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December 10

Americans and the metric system

How come many people in the USA seems to be so opposed to using the metric system? — Preceding unsigned comment added by 2A00:801:210:54F6:8093:E0B9:4DBE:31C7 (talk) 06:46, 10 December 2015 (UTC)

Maybe because Americans are able to remember a handful of trivial conversion factors, and multiply by numbers other than 10? --Trovatore (talk) 03:20, 11 December 2015 (UTC)

Trivial? Do you easily know how many gallons of water you can fit in 130 cubic feet? I know how many liters of water I can fit in 13 cubic meters without using any time or device at all. --Lgriot (talk) 13:09, 11 December 2015 (UTC)

A cubic foot is about 7 gallons; I know that off the top of my head, so 900, give or take. What's the problem? --Trovatore (talk) 18:50, 11 December 2015 (UTC)

The problem is that you are 7.45% wrong. --Lgriot (talk) 19:00, 11 December 2015 (UTC)

So what? If I need an answer better than that, I won't do it in my head. Mental arithmetic is for quick estimation; it doesn't have to be precise. If you need a precise answer you pull out a calculator. --Trovatore (talk) 19:05, 11 December 2015 (UTC)

Of course! How silly of me, there is absolutely no time wasted in that. Apologies, I am a fucking moron. --Lgriot (talk) 19:56, 11 December 2015 (UTC)

There's no need to get upset. But I stand by my remarks. The mental-arithmetic advantage of metric is very limited. There are very few real-life situations where you need a precise result that is easy to calculate in metric but hard to calculate in some other system. In naturally occurring problems, the inputs are not round numbers, so if you need a precise result, then you either need to be really really good at that (in which case you can probably do it in US customary as well), or else you need mechanical assistance.

Mental arithmetic is mainly for estimation, and I will grant that there are some realistic situations where estimation is a little easier in metric. But not that much easier. Just learn a few constants and you're good, assuming you can multiply approximately in your head. --Trovatore (talk) 20:06, 11 December 2015 (UTC)

Apologies for the un-needed swearing. We probably have very different brains, but whenever I am doing DYI in America and I need to put a frame at the center of a wall, I find I waste a lot of time figuring out the center of a wall that is 153" and 9/16th and then add or subtract 9" and 5/8th on each side for the position of the anchors. How do you do that quickly? So I just drop the damn tape-measure in inches, pick up the one in cm and I know immediately that the center of 390.04cm is at 195.02 and adding or removing 24.29 cm from that is all done entirely in my head, precision is achieved with no calculator needed. --Lgriot (talk) 21:13, 11 December 2015 (UTC)

It took me 2 or 3 seconds to see that it's 76.5 and 9/32nds. Can this fraction be simplified? No, so you're done. (just double the denominator to halve the fraction). 86.5 and 9/32nds. Now it becomes easy enough to look on the tape measure and do the rest visually. This is why people who grew up in metric only shouldn't use English and vice versa, it's almost like another language. Sagittarian Milky Way (talk) 21:47, 11 December 2015 (UTC)

I am confused here: my tape measure will not show 76.5 and 9/32nd, it will show 76 and 25/32nd if it is that precise, more likely I would end up settling for 76 and 12/16th, (only if I don't have a cm tape-measure, I am glad home depot started supplying those cm versions, probably for the Mexican builders who must also prefer them). --22:36, 11 December 2015 (UTC)

Oh for the love of.. Find 76 and a half on the tape measure, subitize 4 tick marks up by eye and make a mark halfway between the 4th and 5th tick. This seems common sense enough. Find the same part of the 86th inch and then move your eye down three "1/8th-size tick marks" and you're there. You'd only hope to be able to simplify the 9/32nds fraction to not have to deal with such big ass denominators when finding the anchor points but you can't so you don't. They should do a study, Americans might be better at fractions because of our measurement system. It's understandable that it's hard if you're not born into it, it'd take me years or decades to get as good at metric as people that are born into it are. I don't have a good intuitive feel for many metric units so I might convert to approximate US in my head. Sagittarian Milky Way (talk) 23:55, 11 December 2015 (UTC)

You may be right I am rubbish at mentally adding fractions --74.101.111.23 (talk) 00:43, 12 December 2015 (UTC)

Well, now that you mention it, I might well do the same thing, for that particular use case. If I weren't so violently allergic to anything resembling puttering around the house, that is. It's good to be flexible in your approach. Know different systems, and use whatever works best for the particular task. I have no problem with that. I do have a problem with metric fundamentalists who want everything else to go away. (Even worse are the sort of SI fundamentalists who insist that everyone say "micrometer" instead of "micron".) --Trovatore (talk) 21:21, 11 December 2015 (UTC)

Haven't met these fundamentalist yet! To be honest, I would love the imperial system if it was consistently in base 12 (12 inches to a foot, but also we would have an inch divided in 12th, not 8th, we would have 12 ounces to a pound, 12*12*12 pounds to an imperial ton etc.). Then mental calculations would be even faster than in the metric system, because of divisibility by 2, 3, 4 and 6. --Lgriot (talk) 21:36, 11 December 2015 (UTC)

(ec) Micron is a perfectly cromulent and useful unit. Sometimes, it's just better to be quicker to say (see liter vs. cubic decimeter). Sagittarian Milky Way (talk) 21:47, 11 December 2015 (UTC)

Agree with that. I am also perfectly ok with Klick instead of Kilometer. --Lgriot (talk) 22:22, 11 December 2015 (UTC)

Familiarity and inertia. This explains why the US is comfortable with power stations rated in MW, light bulbs in watts, computer speeds in metric multiples of Hz, and athletes competing in the 100m, 200 m, 1500 m etc. Widneymanor (talk) 09:21, 10 December 2015 (UTC)

Wikipedia has an interesting article on Metrication in the United States.--Shantavira|^{feed me} 09:35, 10 December 2015 (UTC)

• The United States tends to be slow adopting international standards of various kinds (it's also one of the few places that doesn't use ISO 216 paper size, which makes printing US documents endlessly annoying) for a couple of reasons. The public never likes changes, especially when they're perceived as foreign (Metrication in the United Kingdom has the same problem – populist politicians are good at spinning this sort of thing as a "foreign invasion"), and being relatively isolated (it only has two land neighbours) with a large internal economy, it can ignore what other countries do in a way that a state in, say, Central Europe with half-a-dozen neighbours can't. The biggest benefit of adopting the metric system would arguably be trade with other metric countries, and the US gets around that with dual labelling. (For another example of this neighbor effect, see Right- and left-hand traffic. The big continents are dominated by right-hand drive (except for roads in southern Africa and the Indian subcontinent, which are largely isolated from the larger networks) because being an outlier causes so many problems that the public and financial upheaval was worth it, but many islands remain left-hand drive because there's little benefit to changing.) Or as Grampa Simpson once said: "The metric system is the tool of the devil! My car gets forty rods to the hogshead and that's the way I likes it!" Smurrayinchester 09:36, 10 December 2015 (UTC)

Smurrayinchester. What are the "two land neighbours"? The only one I can think of is the Republic of Ireland and the United Kingdom article seems to confirm that. CambridgeBayWeather, Uqaqtuq (talk), Sunasuttuq 13:40, 10 December 2015 (UTC)

CambridgeBayWeather, Smurrayinchester's parenthesized mention of the UK was complete, so he'd reverted to taking about the US. Rojomoke (talk) 14:01, 10 December 2015 (UTC)

I completely missed the closing bracket after "invasion". CambridgeBayWeather, Uqaqtuq (talk), Sunasuttuq 14:08, 10 December 2015 (UTC)

Forty rods to the hogshead? That sounds not only inefficient, but explosive. – b_jonas 10:29, 10 December 2015 (UTC)

We Americans usually say miles per gallon. I gather the British do too. No reason to conform to someone else's standard just to be conforming. Oh, and the length of a cricket pitch is 4 rods. ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:28, 10 December 2015 (UTC)

We (or rather, the car manufacturers) do indeed still often refer to car performance in terms of miles per gallon (caution, Imperial not US gallon). Unfortunately, all our petrol stations now dispense in litres: I assume this is deliberate obfustication. {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 14:28, 10 December 2015 (UTC)

However, we would usually say one chain or 22 yards. Alansplodge (talk) 12:14, 10 December 2015 (UTC)

Yes. I chose rods because someone mentioned rods. And the length of a cricket pitch is also one-tenth of a furlong. And I concur that switching to metric for gasoline is deliberate obfuscation. Thankfully that plague has not hit the USA yet. ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:29, 10 December 2015 (UTC)

Just out of interest, in the UK, if you say right hand drive, it means that the steering wheel is on the right i.e the car drives on the left side of the road. Widneymanor (talk) 11:18, 10 December 2015 (UTC)

Correct [1]. Alansplodge (talk) 12:09, 10 December 2015 (UTC)

