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August 2

resistors

can two resistors be in series to each other if there is a battery between them? — Preceding unsigned comment added by 99.146.126.108 (talk) 02:14, 2 August 2014 (UTC)

Sure, it's possible, in the case of a three-component circuit. Even in an arbitrarily complicated circuit, two resistors with a battery in between them and no other connections to the battery will be Thévenin equivalent to the battery in series with the two resistors in series. Red Act (talk) 02:34, 2 August 2014 (UTC)

Fully hydrogenated vegetable oil

My understanding is that completing the hydrogenation process eliminates any trans fats, however, this isn't often done because the result is too solid. Wouldn't blending the fully hydrogenated vegetable oil with non-hydrogenated vegetable oil allow them to achieve the desired consistency without any trans fats ? StuRat (talk) 02:20, 2 August 2014 (UTC)

Yes. And it is in fact done, that's what Crisco is made of:

Ingredients: SOYBEAN OIL, FULLY HYDROGENATED PALM OIL, PARTIALLY HYDROGENATED PALM AND SOYBEAN OILS, MONO AND DIGLYCERIDES, TBHQ AND CITRIC ACID (ANTIOXIDANTS).

Not sure why they had to also add trans-fats, but the main stuff is like you suggest. Ariel. (talk) 03:28, 3 August 2014 (UTC)

Yea, that's the big Q, what does the PHVO do for them that the blend I suggested doesn't ? StuRat (talk) 03:33, 3 August 2014 (UTC)

I don't know why they add it - their label claims "0 trans fat" which is an obvious lie, which they are allowed to do because it's less than 0.5 grams per serving. Looks like 12 g fat in total, 3g saturated, 8.5g unsaturated (note they are happy to use decimals here!), 0.5g trans. Maybe they use it to exactly fine tune the melting point? I've seen other recipes that don't include PHVO and just get the desired melting point by adjusting the other two. More common these days is palm oil without hydrogenating it at all - but then you need more of it and can't put as much unsaturated oil and your label looks worse despite actually being better. Lies, Damned Lies, and Nutrition Labels. Ariel. (talk) 19:29, 3 August 2014 (UTC)

I don't know details, but I can forward a guess. Imagine you're a beanbag chair manufacturer. Key to the performance of your chair is the softness and resiliency of your "beans". Now imagine that instead of filling the chair with a single "bean" of the correct hardness, you had to mix too-hard beans with too-soft beans (e.g. "beans" made of steel and "beans" made of gelatin). You'd never get the correct behavior, despite the "beans" being the correct hardness "on average". Similar arguments can be made for vegetable oils. Triglycerides with only one or two unsaturated bonds will behave differently than a mix of saturated and polyunsaturated triglycerides which average to one or two unsaturated bonds per molecule. - Unfortunately, I can't say what particular property something like Crisco needs which means a mix would not suffice. But "desired consistency" isn't the only consideration. Melting point is another, and while consistency and melting point are related, they're not identical, as you can have a mix which goes from firm to molten suddenly, or one that slowly transitions through "oozy". Perhaps it might have to do with phase separation, where a mix would gradually partition out on long term storage into a solid, saturated phase and a liquid, unsaturated phase, but where including a small amount of PHVO prevents such behavior. That's pure speculation, though. -- 160.129.138.186 (talk) 23:13, 4 August 2014 (UTC)

Where does Rainier end?

I guess this is a science question, more or less.

Recently I was hiking in Mount Rainier National Park. I was hoping to get onto Rainier itself, not to the summit, but just to physically step on the mountain, but I couldn't make that happen — at least, not by my interpretation, looking at the images on Google Maps.

But at least a couple of different people told me I was on Rainier. And looking again at the satellite images, it's hard to be quite sure they're wrong — the mountain is a little like a candle that's melted down, with rivulets of wax going off in all directions. I could have been standing on one of those wax globs, I guess.

So what say ye? Was I on the volcano as she is goodly understanded? I hiked from the visitor center at Sunrise Ridge, which is about here, to "Frozen Lake", which is about here. I know, short hike, but we were short on time; had to catch a plane. --Trovatore (talk) 04:18, 2 August 2014 (UTC)

Rainy, Rainier, Rainiest. Sorry. DuncanHill (talk) 04:24, 2 August 2014 (UTC)

Rainier is a volcano, so if you were standing at the base of the mountain, on or above volcanic debris from the mountain, that should qualify as being "on" the mountain. ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:24, 2 August 2014 (UTC)

Well, so that was sort of my question. Are the points I mentioned on ejecta from the volcano? --Trovatore (talk) 04:28, 2 August 2014 (UTC)

But then again, it's not the whole question. Sometimes volcanoes deposit enormous quantities of ash some distance from the peak. I suppose geologists have some criterion for distinguishing what is and what is not the volcano. Then again, they may not. Either way, someone here might know. --Trovatore (talk) 04:30, 2 August 2014 (UTC)

By my reasoning, I would side with your opinion. Since there are named mountains between the location at Frozen Lake, and Mt. Rainier, then, technically you would be on the foothills of one of the other mountains, (imo). Here is a nice PDF map (which takes forever to load)   —71.20.250.51 (talk) 04:49, 2 August 2014 (UTC)

As a coincidental aside, I noticed your improper use of "ye" — I just finished a discussion about that (over here). It seems that ye is from þ^e —Which is just "the" (but is actually a bit more complicated) 71.20.250.51 (talk) 05:10, 2 August 2014 (UTC)

No, I'm afraid you over-interpreted the response there. What you were reading as ye is actually just-plain the, with a thorn. However, there is (or was) indeed a pronoun ye, which is a different word. --Trovatore (talk) 08:11, 2 August 2014 (UTC)

And neither is apparently related to D or dese "da and dat" dialects. InedibleHulk (talk) 23:37, August 2, 2014 (UTC)

There can be only one correct answer to such questions of geography! So what you'll want is a geological map of Rainier, with which you can inform outrageous claims of geographic sovereignty. There's no shortage of those! Start with the 1:24,000 Surficial geology of Mount Rainier National Park, Washington. I'll leave it to you and your co-hikers to debate which geological features historically constitute Mount Rainier. (Obviously you must look to the subsurface to establish the boundary, because the surface features are subject to erosion and are unsuitable for establishing permanent boundaries).

Of course, you may find yourself in the company of fellow hikers who espouse the thalweg principle, which may provide contradictory boundaries to the subsurface material. When geological fact and superficial hydrology contradict, the only solution is senseless warfare to establish the border, which must exist at one specific line that can be mathematically derived from irrefutable scientific data and principles. Nimur (talk) 05:19, 2 August 2014 (UTC)

• Defining a "mountain" aside from the peak itself is tricky business. Other than monadnocks which rise abruptly from relatively flat plains, most mountains are parts of some rather complex topography, and defining the difference between one "mountain" or the next really comes down to local conventions. One system for defining mountains can be found under Topographic prominence, but I'm not even sure that's helpful hear. We can easily define Mount Rainier's summit as a distinct point, but deciding whether some patch of land an arbitrary distance from that summit is "part" of Rainier, or not, is really a semantic nightmare. Local conventions define a "mountain" (in terms of a geographic area, rather than merely a summit) different from locale to locale. For example, Catoctin Mountain is a 50 mile ridge within the Appalachian system; in other places similar structures may be called a mountain range and would define each of the various peaks a distinct "mountain". See, for example, the Black Mountains (North Carolina), which is a smaller geographic feature, but is structurally similar to Catoctin Mountain (a prominent ridge of high peaks), but which is considered locally to be a series of distinct mountains. --Jayron32 05:35, 2 August 2014 (UTC)

Although this might be a different trail,[this must have been the trail, until you reached the junction to Frozen Lake trail] it describes the area; it seems that you were on Mt. Burroughs (or foothills thereof):[1] (and the map linked by Nimir seems to corroborate this).   —71.20.250.51 (talk) 05:57, 2 August 2014 (UTC)[edit:06:06, 2 August 2014 (UTC)]

OK, thanks, all. Maybe there's not as clear a demarcation as I would have thought. To me, looking subjectively at the relief map, the stuff we were walking on looks like a lot of the little bumpy stuff in the region, which doesn't seem to me to be part of the mountain. I guess I need to figure out where I want to be next time. If I could make to Camp Muir, that would be good enough. --Trovatore (talk) 18:26, 2 August 2014 (UTC)

An end to "Rainier" will happen when the paleface acknowledges its old Indian name which is "Takhoma".

