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May 14 Information
I've been working on Zoological Society of London and I have two questions about officers of that society:
- (1) Zoological Society of London#Presidents - there are seven links there to pages about titles, rather than people. Effectively, those seven links need to be disambiguated to point to the right person. Can anyone here help with working out which earls, lords, marquesses, dukes and viscounts are which?
- (2) Zoological Society of London#Secretaries - there are two entries missing (the officers of this society serve for three year terms). These two missing entries are currently marked by [...], but if anyone can find out who those two missing entries are, I'd be very grateful.
Thanks. This may be more of a history question - will post a link from over there as well. Carcharoth ( talk) 00:04, 14 May 2009 (UTC)
- Why don't you raise this content question here ? Cuddlyable3 ( talk) 14:45, 14 May 2009 (UTC)
- I was kind of hoping people here could help. I've sometimes asked questions here about obscure stuff for articles and got answers and sources that have been channelled back into the articles, thus improving them. Sometimes you are more likely to get an answer here than on the article talk page, though you are right in that that should also be tried. See also Wikipedia:WikiProject Reference Desk Article Collaboration and Template:WPRDAC. Carcharoth ( talk) 21:17, 14 May 2009 (UTC)
Is an electron a particle or is it an em wave ? —Preceding unsigned comment added by 79.75.124.111 ( talk) 00:22, 14 May 2009 (UTC)
- See Electron which states that "Electrons have quantum mechanical properties of both a particle and a wave". somehow i thinck u new that! - hydnjo ( talk) 00:42, 14 May 2009 (UTC)
- An electron is definitely not an em (electromagnetic) wave. The particle of the electromagnetic field is the photon, not the electron, despite the name. The electron is a different kind of wave. -- BenRG ( talk) 01:22, 14 May 2009 (UTC)
- The electron is neither a wave nor is it a particle. It is an electron. When we attempt to explain its behavior using only classical mechanics it becomes necessary to sometimes treat it like a discrete particle, and other times to treat it like a wave, but this is only because classical physics is inadequate for dealing with the realities of electron behavior. Classical mechanics lacks the ability to create an adequate model for fully explaining electron behavior, and so we end up with the unsatisfying paradox of wave-particle duality. Thankfully, quantum mechanics exists, and it takes care of these apparent paradoxes just fine. See also Copenhagen interpretation for some more background on the philosophy behind the quantum mechanics/classical mechanics tension. -- Jayron32. talk. contribs 03:54, 14 May 2009 (UTC)
SciFi warning - What could be a future way of remotely sampling someone's DNA for analysis, say, from a meter or so away? Could a laser be used? Thank you. 190.17.201.142 ( talk) 00:27, 14 May 2009 (UTC)
- Normally you need to
extract DNA out of
cells, with steps continuing after that. See
DNA extraction.
Mac Davis (
talk) 03:38, 14 May 2009 (UTC)
- There is nothing in our current technology that could be imagined to be used one day for a kind of quick DNA scanning of a cell?
190.17.201.142 (
talk) 03:52, 14 May 2009 (UTC)
- You could imagine an extra-large Glonckian scanner. This is a device that superimposes a copy of itself into the subject and collects a sample, then uses quantum teleportation to move the virtual sample (but not the copied Glonckian scanner) back into the cloud chamber of the original scanner. Of course, Glonks are usually mean to scan much smaller molecules, but one might eventually be built with a really large sampling hydrator to capture an entire DNA molecule. Tempshill ( talk) 04:08, 14 May 2009 (UTC)
- There is nothing in our current technology that could be imagined to be used one day for a kind of quick DNA scanning of a cell?
