Wikipedia:Reference desk/Archives/Science/2008 August 22

= August 22 =

When someone says that they can see the intelligence in an animal's eyes...
...what exactly is the phenomenon that they're describing? I found myself pondering this whilst a Grey Heron and I were silently observing each other at close quarters earlier today. --Kurt Shaped Box (talk) 00:50, 22 August 2008 (UTC)


 * Anthropomorphism might fit. The more something appears to be volitional (an animal, a storm, the sea), the likelier humans are to believe the thing observes and reacts as humans do.  I am not expert on herons, grey or otherwise, but since they feed off things like fish and frogs, the lack of motion and steady gaze likely come from hunting instinct.  There's also not a great deal of brain in a creature weighing 2 kilograms.  — OtherDave (talk) 01:00, 22 August 2008 (UTC)


 * I'm not an expert on herons myself (in fact, this is the first one I've ever seen at a distance closer than 100ft), so I have no idea where they rank in terms of intelligence and I accept that I may just be anthropomorphizing, but during seconds that my eyes met those of the heron, I got a distinct feeling that the bird was 'weighing me up' and 'observing', as opposed to just looking at me. Man, it's really hard to describe. I guess it's a bit like when a pet owner says that they can tell when their dog/cat/bird/whatever is curious or preoccupied by something by the way it looks at them... --Kurt Shaped Box (talk) 01:22, 22 August 2008 (UTC)


 * Birds can be surprisingly intelligent. I have similar experiences when making eye contact with our Cockatiel. It could just be a psychological thing that we're thinking way too hard about. --Russoc4 (talk) 01:52, 22 August 2008 (UTC)


 * On the other hand, magpies were recently added to the very short list of animals that are self-aware, an honor they share with great apes, Asian elephants, and the bottlenose dolphins. . Dragons flight (talk) 07:45, 22 August 2008 (UTC)


 * There's a huge amount that's just how much sclera one can see. There's been a lot written about that of late—that humans judge eyes with a lot of white visible to be closer to their own intelligence, and the question of why humans evolved to have so much visible (unlike most animals). Additionally I think the ability of the animal to focus on one discrete object or make eye contact helps. Things that are looking all over the place look wild. When my dog makes eye contact with me and holds it, it's hard to argue that there's some kind of connection. --98.217.8.46 (talk) 02:38, 22 August 2008 (UTC)


 * Could the sclera thing also explain why animals with pale irises are often considered to be more vicious or angry-looking than animals with dark irises? In many animals, the iris pretty much covers the same area of eye as the 'whites' of ours eyes do. Consider these two Herring Gulls: --Kurt Shaped Box (talk) 23:03, 22 August 2008 (UTC)




 * I think the reason why an animal that looks into your eyes seems intelligent is as follows: This implies that they know you can see them with your eyes, which requires a certain degree of intelligence to work out. StuRat (talk) 02:59, 22 August 2008 (UTC)
 * In other words, you get the feeling that the animal has a theory of mind, which is significant, because baby humans don't catch on to this for a while. ike9898 (talk) 16:41, 22 August 2008 (UTC)


 * There are a few references at Empathy which would imply that there is a possible difference between ability to identify with others of the same species, and other species. --Ayacop (talk) 08:06, 22 August 2008 (UTC)


 * Don't forget that humans were prey (as well as predator) for most of our evolutionary history, so it's possible that when we notice another creature watching us, we pay more attention. Doesn't even have to be the archetypal saber-toothed tiger.  — OtherDave (talk) 15:49, 22 August 2008 (UTC)


 * Isn't George W. Bush our current expert on this question? Or at least, he was until a couple of weeks ago when Putin apparently got an occular transplant and invalidated Bush's previous conclusions.


 * Atlant (talk) 13:50, 23 August 2008 (UTC)

Drunk Driving deaths by country
I'm looking for a refernce source that will list drunk driving and or alcohol-related deaths by country. So far it looks like I could probably find those statistics if I searched country by country, but I was hoping some website existed where it's already been aggregated. --Shaggorama (talk) 02:26, 22 August 2008 (UTC)


 * Unfortunately I can't answer your question, but I'm prepared to offer some comments and advice which will make it more difficult for you to trust any results you find. You'll need to be very careful with the definitions that you use; I suspect it will be difficult for you to find a genuine apples-to-apples comparison.  Do you define drunk-driving deaths as those where an intoxication-related criminal charge was laid?  Do you count the case as an 'alcohol-related death' if it involved a sober driver and a drunk pedestrian?  Do you look at blood alcohol content&mdash;remember that the legal limit varies from country to country and may also depend on type of license.  (A look through our Driving under the influence shows limits ranging from zero to 0.08%.)