A British author Captain George Vancouver, in 1792, named the great peak "Mt. Rainier." in honor of Admiral Peter Rainier, of the British Navy. Literature is practically silent about the Mountain for more than sixty years. Those years witnessed the failure of England's memorable struggle to make good Vancouver's "annexation." Oregon was at last a state.

The Northwestern Indian peopled the unknown with spirits good and bad, and felt the Power that dwelt on Tacoma. They told this Flood myth:

WHY THERE ARE NO SNAKES ON TAKHOMA

A long, long time ago, Tyhce Sahale became angry with his people. Sahale ordered a medicine man to take his bow and arrow and shoot into the cloud which hung low over Takhoma. The medicine man shot the arrow, and it stuck fast in the cloud. Then he shot another into the lower end of the first. Then he shot another into the lower end of the second. He shot arrows until he had made a chain which reached from the cloud to the earth. The medicine man told his klootchman and his children to climb up the arrow trail. Then he told the good animals to climb up the arrow trail. Then the medicine man climbed up himself. Just as he was climbing into the cloud, he looked back. A long line of bad animals and snakes were also climbing up the arrow trail. Therefore the medicine man broke the chain of arrows. Thus the snakes and bad animals fell down on the mountain side. Then at once it began to rain. It rained until all the land was flooded. Water reached even to the snow line of Takhoma. When all the bad animals and snakes were drowned, it stopped raining. After a while the waters sank again. Then the medicine man and his klootchman and the children climbed out of the cloud and came down the mountain side. The good animals also climbed out of the cloud. Thus there are now no snakes or bad animals on Takhoma.

See "The Mountain that was 'God' Being a Little Book About the Great Peak Which the Indians Named 'Tacoma' but Which is Officially Called 'Rainier'" 84.209.89.214 (talk) 13:56, 3 August 2014 (UTC)

This is a lovely little find! I do sympathize with the position that it's too bad to have the mountain named after " an undistinguished foreign naval officer whose only connection with our history is the fact that he fought against us during the American Revolution". However, I'm not sure I could accept calling it Tacoma; even if that is the historically better justified name, it's now too connected with the city. --Trovatore (talk) 04:17, 4 August 2014 (UTC)

Actually, "Mount Rainier" is a uniquely appropriate name for it -- because as DuncanHill correctly pointed out, it is much rainier than, say, Yellowstone (and, in fact, even that old Indian legend supports this name, because it specifically talks about rain that flooded all the land). We'll just have to start pronouncing it slightly differently, that's all! 24.5.122.13 (talk) 09:47, 4 August 2014 (UTC)

Actually no, the name "Rainier" is French composed of the Germanic elements ragin ‘advice’ + hari, heri ‘army’. If you would hear of rain, learn the native Indian word for rain karyage or the Hopi name meaning rain Yoki. Sokanan is an Algonquin name that also means rain.

So what shall we say to these palefaces who came to take the name of Tacoma to put on their city by the shining sea? These are words of Aseenewub: This is what was spoken by my great-grandfather at the house he made for us ... And these are the words that were given him by the Master of Life : "At some time there shall come among you a stranger, speaking a language you do not understand. He will try to buy the land from you, but do not sell it; keep it for an inheritance to your children." We must say No, because if the Creator placed Mount Tacoma where it is, then it is in the right place.

Is it claimed that we should thank this paleface for the rain in his name? That is the sauciness of one who speaks with forked tongue. Hear then How Glooskap changed certain saucy Indians into Rattlesnakes:

You know At-o-sis, the Snake? Well, the worst of all is Rattlesnake. Long time ago the Rattlesnakes were saucy Indians. They were very saucy. They had too much face. They could not be put down by much, and they got up for very little. When the great Flood was coming Glooskap told them about it. They said they did not care. He told them the water would come over their heads. They said that would be very wet. He told them to be good and quiet, and pray. Then those Indians hurrahed. He said, "A great Flood is coming." Then they gave three cheers for the great Flood. He said, "The Flood will come and drown you all." Then these Indians hurrahed again, and got their rattles, made of turtle-shells, in the old fashion, fastened together, filled with pebbles, and rattled them and had a grand dance. Afterwards, when the white men brought cows and oxen into the country, they made rattles of horns. Yes, they had a great dance. The rain began to fall, but they danced. The thunder roared, and they shook their rattles and yelled at it. Then Glooskap was angry. He did not drown them in the Flood, however, but he changed them into rattlesnakes. Nowadays, when they see a man coming, they lift up their heads and move them about. That's the way snakes dance. And they shake the rattles in their tails just as Indians shake their rattles when they dance. How do you like such music?

It is many moons since the Great White Father drove the Rainier back to the circle of his tribe. Black Elk of the Oglala Sioux explains how everything an Indian does is in a circle, and that is because the Power of the World always works in circles, and everything tries to be round. In the old days when we were a strong and happy people, all our power came to us from the sacred hoop of the nation, and so long as the hoop was unbroken, the people flourished. The flowering tree was the living center of the hoop, and the circle of the four quarters nourished it. The east gave peace and light, the south gave warmth, the west gave rain, and the north with its cold and mighty wind gave strength and endurance. But Rainier sailed from the east and brought the Indian neither peace nor rain. So it is not to his name that we look up. Instead we address our thanks to our ancestors and to the Great Spirit that made Mount Tahoma in words of praise that are too sacred to post here (though an editor who diligently seeks can find them hidden nearby.) 84.209.89.214 (talk) 19:40, 4 August 2014 (UTC) This post was deleted then recovered. 84.209.89.214 (talk) 15:35, 5 August 2014 (UTC)

flower

small & cute flower

somebody knows the flower in the picture?

79.181.60.192 (talk) 11:16, 2 August 2014 (UTC)

That's a foxglove. Probably the common foxglove Rojomoke (talk) 11:36, 2 August 2014 (UTC)

thanks

79.181.60.192 (talk) 11:38, 2 August 2014 (UTC)

Where'd you see it? --Trovatore (talk) 18:29, 2 August 2014 (UTC)

Does whole Chia Seeds dismantled anywhere in the Digestive system?