190.17.201.142 (
talk) 03:52, 14 May 2009 (UTC)
- I suppose one might be able to sample dead skin cells by blowing air-flows over the person in question. Once you have a sample (even a small one) then extracting the DNA and running some kind of classification scan on it could probably be automated and brought down to a couple of minutes. But the trouble with sampling at a distance like that would be lie in being 100% sure that the material you get a hold of did actually come from that person. Cross-contamination is a serious problem for DNA magnification techniques - just one DNA molecule from someone else would be plenty to screw up the results. I suspect that we'd use some other identification technique in the future. Between photographs, super-low-dosage X-rays and other remote sensing techniques - I'm sure you could easily gather enough biometric data to figure out who someone is.
SteveBaker (
talk) 04:47, 14 May 2009 (UTC)
- you could fire a very tiny projectile, that knocked off a few cells, or jab with a long thin needle very quickly. Perhaps a kind of smart dust or nanobot could accomplish the mission. Graeme Bartlett ( talk) 10:30, 14 May 2009 (UTC)
- Think about it. Cuddlyable3 ( talk) 14:38, 14 May 2009 (UTC)
Today I was discussing the concept of semi-durable goods with a friend, things like furniture, book shelves, plastic bins you might keep on your desk or for your clothes etc. I have also seen lots of yard sales + things on the side of the road, (old chairs, furniture etc) and It got me thinking about what the average life of most of these goods is. How long does the average ikea table last? Bookshelf ? Chair? etc. Seems to me there is a big range, from 6 mo's for the worst of it up to 100's of years for the best. Anyone have any thoughts on where to get this data? Or ever see it discussed? —Preceding unsigned comment added by 72.230.5.95 ( talk) 01:04, 14 May 2009 (UTC)
- Depends on what you mean by lasting. Do repaired items count as lasting? Because then the lifespan of a piece of furnature is indefinate, see the Ship of Theseus paradox for more... -- Jayron32. talk. contribs 03:48, 14 May 2009 (UTC)
- Well, things like tables don't ever wear out - they get progressively more marked and chipped and so forth - but the "life" of the object is almost infinite. We have a 200 year old hall table and it's 100% functional. I don't see why it wouldn't be functional in another 200 years. Certainly some classes of furniture can get broken - but that's a random event that's not in any way related to the age of the furniture. So I don't think you can put a lifespan on that - if it breaks, it's a random event that's as likely to happen on the day you buy it as on a day 200 years later - and if it just gets unacceptably "scruffy" then it's down to your tolerance for scruffy furniture - it'll still be perfectly functional when it's so beat up that you decide it's at the end of it's life and replace it. Obviously, upholstered furniture has a more certain life - but you can always re-upholster anything like that as many times as you need to. We had a pair of sofa's that saw hard duty in our family room (they were really seriously abused) and they were terminally scruffy by 15 years old. However, a few hours with a sewing machine and a staple gun - and they looked brand new again. Things like bookshelves literally can last forever. The bookcase in my study was the one that came "free" with a complete set of Encyclopedia Britannica's in 1960. The books are long gone (who needs them when you have Wikipedia?) - but the bookcase lives on.
- There are antique pieces of furniture in daily use in some people's home that was made many centuries ago - it's still 100% functional. Just about the only furniture we've even been forced to throw out was a pair of crappy MDF computer desks that both failed due to the poor choice of construction techniques - but my victorian writing desk gets daily use - and will undoubtedly outlive me!