Banned-user trainwreck
The following discussion has been closed. Please do not modify it.
Forty rods to the hogshead? I doubt if Grampa would like it at all. That's 195 m per 245 L, i.e., a fuel consumption of 1255 litres per km. My largish V6 GM car uses about 0.9 litres per km. Of couse if you had the sense to use SI/metric, such estimating errors are very much less likely. 60.228.70.176 (talk) 14:02, 10 December 2015 (UTC) Yes, 40 rods is one furlong or one eighth of a mile and a hogshead seems to be 63 US gallons, so 504 gallons per mile. An M60 tank manages better than one mile per gallon. Alansplodge (talk) 15:56, 10 December 2015 (UTC) IIRC the reason why the UK moved to selling fuel in litres in the 80s - before it was required by legislation - was that the fuel became so expensive that the mechanical digits then used on the pumps couldn't turn fast enough to keep up. Of course, it does mean the price looks better as well. Richerman (talk) 18:19, 10 December 2015 (UTC) This has some more examples of vehicles which have better mileage [2]. It evidentally includes a LCAC hovercraft. However it also depends on your definition of Hogshead as it's claimed there's no standard one and in particular, no standard one for petrol or diesel (which our article supports). That said, the difference are small enough that you're not likely to even double the efficiency. Nil Einne (talk) 22:23, 10 December 2015 (UTC) One reason might be that manufacturers and retailers used the change to the metric system to downsize their products. For example, a 455-460 cubic inch car engine (7.5 liters) was considered among the largest before conversion, but when they wanted to downsize engines they switched to metric and the 5.7 liter engine became the largest engine available in many models. So, US consumers started to assume that anything in metric was that way to cheat them, and avoided buying such products. Requiring both types of units to be shown equally prominently, until all consumers adjusted to the new units, might be one way to solve that. StuRat (talk) 18:31, 10 December 2015 (UTC) Let us all adopt the FFF system.   → Michael J Ⓣ Ⓒ Ⓜ 22:20, 10 December 2015 (UTC) Nice theory, StuRat. And it might well be that some (dumb) Americans think that the metric system is about cheating the customer. But your theory isn't right. Manufacturers like GM, Ford, Chrysler up until the 1980's had the US market almost to themselves. They did not export US production (except in very small quantities in the luxury market), but they had factories in other countries. They got by with their unsophisticated big iron V8's up to 7.5 L in the USA, but their overseas factories never made engines that large. They made different, smaller, engines to suit local markets. Then the Japanese and European competition hit. Then Korean competion. To remain competitive, GM had to do a number of things. One was to standardise on a "World Standard" alloy V6 in 3.5 litre capacity. But is is a far more sophisticated design than their old big iron. More power and less weight so such up the power. I have the 3.5 L engine in my car, it is much more responsive than the old 5.7 litre iron V8. And with much better fuel consumption. Another example: Plywood and MDF used to be made in a standard size 4 foot by 6 foot (914 x 1828 mm). When metrication came to this country decades ago, the factory machines still of course made the size they were built up for, with limitted adjustment range. So shhets were just sold in size 915 x 1830 mm for the next 20 years or so. Later on the industry standardised on 1200 x 2400 mm. Yep, they went up, not down. Sawn timber sold "undressed" is and was alawys sold over size anyway, so you can plane it. One more example: Milk was sold in 1 pint bottles (568 mL). After metrication, the container size was rounded UP to 600 mL. Yep, they went up, not down. And no, they didn't call a 568 mL container a 600 mL container - thet would be illegal. So, StuRat, you've got it wrong. 60.228.38.228 (talk) 01:21, 11 December 2015 (UTC) US car manufacturers surely had many reasons for downsizing the engines, but that's not relevant here. They determined that US consumers would not be willing to pay as much for cars with the new, smaller engines, so they decided to disguise that fact by moving to metric. This is what left a sour taste in consumer's mouths. StuRat (talk) 04:40, 11 December 2015 (UTC) My country went metric decades ago. Marvellous. So much easier. So much less error prone in calculations. The goverment had the schools teach the MKS metric system essentially one generation prior to metric weights and measures legislation, so when things started to be sold in metric sizes, we all went, "about bloody time!" MKS is of course 99.99% the same as SI metric. 60.228.38.228 (talk) 01:28, 11 December 2015 (UTC) How do you divide a meter into thirds? With our system, it's easy. A foot is a third of a meter. 4 inches is a third of a foot. Nothing error-prone about it. You've been brainwashed by conformists. ←Baseball Bugs What's up, Doc? carrots→ 03:15, 11 December 2015 (UTC) Why stop at thirds? Let's all move to a system that makes it a snap to divide weights and measures by 19. -- Jack of Oz [pleasantries] 07:20, 11 December 2015 (UTC) The biggest drawback to anarchy is that it is extraordinarily conservative. And while the U.S. scarcely seems like an anarchy, when it comes to a certain subset of business practices, the legislature doesn't feel like it should be involved. Constitutional provisions like freedom of expression and institutional doctrines such as local control of schools probably hinder a 'metrification' program. There's also just a loss of morale involved: as the result of past desultory efforts toward metrification, people don't think it's going to happen - say, manufacturers assume customers want to hear how many BTU a furnace puts out, and customers assume it is more useful to compare BTUs than a different unit that is less readily researched. They assume, I think, that any metrification effort will just be so much noise by a few people looking to collect a paycheck, soon forgotten. (There's an article Metrication in the United States that doesn't touch on any of these points; I'm just giving my feeling) That doesn't mean that where metric is genuinely made universally available - like the ml volume on product labelling - that it can't catch on eventually. Wnt (talk) 02:51, 11 December 2015 (UTC) The basic flaw with metrics is that they are not based on "human" measurements. We used them in school science classes, decades ago; and as you note, they tried to get the public to "think metric" in the 1970s. It didn't work. And until (or if) the public decides to start thinking in the artificial realm of meters and centimeters instead of the more natural yards, feet and inches, it still won't work. Maybe in a few generations. But not yet. ←Baseball Bugs What's up, Doc? carrots→ 03:13, 11 December 2015 (UTC) That argument would make more sense if the rest of the world hadn't switched. Well, other than Liberia and Burma. Mingmingla (talk) 03:28, 11 December 2015 (UTC) Quite right. And Bugs missed my point. My country phased it in, carefully planned. First, they taught the MKS sustem in schools. So you had a whole lot of school leavers accustomed to doing all manner of calculation and thinking in metric. THEN, they passed laws requiring anything sold or purchased to be specified in metric dimensions. Dual labelling was permitted only for a short time, and the metric dimensions had to be more prominent. If you just introduce the metric system overnight, young people will adapt quite quickly, but older people will resist it sufficiently to make it necessary for dual labelling for years, which defeats the whole idea, as everyone just keeps thinking the old way. If you just teach metric in schools but not pass laws to compell use, then again it will fail, because as soon as people leave school, their elders & bosses will make them forget it. But what is a mystery to me is why Americans don't see how easy the SI metric system makes everything. And how much money it saves in commerce and industry. — Preceding unsigned comment added by 60.228.38.228 (talk) 03:49, 11 December 2015 (UTC) I don't like centimeters, they're too small. But they're too big for precision work. I like inches and millimeters. And I'm perfectly capable of understanding the metric. Sagittarian Milky Way (talk) 04:03, 11 December 2015 (UTC I think our liquid measurements are awesome, too. It goes cup, pint, quart, half gallon, gallon. A convenient name for every power of two in the range where you need it most. There's also an ounce, 1/8th of a cup; tablespoon 1/3rd ounce; teaspoon 1/3rd tablespoon and that's 5 milliliters. Sagittarian Milky Way (talk) 04:11, 11 December 2015 (UTC) The pound is a better base mass as it's more in line with the size of the amount of food or drink you consume in one sitting. It's also a moderately large beer (which used to be sold in pints that equal exactly 1 pound). It's equal to 4 smartphones or 1 tablet (approximately). A kilo would be a huge drink or meal (half a 2 liter soda bottle!) Sagittarian Milky Way (talk) 04:21, 11 December 2015 (UTC) A horse is 1,000 pounds. If it's 4 digits, it can't be lifted. A ton is 2,000 pounds, slightly smaller than your tonne of 2,204.68 pounds. An ounce is 1/16th ounce (because it's based on a pint not a cup, remember). Non-metric sucks at small masses. People just use grams for small things like base metal coins unless they're really stupid. Sagittarian Milky Way (talk) 04:27, 11 December 2015 (UTC) An acre more closely corresponds to the smallest area that looks like "land" when it's square and empty and you stand in that middle of it. It's what you can plow in one day with an animal. A hectare is a bit bigger. A kilometer is a bit small for road measurements and larger geography. A mile is better. Fahrenheit has a more useful distribution of degrees for weather. Who needs all those Celsiuses above 58 or something? They never happen. It's a waste of space. Sagittarian Milky Way (talk) 04:35, 11 December 2015 (UTC) So, I can plough 1 acre of land with an animal (presumably a hourse or an ox)? Gee that's real good to know. Nobody in this country has used animals to pull ploughs for about 100 years. We use tractors with a power output of hundreds of horses. Same in the USA. In fact the USA produced the first commercial tractor. You can always find a few minor advantages in almost anything. You might say the 1952 Chevrolet is better because it has strap handles in the back for Granny to hang on to. They don't put the strap handles in now. I liked the 2-way tailgates on the 1970's Ford station wagons. However, I'll stay with my 2007 GM car - it's very considerably safer, has a lot more acceleration, much better fuel consumption, much better paint, far better handling, really good stero system standard, etc etc. 1.122.35.134 (talk) 06:33, 11 December 2015 (UTC) Americans are not opposed to using the metric system voluntarily. Our drug dealers have long sold cocaine by the gram and a "kilo" is a significant quanity of marijuana. Our wines are sold in 750 milliliter bottles. And in the old days long before digital, many serious photographers used 35 mm cameras. What Americans object to is being forced to use the metric system. The metric system is neither sacred nor inherently superior in every situation. Cullen328 Let's discuss it 07:12, 11 December 2015 (UTC) That sounds a bit straw man-like to me. Who has ever tried to force the USA to go metric? How would they go about actually achieving that goal? -- Jack of Oz [pleasantries] 07:24, 11 December 2015 (UTC) The Australian IP contributor has been extolling the virtues of compulsory metrification. That's not, of course, a question of forcing the United States to go metric, from outside the United States, but it is still a matter of force. --Trovatore (talk) 07:27, 11 December 2015 (UTC) "The Australian contributor" is our old friend WickWack, incidentally. Perhaps it's time to bring this discussion to a close. Tevildo (talk) 09:26, 11 December 2015 (UTC) Tevildo thinks, apparently, that there is only one person in Australia, called "WickWack". Actually, there's about 25 million of us. About one tenth the population of USA, so for every 10 American contributors to Wikipedia, there ought to be one Australian. Or perhaps "WickWack" is Tevildo's term for Australians. 1.122.35.134 (talk) 14:15, 11 December 2015 (UTC) Your MO and specific location say "WickWack". ←Baseball Bugs What's up, Doc? carrots→ 16:02, 11 December 2015 (UTC) JackofOz, that would involve laws and regulations requiring that traffic signs give speed limits in kilometers per hour, rather than miles per hour. Or that signs must state that a large city is so many kilometers away, instead of so many miles away. Or selling gasoline and milk measured in liters, not gallons. Or meat, fish and vegetables weighed by the kilogram, not by the pound. Or that tape measures must be denominated in decimal fractions of a meter, not feet, inches and fractions. And so on. Force of law and regulation is the "force" I was referring to. Americans rebelled quite decisively against such laws when they were tried here a few decades back. Cullen328 Let's discuss it 07:57, 11 December 2015 (UTC) That doesn't really seem to answer the question though. Why are Americans happy to be forced to used their old units mostly adopted from the British despite the numerous flaws of said units, but unhappy to be forced to use the metric system which is better in most ways (particularly since for better or worse, nearly all modern human cultures use the decimal number system for everyday use)? That ultimately is at the hard of the question and saying "they preferred to be forced to use the old system rather than forced to use the metric system" isn't a particularly satisfying answer. It also doesn't really address the issue of why Americans are unhappy to use the metric system voluntarily in most areas of life where it is mostly unrelated to "force" again despite the numerous advantages which the rest of the world have noticed, since in most countries regardless of how they go there, few people want to return to any old system and think the US units are frankly dumb. Again that is at the hard of the question. (Personally I think several earlier answers have largely address these issues, but the point remains, your comments don't really seem to have helped answer the question.) Nil Einne (talk) 08:55, 11 December 2015 (UTC) The original question assumes facts not in evidence. Cullen disputed the premise of the question, pointing out, correctly, that Americans do in fact use the metric system quite happily. We're just opposed (most of us) to having it written into law. I think that was a useful response to the question, though, as you say, it was not directly an "answer" to it. --Trovatore (talk) 09:14, 11 December 2015 (UTC) That an acre is 1 day of plowing with an animal is a lot more well known in the US (even in the city) than in metric countries (yes, ox or horse). I think that's how the unit started - it's 1 chain times 1 furlong exactly (a furlong is a "furrow-long" — the length of the furrow in the field) the 20x200 meter field shape was because turning the plough around was a pain in the ass. A hectare is what 2.59 acres or something? If I started the metric system I would've made the decimeter the base unit, or maybe 100 millionth of the meridian or circumference (20 or 40 centimeters). You used 10 millionth of the half meridian instead so it's 100 centimeters. One thing that metric is awesome for though (besides huge, tiny or scientific measurements) is cubic measurements (1 L = 10 cm3 = 1000 mL = 1 kg H2O ¤ 1 m3 = 1000 L = 1000 kg H2O = 1 t H2O ¤ 1 mL = 1 cm3 = 1 g H2O). It's still inferior for culinary use. I'm not sure if converting by 10s, 100s, etc. is a big a benefit as metric proponents say it is. If everyone in Britain can get good at driving a freaking clutched car and converting by 12s, 20s, and 240s then humans can get used to converting by the 2s, 3s, 4s, 8s, 12s, 16s and 36s in US measures if they grew up with it. Metric is part of the culture of 99% of the countries now though so they shouldn't change back and Customary with a little metric where the Customary is unusually cumbersome is part of American culture still and shouldn't be eradicated like Welsh (or Manx, Scottish, Cornish, Gaelic etc.). Americans don't mind to put skyscrapers everywhere yet love low-tech crap like classic rock, 8 liter V8's and Republicans (and inches). Europeans like to keep their surroundings historical (not that that's a bad thing) yet love advanced things like electronic music, metric, and progressivism. Even their logos, news programs and stuff look awesome and futuristic. The high tech stuff is probably a foil for all the pre-industrial stuff they see all day. Potato/potahto. We're the last country of any import to use traditional units, so what's so wrong with that? (They were teaching me 5,280 feet in a mile at age 6, too. That probably seems ridiculous to you) Sagittarian Milky Way (talk) 08:05, 11 December 2015 (UTC) The advantage of the metric system is very much more than the 10^n multiplier - though that it is in itself a strong advantage. The "customary units" system as the USA calls it involves lots of weird looking constants in just about every calculation, and you need a calculator, or pencil & paper to do them long hand. In the SI metric system there are no weird constants, just the occaisonal pi. In lots and lots of routine calculations, you can (if you were taught properly in primary school) do them in your head. And the SI metric system facilitates dimensional analysis, which is incredibly powerfull at showing errors in formulas, whether incorrectly remembered or worked out on the spot. There's metric and there's metric. All metric systems had x10^n multiplication, but as I said, that's only part of it. 100 years ago the Europeans used theh CGS metric system - an improvement over customary units. In the 1950's they changed to the MKS metric system, a worthwhile improvement over CGS. Then, on about 1970, the Europeans changed to the SI system, a minor improvement over MKS. So three lots on improvements in total over customary units. And the silly Americans still stick with customary units. Its a bit like as if Euros changing over the years from a horse to a 1920's car, then a 1950's car, then a 1970's car. Getting better each time. But the silly Americans are still saying "nobody forces us to do anything, we stay with our horses because we like them." 1.122.35.134 (talk) 09:29, 11 December 2015 (UTC) It does not usually require paper or a calculator! When you grow up with it it's way easier than it looks. Even more so for people who use them frequenter than average like carpenters and builders. They would soon instantly know how many feet it is when they see 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90 or 96 inches and maybe higher and also the reverse. Even if you don't know the number exactly you would have a good estimate for how many yards in a mile (1,760) just because you drive all the time and the road signs are all in yards when it's less than a quarter mile (440 yards). And similarly for other things. Sagittarian Milky Way (talk) 09:52, 11 December 2015 (UTC) And I'm sure that many Americans are perfectly capable of mentally converting any common metric units to the other common metric units. Sagittarian Milky Way (talk) 09:58, 11 December 2015 (UTC) There is really no such thing as one system of measurement being better than another. It can be better for certain purposes, sure. Use whatever works best for you, and then learn how to convert units, so you can talk to people who use different ones. It's really not hard, and it's unreasonable for you to demand that others give up units that are convenient for them, just to save you some utterly trivial arithmetic. --Trovatore (talk) 09:34, 11 December 2015 (UTC) That paragraph is so true. Sagittarian Milky Way (talk) 09:52, 11 December 2015 (UTC) The US uses metrics where it makes sense to. But the argument that "everyone else uses it" is bogus - it's the conformist argument. Americans don't conform to someone else's system just because those someone-elses think we should. ←Baseball Bugs What's up, Doc? carrots→ 10:12, 11 December 2015 (UTC) The American assertion that they can't be forced to do something, and won't accept laws that make the metric system mandatory, is pretty daft when you look at the big picture. The USA used to have a very sound economy, because they used to make everything. Now they make less and less. They buy things from China, and borrow money from China. So the big question is: why have they becaome so uncompetitive? Not using the metric system is part of it. Forget silly old Granpa and his hogsheads, the metric system reduces the cost of doing commerce, reduces the cost of research and development, and reduces the cost of making things. Though I admit that customary units is only a small part of the reasons why manufacturing in the USA is now uncompetitive. The big reason is that, yes, they passed laws about polution and occupational health and safety that are beyond what other countries have - over the top in fact. Over a certain point, safety cannot be increased by legislation - it just increases costs. So on the one hand they reject a law that would make things easier (metrication) but totally accept environmental and OH&S laws that ruin them! Makes no sense at all. And makes the claim above that they can't have a (good) law null and void. 1.122.35.134 (talk) 10:52, 11 December 2015 (UTC) Nobody forced virtually all other countries to go metric. They went metric because it simplifies things and lowers costs. Nobody is forcing America to go metric. We just find it hard to understand why they won't. 1.122.35.134 (talk) 10:52, 11 December 2015 (UTC) American companies, and indeed American consumers, don't accept that you could be prohibited from writing the words "ONE GALLON" on a container you're selling. Nor would they accept that you ought to be banned from selling exactly that much liquid, and required to sell more or less instead. And though I don't know, I'm awfully skeptical that the Chinese accept any such ban either - their country isn't really renowned for business regulation - but as you say they have an export focus, so I feel sure they're willing to provide whatever units the rest of the world wants to buy in. Wnt (talk) 14:26, 11 December 2015 (UTC) China is an SI metric country. Importers in other countries can have the products re-labelled or specially labelled (by the manufacturer) if they wish. Chinese compliance is tighter than the Japanese - a metric country but who has its own standards for many things. Foe example, China makes its' nuts and bolts to Euro metric standards, but the Japanese have some odd ones, that are metric, but not European metric. A bit like the British Association standard for small nuts and bolts - again, it's metric, but not standard metric, and incompatible. 1.122.35.134 (talk) 16:00, 11 December 2015 (UTC) Sorry, what's the improvement of MKS over CGS? There is the whole electrostatic versus electromagnetic difference between electrical unit definitions, but as MKS per se technically doesn't specify electrical units, that's not an intrinsic benefit. I'm not sure what other worthwhile improvements there are by using the metre over the centimetre while simultaneously going from the the gram to the kilogram. -- 160.129.138.186 (talk) 16:14, 11 December 2015 (UTC) A question that I asked some time ago, which was never really answered, was "Why does the US use thousands of pounds when talking about trucks?" https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Miscellaneous&oldid=627531150#Why_does_the_US_use_thousands_of_pounds_when_talking_about_trucks.3F So if the US was to go completely metric, would they refer to trucks in thousands of kilograms or tonnes? As an aside, I grew up in a metric country (Australia) and moved to Britain. Even after 20+ years, I still use metric every day. My recipe books are metric, my rulers and scales are metric, and I don't need to convert to the other system. Driving isn't a problem as the speedo is just a number and the appropriate speed is posted on the road. So long as the number on my speedo is the same as the posted number we're good! I find it funny when they say a car gets X miles per gallon, as you haven't been able to buy a gallon of petrol since the late 1980s. TrogWoolley (talk) 11:35, 11 December 2015 (UTC) An interesting question, because when you look at all sorts of international standards & usage conventions, it seems that the USA just likes to do everything "the American way" i.e, different to the Europeans. There is seldom any real reason, they just do things differently. Since truck capacities and truck loads are called out in thousands of Kg just about everywhere, perhaps the Americans would do the same, as it is sensible, or perhaps they would go for tonnes, just to be different? 1.122.35.134 (talk) 11:58, 11 December 2015 (UTC) Here is an interesting article from only last year on this very topic. --Jayron32 12:43, 11 December 2015 (UTC) The "acres" given above are an example of something that will never change. If you look for a home in the U.S., most of the time you're looking at acre lots, half-acre lots ... and those lots are going to stay the same size, especially because as a consumer in many places you'd pretty much have to know someone in local government to be able to subdivide them. If someone is selling ".404 hectares", the consumer will probably ask you how much that is in acres ... alternatively he might think he knows, in which case either he's right, in which case you've gained nothing, or he thinks it's more land than it is, in which case he might waste your time before he looks in more detail and changing his mind, or he might think it's less, in which case he goes right past your listing without stopping. I don't see any way that listing property in hectares will result in anything but pain for the seller. Even if a developer subdivides in odd-sized lots, there's no particular reason to use hectares. Wnt (talk) 14:37, 11 December 2015 (UTC) And there's no particular reason to use acres. Do you measure your house floor area in acres? I guess not. At one time, residential land in Australia was sold in approximate half-acre or quarter acre lots too. It was always approximate because town planning is and was always done "pre-calc", which means done on paper without regard for slopes, drainage, etc. Then when the land is surveyed, the surveyor measures the actual on-the-slope area. I bet it works that way in the USA too, because it is so sensible. You can hardly expect the planners to know the exact area before its surveyed. But since we went metric decades ago, nobody under 60 years of age really knows what an acre is. We mostly know what a hectare is (10,000 m2 - 100 good male adult paces on a side), and we know what a typical modern city r4 ("r4" is a standard town planning residential scheme - 4 dwellings per 1000 m2) land parcel is (160 to 250 m2), But, if you want a house of so many square meters floor area, the usual 85 m2 or so for a 2-car garage, room for the x-many square metres swimming pool, and a yard for the bar-b-q, you can mentally tot it up in the blink of an eye and visuallise the how realtor's offering will stack up. No, it's rather the non-metric system that will cause the seller (and the buyer) pain. Note that the hectare is not an System Internationale unit, it is a semi-obsolete European unit. If the USA was to go metric, properly, they would be measuring land in square metres. 1.122.35.134 (talk) 15:42, 11 December 2015 (UTC) House flooring is typically given in square feet. Lot size is typically given in acres or fractions thereof. Unless we plan to export land, there's no monetary reason to switch to square meters and hectares. ←Baseball Bugs What's up, Doc? carrots→ 16:00, 11 December 2015 (UTC) Yeah, I thought so. So you have to convert acres to square feet in order to figure out how to use the land. Not a big deal perhaps, we know an acre is 43,560 square feet. But why not measure both in the same units and make it easy? It's all these weird conversion factors in US customary units calculation that make mental arithmetic difficult and facilitate error. 1.122.35.134 (talk) 17:16, 11 December 2015 (UTC) Different units exist in different sizes to facility human understanding. Humans have a limited number sense, whereby there is a difficulty in internalizing and making meaning out of very large or very small numbers. One could for example measure everything using a single unit, say the meter. The problem becomes expressing the size of a bacteria, and the distance to Mars, only using meters interferes with people's ability to "internalize" such numbers in a way that makes sense to them. Most people can only deal with numbers of a limited number of digits (say 3-4 digits on either side of the decimal place) before their brain can no longer intuitively connect the string of digits to its real size. Thus, a measurement of 1,500 kilometers may be more meaningful to a person than 1,500,000 meters, or 1,500,000,000 millimeters, though they are all equivalent. All measurements exist for the convenience of the people using them, people will tend to adopt a measurement system which is convenient for their own purposes. Expressing small areas in square feet, and large areas in acres, is useful in this regard: people know how big a square foot is. They know how big an acre is. So for small numbers of each, they can visualize, for example what a 1500 square foot house should look like, and also what a 3 acre plot of land should look like. The human brain has a harder time conceptualizing what 130,000 square feet looks like, or what 0.034 acres looks like, even though they are equivalent. The purpose of different sized units has little to do with how they facilitate conversion (though, I fully agree that the metric system wins hands down there), but with how the different sized units facilitate understanding of the connection between size and number. For further reading on this topic, these articles are all about the problems with the human mind and conceptualizing large numbers: [3], [4]. Also related is the notion of The Magical Number Seven, Plus or Minus Two, which is the landmark paper on the limits of human information processing; the number of digits in a number that a person can make "sense" of is closely related to (though not directly addressed by) the limits discussed in that paper. The way the human mind estimates the size of things related to number is called Subitizing, and while there are techniques which can be used to "train" the mind how to do it better, natural human limits on the ability to do so is limited. That's why people don't express everything in the same units. --Jayron32 17:37, 11 December 2015 (UTC) Also, crop yields in America are usually given as bushels per acre, while crop yields in Europe (and maybe elsewhere) are usually given as kilograms per hectare. Hectares are alive and well, unless they are no longer growing crops in the rest of the world. ←Baseball Bugs What's up, Doc? carrots→ 16:07, 11 December 2015 (UTC) The Hectare is not an SI unit. Look it up and check. The title deeds for the land I own are in square metres. The town planning scheme maps, sewage and drainage plans, etc are all in metres and square metres. Nothing official is in hectares. I suspect this is part of the problem with discussing this kind of issue. Americans think there are two systems - their system (which they call "customary units") and the "metric" system. In fact, there are many metric systems - local systems, CGS, MKS, and SI (= MKS improved). European experience and carefull thought by their standards bodies led in an evolutionary way to SI - the World standard since about 1970. If you are going to try and mix old metric systems units up with SI, or confuse them for SI, then naturally you will get less advantage than you will with full compliance with SI. A bit of googling showed that Australian farmers variously rate their yields in kg/Hectare, and tons/hectare. kg/m2 would be more compliant with SI (for wheat, 0.2 to 0.3 kg/m2 is typical), but it probably doesn't much matter, it's a dead easy conversion (1 tonne/hectare equates to 0.1 kg/m2), yields in any given geographic areas should be much the same, and when they sell it, the grain buyer is only interested in total weight and moisture content. 1.122.35.134 (talk) 17:16, 11 December 2015 (UTC)