If someone eats Chia seeds when they are whole (unpeeled\uncrushed), Can their Fibrous' bark be dismantled so that most of the nutrients in them be available to the body? thanks. Ben-Natan (talk) 13:07, 2 August 2014 (UTC)

According to our article (Salvia_hispanica#Preliminary_health_research), no, they need to be milled for optimal nutritional benefit. StuRat (talk) 13:32, 2 August 2014 (UTC)

I don't think you can generalize from that sentence there ("One pilot study found that 10 weeks ingestion of 25 grams per day of milled chia seeds"...) that the seeds needs to be milled in every case... Ben-Natan (talk) 14:52, 3 August 2014 (UTC)

Also bear in mind that this is is going to be an issue with just about any seed; if you don't at least break the seed coat then there's a good chance that you won't be digesting any of those nutrients within. Sebastian Garth (talk) 02:05, 5 August 2014 (UTC)

HBV

If hepatitis B is more easily transmitted and also there are more cases of it compared to HIV, why is it not included in the standard std panel test in most countries along with Chlamydia, Gonnorhea, Syphilis and HIV? — Preceding unsigned comment added by 90.192.113.228 (talk) 19:01, 2 August 2014 (UTC)

Help wanted at the Entertainment desk (botanists, arboriculturists, etc wanted)

Rather than insisting that the OP re-post here (and the question does also involve computer gaming), I am drawing your attention to: Entertainment#Real_Life_Version_of_Runescape_Magic_Tree (crap, yes indeed, see below, thanks Andy!). Thanks in advance! ---Sluzzelin talk 19:03, 2 August 2014 (UTC)

I assume you meant to linkWikipedia:Reference_desk/Entertainment#Real_Life_Version_of_Runescape_Magic_Tree AndyTheGrump (talk) 19:29, 2 August 2014 (UTC)

Untreated cancer survival rates

Imagine a group of people who have just been diagnosed with the same kind of cancer at the same stage: some of them are weak and elderly, some are young and strong, and we have some who are young and weak and others who are old and strong. Statistically speaking, which of the four groups will likely have the longest life expectancy? I'm assuming no unrelated deaths, e.g. heart attacks or car crashes, because of course that will skew the elderly groups. I can imagine that the stronger and younger people won't succumb as easily to identical cancers, but I can also imagine that cancers in the stronger and younger people will be more vigourous, so I'm not sure what to think — especially since I don't know if my imaginations are right. I've looked at articles on various cancers, and none of them tend to say which populations have the longest life expectancies; with that in mind, the ideal answer will provide details about specific cancers instead of attempting to provide a general answer for all types of cancer. Nyttend (talk) 20:00, 2 August 2014 (UTC)

I've read many times that most men who die of old age technically have prostate cancer (like 70% if I'm not off), which is usually slow growing and encapsulated. I'll refer you to google for sources and stats. Of course my neighbor is going on her third year now with lung cancer that had spread to the brain. Average survival of that with treatment is less than six months, so I think treatment is usually the preferred option in most cases. μηδείς (talk) 21:31, 2 August 2014 (UTC)

Understood; I'm basically trying to understand the effects of age and weakness on cancer growth, and of course the stats on that will be greatly skewed if we include cancers that are treated. Nyttend (talk) 21:42, 2 August 2014 (UTC)

Another thing to consider is why you wouldn't include heart attacks. Even if the cancer isn't directly involved (like through an embolism chunk), it can create stress through physical discomfort, and thinking about the cancer can mentally stress people. Some people grow wiser and calmer with age, others more paranoid about every ache, pain or looming spectre.

In that sense, the strong, in physical and rhetorical heart, should survive. For longer. InedibleHulk (talk) 23:47, August 2, 2014 (UTC)

Then again, cancer relies on the same energy processes normal cells do, so if you're at peak performance, so are they. Dying cures it. InedibleHulk (talk) 23:50, August 2, 2014 (UTC)

I ignored heart attacks as a sample of unrelated deaths, e.g. you're diagnosed with advanced melanoma and die two days later of a sudden heart attack. Of course I understand that heart attacks (and other common causes of death) can be fatal because of cancer-caused systemic weakness or other cancer-caused reasons; I was attempting to ignore only things that would have happened to the patients had they not had cancer. Nyttend (talk) 01:24, 3 August 2014 (UTC)

Fair enough. InedibleHulk (talk) 01:30, August 3, 2014 (UTC)

Another sort of stress I just learned (a bit) about is oxidative stress. Coincidentally, it seems "likely to be involved in age-related development of cancer". Seems to "suppress apoptosis and promote proliferation." Which again, can be good or bad, depending which cells are stressed. InedibleHulk (talk) 00:05, August 3, 2014 (UTC)

This summary answers some of your questions about physical activity, saying it may be linked to reduced risk of cancer recurrence in addition to its normal positive effects in reducing depression, etc. This study showed people who were fitter at diagnosis had an increased chance of surviving colorectal cancer.

As for age, here are some statistics for survival based on age at diagnosis; it sums up that "Five-year net survival is highest in the youngest adults for nearly all cancers, with survival generally decreasing with increasing age".

I didn't find any exploration of the interaction of these two factors :) 184.147.144.166 (talk) 00:08, 3 August 2014 (UTC)

Climbing steps for exercise

Has anything been studied about the health benefits of walking up long flights of steps as exercise, compared to going to the gym, etc? --rossb (talk) 20:43, 2 August 2014 (UTC)

I don't see a direct answer in our article on stair climbing, but some of the information and references there might be of interest.--Srleffler (talk) 20:57, 2 August 2014 (UTC)

The only additional concern with stairs (along with the usual cautions about overdoing any exercise) is that impact injuries could damage the feet and legs. This is more likely on cement steps, with wood being an improvement, especially if covered with carpet. Footwear also matters, of course. And, of course, if the person has poor balance or is otherwise impaired, falling might be a worry, too.

One downside of gyms is the potential to pick up infectious diseases there. I got plantar warts from my high school gym, for example. It took years to get rid of them. StuRat (talk) 00:04, 3 August 2014 (UTC)

An upside is the stuff gyms have for all (or some of) your other fitness needs. Stairs are stairs, and that's fine, but that's all. Some stairwells are also pretty filthy. InedibleHulk (talk) 00:53, August 3, 2014 (UTC)

And muggers/rapists can be hiding in stair wells, so I'd stick with open stairs in public places. StuRat (talk) 02:31, 3 August 2014 (UTC)

I don't know. I've heard bad things about well-lit and familiar public places. InedibleHulk (talk) 02:38, August 4, 2014 (UTC)

At the corporate headquarters, some years ago, after lunch i would ride the elevator down to the basement, then run up the stairs to the 20th (or so) floor where the stairs ended, then walk back down to the 5th floor where my office was, and I found it quite beneficial. In some more modern buildings, it sets off an alarm if you enter the stairs. I never encountered a plausible mugger or rapist in the stairs. (More's the pity). Edison (talk) 23:25, 3 August 2014 (UTC)

OP, could you be more specific about what you're looking for? As IH mentioned, a gym obviously offers many benefits over stairs simply due to the multitude of exercise options it gives you. Including stair climbing machines. It's not really much of a comparison, like asking whether eating fish has health benefits over a more varied diet that also includes fish. Are you asking about a comparison between climbing stairs versus using stair machines, such as a StairMaster? Here's an article that looks at the calorie burning of various activities, including stair climbing versus walking and running. Matt Deres (talk) 14:32, 4 August 2014 (UTC)

The reason I asked the question is that I'm wanting to get more exercise, and local to me in Purley, South London, is an outdoor flight of steps (containing over 150 steps) and I've started including it in my regular walks, assuming this will be beneficial. One advantage over the gym is of course that it's free! But I expect I ought to supplement it with other exercises.--rossb (talk) 18:10, 4 August 2014 (UTC)

Definitely beats walking or running horizontally. One possible advantage of a stair machine is its constant height from the ground. Depending how hard you push yourself, you may prefer being exhausted in a gym, rather than on the 150th wet stair, with vertigo. But yeah, a good gym can literally rob you far worse than a mugger, and hardcore trainers can figuratively rape your soul. InedibleHulk (talk) 01:35, August 5, 2014 (UTC)

Well, you can't beat free, but there are downsides. Besides inclement weather (in England?!), there's the simple mechanical problem of getting back down the stairs, which is probably more dangerous than going up them. If you slip going up, you tend to fall on your hands, but slipping down can be much more... precipitous. On the other hand, getting out of bed in the morning can be dangerous as well. Matt Deres (talk) 01:58, 5 August 2014 (UTC)

August 3

Is success of countries due to better human biological capital?

http://westhunt.wordpress.com/2014/07/31/biology-and-human-capital/ As in scientific article above, is there generally any evidence of some societies having greater human capital? Is it due to evolution through natural selection or perhaps through other means?74.14.72.22 (talk) 02:10, 3 August 2014 (UTC)

I'd say it's cultural, not genetic. That is, it's memes, not genes. For example, the tendency of a culture to value innovation over tradition is important to the long-term success of that culture.