- SteveBaker ( talk) 04:41, 14 May 2009 (UTC)
- If you are looking for record breakers look at furniture from old tombs (e.g. [1]). This is mostly a question of durable materials. laminated particle board or Medium density fiberboard contains glues and binders that will dissipate or change over time. So it's unlikely our descendants will find many "ancient" examples of that. Despite it's reputation plastic is only durable under ideal storage conditions. Otherwise the plasticizers will get lost over time and the piece will become brittle. Whether a piece of furniture survives depends a lot on what value their owner assigns to it. The Germans have a funny nickname for their bulky trash pick-up days "furniture trading day". (OR One of my ancestors is remembered by reportedly using a Rosewood cabinet as firewood. They had just gotten brand new plywood furniture.) 71.236.24.129 ( talk) 08:58, 14 May 2009 (UTC)
![[1]](http://images.google.com/imgres?imgurl=http://daphne.palomar.edu/mhudelson/WorksofArt/02Egyptian/2121.jpg&imgrefurl=http://daphne.palomar.edu/mhudelson/WorksofArt/02Egyptian/2121.html&usg=__krmlSehu7QQHnGu1CY4gd1xFSWE=&h=577&w=386&sz=96&hl=en&start=3&sig2=AMom13seDyvFA_3hoZr8Iw&tbnid=krl_I3a9KPay0M:&tbnh=134&tbnw=90&prev=/images%3Fq%3DTutankhamun%2527s%2Bthrone%26gbv%3D2%26hl%3Den%26sa%3DG&ei=CdULSvSuBKmktgf3sfD4Bw){kind=link}
- When we lived in Germany (Moenchengladbach) in the late '70s it was also known as the "monthly schrank," a schrank [sp?] being a large item of furniture something like a Welsh dresser. The custom was that anyone looking for 2nd-hand furniture or other items such as stereos would tour the streets and take whatever they wanted before the municipal lorries came round to collect the remainder. There was no social stigma attached, and a lot of the goods put out were good quality and in good condition. 87.81.230.195 ( talk) 23:34, 14 May 2009 (UTC)
- Here are hypotheses about the lifetime of semi-durable household goods. They may or may not be possible to quantify by collecting data from sources such as media advertisements, private ads, repair services and municipal trash dumps.
- An item can have more than one average lifetime
- The time it stays fashionable
- The time it is saleable, new or used
- The time it is useable, including justifiable repairs
- The time it is collectable.
- The above lifetimes are different for a high-consumption relatively wealthy society or an economically challenged society. Cuddlyable3 ( talk) 14:23, 14 May 2009 (UTC)
- An item can have more than one average lifetime
- Here are hypotheses about the lifetime of semi-durable household goods. They may or may not be possible to quantify by collecting data from sources such as media advertisements, private ads, repair services and municipal trash dumps.
- And all bets are off for your wooden furniture if you get termites. 65.121.141.34 ( talk) 19:56, 14 May 2009 (UTC)
- I would never touch second-hand furniture for fear that it might have bedbugs (Cimex lectularius). They seem to be spreading rapidly. They are a real horror. I won't even sit on a chair any more in a waiting room or other public place. I no longer go to movies or theaters. When bedbugs become well established in a home, they are almost impossible to get rid of, like cockroaches. At least cockroaches do not suck your blood. Wikipedia has an article on bedbugs. Also see bedbugger.com. - GlowWorm.
- If you aren't against bugs in general check out this guy for a natural countermeasure: Scutigera coleoptrata. 71.236.24.129 ( talk) 10:21, 15 May 2009 (UTC)
You know when you look up into a clear blue sky (could be anything, really, but this is an example), and you see little tiny round 'bubbles', almost like bacteria, but you can't quite look directly at them because they are on the surface of your eye (I'm not mad, everyone I know sees them)? What are they called and, more importantly, what are they? Actually bubbles in the liquid on your eyes? Do they even have a name?-- KageTora - (영호 (影虎)) ( talk) 02:57, 14 May 2009 (UTC)
-
floaters.