 * Some anti-drunk-driving organizations are also a bit dishonest with their statistics, reporting fatalities as 'alcohol-related' as long as at least one individual involved in a collision had any measurable blood alcohol content, regardless of the circumstances of the accident or who was actually at fault. TenOfAllTrades(talk) 02:54, 22 August 2008 (UTC)


 * I'm with both of you. I'm not inclined to really trust the numbers I find, but I'm not in a position to produce them myself so for my purposes I'll take what I can get. One of the reasons I'm looking for one single resource is I'm hoping it would largely unify the definitions used in producing the stats. But I'm probably being naive, seeing as I am looking for statistics that, as TOAT pointed out, are often produced by biased propagandizing organizations. --Shaggorama (talk) 03:18, 22 August 2008 (UTC)


 * Sorry about the confusion&mdash;there's actually just one of me. :D I forgot to indent my second paragraph (now fixed).  Even if you get your numbers from 'honest' sources, you're apt to run up against the 'definitions' problem (0.03 is over the limit in Poland but not in Portugal, so might be reported differently by police and governments in the two countries) and the 'detection' problem (not all jurisdictions necessarily test all drivers for intoxicants).  Best of luck to you, however! TenOfAllTrades(talk) 15:06, 22 August 2008 (UTC)

Some stuff to try: a 2007 report (PDF file) from the World Health Organization that includes a chart (page 3) comparing stats in about 30 countries. There might (not sure) be something also in this WHO report (links to several pdfs) on traffic accidents. There could also be stats in this Global Road Safety Partnership report (PDF), though for developing countries only. Finally, it seems the International Road Federation has stats, but not for free. Hope something here helps,WikiJedits (talk) 19:36, 25 August 2008 (UTC)

not a question, but... worth it (LHC)
"The Large Hadron Collider is set to fire up on September 10. Not sure why, but don't want to slog through tedious explanations of the Higgs boson and the Standard Model? Have a look at this informative rap narrative, delivered by persons in lab coats and hard hats."

http://blogs.spectrum.ieee.org/tech_talk/2008/08/switzerlands_nerdcore_scene.html

You'll laugh your head off. --Halcatalyst (talk) 02:34, 22 August 2008 (UTC)


 * I think they left out the part about how it'll blow up the world, right? ;-) --98.217.8.46 (talk) 02:52, 22 August 2008 (UTC)
 * The good thing about blowing up the world is that you can't end up looking bad because of it. If they'd rapped about the end of the world and it didn't happen, we'd all laugh at them. This way, whatever happens, they can't be proven wrong. --Tango (talk) 02:54, 22 August 2008 (UTC)
 * This is the way the world ends
 * This is the way the world ends
 * This is the way the world ends
 * Not with a bang but a whimper.
 * The Hollow Men --Halcatalyst (talk) 03:50, 22 August 2008 (UTC)


 * Heh. I just read Flashforward (novel), a SF novel dealing with the LHC. --—— Gadget850 (Ed)  talk  -  13:43, 22 August 2008 (UTC)


 * I like the idea but the rapping is awful. They could stand to take some lessons from Weird Al. -- BenRG (talk) 14:25, 22 August 2008 (UTC)
 * Maybe that's why the performers preferred to remain anonymous, heh. --Halcatalyst (talk) 16:14, 22 August 2008 (UTC)

Frostbite
If frostbite is caused by the body trying to maintain the core body temperature, is it possible to get frostbite if only one part of your body is exposed to extreme cold, for example if you stick your hand in liquid nitrogen? —Preceding unsigned comment added by 218.5.84.167 (talk) 05:55, 22 August 2008 (UTC)
 * Did you read frostbite. It usually affects toes or extremities of the body. Graeme Bartlett (talk) 07:09, 22 August 2008 (UTC)


 * Extremities generally lose heat faster, but you can get frostbite anywhere if that part of your body gets cold enough. And yes, holding your hand in liquid nitrogen would do it.  (Incidentally, it's not instaneous.  Brief contact with LN2 will create a significant signal of pain and normally one would yank their hand back before it froze.  The same way that touching hot things will generally cause you to recoil before any major damage is done.)  There are cases where someone's leg stepped through a frozen lake and they quickly got frostbite on their leg while the rest of them was okay.  That's probably most analogous to what you are asking.  Dragons flight (talk) 07:38, 22 August 2008 (UTC)