As far as genetics go, they may help a population to succeed in a given environment. For example, natives of polar regions tend to become short and fat after thousands of years, which helps them to retain heat. However, those adaptations may not serve them well outside their own climate. StuRat (talk) 02:28, 3 August 2014 (UTC)

So if populations can dapt like that, perhaps they also evolved different behaviors and cognitive abilities, and because of that some people are more successful than others.74.14.72.22 (talk) 02:49, 3 August 2014 (UTC)

For such genetic changes to take place, there must be something different in the environment that kills off people who don't adapt. In my example, it's the cold. What evolutionary pressure would force one population to need to become more intelligent than others, in order to survive ? (One possible answer might be that in an environment where life is easy there would be no pressure to adapt, but in such an environment population would quickly grow to a point where competition for resources would force adaptation, at least until birth control was invented.) StuRat (talk) 02:55, 3 August 2014 (UTC)

These genetic changes did in fact take place in the Ashkenazim Jews, there is a paper on that by Gregory Cochran called Natural History of Ashkenazi Intelligence74.14.72.22 (talk) 03:22, 3 August 2014 (UTC)

The blog is by Cochran too in case you hadn't realized that already. And he didn't exactly pinpoint the "intelligence genes" and definitively proved that the Ashkenazim genetic changes did "in fact take place". Don't make it sound as if Cochran et al.'s paper has been accepted widely, because it's not. Here's one rebuttal. Here's another. All of Cochran et al.'s evidence in their paper is circumstancial. Even conjecture, e.g. when they linked genetic diseases among the Ashkenazim to increased intelligence, or the assumption that wealth equates to intelligence.

Again, the Ashkenazim have only been a distinct ethnic group for a few centuries. How many generations is that? And they somehow evolved the genes for better IQ in that period of time? It is true that Ashkenazim Jews were indeed genetically isolated, preferring to intermarry within their group. They indeed prized intelligence as a trait. But none of these can be demonstrated to translate to actual evolutionary pressure. I mean, Jewish parents did not exactly kill or sterilize children who couldn't understand Algebra did they? Jewish women didn't marry Jewish men for their intelligence alone. Or is Cochran saying that merely the expectations of parents to have smarter children enabled them to bear smarter children? Evolution isn't exactly Lamarckism anymore. So while Ashkenazim may have more Nobel prize winners as of the moment, it's a bit of a leap to declare that it's because they have evolved to be geniuses.-- OBSIDIAN†SOUL 18:00, 3 August 2014 (UTC)

Warfare, for one thing, would be just such an evolutionary pressure -- people who are smarter can invent better weapons (and more efficient ways of producing them), which would help them kill their not-so-smart enemies in battle while also giving them a better chance to survive to fight another day. 24.5.122.13 (talk) 03:45, 3 August 2014 (UTC)

And even smarter people wouldn't engage in warfare in the first place... AndyTheGrump (talk) 03:58, 3 August 2014 (UTC)

At which point they get conquered by their enemies, as the Romans were. 24.5.122.13 (talk) 05:31, 3 August 2014 (UTC)

See Guns, Germs, and Steel. Johnuniq (talk) 03:27, 3 August 2014 (UTC)

Can someone please provide a clear, unarguable definition of "successful" as it relates to countries? HiLo48 (talk) 03:32, 3 August 2014 (UTC)

Economic prosperity, as measured, e.g., by per-capita GDP, would be a pretty much universally accepted definition of a successful country. 24.5.122.13 (talk) 03:53, 3 August 2014 (UTC)

Says who? And measured over what timescale? AndyTheGrump (talk) 03:56, 3 August 2014 (UTC)

I guess that definition just failed "unarguable". HiLo48 (talk) 03:58, 3 August 2014 (UTC)

What do you mean, "says who"? Are you saying that economic prosperity is not a definition of a country's success, or that per-capita GDP is not a good measure of economic prosperity? 24.5.122.13 (talk) 07:28, 3 August 2014 (UTC)

It may well be. but that wasn't the question. HiLo48 (talk) 07:38, 3 August 2014 (UTC)

Define "success". ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:15, 3 August 2014 (UTC)

Oi, I already asked that. HiLo48 (talk) 04:19, 3 August 2014 (UTC)

Yes, but the OP didn't answer it. ←Baseball Bugs ^{What's up, Doc?} carrots→ 07:38, 3 August 2014 (UTC)

GDP is one marker of success, as is a high level of cultural achievement74.14.72.22 (talk) 07:45, 3 August 2014 (UTC)

Many these days will argue that the way in which a country's wealth is distributed among the populace is possibly more important than total GDP. HiLo48 (talk) 07:58, 3 August 2014 (UTC)

John Rawls famously argued that the way the most disadvantaged person in a society fares is a good measure of that society's quality. Certainly the median GDP might be a better indicator of popular prosperity than the average GDP. Of course, the "G" in GDP makes every such measure very much problematic - if I total a car and buy an identical replacement, the GDP is plus one car, but the overall state of the economy is the same. Similarly, GDP ignores depreciation of e.g. natural resources. A radical different measure is Gross national happiness.... --Stephan Schulz (talk) 08:35, 3 August 2014 (UTC)

Distribution of wealth more important than total GDP?! Are you out of your mind?! By that standard, Cambodia under the Khmer Rouge, where everyone was equally dying of starvation, would be a more successful country than the USA -- which is patently, outrageously false on the face of it! 24.5.122.13 (talk) 23:37, 3 August 2014 (UTC)

So.... scientific racism again, eh? From the same guy who thinks homosexuality is the result of pathogens? Not exactly what I'd call persuasive.

The argument that some human populations are just more intelligent than others and thus the reason for the economic differences in modern nations only works if you completely disregard such annoying things like warfare, geography, and human migration. Particularly the inconvenience of several centuries of colonial subjugation and cultural rape. The argument that these had absolutely nothing to do with why most of the most economically successful countries today have mostly European populations is naive at best.

If 90% or more of the native population of the Americas didn't die of Old World diseases, if Genghis Khan didn't force half the world to flee west, if China hadn't banned ocean-going ships, if the Sahara desert didn't isolate the rest of Africa from Eurasia, if the glacial retreat didn't decimate the large herds of megafauna supporting nomadic human populations, etc. the world might be quite a different place right now. So many ifs, and none of them can be attributed specifically to genetics. I agree that the best counterargument to Cochran's position would be Guns, Germs, and Steel.

You don't exactly need to be a genius to know that aiming a gun at someone's head can force them to do what you want them to for your own gain. Even Cochran's favorite supposedly genetically predisposed geniuses, the Ashkenazim, only exists as a distinct ethnic group for a few centuries.