Dauto (
talk) 03:01, 14 May 2009 (UTC)
- Incredible! This is why I love Wikipedia! Thanks!-- KageTora - (영호 (影虎)) ( talk) 04:30, 14 May 2009 (UTC)
There was a tropical disease I heard about in Guam that humans would contract when they rubbed their backs against the trunks of palm trees for itch relief. Tiny microorganisms would be left on your body and you would feel very bad and cause your skin to itch more. To my knowledge it did not particularly afflict Guamanians, I just heard about it in the Navy hospital. Can not remember if this was fatal. Can anybody help? I thought it was Chagas disease but after reading the article I am not sure this is the case. Mac Davis ( talk) 03:30, 14 May 2009 (UTC)
I've been watching NASA TV to see the crew of STS-125 capture the Hubble Space Telescope and start servicing it. One thing puzzled me about the entire process: Why does it take so long? After Atlantis crept up on Hubble over several hours, it stopped for some 40 minutes about 50 feet away. The robotic arm then took an age to creep up to the grapple point on the Hubble. After the Hubble was captured by the arm, it was just held there for at least another 30 minutes (an orbital sunrise and an orbital "midday" came and went), until the Hubble was eventually drawn into the cargo bay and docked to the waiting servicing pallet. In all, most of the second day was spent getting to and capturing the Hubble. So what was going on with the long waits and slow pace of things? Astronaut ( talk) 05:38, 14 May 2009 (UTC)
- It's probably something to do with trying to synchronise your own speed with that of the object you are trying to capture. After all, they are both travelling at 16,000 mph. They're not just floating. And after all, they don't want to break Hubble, otherwise that would make the mission pointless, so they have to be careful and do a lot of preparation and checks inside the spacecraft before they start to do anything.-- KageTora - (영호 (影虎)) ( talk) 06:35, 14 May 2009 (UTC)
- They are being exceptionally cautious - both the Shuttle and the Hubble Space Telescope are stupidly expensive pieces of machinery (in Hubble's case, nearly irreplaceable). So they pause after every step to make sure everything is still working right, that everything is as it should be, before proceeding to the next step. Also, keep in mind that the Hubble weighs eleven tons - that's not the kind of mass you want to have crashing into your spacecraft at high speed! Hence, all the manoeuvring is done very slowly, again, to avoid breaking anything (the same way as you walking more slowly when carrying a tray of glasses filled with juice). — Quantum Eleven 11:06, 14 May 2009 (UTC)
what iz global positioning system —Preceding unsigned comment added by 117.198.240.128 ( talk) 10:08, 14 May 2009 (UTC)
- Please see our article on Global Positioning System and come back if you have any further questions. -- antilived T | C | G 10:10, 14 May 2009 (UTC)
- GPS = you can haz your location...
79.122.112.53 (
talk) 11:16, 14 May 2009 (UTC)
- Wouldn't cats prefer to csn haz Cheeseburger Positionig System? --
Ferkelparade
π 11:25, 14 May 2009 (UTC)
- Cats can haz needz both CPS and GPS. It's useless to know only where cheezburger is - if you don't know your relative position to it, you can't haz it.
Nimur (
talk) 13:33, 14 May 2009 (UTC)
- Need lotz and lotz of lolSats. SteveBaker ( talk) 19:09, 14 May 2009 (UTC)
- This article may help. Cuddlyable3 ( talk) 13:35, 14 May 2009 (UTC)
- Cats can haz needz both CPS and GPS. It's useless to know only where cheezburger is - if you don't know your relative position to it, you can't haz it.
Nimur (
talk) 13:33, 14 May 2009 (UTC)
- Wouldn't cats prefer to csn haz Cheeseburger Positionig System? --
Ferkelparade
π 11:25, 14 May 2009 (UTC)
- GPS = you can haz your location...
79.122.112.53 (
talk) 11:16, 14 May 2009 (UTC)
hi, i've got this question's numerical answer but i'm confused about the units.
the question is : convert 7350 N/m2 into cgs units
what i did: 7350 * 105 gcm-2s-2m-2
7350 * 105 gcm-2s-2(100 cm)-2
7350 * 105 gcm-2s-2 (10000 cm)-1
7350 * 10 gcm-2s-2cm-1
this is where i'm confused. the cm-1 cancels the cm and the answer becomes g/cm2, but i (and you) know that it should be gcm/s2, or should the cm-1 not come at all from the 4th step to the 5th step??