Fellow contributors, may I implore a few of you to pause, research some referenced answers, and then either resume this discussion or relocate it to a different place?

Here is The United States and the Metric System, published by NIST (our Government's agency that standardizes weights and measures, part of our Department of Commerce). Some facts: publications of the Federal Government have been using metric-like units since at least 1800; the metric system is actually used as the standard to define the "conventional" units like inches and pounds. At several times in the 1970s and 1980s, specific legislation was attempted to mandate metric units: for example, see the history of the Metric Conversion Act of 1975.

The original question asked why many people are opposed to metric units; this is a faulty premise. We have used metric units for a long time for many tasks. We do not use them for every task. Sometimes, the metric system is just less useful, particularly when decimalized math is not relevant to the problem.

There has been a lot of discussion of miles, acres, and gallons... but bear in mind that Systeme Internationale is a complete set of physical units. Has anyone ever tried to meter a camera's photographic exposure using candelas? That's the SI unit. Give it a shot some day. There is more to this story than simple conversion between cubic-centimeters-of-water and grams-of-water.

Nimur (talk) 17:12, 11 December 2015 (UTC)

We do not use them for every task. Sometimes, the metric system is just less useful, particularly when decimalized math is not relevant to the problem. Ah! That must explain why:Mars Probe Lost Due to Simple Math Error where $billions of astronautical space stuff was lost due to not using the metric system for every task.--Aspro (talk) 21:22, 11 December 2015 (UTC)

The Mars Climate Orbiter was lost to a failure of integration testing. It happened to be units, but it could have been any number of other things.

To be fair, integration testing is a huge pain in the butt, at least an order of magnitude harder than unit testing, and you're never going to catch everything. Anything you can do to reduce the number of potential problems that integration testing is expected to catch is all to the good, and unit standards across the whole project might arguably have helped with that. Still. When the stakes are that high, you gotta do the testing. That's the main takeaway. Units are a secondary issue. --Trovatore (talk) 21:29, 11 December 2015 (UTC)

Exactly: there is no reason to believe that the subsystems would have worked together "if only" everything had been in metric. NASApublished a series of technical findings that provide a little more color and depth to this story. A few quotes that resonate: "the small mission navigation team was oversubscribed and its work did not receive peer review by independent experts." "Some communications channels among project engineering groups were too informal." "The process to verify and validate certain engineering requirements and technical interfaces between some project groups, and between the project and its prime mission contractor, was inadequate."