While I don't disagree that some ethnic groups do have more accomplishments in some areas than others, I believe this is mostly environmental. Some cultures encourage scholarly interests, some encourage warfare; some encourage unquestioning obedience, some encourage skepticism, etc. None of these are necessarily genetic. Case in point the Ashkenazim who were forced by xenophobia in the Middle Ages into developing a culture focused on trade and finance. Being good at math and economics because their culture encourages it doesn't necessarily mean that it's evidence that they have evolved to become bankers.-- OBSIDIAN†SOUL 11:33, 3 August 2014 (UTC)

You have given voice to suspicions I share about the OP's premise. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:50, 3 August 2014 (UTC)

BTW, social Darwinism is the name of the mostly discredited theory that successful nations succeed due to genetic superiority (although this term has other meanings, too). There is one sense in which it is true, I suppose, and that's resistance to disease. Isolated populations tend not to have much resistance, which is deadly for them when they come into contact with larger populations which carry diseases they have not encountered before. StuRat (talk) 12:51, 3 August 2014 (UTC)

Success is often a function of superior weaponry. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:50, 3 August 2014 (UTC)

Which can be bought by whoever wants to avoid spending that money on its less able citizenry. HiLo48 (talk) 20:55, 3 August 2014 (UTC)

Except that it first has to be developed and produced, so whatever nation has a bigger supply of technological geniuses and a stronger industrial base for turning their blueprints into metal will still have the advantage -- having better weapons as a result will only REINFORCE this advantage. 24.5.122.13 (talk) 23:43, 3 August 2014 (UTC)

Being good at war doesn't equate with having a higher average intelligence in the population. Unless you're arguing that the Mongol Hordes had better tech and more scholars than Imperial China and Indian Kingdoms? Or the Germanic tribes that swept through Europe were more civilized than the Roman Empire? Both the Mongols and the Germanic tribes went on to found economically "successful" states after subjugating the existing ones as well. And there are more examples of this. Like the Hyksos conquest of Ancient Egypt, the Islamic conquest of Persia, the Huns rampaging through Europe, etc.

For that matter, most of the technology that enabled Europeans to conquer the rest of the world during the colonial period did not originate indigenously or at least were not exclusive to them. Gunpowder and cannons for example, came from China. The various sciences and nautical technology came from more ancient sources, particularly in the Mediterranean and the Middle East. Even more basic technology missing from the Americas, like advanced metallurgy and wheels, are not exactly European-exclusive technology is it? When the purported products of their superior intellect is actually borrowed, how exactly does that prove that they have a "bigger supply of technological geniuses"? It's even more apparent when you realize that the colonial era resulted in a positive feedback of more technology, more resources, and even bigger weapons. All of which borrowed, stolen, adapted.

Yes bigger weapons does mean a more successful state. But bigger weapons is not automatically the result of higher intelligence. Nor does it in any way lead to the conclusion that it is therefore genetic. If anything, it proves the opposite. You don't inherit the genes for forging and using a sword. You learn it.-- OBSIDIAN†SOUL 01:33, 4 August 2014 (UTC)

I am not arguing for social Darwinism, I am saying that we have proof for changes in genes that mediate behaviors and that behavior and pretty much anything is genetic and heritable (http://jaymans.wordpress.com/2014/04/15/more-behavioral-genetic-facts/ & http://jaymans.wordpress.com/2014/03/31/the-son-becomes-the-father/). That fact can't be disputes, in fact what we call culture is basically expression of these innate behaviors. What my question is asking is when did these adaptations happen in different human populations that led to more successful cultures and societies or less successful.74.14.75.23 (talk) 00:29, 4 August 2014 (UTC)

Where has the OP defined what they think "success" means? ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:34, 4 August 2014 (UTC)

I said its GDP, cultural achievements, etc. Read the article in OP to see what is being talked about.74.14.75.23 (talk) 00:54, 4 August 2014 (UTC)

You're making an argument for ethnic superiority. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:07, 4 August 2014 (UTC)

No. Perhaps the facts may present something resembling that argument. Doesn't mean we should shy away from its discussion due to some misplaced sense of political correctness.74.14.75.23 (talk) 01:23, 4 August 2014 (UTC)

Playing the PC card only serves to demonstrate what I'm saying. Who decided those criteria GDP and "cultural achievements"? The ones who have a strong GDP and consider their own "cultural achievements" to be superior. ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:42, 4 August 2014 (UTC)

So what if 74 IP is making an argument for ethnic superiority? In science, there's only ONE criteria for evaluating an argument, and that is, whether the argument is supported by the available EVIDENCE! So just because the argument advocates a certain ideology (NO MATTER how unpopular or seemingly repugnant) DOES NOT give you an excuse to dismiss it right off your baseball bat -- it still has to be evaluated to see if the EVIDENCE supports it or not! 24.5.122.13 (talk) 05:15, 4 August 2014 (UTC)

"Evidence" in topics like this consists solely of looking for stuff that supports the pre-determined hypothesis of alleged racial superiority. Figures don't lie, but liars do figure. If you determine that nation A has a higher GDP than nation B, you have not demonstrated that nation A is more "successful" than (i.e. superior to) nation B - all you've demonstrated is that nation A has a higher GDP. ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:35, 4 August 2014 (UTC)

If figures don't lie, then how do you explain that study (quoted in the article Race and Intelligence) which found that blacks have an average IQ of 83 85 (that's borderline close to mental retardation, just so you know), Latinos have an average IQ of 89, but whites and Asians have an average IQ of over 100, and Ashkenazi Jews something like 115 113? 24.5.122.13 (talk) 00:45, 5 August 2014 (UTC)

Quite easy to explain. (1) Those tests are written by people who would tend to score high on the tests they create; (2) an IQ test measures nothing except one's ability to take that IQ test; and (3) intelligence is not in races or ethnic groups, it's in individuals. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:52, 5 August 2014 (UTC)

Precisely the kind of politically-correct non-answer that liberals are so famous for. BTW, are you aware that you can't spell LIbeRAl without spelling LIAR? 24.5.122.13 (talk) 05:44, 5 August 2014 (UTC)

(Aside: Man, how I absolutely HATE all sans-serif fonts -- you can't tell between a capital I and a lowercase L!) 24.5.122.13 (talk) 05:47, 5 August 2014 (UTC)

Your response (other than our shared dislike on sans-serif fonts) is a non-denial denial. ←Baseball Bugs ^{What's up, Doc?} carrots→ 13:34, 5 August 2014 (UTC)

Why would I have to deny a statement that ain't got no leg to stand on? I know you LIbeRAls very well, and I'm VERY familiar with your favorite rhetorical tactic when the evidence contradicts your preconceived conclusions (whether it's the "all races have equal intelligence" concept, as is the case here, or something else like global-warming alarmism, anti-nuclear propaganda, or any of a whole bunch of other pet causes): Instead of disputing the evidence on its merits like real scientists should, you LIbeRAls (1) dismiss the evidence right off the baseball bat without giving any valid reason, (2) try to impugn the qualifications and/or motives of the people who came up with the evidence, and (3) restate your original preconceived notion in the form of a slogan while giving no evidence of your own to support it, as if the contrary evidence had never been brought up AT ALL. Which is PRECISELY what you did here, except you switched items (1) and (2) around. Problem is, this relies on AT LEAST THREE logical fallacies -- cherry-picking, ad-hominem fallacy and argument from ignorance -- so by using this tactic, all you're doing is discrediting YOUR OWN credibility! 24.5.122.13 (talk) 00:48, 6 August 2014 (UTC)

BTW, don't you see the irony in summarily dismissing the statistical figures from an entire scientific study right after saying that "figures don't lie"? Perhaps you should have said instead, "Figures don't lie, unless they contradict my preconceived conclusions". 24.5.122.13 (talk) 01:01, 6 August 2014 (UTC)