(i could have done it the easy way. N/m2 is pressure. so i could have written it as pascal and converted it into barye. but, unfortunately, barye hasn't been taught in our school. so, i can't possibly use that method) —Preceding unsigned comment added by 122.50.131.71 ( talk) 14:16, 14 May 2009 (UTC)
- Search google for unit conversion and you can get all kinds of cool unit converter calculators. 65.121.141.34 ( talk) 14:25, 14 May 2009 (UTC)
- How about using dynes, which are the CGS unit of force? Google can do that conversion. Nimur ( talk) 14:34, 14 May 2009 (UTC)
- Your mistake is in your first line, you did not correctly convert Newtons to correct units in CGS system. Verify your units. Even in CGS, a unit of force should still be a mass times an acceleration. It looks like you mixed up the conversion of Newtons and the conversion of meters to centimeters in to the same line, and did it incorrectly. There should be no cm^-2 on that line, it should just be cm. Nimur ( talk) 14:40, 14 May 2009 (UTC)
Hi I'm a bit confused by the events of Metaphase I compared to metaphase II. In metaphase I I believe the bivalents line up randomly at the metaphase plate. This is a source of variation in meiosis. But when it comes to metaphase 2 - do the chromosomes line up randomly again before they split? Is this is another source of variation? I have read the meiosis article but am still a little confused. Please help! —Preceding unsigned comment added by 139.222.240.42 ( talk) 15:30, 14 May 2009 (UTC)
- As described in our
Meiosis article:
- Anaphase I separates homologous chromosomes
- Anaphase II separates sister chromatids
- If there were no recombination and no mutation, then anaphase I would generate variation (by randomly segregating homologous but not identical chromosomes) whereas anaphase II would separate identical sister chromatids. Because of mutation and recombination, sister chromatids can differ, so differences arise at both steps. Does that help? -- Scray ( talk) 22:30, 14 May 2009 (UTC)
- Meiosis is definitely complicated, and you're not alone in being confused. When the chromosomes are copied they form identical sister chromatids that join up with the other homologous pair. The task of metaphase I is to randomly segregate the pairs of sister chromatids from each other so that the resulting cells are basically a random combination of the chromosomes that were originally inherited from your father and mother. This is clearly a source of variation and it basically describes independent assortment of alleles that are carried on different chromosomes. The task of metaphase II is to separate the sister chromatids so that there's only 1 copy of each chromosome. There isn't quite as much randomization at this point since the sister chromatids that are being separated were initially identical to each other. However, due to random crossing over that happens during the first part of meiosis, at the time of metaphase II, the sister chromatids are themselves different patchworks of the maternal and paternal chromosomes and this leads to an additional level of randomization in the final gametes. Does that help any? --- Medical geneticist ( talk) 23:03, 14 May 2009 (UTC)
Yes thanks a lot for your help!
Why do they inject nitrogen into oil fields instead of regular air? 65.121.141.34 ( talk) 16:13, 14 May 2009 (UTC)
- Because air contains oxygen, which may chemically react with components of the oil. Nitrogen is chemically inert and will not produce any undesirable reactions. --
Jayron32.
talk.
contribs 18:20, 14 May 2009 (UTC)
- Oxygen is also a key component of
combustion. Nitrogen is safer. cheers,
10draftsdeep (
talk) 18:28, 14 May 2009 (UTC)
- Particularly under the high pressures gas is injected at under EOR. TastyCakes ( talk) 18:47, 14 May 2009 (UTC)
- Oxygen is also a key component of
combustion. Nitrogen is safer. cheers,
10draftsdeep (
talk) 18:28, 14 May 2009 (UTC)
- I have been under the impression that unrefined crude oil is not very easy to ignite, though I suppose that a lot of safety measures are needed since it would be a very expensive and dangerous fire.