Like many accidents, the failures in the Mars Climate Orbiter mission were many, and they persisted because of human factors and organizational dynamics. It is overly-simplistic - and not very instructive - to blame a mission failure on one single defect in design: complex systems have many defects, and they are still expected to work correctly. Nimur (talk) 16:16, 13 December 2015 (UTC)

Wrong comparison. Candela is the unit for emitted luminous power. No wonder it is not used photography. Use SI unit cd/m2. Practicle real life eample: Light Meter--Aspro (talk) 21:35, 11 December 2015 (UTC)

Did you specifically look for a meter that exclusively reports non-SI units, or was that an accident?

If you want a real scientific instrument to measure light level, I recommend the Konica Minolta T10M and its newer series follow-ons. You can't buy it on Amazon: you'll have to talk to a real sales representative to get a price quote. Nimur (talk) 16:16, 13 December 2015 (UTC)

Oh, the foot candles thing. US literature just convert ISO 2720:1974 into Foot Candles so as not to confuse John Doe but the meters conform to SI unit cd/m2. Look at where you cameras/ light meters are made and they will conform to an ISO standard -if they are not an antiques. Yet it goes back to my point, that it is the illumination upon the film (candles per unit area) that maters not the luminance in 'Candles' of the subject). --Aspro (talk) 17:28, 13 December 2015 (UTC)

Cameras are horrible. The angle of field of view for a combination of a modern digital camera (still or video) and lens is generally given as 35 mm equivalent focal length. In this, the name "35 mm" refers to the size of a particular once popular photographic film standard together with padding. It is hard to guess the actually used image capture size that type of film uses, and that's the conversion factor for this style of specification. Some saner camera data sheets also give the angle of field of view, but for many, the equivalent focal length is all there is, and I personally always have trouble translating that. – b_jonas 10:46, 12 December 2015 (UTC)

Indeed. And, the moment you throw in the subjective bits, like photopic curves in photometry, all units become meaningless. Cameras are terrible scientific instruments, yet we use them anyway - so somehow, we manage to engineer and manufacture them... Nimur (talk) 16:16, 13 December 2015 (UTC)

Jumping on this gripe sidetrack (sorry): SI units would seem more consistent to me if a coulomb (or replacement unit) were 1 mol of electrons. Instead there's some goofy definition of the ampere that everything is based off of that might as well be a new Imperial unit for all the sense it makes. Wnt (talk) 10:57, 12 December 2015 (UTC)

Perhaps it clarifies the question if I see what feels so wrong about using two systems simultaneously. (“Metric“ is the wrong word, I think; for example, because Fahrenheits are also part of the problem, as the problem is intuitively perceived). Just two things: excessive work and absurdity of the situation. When you use just one system of units (in the most naive sense of the word: just an internal method that suggests intuitive marks about how big a certain kind of quantity is), you can immediately “feel” how big a number is, that process does not involve any specially designed multiplication. Nothing that follows any special rules of multiplication and needs to be driven along by your will as such multiplication. When you are forced by your neighbourhood to use other systems as well, you often acquire the problem of conscious conversion, which could have been avoided. Someone needs to ask himself: “he said thirty feet; how to convert that number into metres to know intuitively what that quantity means for me? am I sure I converted the number properly, or he really means a giant that high? feets are so artificial, so unnatural…”. At the end of the day, when people have two systems of units, there is the question why couldn't they have more of them? There is no inherent advantage about any system at all, that is, no such advantage that is practically important in our daily lives; so, being forced by someone's neighbourhood is the only reason to add a certain system of units for use in your intuition, that is to learn it; so the final question is, “whom should one comply with?”. Since units of measurement are not like natural language: you need to comply with someone to achieve practical results; so the question is, who is the right guy, how is he described… That is why using two systems simultaneously looks absurd when you think of it: it looks like an unfinished attempt to resolve questions of power despite excessive work that is entailed from such ever unfinished resolution…

PS: I wonder why this question is in the section on “Science”, what it has to do with science. Perhaps “Humanities” would be a better place for it? Mightbe, there it would find some better answers than here… - Evgeniy E. (talk) 13:59, 12 December 2015 (UTC)

How about some facts:

1. Most countries in the world have switched over to the metric system.
   • According to Metric_system#Usage_around_the_world, in 2007 only Liberia, Burma and the US did not. Libia has since switched over, and in 2011 Burma began in the process of switching. It's now believed that the US is now the only country in the world that hasn't switched over.
2. The population of the world is 7.3 billion, only 0.3 billion people live in countries that don't use metric.
   • Many Americans believe that a switch to metric would be a good thing - so the number of "hold-outs" is even smaller than 0.3 billion.
   • When some Americans argue that non-metric is somehow better, they are a tiny minority of the world's population.
   • If the US 'hold-outs' were correct, then you would expect that a significant number of people in other countries would be demanding a return to the non-metric system.
   • Not one country has ever switched back - and outside of the US, there appear to be no significant groups of people demanding a reversion to pre-metric systems. The only counter-example I could find was that highway projects in Kentucky and California were decided to de-metricate because of the cost of doing business with contractors who were still using non-metric units.
3. It follows that whatever objections that Americans have to using metric has to be either cultural or historical...a form of Vendor lock-in.
4. When one group of people use metric and another does not - then when they interact, you run into problems. When countries of the world were less connected, this was a smaller problem - but it's getting worse over time.
5. Within the US, scientific applications now use the metric system - so even strictly within the US, there are incompatibilities and difficulties.
   • The SOHO solar observatory came close to being lost due to a metric/non-metric screwup - but nobody learned a lesson from that because in the following year...
   • American taxpayers lost $328 million due to a metric/no-metric screwup in the Mars Climate Orbiter.
   • The Gimli Glider incident came very close to killing 200 people due to a metric/non-metric screwup.
   • The confusion between 'g' (meaning grams, outside the US) and 'g' (meaning 'grains', inside the US medical system) has resulted in at least one death that we know about - the number of deaths and injuries that we don't know about is probably much greater.
6. The oft-cited reason for the US failing to switch to the metric system because of cost is overrated. A gradual change-over, such as has been happening in the UK over the last 30 years, is almost imperceptible. The UK has not yet completed the process - for example, replacing millions of road signs with distances in kilometers instead of miles has not yet been done. Since 1795, when France was the first to adopt it, every single country in the world (with the exception of the US) has successfully transitioned. It clearly can be done - even by large, industrialized nations.

SteveBaker (talk) 15:35, 12 December 2015 (UTC)

Doctors don't use grains anymore if I'm not mistaken. Sagittarian Milky Way (talk) 15:51, 12 December 2015 (UTC)

And Intestate 19 had metric until the signs were changed back. The road is just a short spur to Mexico where they'll be using metric anyway and has no major US settlements besides the terminus (and that city is not that big even by Arizona standards). Sagittarian Milky Way (talk) 15:59, 12 December 2015 (UTC)

Imperial is more widespread than some people might think. In aviation worldwide heights are measured in feet. Precious metals are sold in ounces (that's your Troy ounce, which is bigger than the grocer's variety). Interchanges between units are logical and easily visualised (a gallon of water weighs ten pounds and one fluid ounce of water weighs, unsurprisingly, one ounce). Britain saw through the metrication fraud at the turn of the millennium - why, MPs asked, at the dawn of the new age should Britons go to jail for selling apples by the pound? So they dismantled the whole ridiculous structure, and Britons are free to sell their apples by the pound if they want (though trading standards will jail them if the scale they use isn't calibrated in metric). 80.44.164.220 (talk) 17:10, 12 December 2015 (UTC)

• What a load of penis envy. When Trump becomes president, not only will he build a wall and force Mexico to pay for it, he'll recapture Churchill's bust, corner the market on soccer balls, offer CCC breasts to all who request them, and have the human body temperature reset to a refreshing 72 degrees, an no I don't mean Kelvin. μηδείς (talk) 23:09, 12 December 2015 (UTC)

Have to disagree with μηδείς and agree with Donald. Churchill should return to the Oval Office but Donald Trump's CCC coiffure does make him look top heavy. Wonder he doesn’t fall over in the wind. As to what should or should not lay below the décolletage – I offer no comment. --Aspro (talk) 19:19, 13 December 2015 (UTC)

When Trump becomes president, it'll be the death penalty for killing a cop. Suicidal individuals will then go out and kill cops so as to force the state to put them to death. The threat of execution does not deter those who feel their lives have no meaning. But Trump is not wise enough to know that. Akld guy (talk) 05:58, 14 December 2015 (UTC)

State laws about murder and capital punishment vary, and the US president has no jurisdiction. Also, there's no way to know who might be inhibited from committing violent crimes due to fear of the consequences. We only know about the ones who go ahead and do it. ←Baseball Bugs ^{What's up, Doc?} carrots→ 08:00, 14 December 2015 (UTC)

Have you not been following the news? Even here in NZ, Trump's execution-for-cop-killing made the headlines last week when he mooted it as a possible campaign platform. Akld guy (talk) 10:58, 14 December 2015 (UTC)

Oh, he says a lot of things, many of which are not going to happen. ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:02, 14 December 2015 (UTC)

Bird identificaton

Can anybody identify the bird in the two pictures, pic one, pic two. It was found in Ulukhaktok, possibly yesterday but I'm not sure yet. It has webbed feet so it's obviously some sort of waterfowl. Could it be a guillemot? I don't have any measurements but the glove would be about 25 cm (9.8 in) long. CambridgeBayWeather, Uqaqtuq (talk), Sunasuttuq 11:08, 10 December 2015 (UTC)

It was found yesterday. Of course normally the only birds left at this time of year are snowy owls and ravens. CambridgeBayWeather, Uqaqtuq (talk), Sunasuttuq 14:02, 10 December 2015 (UTC)

It turns out to be a juvenile common eider. CambridgeBayWeather, Uqaqtuq (talk), Sunasuttuq 16:09, 10 December 2015 (UTC)

Ah yes, a duck is much more difficult to identify when it doesn't walk like a duck and quack like a duck anymore. – b_jonas 10:13, 11 December 2015 (UTC)

Are smiling faces more attractive than not-smiling faces?

It seems to me that, when people smile, their faces become more attractive or prettier. Is it me, or is there an objective truth behind this? 140.254.136.179 (talk) 15:40, 10 December 2015 (UTC)

Yes; see Study: Smiling Makes You More Attractive, and referring to earlier research, Eye contact and a smile will win you a mate. Alansplodge (talk) 16:14, 10 December 2015 (UTC)

Also, smiling watches is an interesting fact about "smiling".216.80.117.134 (talk) 16:26, 10 December 2015 (UTC)

Note however that these are recent studies, and that it is not necessarily a universal. Smiling was rarely used for portraits as it was considered mischievous or even the un-trustworthy. [5] Extract: "By the 17th century in Europe, it was a well-established fact that the only people who smiled broadly, in life and in art, were the poor, the lewd, the drunk, the innocent, and the entertainment." So smiling was not necessarily considered attractive to all parts of society. --Lgriot (talk) 12:55, 11 December 2015 (UTC)

Why is it so hard to walk on all fours?