Rushton & Jensen, if I remember rightly. Nope, not Rushton & Jensen -- this data was quoted in The Bell Curve by Herrnstein and Murray. 24.5.122.13 (talk) 00:50, 5 August 2014 (UTC)

Yep, also see The 10,000 Year Explosion and Race, Evolution and Behavior. — Preceding unsigned comment added by 74.14.75.23 (talk) 03:22, 5 August 2014 (UTC)

I wouldn't call RE&B a reliable source -- it has good data, but some VERY faulty analysis. 24.5.122.13 (talk) 00:52, 6 August 2014 (UTC)

I think it is far more important to look at the "other means" than natural selection. We know full well that countries like China and Ireland have gone from being bastions of learning and civilization to the objects of discrimination and contempt and back again. We know that there are obvious causes for lowered intelligence like malnutrition, lead and other toxins, bottle feeding and so forth. We know that intensive treatment of learning disabilities and an equally intensive investment in education of those who are normal and above can pay off well. And there is also a gradually increasing body of epigenetics that tells us that we should take some the ideas of Lysenkoism quite seriously - that it really is possible that how one generation is treated may have an effect on several that follow after it. For all these reasons, it is vital that we understand that human capital - just like financial capital - doesn't just fall from heaven; it needs to be carefully developed and protected. Wnt (talk) 20:16, 5 August 2014 (UTC)

As Wnt pointed out, these studies really do seem to pick and choose their evidence. Ignoring inconsistencies in history. If intelligence was genetic, ethnic groups with "superior intelligence" should have always been successful. Great civilizations should have stayed restricted to particular lineages. But they don't.

You can trace cultural influences quite readily, passing down from civilization to civilization (e.g. writing from Ancient Egyptians giving birth to the development of writing in neighboring later civilizations). But the groups remain ethnically separate, e.g. Greeks who later developed a phonetic alphabet that ultimately descended from Egyptian hieroglyphics are not descendants of Ancient Egyptians. In turn, Greece, once the cradle of western civilization, are not exactly an economic powerhouse still. Same with Romans who coopted Greek accomplishments later on, and even later on, the Germanic tribes of the Holy Roman Empire. Germanic peoples are not Romans, Romans are not Greeks, and Greeks are not Ancient Egyptians. It's culture being inherited not genes.

Nor can you easily measure the "accomplishments" of each civilization and compare them to figure out which had more intelligent people. Literally a [who domesticated the] apples and oranges [first] thing. Mesoamerican city-state civilizations (Mayan, Olmec, Aztec, etc.) had invented writing, the zero, and had one of the most accurate astronomical observations in the ancient world; yet they never developed advanced metallurgy. The Incan Empire was a vast complex bureaucratic civilization linked by continent-spanning paved roads; yet they never invented writing nor the wheel. Which of these two were more advanced?

Determining "success" by economic wealth is also not quite the measurement you're going for if you're gauging intelligence. Economic success isn't the sole result of, or even the main result of, intelligence. A lot of it depends on the starting environment, opportunism and yes, luck. After all, there are numerous instances of less technologically advanced ethnic groups conquering or assimilating older ones (some of them actually being retained as the ruling class). From the Germanic conquest of the western Roman Empire, to the Mongols overrunning the Chinese Empire and Indian Kingdoms, to the Hyksos invasion of Ancient Egypt. You can't argue that these conquerors were "more intelligent" when they were basically skin-wearing savages in comparison to the civilizations they held hostage or destroyed outright.

Because culture isn't genetic or innate. Even the linked blog purportedly showing how the "success factor" is genetically inherited because nobility/conqueror and wealthy families tend to stay on the elite strata for generations is a flawed conclusion to real evidence. Occam's razor would point the finger at the pile of gold handed down through generations rather than DNA. A healthy well-nourished kid with first-class education will almost always have better IQ results than impoverished kids whose parents didn't even have enough money to send them through primary school. IQ results are far more greatly affected by level of education, familial environment, childhood nutrition, and even language comprehension than it is affected by how smart your parents are. There are papers upon papers of this. That is a factor too large to be ignored by these studies. And yet they do ignore it.

There are several links and other books given already on criticisms and counterarguments to Cochran et al.'s The 10,000 Year Explosion, have you read them? Because this assertion that the success of countries is due to genetic superiority isn't as noncontroversial as you make it out to be. Just because they published books doesn't mean it has gained a lot of traction in the scientific community. And for the last time, be aware that the blog you originally linked to is by Cochran. "Proving" it by linking papers and books also by Cochran is circular sourcing. Unless you're just imploring everyone else to agree with you, then we're just wasting time here. They are not non-answers. There really is more to the objections than just being "not PC". -- OBSIDIAN†SOUL 00:55, 6 August 2014 (UTC)

I call rubbish on your statement that "IQ results are far more greatly affected by level of education, familial environment, childhood nutrition, and even language comprehension than it is affected by how smart your parents are" -- most studies actually indicate that IQ is a HIGHLY heritable trait, with between 45% and 80% heritability. So in fact, it's the OTHER way around -- how smart your parents are is a far bigger factor in determining your IQ than what school you go to or what you eat for breakfast! 24.5.122.13 (talk) 01:10, 6 August 2014 (UTC)

And as for your statement that "If intelligence was genetic, ethnic groups with "superior intelligence" should have always been successful", that is a non-sequitir -- IQ studies indicate that intelligence indeed does have a strong genetic component, but as StuRat and some others correctly pointed out, superior intelligence does not always translate to a nation's success. 24.5.122.13 (talk) 01:21, 6 August 2014 (UTC)

Eh? We are discussing whether the success of nations is due to genetic superiority aren't we? Not simply that IQ is inheritable. Because let me quote something from the article for you: "Estimates in the academic research of the heritability of IQ have varied from below 0.5 to a high of 0.8 (where 1.0 indicates that monozygotic twins have no variance in IQ and 0 indicates that their IQs are completely uncorrelated). Turkheimer (2003) found that for children of low socioeconomic status heritability of IQ falls almost to zero." Emphasis mine. If that isn't a clearer indication of the far stronger effect of environment, I don't know what is. It's not how smart your parents are, it's how rich.

And you haven't exactly shown why that statement is non sequitur. Can you explain then why the dominant ethnic groups today are not the same dominant ethnic groups in the past? Linking me to Heritability of IQ doesn't exactly prove anything regarding that, does it? -- OBSIDIAN†SOUL 01:35, 6 August 2014 (UTC)

Getting up

Why do humans experience a mild loss of balance when getting out of bed in the middle of the night for example to go to the toilet but not in the morning when waking up? 90.194.60.138 (talk) 12:35, 3 August 2014 (UTC)

If you get up quickly, say if you need to go to the bathroom immediately, there can be a drop in blood pressure to the brain that causes you to get dizzy. Sitting up first, then standing up a minute later, is a good way to prevent this. (I believe the heart beats faster to maintain pressure to the brain, but there's a lag between the low blood pressure signal and when the countermeasures take effect.)