65.121.141.34 (
talk) 18:49, 14 May 2009 (UTC)
- Well yes and no... At high pressures and somewhat high temperatures, as experienced in most oil and gas reservoirs, crude is probably somewhat combustible, at least that's my understanding since fire flooding is used in places (no wikipedia article on it, but here is a patent on the subject). That coal seams can burn for as long as they do seems to support that. But the real danger is that "light ends" (short hydrocarbon chains) will come off of even the heaviest crude oil to some degree, and these are very combustible. Add to this that oil wells will frequently encounter gas and gas condensates (in varying quantities) and I think it is clear that there is enough flammable stuff in an oil well to justify avoiding the use of oxygen. TastyCakes ( talk) 20:15, 14 May 2009 (UTC)
- I have been under the impression that unrefined crude oil is not very easy to ignite, though I suppose that a lot of safety measures are needed since it would be a very expensive and dangerous fire.
65.121.141.34 (
talk) 18:49, 14 May 2009 (UTC)
- You'll find nitrogen used in other applications as well. For example, most beer kegs use
Carbon dioxide as a propellant, since it is a natural product of the fermentation process, so adding extra CO2 to the system seems like a fine idea. However,
Guinness and a few other high-end specialty beers will use nitrogen instead. CO2 will dissolve in water to form
carbonic acid which will alter the flavor of the beer. For really malty beers like stout, the additional sour flavor from the acid can change the flavor profile in ways the brewer does not want. Nitrogen will not produce a detectable change in flavor, plus being less soluble in water, nitrogen tends to produce smaller bubbles than CO2 does, which produces the characteristic "waterfall" effect of a well-poured pint of stout. --
Jayron32.
talk.
contribs 18:56, 14 May 2009 (UTC)
- They also offer it as a substitute for air in tires, claiming it leaks out less (or more slowly) due to the nitrogen molecules' larger size. TastyCakes ( talk) 20:51, 14 May 2009 (UTC)
- You'll find nitrogen used in other applications as well. For example, most beer kegs use
Carbon dioxide as a propellant, since it is a natural product of the fermentation process, so adding extra CO2 to the system seems like a fine idea. However,
Guinness and a few other high-end specialty beers will use nitrogen instead. CO2 will dissolve in water to form
carbonic acid which will alter the flavor of the beer. For really malty beers like stout, the additional sour flavor from the acid can change the flavor profile in ways the brewer does not want. Nitrogen will not produce a detectable change in flavor, plus being less soluble in water, nitrogen tends to produce smaller bubbles than CO2 does, which produces the characteristic "waterfall" effect of a well-poured pint of stout. --
Jayron32.
talk.
contribs 18:56, 14 May 2009 (UTC)
- Well, that doesn't make any sense... Air is Nitrogen, Oxygen, and a Carbon Dioxide (and negligibly small quantities of anything else) (on checking, Argon is actually more common that CO2... but I think we're already in the "negligible" domain). Nitrogen is the lightest molecule of those, with a higher drift-velocity. It would leak out faster than air. It could be argued that less inert nitrogen reacts less with the tire rubber/synthetic, but that's also flimsy logic compared to the rate of mechanical, frictional wear against the road surface. Sounds like a scam...
Nimur (
talk) 21:31, 14 May 2009 (UTC)
- It may be lighter, but it has a larger radius than Oxygen (although I can't find an exact number right now). I don't think you could really use CO2 because of acidity issues, and any other "inert gas" is likely to be too expensive and no better than nitrogen, size-wise. I don't think pure Oxygen would really be an option either, due to corrosion and explosion dangers. They also claim that having pure nitrogen without any moisture has benefits, including reduced corrosion (not a big issue as far as I know). I tend to side with you, however, without a proper study showing otherwise I am skeptical as to the benefits of it. Here is an article on the subject. TastyCakes ( talk) 21:47, 14 May 2009 (UTC)
- Well, that doesn't make any sense... Air is Nitrogen, Oxygen, and a Carbon Dioxide (and negligibly small quantities of anything else) (on checking, Argon is actually more common that CO2... but I think we're already in the "negligible" domain). Nitrogen is the lightest molecule of those, with a higher drift-velocity. It would leak out faster than air. It could be argued that less inert nitrogen reacts less with the tire rubber/synthetic, but that's also flimsy logic compared to the rate of mechanical, frictional wear against the road surface. Sounds like a scam...