 * I agree with Dragons flight. To the person posing the question, it's a bit misleading to say that frostbite is caused by the body trying to maintain core temperature.  In a localized situation, like the hand in nitrogen or feet frostbitten from immersion in the water, the frostbite's caused by (a) reduced blood flow followed by (b) freezing of tissue (as the frostbite article points out).  In a whole-body situation (see Jack London's To Build a Fire) yes, the reduced blood flow occurs in all the extremities.  If you were cross-country skiing in bitter cold, with all of your body well protected except your face and ears, your core temperature would probably be just fine.  Stay exposed long enough, though, and you'll get frostbite.  — OtherDave (talk) 16:11, 22 August 2008 (UTC)

Physics with Calculus queston, regarding differential mass elements
For chapter 9, my book describes the center of mass of a solid body on an x-axis as the integral from x1 to x2 of the differential mass elements all multiplied by 1/Mass

My question is it calls the differential mass elements, by the symbol dm which also occurs as the last symbol of the integral.

Are differential mass elements the mass of my object between 2 infinitesimal close points on the x-axis? In other words if I have a rod from x=0 to x=5, then divide this distance into infinite divisions, and the mass of each sub-distance totally comprises the mass of my object? Therefore summing all the differential mass elements will give you the "area under the curve".

The other way I can see it is that the term differential mass element means the change in mass between adjacent subdivisions of the 5 meter strip of the x-axis. I have helped improve the navigability for finding out information on differentials, but I'm not certain, by reading the wikipedia articles what a differential mass element is. It could either be f(x+dx) - f(x) or it could be dx*f(x+dx) - dx*f(x) is what I've narrowed it down to on my own. Thanks Sentriclecub (talk) 10:11, 22 August 2008 (UTC)


 * An engineer would say (mathematicians look away now) that the differential mass element dm is the mass of an infintesimally thin slice of the body between x and x+dx (a mathematician would talk about the "mass distribution function", but would get to the same result). So, for example, for a thin triangle with mass per unit area ρ between the x axis, the line y=x and the line x=a,


 * $$dm = (\rho) dA = (\rho x) dx$$


 * because the area of the thin slice is xdx. To find the distance of the centre of mass from the y axis you divide the first moment of mass about the y axis by the total mass of the body, so you have:


 * $$\frac{1}{M}\int (x) dm = \frac{2}{\rho a^2} \int_0^a x (\rho x) dx = \frac{2}{\rho a^2} \int_0^a (\rho x^2) dx = \left(\frac{2}{\rho a^2}\right)\left(\frac{\rho a^3}{3}\right) = \frac {2a}{3}$$


 * Gandalf61 (talk) 10:56, 22 August 2008 (UTC)


 * Thank you alot, Gandalf, for your help. I understand a lot better using the language of infinitesimally thin slices than my book's language. (I learned calculus from a Stewart book, so its inconsistent with my physics book which is more pragmatic at how it throws around symbols).  Thanks again. Sentriclecub (talk) 11:05, 22 August 2008 (UTC)


 * No problem. I have a mathematics background, but my son is a student engineer, so I am quite used to doing this type of "tranlsation" ! Gandalf61 (talk) 11:13, 22 August 2008 (UTC)
 * In my experience, mathematicians would say it in the same way, they just wouldn't dare write it down! As long as you understand the real explanation well enough to know that you can trust the hand waving argument, it's so much easier just to wave your hands around. --Tango (talk) 17:35, 22 August 2008 (UTC)

Tornados at night?
Do tornados occur at night as frequently as they do during day?Leif edling (talk) 10:49, 22 August 2008 (UTC)


 * No, but not for an entirely clear set of reasons. The biggest reason is that a warm front collides with a cold front, forming cells is the initiation of what can lead to a tornado.  Pressure systems you could say are propelled by differences in air pressure between colliding "blocks" of air.  The sunlight heats these blocks of air, and increases the likelihood of discrepancies between contiguous blocks of air.  When the sun is out, these "moving blocks of air" are more likely to collide, and at higher kinetic energies, thus leading to increased likelihoods of the prerequisite conditions.  As an analogy, pretend white and black mice are playing in a tank, moving at random.  Now randomly sweep a lit cigarette around in the tank.  This stirs up the mice and makes them even more likely to wind up one-atop-another.  Sun feeds the weather system energy, and it makes things more volatile and chance climate events more probable. Sentriclecub (talk) 11:01, 22 August 2008 (UTC)