I tried to walk on all fours. I just couldn't do it. My legs were much longer than my arms, and walking was just not comfortable, and running seemed impossible. 140.254.136.179 (talk) 15:48, 10 December 2015 (UTC)

Because humans evolved over time to have a body organization that favors Bipedalism. How this came to happen to YOU in particular is covered at Human skeletal changes due to bipedalism. --Jayron32 16:14, 10 December 2015 (UTC)

However, many reports of feral children suggest that they preferred to walk on all-fours, so possibly these skeletal adaptations can be overcome with practice. Alansplodge (talk) 16:20, 10 December 2015 (UTC)

And I found a documentary called The Family that Walks on All Fours. Alansplodge (talk) 16:38, 10 December 2015 (UTC)

The singular of "data" is not "anecdote". By that I mean that one human (or a small number of countable humans) likes to walk on all fours is not meaningful when considering the properties of humanity. See Generalizing from the particular for the problem with such thinking. --Jayron32 16:40, 10 December 2015 (UTC)

Alan said it was possible, which even one case demonstrates to be true. As for generalizing it to the entire human population, if your argument is that it's possible for some humans, but not all, then you would need to demonstrate why. For example, are the proportions of those who walk on all fours significantly different ? StuRat (talk) 17:10, 10 December 2015 (UTC)

As noted, being possible does not mean it's useful or relevant to drive behavior or understanding. For example, it is literally possible that I can win the lottery tomorrow, but that fact does not mean it is useful for me to buy a lottery ticket. Quite to the contrary, the data makes it clear that doing so makes me worse off, because statistically, I'm far more likely to get poorer, and often significantly so, merely by thinking that the possible is what should drive behavior and not the likely. Studying and explaining the likely is a more useful act than the possible in this case, since the OP asked why HE couldn't walk on all fours. If the OP were asking what they could do to improve their finances, you would NOT recommend he start buying lottery tickets, you'd instead recommend learning about how most people improve their finances in reliable ways. For exactly the same reason, when wanting to answer why the OP walks the way he does, we take the bulk of humanity into account, not the freak occurrences. --Jayron32 17:29, 10 December 2015 (UTC)

You are still assuming there is something fundamentally different about those cases, beyond just having practiced, despite providing no references to back up that assumption. Occam's razor applies here, meaning assumptions of differences require actual proof. StuRat (talk) 18:21, 10 December 2015 (UTC)

I've made no assumptions. Instead, I've refused to engage in the validity of generalizing from the particular, a well demonstrated fallacy. Which I did reference to so you could read about. You, on the other hand, continue to assert that it's a valid means of drawing conclusions, in direct contravention of accepted logic. Also, you'll note, that I provided references to answer the OP's question directly, so they could read about it and draw their own conclusions, and did so from the beginning. Which is something you last did...lemme check... never... --Jayron32 19:50, 10 December 2015 (UTC)

That you are unable to see the assumptions you have made is not something I can correct with a reference. StuRat (talk) 04:43, 11 December 2015 (UTC)

I'd like to see one or more picture of feral children actually walking on all fours, as opposed to "reports" of it. The average infant is likely to crawl on hands and knees, as even at a very young age their legs are longer than their arms. ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:23, 10 December 2015 (UTC)

Oxana_Malaya has lots of photos and videos of her, e.g. here on youtube [6]. She does seem to use her knees more than her feet when moving around, though sometimes she does use a gait similar to the The Family that Walks on All Fours, which is definitely a two-handed, two-footed "walking on all fours". That family really is a fascinating case, I recommend watching at least a few minutes at the link above to see them walk. SemanticMantis (talk) 19:27, 10 December 2015 (UTC)

The question was "why is it so hard" not "is it possible" so I'm with Jayron here, just because some feral children and one family "do it", doesn't really have any relevance to the question "why is it so hard?". Vespine (talk) 21:22, 10 December 2015 (UTC)

I'm mostly with Vespine and Jayron32 here except that I would say that I think the links and comments from Alanspodge were mildly useful to the discussion. While it didn't answer the question of "Why is it so hard to walk on all fours?", they did relate to the points the OP made in their comment in that it does seem some people, perhaps most people, are able to do it better than the OP. The sources don't demonstrate this so we have no idea, but while I only skimmed through the video, I didn't see anything to suggest they had any unusual genetic body types that made walking on all fours easier, nor with feral children. (It possible their parts of their bodies developed in such a way to make it easier, due to practicing it since childhood.) This doesn't mean it's ever easy or particularly suited to the human body type. While it's possible this is bias from experience, the family odd style of walking still didn't seem to work that well. StuRat's comments do seem unnecessary and unhelpful. Nil Einne (talk) 22:11, 10 December 2015 (UTC)

You said "I didn't see anything to suggest they had any unusual genetic body types that made walking on all fours easier". I agree. Jayron, on the other hand, in saying we can't assume that all people have this capability is suggesting precisely that there is something fundamentally different about the people in the video that makes them capable of this, while other humans are not. I simply asked for a source to support this assumption. StuRat (talk) 04:50, 11 December 2015 (UTC)

Your summary of your and Jayron32's comments isn't particularly accurate. Nil Einne (talk) 08:35, 11 December 2015 (UTC)

Per Nil Einne, I didn't say, to quote you, "there is something fundamentally different about the people in the video that makes them capable of this, while other humans are not." I said 1) we can make no assumption in any direction. To refuse to commit without evidence is NOT the same thing as to commit to the negative assumption, as you are claiming I have done. What I am saying, have said, and will continue to say is that there is no position to be taken, either in the affirmative or negative, on any assertion without evidence. Not that you'll listen to this, because your past and continuing behavior for years has indicated that you aren't terribly interested in improving your understanding of the world, but I will repeated it just to prove to the world that you have been informed of this: There is a difference between not committing to a stance and committing to the negative position. Learn the difference if you want to not look foolish. 2) I also said that the point is not terribly relevant to answering the question and gave sound links to logical issues with using anecdotes as evidence for making generalized statements about humanity. --Jayron32 11:38, 11 December 2015 (UTC)

You said the observation "is not meaningful". If you meant it "may or may not be, and more study would be needed to establish if it is", then you should have said that. StuRat (talk) 15:38, 11 December 2015 (UTC)

The observation is not meaningful to answering the question. It may be meaningful to answering a different question. --Jayron32 15:55, 11 December 2015 (UTC)

Please note that I wasn't disputing Jayron's pertinent links, I just thought it would be interesting to see the other side of the coin. Thanks to those who have spoken in my defence. Alansplodge (talk) 08:58, 11 December 2015 (UTC)

Aye, I understood. I was only responding to Bugs' comment about pictures, of course we're bipedal and that's the main answer, but that doesn't mean we can't share additional relevant references for context and discuss slightly tangential issues (e.g. feral children) SemanticMantis (talk) 14:58, 11 December 2015 (UTC)

• Even if the curvature of the human spine, which becomes less flexible as we age were not against the practice, and even if the relative lengths and flexibility of our arms versus our legs didn't make it difficult, the placement of the foramen magnum at the base of the skull, rather than the back of the skull would force our faces downwards and cause us to have to arch or our our necks quite uncomfortably. Given that, as a child until adolescence I did regularly go up stairs on all fours rather regularly (not in public, where I was admonished); but climbing a 45 degree angle makes a huge difference. Even that was more along the lines of makebelieve than any sort of necessity or even actual convenience--for instance I certainly didn't descend that way. μηδείς (talk) 17:15, 13 December 2015 (UTC)

Concentration of minerals in the Earth crust

We know how our solar system came about, it started with an explosion of a supernova that blew out enormous amount of hydrogen, maybe just a mix of protons and electrons, and perhaps some helium. Along with that it blew out for months or perhaps years some gamma radiation. As a result heavy elements were synthesized. Then the gravity helped to create a central point and some chunks of material began to rotate around it. There was this proto-planet Earth and after a few million years another big chunk slammed into it thus creating the moon. I assume the Earth liquefied because of the blow but then slowly cooled. Why do we have concentration of minerals in the Earth crust? It would be logical to assume that ALL elements should be distributed equally everywhere like when you drop a piece of sugar in a tea glass and stir it thoroughly. I think it is true for aluminum if I am not mistaken. Instead we have places where the elements like copper, iron and others are plentiful making industrial mining profitable. In Russian Ural Mountains there is a mountain that consists entirely of magnetized iron. It won the World War II for them. They converted the chunks of the mountain into T-34s right there. Why is it so? Why do we have copper deposits in some places but not others. The total chaos of creation should have mixed elements equally through the Earth and this is clearly not the case. Thanks --AboutFace 22 (talk) 23:55, 10 December 2015 (UTC)

Have a look at Ore genesis. Dolphin (t) 00:25, 11 December 2015 (UTC)

• See The Elements: Their Origin, Abundance, and Distribution by P. A. Cox, and come back if you have any complaints. This book is worth its weight in gold, although you need not spend so much as its weight in aluminium to acquire it. μηδείς (talk) 04:20, 11 December 2015 (UTC)

For why the Earth isn't homogeneous, try Planetary differentiation. Mikenorton (talk) 12:48, 11 December 2015 (UTC)

We have an article on Magnitogorsk, which alas is very short on geology. For specifics information about the raising of the mountains during an arc-continent collision see [7], which is freely accessible and very detailed... except about how the iron fits into the picture, which it discusses not at all. (the general idea is discussed at forearc but I am wary that I may misunderstand some vital details) The Cox reference suggested above is a great idea; regrettably Ошибка: не удалось открыть страницу. Wnt (talk) 13:45, 11 December 2015 (UTC)

This link says that the Magnitogorsk deposit is a magnetite skarn, so formed by the effects of hydrothermal fluids driven by heating around an intrusion, interacting with existing sedimentary rocks, particularly limestones. Mikenorton (talk) 11:49, 12 December 2015 (UTC)

Not directly related to your central question, but your description of supernovas is not really correct. Supernovas don't "[blow] out for months or perhaps years some gamma radiation", unless by that you're talking about the photons produced by the supernova traveling away through space (which will of course travel until they hit something, which for any individual photon could take billions of years, or never happen). The supernova explosion itself takes a few seconds at most. Supernovas do create heavier elements in the explosion event, but many elements heavier than helium are created inside stars during their lives by fusion reactions. See nucleosynthesis. And here's Crash Course Astronomy on the lives and deaths of high-mass stars. --71.119.131.184 (talk) 18:36, 11 December 2015 (UTC)

December 11

Calculating orbital distance based on 2 observations

[8]

The two observations show movement of the new dim object relative to Alpha Centauri A and B. So, why can't we find the movement, say in terms of arc seconds, then figure out how long it would take to move 360 degrees based on that, and derive the orbital distance from that ? Some potential problems I see:

1) This assumes it's in orbit about the Sun. If it's in the Alpha Centauri system, or not bound to either, then this won't work. (If in the Alpha Centauri system, it might have already made an orbit in the observation period, but then presumably we would have more observations).

2) This won't take acceleration into account.

3) Let's assume it's in our solar system. This doesn't consider movement towards and away from Earth (which is essentially the same as towards or away from the Sun, at that distance). Would movement toward or away from the center of our solar system change the calcs ? (I realize that this implies acceleration, but if that accel is only towards and away from the center, rather than normal to this direction, does that matter ?)

Also, a second Q: There are questions about why it wouldn't have been observed more often. Could it be varying in signal strength for some reason, in the frequency detected (short microwave wavelengths), such that it drops below the observation threshold ? StuRat (talk) 15:21, 11 December 2015 (UTC)

• The original paper is here. The authors aren't even sure that it is orbiting us – all they can say is that it's comoving with the Centuari system but doesn't seem to be bound to it. As for why it wasn't seen before, they suspect that it "could not have been detected with the VLT-NACO data [the last major survey of that area of space, done in 2004 to 2005] because, due to the intense glare from Cen AB, it was intentionally blocked out of view." This makes precovery very difficult - if you look at Figure 2, between about 2000 and 2010, it was almost overlapping the Centauri system. It's only now that it's moved further away from the star system that it's become visible. Smurrayinchester 15:53, 11 December 2015 (UTC)

(edit conflict) Let us assume that object is in orbit around the sun and that we as observers are roughly in the focal point of the ellips (i.e. comparatively close to the Solar System's center of mass). Then the orbit is decribed by Kepler's second law: $P\cdot {\tfrac {1}{2}}r^{2}{\frac {d\theta }{dt}}=\pi ab$ with P the period, r the object's current distance from the focal point (us) and a and b the semi-minor and semi-major axes of the ellipse. From the two pictures, the only thing we can directly calculate is ${\frac {d\theta }{dt}}$, so there are simply too many unknowns. Only if we assume that the orbit is circular (i.e. $r^{2}=ab$) can we find the orbital period, and, from that, the object's distance. - Lindert (talk) 16:04, 11 December 2015 (UTC)

Thanks. I take that the mean that movement (and hence acceleration) towards and away from the Sun does affect the orbital period. StuRat (talk) 16:08, 11 December 2015 (UTC)

Yes, you could say that; of course if you knew the acceleration, you'd also know the distance simply from Newton's law of gravity. - Lindert (talk) 16:34, 11 December 2015 (UTC)

My guess is that to predict where something is going to be in the future - you need to know where it is now, and it's velocity. Each of those requires three numbers (like X,Y,Z and dX, dY, dZ) - so you have a system of equations with six unknowns. If your observation is only a 2D thing (azimuth/elevation for example) then each observation provides only two "knowns" - so you need three observations to produce six knowns with which to calculate the six unknowns. SteveBaker (talk) 18:20, 11 December 2015 (UTC)

Yes, that is fundamentally true, but I doubt that three measurements is always sufficient. And for orbiting objects that are very far away, some of the information may be redundant, considering the accuracy of the measurements, because we pretty much know already that they will move in a 'straight' line across the sky, hence the third measurement may give us only one extra unknown. - Lindert (talk) 18:40, 11 December 2015 (UTC)

Sure - and you can start making wild assumptions, like assuming that an unknown object is probably perfectly orbiting in the plane of the ecliptic and probably not moving in a retrograde orbit. That sort of assumption might turn out to be completely wrong, but it's a good way to constrain the unknowns from 6DOF to lower degrees of freedom. That lets you construct an assumed trajectory even if you don't have enough information to completely constrain it.