Nimur (
talk) 21:31, 14 May 2009 (UTC)
- I'm pretty sure drift velocity will affect diffusion (leaking) a lot more than atomic radius. The pore sizes are less of an important factor than the statistical likelihood that an individual gas molecule will get to a pore. Thus the lighter, faster gas diffuses faster. See
Graham's law for more on differential rates of gas flow. N2 will diffuse about 7% faster than O2. If diffusion leaking were actually occurring on relevant timescales, a 7% worse performance would be noticeable. I conclude that "leak reduction" is not at all the motivation for Nitrogen in tires OR enhanced oil recovery. It's much more likely that chemical reactivity is the issue in both cases (although of dubious benefit for at least the tire case).
Nimur (
talk) 22:34, 14 May 2009 (UTC)
- Surely it is more a matter of the average pore size/hole size of vulcanized rubber than anything else? I would also think the viscosity of the two gasses at tire temperature would play a bigger part than their drift velocity for long term leak purposes, although I don't know the values for nitrogen or air. In any case, you don't have to convince me, I'm not going to buy it any time soon ;) TastyCakes ( talk) 22:41, 14 May 2009 (UTC)
- I'm pretty sure drift velocity will affect diffusion (leaking) a lot more than atomic radius. The pore sizes are less of an important factor than the statistical likelihood that an individual gas molecule will get to a pore. Thus the lighter, faster gas diffuses faster. See
Graham's law for more on differential rates of gas flow. N2 will diffuse about 7% faster than O2. If diffusion leaking were actually occurring on relevant timescales, a 7% worse performance would be noticeable. I conclude that "leak reduction" is not at all the motivation for Nitrogen in tires OR enhanced oil recovery. It's much more likely that chemical reactivity is the issue in both cases (although of dubious benefit for at least the tire case).
Nimur (
talk) 22:34, 14 May 2009 (UTC)
- (undent) Just to correct an inaccuracy above, if gas is leaking out of pores, the pores are likely millions of molecular radii across, and so the size of the molecule has NO bearing on the issue. All that matters is the molecular mass of the molecule, because at any given temperature, heavier molecules move slower, which means they "hit" the hole less often than do lighter gases. That is the only relevant property when considering this. Thus, regardless of the volume or linear size of the nitrogen molecule vis-a-vis the oxygen molecule, its only the mass that affects the leakage. See
Graham's law for more info. The third paragraph of the "history" section explains it quite well. --
Jayron32.
talk.
contribs 22:53, 14 May 2009 (UTC)
- Hmm ok I guess that makes sense. Do you know how big the "holes" are in tire rubber? Are they really that much larger than nitrogen molecules? TastyCakes ( talk) 14:10, 15 May 2009 (UTC)
- Removing oxygen also avoids the development of bacteria (bugs) that can foul a well. Besides avoiding other chemical reactivity I think this is the major reason for oxygen and carbon dioxide removal. They even have to degas any surface water they inject.-- OMCV ( talk) 13:07, 15 May 2009 (UTC)
wat is it made up of..ect. anybody know? its not on wikki —Preceding unsigned comment added by 66.237.50.35 ( talk) 16:17, 14 May 2009 (UTC)
- Assuming the nitro group is not directly bound to the benzene ring, then this is what it is: http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1p0413 -- Russoc4 ( talk) 17:10, 14 May 2009 (UTC)
- To answer the poster, a chemical name tells you exactly what it's made up of: it's a nitro attached to a styrene molecule. You can see that styrene has several different shapes/parts, so what we can't answer is exactly where the nitro is attached. Russoc mentions one possibility (that compound has some interesting chemical reactions possible!). Also, meta-nitrostyrene and para-nitrostyrene (with the nitro attached to the benzene ring in various places) have some uses, especially in their analogous nitro polystyrene polymer form. Apparently you can either polymerize the nitrostyrene directly or else polymerize styrene (or some other derivative) and then nitrate it. DMacks ( talk) 20:08, 15 May 2009 (UTC)
What is the saturation point of KCN? Where would I find this information? 128.193.170.120 ( talk) 17:50, 14 May 2009 (UTC)
- Potassium cyanide, see properties. David D. (Talk) 17:59, 14 May 2009 (UTC)
Is there any kind of technology on the internet that lets you take a climate chart of a particular location, provided by the site, and do a search to come up with all the climate charts around the world that correspond most closely with the initial chart? This climate chart would include average monthly highs and lows and average monthly precipitation. —Preceding unsigned comment added by 189.4.53.90 ( talk) 19:18, 14 May 2009 (UTC)
We currently almost always launch rockets east when going to orbit (to benefit from the rotation of the earth). My question is if there is any consequence to always launching east, like possibly slowing the length of the day since you're pushing the earth back?