 * I've been living in the northern part of Texas - slap bang inside "Tornado Alley" - for the last 15 years and I've gotta say that the only tornadoes we've heard about have happened in springtime - right around dusk. Between (say) 5pm and 10pm.   I can't recall a single one happening outside that range.  In terms of a warm front colliding with a cold front and a 'wall cloud' forming (the predecessor to a tornado)- it kinda makes sense that air that's been heated by the ferocious sunshine around these parts for the entire day might collide with colder air blown in from areas where the sun has already set and the air is cooling down.  That would increase the prevelance around dusk.  In the height of summer, nighttime temperatures are pretty similar to daytime temperatures because the ground has heated up and is acting as a reservoir of heat - so I guess that explains why tornadoes are not so common in the height of summer around here.


 * I've actually driven right underneath a tornado that was just forming and which touched down less than a mile away. It was AMAZING.  All of the stories you hear and TV/Movies you see can't prepare you for the ferocity of the real thing.  My car was a super-lightweight MINI Cooper - and it was a convertible.  I was thinking that this was possibly the first time I really wish I'd bought a Hummer!


 * SteveBaker (talk) 18:56, 22 August 2008 (UTC)

Apple
Why does an apple turn brown few minutes after when it cut? —Preceding unsigned comment added by Kelvin caesar (talk • contribs) 12:12, 22 August 2008 (UTC)
 * According to our article, "Sliced apples turn brown with exposure to air due to the conversion of natural phenolic substances into melanin upon exposure to oxygen. Different cultivars differ in their propensity to brown after slicing. Sliced fruit can be treated with acidulated water to prevent this effect." Algebraist 12:20, 22 August 2008 (UTC)


 * And if you meant Apple I, it was already brown before they cut it. Nimur (talk) 15:15, 24 August 2008 (UTC)

Is it right that accidentally snorting msg can cause bleeding from nose and eyes?
This question has been removed. Per the reference desk guidelines, the reference desk is not an appropriate place to request medical, legal or other professional advice, including any kind of medical diagnosis or prognosis, or treatment recommendations. For such advice, please see a qualified professional. --EronTalk 13:34, 22 August 2008 (UTC)


 * Meta-discussion has been moved to the talk page. Please confine comments about the operation of the Reference Desk to Wikipedia talk:Reference desk.  Please refer to the discussion there before adding to this section.  Your assistance is appreciated. TenOfAllTrades(talk) 01:39, 23 August 2008 (UTC)

drug reaction
-- Coneslayer (talk) 13:54, 22 August 2008 (UTC)

Olympics
What olympic sports can I still do when heavily pregnant?

Has anyone done this?? —Preceding unsigned comment added by 86.128.218.142 (talk) 16:41, 22 August 2008 (UTC)


 * I don't see any reason why you couldn't participate in some of the shooting events (unless the IOC has some rule against it). I'm pretty sure nobody has ever done it before. (Somewhere out there, there's an advertising executive drooling over the idea.) Clarityfiend (talk) 17:17, 22 August 2008 (UTC)


 * Being heavily pregnant pretty much is guaranteed to deteriorate your performance at any physical sport. I imagine even something like shooting, which requires a variety of physical aspects to be really great (concentration, control over breathing, etc.) would even take a small hit from the changed physiology and additional burdens of pregnancy. You don't need much to push you out of the runnings alltogether. --98.217.8.46 (talk) 18:18, 22 August 2008 (UTC)


 * If the question is really "What can I still do" - and not "What can I possibly be competitive at" - then there are a lot more options. If you're just asking what events you can complete safely - then the possibilities are wide open.  You can (for example) still swim - so you could do short distance swimming events.  Some things (like maybe the 'luge' event in the winter olympics) are possible - but totally not safe for the baby.   But in terms of being competitive - I agree that you're probably limited to shooting and archery,  which require less physical effort than most olympic sports - but as '98 says - it's doubtful that you could attain the breathing control needed to win such an event.  In the past there have been other events like Ballooning, Boules, Gliding and Motorsports that would maybe have been within reach.  In the winter games, you could probably participate in Curling too. SteveBaker (talk) 18:38, 22 August 2008 (UTC)


 * The advice here has been from a sports performance perspective; you should see your doctor (we cannot give medical advice here) for medical advice if you actually do intend to engage in any competitive sports while pregnant rather than this being a theoretical question. --Random832 (contribs) 18:57, 22 August 2008 (UTC)


 * A search on "olympics pregnant" turned up this article: -- BenRG (talk) 19:14, 22 August 2008 (UTC)