If you read astronomy journals about Near-Earth object detection, you'll see that these types of assumptions are frequently applied when data is very sparse. As more observations become available, there is confirmation or refutation of previous assumptions; and the error-bars just get tighter and tighter after each subsequent measurement. The math of Bayesian linear regression provides one way to combine each observation. The more data you have, the less you need to depend on wild assumptions.

In actual reality, the model needs to be bigger than 6DOF, because orbits are imperfect; objects wobble; other solar-system objects affect the orbit too.

I subscribe to Orbital Debris Quarterly (a publication of NASA Johnson Space Center); every few months they give an update of latest news and events in orbital debris science. In addition to recent observations, they also publish a software catalog - including ORDEM, an algorithm and a whole digital database. Here's information on how they take the measurements. You can see how they go from a first-observation to the construction of an orbit ephemeris. A corresponding object catalog, the NEO catalog, tracks objects that are less likely to reenter Earth's atmosphere as debris.

Nimur (talk) 20:06, 11 December 2015 (UTC)

Thanks for the replies so far. Anyone care to take on the second part ? StuRat (talk) 07:24, 12 December 2015 (UTC)

Not much to add, except that an ideal orbit has six orbital parameters (six degrees of freedom), which can be expressed in various ways, see orbital elements. A still photograph gets you two pieces of information so it takes at least three such photographs to solve for the parameters/orbital elements. Bubba73 ^{You talkin' to me?} 05:50, 14 December 2015 (UTC)

Sure, I'll take a shot at the second part. Yes, it's possible, but I don't think it's likely. Red dwarfs and brown dwarfs exhibit two main forms of variability: they could be BY Draconis variables or flare stars, or both. The former generally vary by less than 0.5 magnitudes. Flare stars can increase in brightness by a few magnitudes in just a few minutes, and fade to normal in a few hours. So it's possible that both observations of this object happened right when it was flaring, whereas other surveys photographed it when it wasn't flaring. This would be rather extraordinary luck, but it isn't impossible. --Bowlhover (talk) 09:28, 14 December 2015 (UTC)

Super attacks

Is it possible for a person to have 2 or more independent (I.e. 1 didn't cause the other) life threatening attacks at the same time? For example a heart attack and a stroke or an anaphylactic shock and a seizure etc. What would happen in such cases? — Preceding unsigned comment added by 2A02:C7D:B901:CC00:D198:4CE1:9927:97A3 (talk) 21:22, 11 December 2015 (UTC)

Let's say that one is taking care of bees, and has a brain attack. He falls down, his protective clothing is opened and he is stung by a bee. This produces anaphylactic shock. The scenario is plausible. I won't speculate about the outcome. Tgeorgescu (talk) 00:07, 12 December 2015 (UTC)

Although you could argue those weren't truly independent. However I think gets on to an important issue, namely that it seems unlikely you can come up with a clear definition of independence that will be able to seperate all cases. For example, the OP said "I.e. 1 didn't cause the other", but this seems a very weird definition of independence. While definitely when one clearly causes the other, e.g. if someone has a heart attack and crashes their car suffering major traumatic injuries you would probably say these aren't independent; there would also be cases where you have simultaneous life threatening problems where it's questionable if one cause the other, but which most people would say aren't independent because they both happened because of something else which arguably wasn't life threatening as and of itself. Consider for example if you fall down because you screw up and in doing so badly damage your spine and also get stung by a bee or other examples where the fall wasn't cause by a life-treatening "attack" but causes two or more life threatening "attacks" (you could likewise imagine the car crash scenario). In fact, you get the added complication of what's life threatening. Consider the case of [9] for example. A Paradoxical embolism would normally be consider a very serious or life-threatening condition, but the reason would be because it could easily cause a stroke, MI or that sort. See also [10]. And while doctors would normally do their best to figure out what's going on, it may not always be the case that they can be sure whether the heart attack caused a clot which cause the stroke [11] or something else happened. (And besides, even when they do believe this is what happened, it would often be at most an educated guess based on symptoms etc. Particularly if they were successful in treatment so there was no autopsy. Nil Einne (talk) 06:54, 12 December 2015 (UTC)

And, of course, it is possible that a person could have multiple independent acute conditions at once. You could compute the probability if you knew the portion of the person's recent life during which they had an acute attack of each type. For example, if they have acute attack type A 1% of the time, and acute attack type B 2% of the time, and they really are completely independent of one another, then (1/100) x (2/100) of the time, or 2/10000ths or 1/5000th of the time, you would predict they would suffer both concurrently. However, this is such a small portion of the time that if there is even the slightest dependence, either positive or negative, that will swamp out this number quite quickly. StuRat (talk) 07:19, 12 December 2015 (UTC)

Doctor: "Mr Burns, you seem to have every disease known to man, simultaneously, such that the effects of each is precisely countered and balanced by the effects of the others."

Montgomery Burns: "So, I'm in perfect health then !" StuRat (talk) 07:28, 12 December 2015 (UTC)

Two questions about steroids and testes

I would like to know if the following rumors is correct or no. people say about taking steroids as a bodybuilder, causes to the testes to be smaller. Is it right? Second, if it's right, it doesn't make sense to me - apparently, because that testosterone (if I understand well that is the steroid that the build-builders usually use) supposed to make it bigger as a male hormone. 22:10, 11 December 2015 (UTC) — Preceding unsigned comment added by 92.249.70.153 (talk)

Confirmed in Anabolic steroid#Feminization. It says it inhibits natural production of testosterone, and sperm production. Graeme Bartlett (talk) 22:22, 11 December 2015 (UTC)

As for why, "Feminization can be noticed in men due to the conversion of excessive testosterone into female hormone estrogen." [12]. StuRat (talk) 07:20, 12 December 2015 (UTC)

Hmm, could that be a separate effect, though? I knew about the conversion, but I thought that was the explanation for breast hypertrophy, not shrunken testicles.

The latter I've always attributed to negative feedback — the body senses that it has enough testosterone so it stops making it. But maybe I just assumed that. Actually the linked article doesn't seem to say one way or the other. Anyone have more information on this? --Trovatore (talk) 08:02, 12 December 2015 (UTC)

Yes, that seems reasonable, but we need a source to confirm. StuRat (talk) 06:47, 13 December 2015 (UTC)

There is another factor that might contribute. Bodybuilders are by definition (usually) causing their muscles to become bigger, and as a result they look bigger overall; however, if their testicles remain at best the same size (having no significant muscle mass) these will look smaller by comparison. {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 14:10, 14 December 2015 (UTC)

For further reading, see Anabolic steroids – a problem in popular sports by Ulrich Hoffmann, Institute of Pharmacology, Ernst-Moritz-Arndt University. Alansplodge (talk) 17:34, 14 December 2015 (UTC)

December 12

Alcohols effect on CNS

We all know that alcohol affects the central nervous system slowing down reactions and muscle movements etc but does this mean it also has an effect on involuntary movements such as breathing or heart beats? And I mean in the short term, not long term problems as a result of drinking. And also assuming the person has no log term health problems. 2A02:C7D:B901:CC00:1492:CF54:6C39:5046 (talk) 10:09, 12 December 2015 (UTC)

See Alcohol intoxication#Acute alcohol poisoning. Excessive alcohol consumption can indeed cause fatal respiratory depression. Tevildo (talk) 10:46, 12 December 2015 (UTC)

Do insects learn?

We know that cats learn. I mean a very basic thing: we notice that at one time, a cat does something in one way, but later, it chooses to follow a different way to do that very thing. For example, it may learn to recognise certain people, or it may learn how to open doors, or it may learn a certain location that helps achieve certain ends, or it may learn actions to avoid in a certain location or in presence of certain people. We know that cats do the same things differently at different times, based on their unique experience (the point of uniqueness of behaviour is important: for one aspect, since it is impossible to pre-enumerate every possible behaviour, that implies that a change in behaviour corresponds to a real change in the structure of their brains, it doesn't boil down to a mere illusion of observation). Do we know the same, at least in some marginal cases, about insects? Can they learn at least sometimes? Or they never learn at all? I know that questions about consciousness could be debated to no end, but this question is not about consciousness. Thank you. - Evgeniy E. (talk) 10:20, 12 December 2015 (UTC)

We don't have an article specifically on insect learning, but see Ant#Learning and Bee learning and communication. This paper might also be useful. Tevildo (talk) 11:19, 12 December 2015 (UTC)

Thank you, much appreciated. I edited the place where I looked for the answer. - Evgeniy E. (talk) 12:55, 12 December 2015 (UTC)

From those example, you can see that insect "learning" is rather limited, more what we would call memorization, like memorizing the path to food. However, more fundamental learning, like a new language (say used by another species), might well be beyond them. Cats and dogs, on the other hand, are able to learn at least a few words of our language. StuRat (talk) 06:40, 13 December 2015 (UTC)

The essential difference between learning to respond to a certain type of flower (as bees can do) and learning to respond to a certain spoken word (as dogs can do) is not obvious to me. Looie496 (talk) 12:24, 13 December 2015 (UTC)

For a computer programming POV, it's the difference between loading more data into an existing program, like the location of a food source, versus writing a new program, like one to communicate in a new language. For example, an electronic microwave oven has some ability to remember, in that you punch in the temperatures and times for each cycle, and it follows those commands. But you're not going to get a microwave that isn't designed for speech recognition to spontaneously understand you (even if we assume a microphone was attached to it). From a biological POV, remembering a location requires far fewer nerve cells and connections to establish, and falls into the category of "instinct" (the instinct to locate food, remember it's location, and return to that location with others, for example). But to learn something completely novel requires more brain than they have. StuRat (talk) 21:56, 13 December 2015 (UTC)

They do learn - in almost all the ways you mention for a cat. I'm not entirely sure whether you meant the question to relate to invertebrates in general, or limited to insects, so I will stick to insects for the moment. You will find some of their learning abilities described in Pain in invertebrates#Conditioned avoidance and Pain in invertebrates#Cognitive abilities. Drone bees will learn to suppress extending their proboscis when this results in an electric shock. Fruit flies learn to avoid areas that are too warm (like my cats in summer!). Bees are able to form concepts - a method of advanced learning. Both ants and bees show evidence of numeracy (to the best of my knowledge, this has not been shown in cats!).DrChrissy ^(talk) 12:57, 13 December 2015 (UTC)

Thanks for all additional examples. ;) Well, now I actually wonder whether there are massive groups of animals, who have a brain or at least a nervous system, but cannot learn. ;) (In the sense of developing unique behaviour in response to unique experience). But this question, I suppose, is much more difficult to answer. ;) Most likely, this one can't? ;) - Evgeniy E. (talk) 21:08, 13 December 2015 (UTC)

Not really all that difficult a question to answer - but you need to define what a "brain" is.DrChrissy ^(talk) 00:37, 14 December 2015 (UTC)

I could evade this need by relaxing the criteria to "at least a nervous system" and never-minding the level of its complexity. There is a problem, of course, with the fragment of "massive groups", no-one knows what makes a group "massive". ;) I don't know why I was interested in this follow-up question, so now I preferred to not give any additional specification. Anyway, I got what I needed when I asked the original question. ;) (Now I am confused, though: proving absence of learning in different obscure animals should seem impossible; therefore, there ought to be no references to such proofs anywhere in the Internet or beyond; therefore, the question ought to be difficult to answer). Again, thanks everyone who helped. ;) - Evgeniy E. (talk) 01:28, 14 December 2015 (UTC)

Belated response to your closing question 3 posts above: this one apparently can, if you count forming long-lasting memories as 'learning.' {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 18:19, 14 December 2015 (UTC)

Name of physical property when solid object touches water

If you touch a water bubble with a pencil, the water seems to stick to the pencil. How's this stickiness called?--3dcaddy (talk) 19:08, 12 December 2015 (UTC)

I think the answer is "Surface tension". 80.44.164.220 (talk) 19:14, 12 December 2015 (UTC)

No, the answer is Dispersive adhesion. Surface tension is a different phenomenon. There's quite a good explanation of the physics behind what I believe you're looking for at Wetting. ‑ Iridescent 19:16, 12 December 2015 (UTC)

Isn't surface tension different, but pretty close to the dispersive adhesion you cite? You have cohesion, between molecules of the same substance. And you have adhesion, between molecules of the same substance. --3dcaddy (talk) 21:06, 12 December 2015 (UTC)

It's all part of the same suite of phenomena caused by the types of intermolecular forces present; in water this is primarily hydrogen bonding, and the same kinds of processes are also involved in things like meniscus and capillary action. --Jayron32 21:51, 12 December 2015 (UTC)

What is enq in the following context?

