, people certainly use petroleum jelly (a clear jelly/paste) as a moisturizer. (The original Vaseline was petroleum jelly.) Although it works (sometimes better than other moisturizers), petroleum jelly is usually not preferred anymore because of the "greasy feel". If you listen to the adverts, you'll see they'll often mention "it doesn't feel greasy!" Also being noncomedogenic (not clogging pores/forming acne) is important for some people - petroleum jelly may cause acne issues, depending on how/where it's used. The greasy/non-greasy issue is also probably why medicinal creams are preferred these days to ointments and liniments -- 128.104.112.147 (talk) 19:41, 26 September 2008 (UTC)
- So what makes "greasy" skin cream less undesirable? What's the psychology behind that? --70.167.58.6 (talk) 14:50, 29 September 2008 (UTC)
- I don't know exactly, but I'd guess it's due to discomfort with there being "something" on your skin, or concern over transferring the grease elsewhere. Ointments/moisturizers are usually applied with the hands, and once finished applying, you usually have to clean up your hands with a "greasy" product (or else there is still the "grease" on your hands), while non-greasy products usually absorb into the skin well enough not to require cleanup. -- 128.104.112.147 (talk) 23:18, 30 September 2008 (UTC)
QFT Example?
[edit]The pages under quantum field theory seem to lack examples. Could someone show an example of, say, an electron in a box, perhaps radiating photons to go to lower states, using a QFT, so those of us who aren't intimately involved in it can appreciate better how it works? --Zemylat 22:44, 25 September 2008 (UTC)