 * You could be the cox on a rowing team without too much problem. The rest of the team may not thank you for the extra weight though. Dostioffski (talk) 00:24, 23 August 2008 (UTC)


 * It's vital that you avoid beach volleyball though - trust me - just don't go there! SteveBaker (talk) 03:49, 23 August 2008 (UTC)


 * Why not? Nil Einne (talk) 05:18, 23 August 2008 (UTC)


 * maieusiophobia/maieuticophobia (What?!? No article on that?! Not even a wiktionary entry? I'm shocked!  Deeply shocked.) SteveBaker (talk) 17:52, 23 August 2008 (UTC)


 * I just had a thought. Why not try out for the 4x100 team relay semifinal? There's a fair chance everyone else will drop the baton so you may still make it to the final even if you're a bit slow. And once your team is in the final, you don't actually have to run to win Nil Einne (talk) 17:21, 23 August 2008 (UTC)
 * Continuing the humour, I think sailing and equestrian might be suitable as well, though there might be a bit too much up and down movement. In softball, you can just be the pitcher to avoid running. Table tennis also does not require too much running around. --Kvasir (talk) 22:24, 26 August 2008 (UTC)

Glass figure changing color
I know someone who had a glass trinket that was originally purple, and then one day looked bright blue, and then the next day turned purple again. The person in question was adamant about the fact that the color changes were real and not just a matter of lighting or confusion. I haven't seen the thing myself. (And I don't actually know the person. It's a friend of a friend, the latter of which came to me.) What do you think? --98.217.8.46 (talk) 18:16, 22 August 2008 (UTC)


 * People are very poor at detecting lighting changes. Our eyes continually adapt to try to maintain visual consistency no matter how bright or dim the lighting is - and to correct for color variation (eg at dawn and dusk).  So I strongly suspect that it really was lighting changes - but that the person was unaware of that change.  Failing that - I don't think we have enough information to go on. SteveBaker (talk) 18:42, 22 August 2008 (UTC)
 * Moreover, human color vision is especially poor at the blue–purple end of the spectrum. You may be interested in the Color vision article. Strad (talk) 19:17, 22 August 2008 (UTC)
 * Lighting changes could be the cause, but not for the reasons you suggest. If a glass has more than one optical absorption band in the visible region then natural or synthetic lighting could cetainly induce different pigmentations of the glass, as per my explanation below. Jdrewitt (talk) 20:05, 22 August 2008 (UTC)


 * There are a number of salts that change color based on their hydration state (one example is cobalt chloride). Changes in humidity could conceivably affect the color of such a item. Another potential explanation is photochromism, where changes in lighting level affect the actual (not just apparent) light absorption profile of an object. However, the most likely explanation is probably still perceptual differences, especially if the color change is not reproducible. -- 128.104.112.147 (talk) 19:19, 22 August 2008 (UTC)


 * It might be blurple, especially if the day in question was January 1, 2000. -- BenRG (talk) 19:27, 22 August 2008 (UTC)


 * See Alexandrite. By the way, is the article Ratnagarbhas I stumbled upon giving medical advice? 93.132.170.130 (talk) 19:45, 22 August 2008 (UTC)


 * It may be some variant of a "mood ring". There are "Mood Necklaces" and many of the ones I can find on the internet seem to be somewhere between blue and purple when they were photographed. Since the color of "mood" jewelry is almost entirely based ambient temperature, perhaps the day it was bright blue was a really hot day. Or a really cold one. APL (talk) 19:47, 22 August 2008 (UTC)

Colour changes can certainly occur in glasses. Glasses doped with the rare earth ion Holmium for example appear bright red under flourescent lights and pale yellow under natural light. I made some rare earth aluminosilicate glasses (for scientific purposes) and was amazed how pronounced this effect actually is. It is similar to the effect in the Alexandrite mineral and is the result of different optical absorption bands in visible light. People who make coloured glass for ornamental / art purposes are cetainly aware of the different compounds to use to produce different pigments (see Glass colors and it is not inconceivable that whoever made your glass trinket incorporated some colour changing ion into the glass composition. Jdrewitt (talk) 20:00, 22 August 2008 (UTC)
 * Here is an image of the HoAlSiO glass that I made, the glass is yellow under natural light and red under flourescent light!