I found an exercise in the google: A patient of heart rate of (120/min) his pressure is 150/90 mmHg. Calculate the work done by the left ventricle for 2 seconds.

Sol:-

W= p x ∆V

P= (150+90)/2 = 120 mmHg.

=120 x 1330 = 1.6 x 105 dyne/cm2

∆V = 120/60 sec x 80 ml =160 ml/sec.

W=120 x 1330 x 160 =2.6 x 107erq/sec

W/2sec = (120 x 1330 x 160) x 2=5.2 x 107 erq/sec.

92.249.70.153 (talk) 21:43, 12 December 2015 (UTC)

Looks like a typo for erg. DMacks (talk) 21:49, 12 December 2015 (UTC)

More like a scanno. —Tamfang (talk) 22:27, 12 December 2015 (UTC)

It must be an extremely old article. The erg hasn't been in common use outside astrophysics since about 1960. Tevildo (talk) 23:26, 12 December 2015 (UTC)

Well, just for the exercise: 120 mmHg (average) x 133.322387415 (Pa/mmHg) = 15999 Pa = 15999 N/m² = 15999 kg m^-1 s^-2. Because one dyne = g cm /s², it gets a 10^-5 conversion factor, which then is cancelled by cm² to a 10-fold difference. (It is right around now one remembers that the incursion of CGS units removes much of the vaunted advantage of the so-rational-and-easy-to-work metric system...) Unchanged: ∆V = 2 [beats] / s x 80 ml = 160 ml/s = 0.16 l/s. So W = 15999 Pa x 0.16 l/s = 2560 kg l m^-1 s^-3 ... say waat? ... the assumption, not stated, is that 1 kg = 1 l for blood, so that's 2560 kg² m^-1 s^-3. This is then multiplied by 2 s for 5120 kg² m^-1 s^-2 = 5120 J/s - this is multiplied by (1000 g/kg)²(1 m/100 cm)² for a net 10⁴ conversion factor. And now that I have refreshed my recollection of what I think of cgs, I shall endeavor once more to forget it... Wnt (talk) 15:09, 13 December 2015 (UTC)

When and how Saddam Hussein destroyed his WMD?

It's clear that Saddam had at some point MDWs, but none were found after the Iraq invasion. What happened to his MDW program and arsenal? — Preceding unsigned comment added by Scicurious (talk • contribs) 23:16, 12 December 2015 (UTC)

See United Nations Monitoring, Verification and Inspection Commission and Iraq Survey Group (and weapons of mass destruction, WMD, as well). According to the second article, the survey had "not found evidence that Saddam possessed WMD stocks in 2003". To answer your question, it didn't exist. Tevildo (talk) 23:25, 12 December 2015 (UTC)

That does not answer my question. I am not disputing that there were no MDW weapons in 2003. But what happened to the MDW program between the last use and 2003? Did he use all weapons that were produced? What happened to the factories? Is all buried somewhere? --Scicurious (talk) 23:55, 12 December 2015 (UTC)

WMD conjecture in the aftermath of the 2003 invasion of Iraq summarizes the various conspiracy theories about the issue. The official reports (mentioned above) found no evidence that Saddam had a working chemical weapons programme, so, again, "it didn't exist" is the answer best supported by the evidence rather than speculation. Tevildo (talk) 01:18, 13 December 2015 (UTC)

The conjectures above are rather about the recent events pre-2003. And it might be a fact that in 2003 there were none. I am not disputing this. But it's also a fact that back in the 80s or 90s, he had some, and has even used them. So what happened to the WMD program, stockpile, scientists? I am asking way before Bush + Blair accused Saddam of having WMDs. --Scicurious (talk) 02:41, 13 December 2015 (UTC)

We do have the more general article Iraq and weapons of mass destruction. -- ToE 03:30, 13 December 2015 (UTC)

We found his stockpiles of chemical WMDs used previously. Not sure we found the aluminum tubes used for centrifuges. We had the same evidence of a nuclear program that we have for Iran and North Korea. When the U.S. invaded Iraq, all CIA analysts agreed that he had a nuclear weapons program but disagreed about whether specific components (so-called "dual use" items) were used in the program. This includes Valerie Plame. We see things like chemical weapons used in the Syrian Civil war so they exist. --DHeyward (talk) 03:54, 13 December 2015 (UTC)

Here is a 2005 Report to the President of the United States: The Commission on the Intelligence Capabilities of the United States Regarding Weapons of Mass Destruction. This 600 page book contains over two hundred pages of unclassified, public information about Iraq's purported weapons program - as reported by informed expert witnesses and endorsed by numerous United States senators. The report explains what the Senate commission believed to be factual, with respect to the existence of weapons of mass destruction in Iraq.

Among the many specific statements in this report: chemical weapons facilities did not exist. Evidence of chemical weapons facilities also "did not exist." (Page 121). Biological weapons did not exist. Evidence of biological weapons also "did not exist" - it was "fabricated" (page 80, page 108). The same applies to the nuclear weapons program (page 3); the intelligence analyses of the purported Iraqi program were technically flawed and based on poor intelligence "tradecraft" (page 66); although further details about our Government's ability to conduct nuclear program monitoring are not published because they contain classified information (page 305).

In short, the United States Senate (including Republican senator John McCain) believed that there were no weapons of mass destruction and any evidence of such weapons did not actually exist when President Bush was briefed. Much of the report follows up on these bold assertions with factual data, paper trail investigations; the report outlines proposed motives and other causal factors for these incorrect and false intelligence reports; and makes recommendations for ways to prevent this problem in the future.

If this voluminous information does not satisfy your curiousity, maybe you can rephrase your question. Are you looking for information as reported by some other source? If so, which source?

If you do not believe the (unclassified) factual assertions published by the United States Senate, then whose factual assertions would you rather trust? We can find lots of other resources with lots of other points of view; some other authors believe different facts to be true, and we can point you toward those authors; but at some point, you have to believe somebody, or else resign yourself to a sort of solipsistic ambiguity about all factual information.

Nimur (talk) 04:21, 13 December 2015 (UTC)

Here is one more point of view: Disarming Iraq (2004), by Hans Blix. In this book, Blix (who directed weapons inspections for the United Nations UNMOVIC in Iraq) states: "When our commission was established by a Security Council resolution in December 1999, the Council had recognized that there might still be weapons of mass destruction (WMD) in Iraq, despite the fact that a great deal of disarmament had been accomplished through UN inspections after the end of the Gulf War in 1991. In November 2002, a new round of inspections had been initiated to resolve key remaining tasks in the disarming of Iraq."

UNMOVIC was tasked to oversee Security Council Resolution 687, and its successor Security Council Resolution 1284. This called for Iraq to unconditionally accept the destruction, removal, or rendering harmless, under international supervision, of specific weapons. UNMOVIC actually reported that Iraq was largely in compliance with these resolutions, and there were specific action-items that were called out for escalation. The State Department reported that UNMOVIC reported that Iraq was not in compliance. Depending on whose report you read, you get a different portrayal of the facts, which is exactly what the problem was. The factual evidence was not presented to decision-makers, and consumers of factual information did not closely and critically scrutinize the facts. (Perhaps, as the Senate report I linked above alleges, the decision-makers did not want to be fully-informed). Quoting Blix: "The military invasion of Iraq was all but announced and here we were at the UN sketching a peaceful way to try to ensure the country’s disarmament!"

Nimur (talk) 05:20, 13 December 2015 (UTC)

Some people missed the point of the Q, that at one time there was no question that Saddam had WMD's, he even dropped poison gas on a Kurdish village (Halabja chemical attack). Then, by the US invasion of Iraq, they had apparently all disappeared. The "expert speculation" I heard was that he had them destroyed, to comply with the UN, but did it in secret, so as to keep his enemies, such as Iran, guessing. StuRat (talk) 05:42, 13 December 2015 (UTC)

I believe I saw somewhere that he got rid of then between 1991 and 1993 just after the Gulf War. Sorry I have to do other things and can't look i up. Dmcq (talk) 09:57, 13 December 2015 (UTC)

StuRat DMCQ got exactly the point of my question.

I don't know why others insist on the 2003 situation. I have no doubt there were none on 2003. And although it's interesting to see it confirmed with sources, the question is about what happened (to the factories and stockpile) between the documented use of the WMDs, and, the documented confirmation there were no WMDs anymore. --Scicurious (talk) 13:09, 13 December 2015 (UTC)

Maybe you are choosing not to read the resources I linked; the UN monitored and documented the disarmament subsequent to the 1991 Gulf War, and they published all their reports. The UN continued to monitor and document to ensure that new activities in Iraq did not violate the agreed-upon rules. The process was difficult and not always conducted on friendly terms, but it did take place, and the UN published details extensively. (UNSCOM document archive; UNMOVIC document archive). This stuff is free and available on the internet: you don't need special connections or privileges to see it; you don't need to file paperwork with your government representative to review the bulk of the documentation; it is largely unclassified and available for you to inspect (you don't need any "Internet Activists" to leak it to you). For example, here are a random assortment of official press photos of equipment being destroyed or removed during UNSCOM inspections in the early 1990s. Here's one dramatic photo that is easy for a non-technical reader to understand, specifically of UNSCOM watching 122mm rockets being burned. Everything is published for you to independently review and evaluate. With which part of this extensive documentation are you misunderstanding or disagreeing, or just choosing not to look at?

I can only assume that your braindead refusal to look at these facts is part of your political agenda to ignore facts. This specific problem of intentionally ignoring documented reality has been a historical problem and you are perpetuating a distortion of fact that significantly contributed to the casus belli in 2003.

Perhaps, if encyclopedic sources are too dense for you, you will understand a little better after considering Aaron McGruder's lampooning of the situation from the Boondocks series episode, "A Date With The Health Inspector".

Nimur (talk) 18:34, 13 December 2015 (UTC)

Maybe you are choosing to ignore the maning of the word 'hidden'. Hidden means they cannot be found, otherwise it's not hidden. That's why the UN could find all the weapons. That does not mean Saddam didn't keep some. --Scicurious (talk) 19:57, 13 December 2015 (UTC)

You are essentially parroting the argument put forward by Defense Secretary Donald Rumsfeld. If you are doing this in an intentional fashion, for the sake of playing the apologist, your position has the disadvantage that the present year is 2015, and his argument has been discredited by more than ten years full of new factual information. If you are parroting his argument simply because you are uninformed, you might wish to read some more history. In either case, unless you are asking for scientific references on this topic, this discussion probably does not belong on the Science Reference Desk. Nimur (talk) 20:40, 13 December 2015 (UTC)

To put things a different way, your last comment is very confusing. You initially wanted to know what happened to those WMD which did exist in 1991 and before, to 2003 when they did not exist. While some of the above answers may have been offtopic; even if you didn't initially understand Nimur's answer, the second version of the made it clear that their sources did provide an answer to your question of what happened to those weapons that did exist.

You now bring up "hidden" weapons. Are you trying to ask when the hidden weapons were destroyed? If you are asking this, what evidence do you have for these hidden weapons?

Are you trying to say there were still weapons in 2003 and although these were never found they did exist and were simply hidden? If so, not only do are you coming up with a conspiracy theory apparently without support, your complaints about any of the older answers now seem unfair since these answers did address this claim, even if it hadn't yet been made.

Are you trying to say that the suggestion there were WMD in 2003 wasn't inaccurate at the time since there may have been hidden WMD? If so, again you'll need to provide some refs for the suggestion there was good reason to believe he may have hidden WMD (which would need to be more than Saddam was perfectly willing to do something like that). As again the evidence from sources thus far, particularly from Nimur but also others (again including some of those you complained about) suggests there was no good reason to believe there was a hidden program in 2003.

Nil Einne (talk) 04:24, 14 December 2015 (UTC)

There are two questions: Did he have WMDs? followed by Did he have a WMD program? It is easy to conflate those two questions. The same would be true for Iran, Pakistan, North Korea, Israel, South Africa, etc, etc. While the existence of actual WMDs was circumspect with many doubters, the belief that he had a program was not. Virtually everyone believed he was developing WMDs and that is in the Senate report. It was the reason Clinton bombed him and Valerie Plame even believed he had a WMD program. CIA analysts disagreed on specifics like yellow cake and aluminum tube but not the overall assessment that Iraq was trying to obtain and build WMDs in violation of the UN sanctions. --DHeyward (talk) 05:32, 14 December 2015 (UTC)

The later question seems irrelevant to anything discussed in this thread (note the OP said hidden WMD, not hidden WMD programme) so not sure why you want to take it even more offtopic. Of course what people may or may not have believed because "Collectors and analysts too readily accepted any evidence that supported their theory that Iraq .... was developing weapons programs, and they explained away or simply disregarded evidence that pointed in the other direction" or whatever also seems less important that what the evidence now suggests was really going on, but again this all seems terribly off topic. Edit: I see the OP did mention something about a MWD (sic) program in some earlier comments. But their question was what happened to it, not what people may or may not have believed happened to it in 2003, so your comment still remains off-topic. Also they seem more interested in the actually WMD stockpile and why few or no more were produced, rather than the a WMD program in the theoretical sense. Nil Einne (talk) 13:28, 14 December 2015 (UTC)

December 13

Leadership skills

Does volunteering with listening services such as befriended or Samaritans teach you leadership skills? — Preceding unsigned comment added by 2A02:C7D:B901:CC00:7CE7:1D53:9581:45DA (talk) 09:30, 13 December 2015 (UTC)

It can do, much depends on the role you undertake as a volunteer and how you use your time there. --TammyMoet (talk) 10:06, 13 December 2015 (UTC)

For those unfamiliar with the organizations, we have: Samaritans (charity) & Befrienders Worldwide. -- ToE 14:32, 13 December 2015 (UTC)

Why can ethanol be used as a rocket fuel but gasoline can't?