If you gradually wake up in the morning, then your heart will have time to speed up and increase your blood pressure before you get up. StuRat (talk) 12:39, 3 August 2014 (UTC)

See orthostatic hypotension. --catslash (talk) 16:00, 3 August 2014 (UTC)

In the middle of the night it is quite dark, and you cannot orient yourself so easily, while in the morning you can see what is where. I only speak from my own experience. Edison (talk) 23:20, 3 August 2014 (UTC)

Cats and Kittens

Hi everybody, I was wondering when do cats develop their solitary nature. When both of our cats had litters of kittens, the kittens seemed to enjoy being around other kittens and playing with each other. When and why do they go on to develop such a solitary nature? --Andrew 13:07, 3 August 2014 (UTC)

In my experience, they are rather flexible. If you have a house full of cats, they learn to tolerate one another. In nature, however, they would tend to separate from their mother once they reach adulthood, and avoid other adult cats, except for mating, after that. StuRat (talk) 13:26, 3 August 2014 (UTC)

Feral cats tend to stick together in colonies. Wild cats, however, are solitary. --TammyMoet (talk) 17:32, 3 August 2014 (UTC)

• Puberty. μηδείς (talk) 21:51, 3 August 2014 (UTC)

How are instincts encoded in genome and get converted into information in the brain? Is the process known?

How are instincts encoded in genome and get converted into information in the brain? In asking the question, I'm making some assumptions:

1. Instincts are based on information in the brain
2. The information is not encoded as gross structures in the brain, but like memory

I'm puzzled by how the process works. Consider the example of arousal in postpubescent human males at the sight of human female breasts. It seems that the information needed to enable the instinct is quite complex:

• The instinct should be activated when the individual has reach a certain maturity level
• The individual needs to recognize that the "trigger objects" are on the body of a female member of the same species; recognizing the latter by sight seems itself a complex task
• The individual needs to distinguish breasts from other objects that bears superficial geometric similarity

I compare the human brain to a computer. From that perspective, the question is about how complex programming instructions get decoded from genome and (pre-)installed into the human brain.

How much does science know about the mechanism? — Preceding unsigned comment added by 98.114.41.240 (talk) 14:51, 3 August 2014 (UTC)

Coincidentally, I was thinking about to asking the very same thing! I've been watching our tiny puppy grow up into a gigantic beast. He wasn't brought up with other dogs - so his opportunity to learn things comes only from my wife and I. So how does he know to do a "Play bow" when he wants to play, or lick your chin as a sign of submission? There are lots of "instinctive" doggy behaviors that he has in common with all other dogs that can only come from his genome.

My suspicion is that finding the genetic trail that causes such a complex behavior as chin-licking may be exceedingly difficult...and most likely, the answer is "We Don't Know...yet".

But let's find out whether anyone here knows.

SteveBaker (talk) 15:17, 3 August 2014 (UTC)

Instinct and alike precognition is usually simple subconscious logic or logic based on subconscious informations received. So its just "using your senses and brain" in a natural but usually not conscious way.

Its much like your field of view: You can not recognize objects at the edge of your sight - you need to focus to identify objects - but you will recognize something big suddenly moving even 90 degrees out of your focus and your reflexes will process these information in a surprisingly sophisticated way without "needing" your consciousness.

Your genes "only" contain a master plan how all your cells get build and thus how they work (together). Everything beyond that is a consequence of the collected capabilities of all your organs and thus are "extended" capabilities like "instinct" but also "limitations" (like instinct is subconscious). --Kharon (talk) 18:43, 3 August 2014 (UTC)

Such behaviors are medicate by chemicals, appropriate hormones, some of which perhaps haven't been discovered yet. Others are well known, sexual steroids for example, etc. --AboutFace 22 (talk) 19:57, 3 August 2014 (UTC)

• This is a hugely complicated issue with no one definition of or mechanism of "instinct". Studies on various types of voles, for example, have shown that genetically determined levels of oxytocin determine (ceteris paribus) whether the males of a vole species are monogamous or promiscuous. Various wasps and other lower animals follow fixed action patterns. Whether they experience pleasure from this in the same way we do masturbating or shooting up is an open question.

No one has any idea what the mechanisms are in beaver brains for building dams, but a simple set of genes that cause pleasure in felling trees, hoarding wood, and blocking running water might explain the issue in five easy steps or less.

Human sex seems to require two whole "instincts". The opposite (or sometimes same or both) sexes smell good, and rubbing is pleasurable. The problem at this point is simply that we don't have instruments delicate enough to probe the brain to determine such obvious truths. We may, or may not achieve such knowledge before skyfall. μηδείς (talk) 00:14, 4 August 2014 (UTC)

It might be interesting to note that Charles Darwin devoted a whole chapter of On the Origin of Species (chapter 7) to instinct, he saw it as one of the strongest theoretical challenges to his theory.. Vespine (talk) 02:10, 4 August 2014 (UTC)

See Genetic programming for an idea of how people think the whole business works. Except the genetic programming in an organism does not work directly to say where each thing should go but in setting up an environment where they automatically form. See [2] for where people are trying to simulate the cells of a nematode worm including its 302 neurons - to push the analogy we'll need to crawl (or wiggle) here before walking. And by the way simulating a single cell properly would be much more complex than simulating a worm with general models of cells. Dmcq (talk) 13:27, 4 August 2014 (UTC)

Aerobic exercise

Why is it that walking up a steep hill works your cardio more than cycling. When you're walking up a steep hill or a mountain for a while, you get more out of breath than if you cycle. When cycling, you don't really get out of breath regardless of the distance. Why? — Preceding unsigned comment added by 82.132.244.21 (talk) 14:57, 3 August 2014 (UTC)

You need to cycle up steeper mountains. Or cycle faster. Or both ;-). --Stephan Schulz (talk) 15:04, 3 August 2014 (UTC)

It's all about gearing. Like any 'engine', our bodies are most efficient at certain energy conversion rates and inefficient at others. The wonderful thing about the bicycle is that it can adjust the gearing to the terrain and the speed you want to go to best match the output that our legs can generate. All our bodies have is shifting gait between walking and running - which isn't so good at that.

So when you're walking up that hill, you're demanding more energy than your body is comfortable at generating, so all of the panting, muscle cramps and exhaustion sets in pretty quickly. On a bike, when the going gets tough, you can just drop down a gear and it gets easier (albeit slower)...and when the ground levels off, you can click up through the gears and get more speed for the same, comfortable, energy input.

SteveBaker (talk) 15:09, 3 August 2014 (UTC)

Yes, we may be answering someone who lacks a gearshift, or who lacks a hilly road. Many of us are blessed with both and the will to use them. Jim.henderson (talk) 15:17, 3 August 2014 (UTC)

Thanks. What about rowing machines? Does that work cardio more or less than walking up steel hills and cycling? Rowing machines also don't really get you out of breath. 82.132.244.31 (talk) 16:52, 3 August 2014 (UTC)

I try to do most of my aerobic training with a heart rate monitor (because I'm lazy, and it helps me to overcome the tendency to go slower than I should for good cardio). I can raise my heart rate to more-or-less the same level on a cross-trainer or on my bicycle, or walking up many levels of stairs. I don't measure while walking or hiking. On a bicycle, it's somewhat harder to maintain a constant level because of traffic, turns, and the general need to concentrate on the road, not the heart rate. But on a purely physiological level, I have no trouble to reach the same level on the bike as on the training machine. Of course, I can also cruise at 20 km/h with little exertion. --Stephan Schulz (talk) 18:08, 3 August 2014 (UTC)

The power to weight ratio of most people is below 3 Watt/kg. This means that the maximum sustainable speed for cycling up a hill at 30 degrees inclination will be below 2.2 km/h for most people. People will tend to overexert themselves as they are used to cycling uphil for small distances or running uphil much faster than is sustainable. For short busts it's not a problem for an unfit person to expend a kW of power. But of it's a long stretch you have to cycle, then the effort you need to do to move at the 2.2 km/h snail's pace will be demoralizing to most. Count Iblis (talk) 19:06, 3 August 2014 (UTC)

Concurrent properties in materials?