Jdrewitt (talk) 20:21, 22 August 2008 (UTC) 


 * Follow up: So I forwarded these possibilities on to the person, and they realized that indeed, they had installed fluorescent lights or something like that in the area where it was. In the daytime, it was purple, at night, with the lights, it was blue. Crazy stuff. --98.217.8.46 (talk) 15:38, 23 August 2008 (UTC)


 * Yep - so much for "The person in question was adamant...not just a matter of lighting". It pays to be skeptical! SteveBaker (talk) 17:43, 23 August 2008 (UTC)


 * I think that's a bit harsh, I think the OP meant it was not their perception which was at fault which I would tend to agree with. Jdrewitt (talk) 19:26, 23 August 2008 (UTC)


 * Well, I didn't take any opinion on whether it was lighting or not. I don't know this person, I was just reporting what they said. Truth be told, I think the fact that narrow wavelength light sources can radically affect what certain materials look like would strike a lot of people as rather surprising. From a scientific point of view it makes perfect sense—once I heard that about the light bulb, it's obvious what's going on with it, to anyone who has taken any sort of physics or astronomy course that dealt with spectrums—but the notion that two different light bulbs could radically change the color of something is less intuitive. Even explaining to someone why it's the case takes a little trip down "abstract concept of what colors are" lane. --98.217.8.46 (talk) 20:10, 23 August 2008 (UTC)


 * Sorry - I didn't mean to imply that the OP was unreliable - but when someone says something offhand to a friend and the friend asks you and you ask us - there have been three word-of-mouth tellings of the information - and it's no surprise that odd bits of crucial information become missing or distorted. SteveBaker (talk) 20:52, 23 August 2008 (UTC)


 * Agreed 100%. I tried to indicate my agnosticism of their account accordingly—was just fishing for possibilities. --98.217.8.46 (talk) 14:18, 26 August 2008 (UTC)

On the Topic of Color Changes
Some color prints have been hanging in our local coffee shop for years, exposed to a lot of sky light and artificial light. Not direct sun.

Originally brightly colored, they have changed. The lightest areas have stayed light, the blacks are still black, everything else is in various shades of blue.

How can this phenomenon be explained in terms of chromophores, which were mentioned recently in this page?

Thanks, Wanderer57 (talk) 20:57, 22 August 2008 (UTC)


 * On reflection, various intensities of blue is more accurate than various shades. Wanderer57 (talk) 21:45, 22 August 2008 (UTC)


 * Well, many color printing processes use CMYK (Cyan, Magenta, Yellow, Black) inks - if the magenta and yellow ink faded in the sunlight at a faster rate than the cyan (blue) and black - then you'd get the exact effect you're seeing. SteveBaker (talk) 03:44, 23 August 2008 (UTC)


 * That's precisely it. The black pigment (usually being based on carbon particles) is very durable. The cyan dye or pigment is either more durable or less subject to attack by the incoming spectrum of light that it absorbs. But magenta and yellow are easily destriyed, probably by the incoming ultraviolet light.


 * Atlant (talk) 13:35, 23 August 2008 (UTC)


 * Yep. My thinking exactly. A possible explanation for why cyan (Blue) ink survives the longest is because (by definition) blue objects reflect light at the blue end of the spectrum. (ie at the higher frequencies)  Magenta and yellow inks absorb blue light (that's why they don't look blue).  Since ultraviolet frequencies in the sunlight are the cause of fading and UV light is at the high frequency end of the spectrum, blue dyes that reflect high frequency light are likely to be more fade-resistant than those that absorb it.  Hence the cyan ink survives longer than the magenta and yellow.  Black ink doesn't fade at all because it's based on carbon which absorbs all frequencies but doesn't react because of it. SteveBaker (talk) 17:41, 23 August 2008 (UTC)

Victorian women
I don't know if this question is better placed here, as medicine, or at the Humanities desk, as history. I'm starting here to offer editors a change of pace from black holes.

I'm quoting from a discussion elsewhere.

"Victorian women, through lack of exercise and general laziness, did have quite large posteriors."

Thinking particularly of lower class women in poorer parts of London, what do you think of this generalization?

Thanks, Wanderer57 (talk) 21:43, 22 August 2008 (UTC)


 * That clearly only applies to the upper classes, if at all. My understanding is that much of the "large posteriors" were petticoats. --Tango (talk) 23:12, 22 August 2008 (UTC)


 * It was the height of fashion to have a large bottom - many women wore a "Bustle"...which is a kind of wire contraption worn under the skirt to enhance the size of the hind end. It adds a whole new meaning to "Does this make my bottom look big?" SteveBaker (talk) 03:35, 23 August 2008 (UTC)


 * Yes, that's ass-backwards from the usual meaning. StuRat (talk) 02:00, 24 August 2008 (UTC)