^Topic ScienceApe (talk) 16:51, 13 December 2015 (UTC)

Kerosene has been used as a rocket fuel. I imagine it was preferred over gasoline because it is safer to work with and used to be cheaper. Jc3s5h (talk) 16:56, 13 December 2015 (UTC)

Gasoline _can_ be used as a rocket fuel - Robert Goddard's first liquid-fuelled rocket, "Nell" (1926), ran on gasoline and liquid oxygen. See RP-1 for our article on hydrocarbon rocket fuels - apparently, OTRAG, a 1980's German hobbyist organization, built a rocket that ran on diesel. Tevildo (talk) 18:33, 13 December 2015 (UTC)

The article says the fuel is, "The fuel was intended to be kerosene with a 50/50 mixture of nitric acid and dinitrogen tetroxide as an oxidiser." ScienceApe (talk) 19:09, 13 December 2015 (UTC)

This article (New Scientist, May 1976) states that the prototypes, at least, were diesel-powered. This site has a list of (presumably theoretical) specifications, which include the use of diesel fuel. Tevildo (talk) 20:04, 13 December 2015 (UTC)

This is more of an educated guess than a factual one but based on the characteristics of gasoline. Firstly, consider starting. Have you noticed that just before a LOX kerosene engine starts, little pyrotechnics come on to shower the exhaust nozzle with sparks to ignite the fuel. Imagine using petrol – it is explosive. It could easily over pressure the combustion chamber and blow it apart – or in astronautical terms, cause it to under go rapid disassembly. Say all engines do successfully fire up – what then. Gasoline does not burn smoothly. Both kerosene and alcohol have a lower octane rating... they want to burn as soon as they get hot enough in the presence of an oxidizer. The fuel to air/oxidizer ratio is less important. Petrol on the other hand may pause a moment and think about whether it wants to oxidise and having finally decided to oxidize.... it-can-do-so-sudden. So such an engine running on petrol will not run smoothly. It with stutter and cough. Should it burp in the process, the combustion chambers could well scatter bit of themselves all over the place. To run a petrol rocket engine one needs to run it very rich (i.e., much less fuel than the optimum amount of oxidizer and that lead to a lower SI). Even modern hydrogen/LOX engine are run a little fuel rich. Better to waste a bit of fuel than waste a whole rocket.--Aspro (talk) 18:57, 13 December 2015 (UTC)

 ? Nimur (talk) 19:08, 13 December 2015 (UTC)

Page five:
One odd aspect of Goddard's early work with gasoline and oxygen is the very low oxidizer-to-fuel ratio that he employed. For every pound of gasoline he burned, he burned about 1.3 or 1.4 pounds of oxygen, when three pounds of oxygen would have been closer to the optimum. As a result, his motors performed very poorly, and seldom achieved a specific impulse of more than 170 seconds.

Page 20

Malina and company started experimental work with RFNA and gasoline as early as 1941—and immediately ran into trouble. This is an extraordinarily recalcitrant combination, beautifully designed to drive any experimenter out of his mind. In the first place, it's almost impossible to get it started. JPL was using a spark plug for ignition, and more often than not, getting an explosion rather than the smooth start that they were looking for. And when they did get it going, the motor would cough, chug, scream and hiccup —and then usually blow anyway.

Ref: [13]

Yeah meant flame front propergation velocity not octane. Yeh got lean and rich mixed back to front too.--Aspro (talk) 22:51, 13 December 2015 (UTC)

Ethanol and especially methanol has a higher octane rating, not lower and less fuel would be lean not rich. Sagittarian Milky Way (talk) 19:40, 13 December 2015 (UTC)

@Aspro: It sounds as if your "just before a LOX kerosene engine starts, little pyrotechnics come on to shower the exhaust nozzle with sparks to ignite the fuel" is describing the Radial Outward Firing Initiators (ROFIs) used to burn off excess gaseous hydrogen during the start of LOX/LH2 engines, such as those used on the Space Shuttle, Delta IV, and SLS. Here is an NSF article discussing their operation. See Rocket engine#Ignition for a discussion of the ignition process. ROFIs are not used for engine ignition, and having the engine lit from an external source like that would result in a hard start. -- ToE 13:59, 14 December 2015 (UTC)

I'm highly skeptical that NASA rocket scientists can't figure out how to keep a gasoline rocket from exploding. I mean, the Nazis could play with hydrazine and concentrated hydrogen peroxide, and they're supposed to be dumb, right? I do note that kerosene has more energy per volume than gasoline [14] - 135 vs 125 kBTU/gal according to this. Then again, several grades of fuel oil have even more, but maybe NASA scientists couldn't... then again, there's also the matter of density... I'm seeing a figure of 0.71-0.77 for gasoline and 0.78-0.81 for kerosene ... thrills. I have no idea how that comes out, too much fog in the numbers, but fuel oil is 0.99-1.01, so that probably is out? Then again, the density also controls how big the rocket needs to be, which is also really important, so... well, at this point I admit I'm not a rocket scientist. Wnt (talk) 21:58, 13 December 2015 (UTC)

Aspro's reference is worth looking at. It's _possible_ to start a gasoline-fuelled rocket without it exploding - it's _much easier_ to start a kerosene-fuelled rocket. It's even easier to start a rocket with hypergolic fuel, but the cost of the fuel would be prohibitive for an orbital booster stage (as opposed to a short-range atmospheric vehicle, like the Me-163). I don't know how RP-1 compares in cost with a hypothetical rocket-rated gasoline blend, but I can't imagine it's significantly more expensive. Tevildo (talk) 23:15, 13 December 2015 (UTC)

Cost of fuel isn't the main thing against hypergolics (though they are more expensive), it's the poor isp. I assume you are aware that there are a number of hypergolic booster still flying (Proton, Long March), so cost isn't 'prohibitive'? That, and safety issues. Fgf10 (talk) 14:27, 14 December 2015 (UTC)

BTU's "per gallon" would be the wrong metric. "Per pound," though is a different story. Kerosene is about 7 pounds per gallon while gasoline is 6 pounds per gallon so gasoline would be a better weight to energy tradeoff though not a volume to energy tradeoff. I would think the problem would relate to compression with an oxidizer present. Kerosene in turbine engines behaves nicely. Gasoline engines have spark plugs because it does not behave well. Higher compression engines need purer gasoline to retard the spark as do piston aircraft but they never rely on compression itself as the igniter (so called "knocking" is bad). A rocket motor compressor would suffer the same problems I would think. --DHeyward (talk) 05:50, 14 December 2015 (UTC)

How do waves and winds interact?

Is there a science dedicated to the interaction of winds and waves on oceans or another big mass of water?--Denidi (talk) 19:55, 13 December 2015 (UTC)

There is - see Wind wave. Tevildo (talk) 20:12, 13 December 2015 (UTC)

Also note that waves formed in other ways, like tidal bores, tsunamis, and boat bow waves and wakes, may be affected by wind after formation, especially at the peaks. StuRat (talk) 23:16, 13 December 2015 (UTC)

Hydrology - "the scientific study of the movement, distribution, and quality of water on Earth and other planets"; hydrometeorology - "a branch of meteorology and hydrology that studies the transfer of water and energy between the land surface and the lower atmosphere". Gandalf61 (talk) 12:03, 14 December 2015 (UTC)

If you google the definition of either of those they are not really specific to waves. Hydrology is to do with the movement of water through land to the atmosphere[15] and hydrometeorology is to do with water in the atmosphere and its effects on the weather.[16] Physical oceanography and fluid dynamics (see Boussinesq approximation (water waves)) are the branches of science that would deal with to the processes of wave formation. Richerman (talk) 14:37, 14 December 2015 (UTC)

December 14

Were coalition troops prepared for/expecting an attack with chemical/biological weapons?

The question above made me curious about what the governments knew in 2003. Officially, the governments claimed there were MD weapons, but did they act coherently to this official position? During the invasion, were coalition troops provided with materiel to protect themselves against a chemical/biological attack? --Denidi (talk) 13:25, 14 December 2015 (UTC)

Yes: "Allied troops then invaded Iraq, taking great precautions in case chemical weapons were used against them." From Medical Aspects of Chemical Warfare, The Surgeon General Department of the Army, United States of America (p. 66). Alansplodge (talk) 14:06, 14 December 2015 (UTC)

In this particular case we can work out which you're talking about because you mentioned the year, but you do really need to give more details. Which government are you talking about? There were four countries involved in the initial invasion, and there was the Iraqi government on the other side. The poster above assumed you are talking about the US government, is this the case? Fgf10 (talk) 14:23, 14 December 2015 (UTC)

UK troops would also be of interest. The other two countries, Australia and Poland, sent only token troops.

The United States military very much operated as if the threat from chemical or other unconventional weapons was real. This included provision of training and materiel, as well as operational, organizational, and doctrinal changes.

From the collection at United States Army's Combined Arms Research Library at Fort Leavenworth:

On Point : the United States Army in Operation Iraqi Freedom, by Col. Greg Fontenot et al., has extensive discussion of NBC preparations during the invasion. For example, Countering Iraqi WMD And Ballistic Missile Strikes (pg. 171) discusses plans and operations. In addition to lots of doctrine and organizational information, there are also anecdotes so you can see what "preparation" meant to ordinary front-line soldiers:

"On 28 March 2003, the platoon was in a blocking position near the “Airfield.” Both Horner and Jackson had just awakened and were eating MREs in the back of the company’s cargo truck. The unit received artillery fire, and an adjacent chemical unit’s alarms went off. It also received warning to don protective overgarments and masks immediately. As their masks had been destroyed [in the vehicle fire], their squad leader (Staff Sergeant Carver) had them run to the back of one of the M2s to have some protection. He also had them pull the hoods of the NBC suit as tightly as possible over their heads. By this time the entire company, as well as the chemical unit, was in MOPP 4."

On Point II : transition to the new campaign : the United States Army in Operation Iraqi Freedom, May 2003-January 2005, by Donald Wright and Col. Timothy Reese:

"Reorganization to meet the campaign’s requirements often meant huge growth in the number of commands under divisional authority. At one point, 1st AD added the 937th Engineer Group and the 18th Military Police Brigade, giving it the equivalent of 9 maneuver brigades and almost 39,000 Soldiers. The division accepted further reinforcements, such as a CA brigade, a chemical company, PSYOP companies, and an aeromedical evacuation detachment. Every division in theater underwent its own version of organizational transition as they rapidly adapted to the requirements of the new campaign in Iraq."

Prior to Operation Iraqi Freedom, an ordinary Army division would not normally include a chemical warfare company. This book also contains a photograph of U.S. Army chemical warfare soldiers preparing and reconditioning their equipment in Iraq, to keep it battle-ready.

Even outside of chemical warfare companies, ordinary troops were issued NBC suits. I am not sure if these were universally issued to all American soldiers.

Nimur (talk) 15:28, 14 December 2015 (UTC)

There was a bit of a rumpus when it was discovered that the British Army didn't have enough NBC equipment for everybody; see BBC News - UK troops 'left without key kit' (2003). I'm certain that the intention was for everybody to be protected, but as usual, it didn't go to plan. Alansplodge (talk) 16:32, 14 December 2015 (UTC)

Measuring the mass of non-detected dark matter

This source and our article Large Underground Xenon experiment both give the impression that, by failing to detect even a single dark matter collision, the experiment can place constraints on the mass that dark matter WIMPs must have. But how can anyone predict the likelihood that a WIMP with a given mass will interact with a xenon atom, never having seen one? Wnt (talk) 18:16, 14 December 2015 (UTC)

Why do I want to be a girl?

I am wondering why I want to be a girl. Is there scientific explanations for that sort of thing? I've not done much research into that sort of stuff, so any help?78.148.86.212 (talk) 18:29, 14 December 2015 (UTC)