I'm sure the effect is tiny, but what if it's 500 years from now and we have billions of people launching megaton spaceships eastward to save on their fuel costs? Would the effect then become noticeable? TheFutureAwaits ( talk) 19:31, 14 May 2009 (UTC)
- Actually, some rockets are lunched north into a polar orbit, but you are right, most rockets are to the east. The earth weight is so high, and its spin rate so fast, that in order to slow the length of the day an amount that will be perceptible to people without clock accurate to 10 decimal places, rockets will have no effect until such point that we are launching in the trillions of tons per year range. At that point, there might be an effect, but it will be a very polluted planet with all the rocket exhaust.
65.121.141.34 (
talk) 19:55, 14 May 2009 (UTC)
I think, in the US at least, the only reason rockets are launched east is so they travel over uninhabited water, lessening the adverse consequences of an aborted/failed launch. I don't know about launches outside of Cape Canaveral, though. I am not aware of any physical benefit of always launching east, other than impact speeds of space junk from previous launches would be lessened.As for affecting the rotation of the earth, the wind has a much greater effect than our various items in orbit, by several orders of magnitude. The tidal forces from the moon have an even greater effect. Unless we eventually have a space station a significant percentage of the mass of the moon, there should be no discernable effect. - Running On Brains 20:03, 14 May 2009 (UTC)
- Actually ROB, if you launch east, you already are traveling at 700-1000 mph, so your rocket does not need quite so much fuel to get into a speed high enough for orbit. If you launched west, you would have the opposite effect and your rocket would start at -1000 mph instead of +1000 mph and would need to increase your speed 2000 more mph then an east launch. 65.121.141.34 ( talk) 20:14, 14 May 2009 (UTC)
- What goes up comes (usually) down. Launching a rocket to the east is not done by tilting the rocket on the launch pad. Cuddlyable3 ( talk) 20:22, 14 May 2009 (UTC)
- The angular momentum of the a closed system is conserved, so system consisting of the earth plus the artificial satellites would have a constant angular momentum, which mens the earth wourl slow down, IF the system were closed. However, the system is not closed. the eastward launch requires the expulsion of rocket exhaust in the westward direction.IF the exhaust exceeds escape velocity, then the eastward angular momentum of the system increases. Note that this effect and the transfer effect you originally asked about are trivial by comparson to the effect of tidal drag, which transfers angular momentum from earth rotation to lunar orbital distance. - Arch dude ( talk) 02:07, 15 May 2009 (UTC)
- If and when we reach the technological level of launching trillions of tons into space, i am sure we'll have methods to counter this effect. -- 131.188.3.21 ( talk) 11:15, 15 May 2009 (UTC)
- I'd hope we'd have a working space elevator by then - or at least, that we'd start building our huge space stations in space. Presumably the heaviest parts of a space station are minerals, which can be mined from asteroids - we'd only need to ship organic compounds from planetside. Dcoetzee 03:12, 19 May 2009 (UTC)
- It might be tricky to develop a 0g metal refining operation. Your melted metal would go everywhere wouldn't it? 65.121.141.34 ( talk) 18:11, 21 May 2009 (UTC)