Can a material be transparent as a clear glass and conduct electricity? Be soft as rubber and conduct electricity? Be like soft as rubber and conduct heat? — Preceding unsigned comment added by 80.58.250.94 (talk) 15:22, 3 August 2014 (UTC)

To combine good transparency with good electrical conductivity is a little difficult. Light is an electromagnetic wave, and if a material conducts electricity at optical frequencies, then it will necessarily be reflective (and shiny if its surface is smooth at a wavelength scale). However, there will be a frequency above which the charge-carriers in the material cannot 'keep up' (the plasma frequency), so that the material will cease to conduct and become transparent (while remaining conductive to lower frequency currents). Unfortunately this frequency is higher than that of visible light for all metals. Some metals are transparent in ultraviolet though, and so only just miss being transparent to our eyes. Generally metals start to become transparent in the X-ray band. --catslash (talk) 16:29, 3 August 2014 (UTC)

See Transparent conducting film and Conductive polymer for our relevant articles on the first two substances. Soft materials with high thermal conductivity are common - see thermal grease for an example. Tevildo (talk) 18:55, 3 August 2014 (UTC)

Like Water? --Kharon (talk) 19:02, 3 August 2014 (UTC)

Not really. Water itself has a very low (non-zero, but still very low) conductivity, though ionic solutions are clear, conductive liquids. --Jayron32 01:38, 4 August 2014 (UTC)

A simple material may not be - but composites can have these properties. Salty water is very conductive, and transparent. Rubber that's impregnated with carbon is reasonably conductive, and it's soft. A thin-walled, carbon-impregnated plastic bag full of liquid mercury would be soft, and very conductive. SteveBaker (talk) 15:52, 4 August 2014 (UTC)

Thermally conductive pads are rubber-like and are reasonably good conductors of heat. They are used as a contact material between a heat-producing device and a heat sink. They are likely composites, like the carbon-impregnated rubber mentioned above.--Srleffler (talk) 04:11, 5 August 2014 (UTC)

pelvic hip question

4 yrs ago I was in wreak. many injuries im not trying to sue anyone my problem is other than im 60 is all I was told was I shattered the cap that the ball at end of leg fits in. drs wouldn't let me rehab they said at least a year. I don't know the proper names of the bones cant pronounce them either for that im sorry.now my question is that part of hip. theres a commercial on tv wear att. are advertising metal to metal hip replacement law suit. im not out for money my dislike for lawyers is well I don't use them don't want to help them make a penny. I was I county hospital no regular MD.is this something I need seen about im having some lower back pain now not that often. I just don't want problems down the road I already have a limp from it. if this don't qualify as a question you answer that's cool I will understand. sorry about my 1st grade spelling THANK YOU69.19.14.43 (talk) 16:34, 3 August 2014 (UTC)

You're asking for medical advice, which we cannot provide. You need to see a doctor. ←Baseball Bugs ^{What's up, Doc?} carrots→ 16:42, 3 August 2014 (UTC)

To answer the part of the question we're allowed to answer, that part of the hip is called the acetabulum. See also Hip replacement for our article on the procedure. You do need to contact a doctor for medical advice and a lawyer for legal advice, as Bugs has mentioned. Tevildo (talk) 18:42, 3 August 2014 (UTC)

If you've had a dose of freaky ghost, who you gonna call? The Canadian Haunting and Paranormal Society! Because they're free. InedibleHulk (talk) 02:55, August 4, 2014 (UTC)

Seriously though, get well soon. I know how hip pain feels, but not enough about how to fix it. InedibleHulk (talk) 02:57, August 4, 2014 (UTC)

Medicine: non mainstream therapies

Hi all,

I am not a native English speaker, and I should name a therapy that is inside the field of established science (e.g.: not Chinese medicine, or homeopathy) but not really mainstream. It's ok if I say "unconventional therapy", or in this case it would look like something related to "alternative medicine"?

Thank you! — Preceding unsigned comment added by 188.217.52.241 (talk) 18:51, 3 August 2014 (UTC)

You might need to clarify "inside the field of established science but not really mainstream". Complimentary medicine might be closer than Alternative medicine; regretfully, both of links redirect to the same page.

This article from the National Institute of Health might shed some light: Complementary, Alternative, or Integrative Health: What’s In a Name?   —71.20.250.51 (talk) 20:44, 3 August 2014 (UTC)

Complimentary medicine? Is that like when someone says you look great and you start to feel better? Matt Deres (talk) 02:00, 5 August 2014 (UTC)

I mean a treatment about which already a lot of scientific literature in peer reviewed journals exists, with good results, but that it's not among the most used ones for a given disease.

188.217.52.241 (talk) 20:49, 3 August 2014 (UTC)

I believe I understand what you mean; but I can't find the proper term. "Emergent (new or nacent) medical treatments" might be semantically correct, but that term is used differently in the medical field. Unless somebody has a better idea, I'd go with "unconventional", since "alternative" has a (sometimes unfair) negative connotation. —71.20.250.51 (talk) 23:35, 3 August 2014 (UTC)

"Off-label" is the term for this use of drugs - I don't know if there's a more general term for other forms of medical treatment. Tevildo (talk) 23:43, 3 August 2014 (UTC)

You seem to be describing mainstream, so "unconventional" might not be entirely appropriate. You seem to be referring to therapy that I would refer to as "not currently the dominant therapy". Just because it is not amongst the highest-ranked treatment does not make it "unconventional" or "alternative". Many factors can influence which treatment is dominant, including factors such as cost, availability and practitioner familiarity and bias. You may also be wanting to distinguish the degree to which a treatment has been established, as in whether it has been through clinical trials etc. Various phrases come to mind: "not established", "not trialed", "emerging", "promising", "in minority use", "unproven", "not approved", whatever, depending on exactly what distinction you're trying to make. I do not know what the best medical terminology is in each case though. —Quondum 01:19, 4 August 2014 (UTC)

There are variations between countries about what exactly constitutes "normal" clinical/medical provision. I was amazed to find that physiotherapy, which is mainstream in the UK, is not mainstream in the US, for example. The term in the UK for such therapies (physiotherapy, occupational health, dietetics, for example) is associate health professions. They are not clinically trained so not doctors or nurses, but still have some medical training (usually anatomy and physiology, sometimes pathology). However, here in the UK it is possible to be treated by a homeopath on the NHS, so that might meet the OP's criteria. Also at the Christie hospital in Manchester, therapies such as reflexology are routinely used on patients - as they are in many hospices in the UK. So it depends on your viewpoint. --TammyMoet (talk) 18:22, 4 August 2014 (UTC)

Every therapy to be accepted by official medicine in the United States must be demonstrated to be superior to placebo. From what I've heard about UK "therapies" it is far from the case. --AboutFace 22 (talk) 01:04, 6 August 2014 (UTC)

Classification of various things.

Hi there. I am looking for a system of classification (in public domain) of various everyday things, in short, things a person runs into during their lifetime. I googled a bit and found many websites aimed primarily at high school students or perhaps their teachers like this one. This is not what I want. I don't need a lot of Latin, I don't need biological classifications, I don't need it to be pictorial. I will give an example of what I want but I am not sure such a thing exists.

Living things that move (a category) ==> human (a subcategory) ==> face (subcategory) ==> nose (a subcategory) A lot of this stuff, as you can see, is trivial, however, it takes a lot of brainstorming to make it really comprehensive. Does anybody know of such a classification? Thanks, --AboutFace 22 (talk) 18:57, 3 August 2014 (UTC)

It is indeed a hard problem to provide such a general classification. OpenCyc and WordNet and two such databases of knowledge, but I don't know if they are public domain. OpenCyc has taxonomic classifications and WordNet has notions of semantic similarity. --Mark viking (talk) 19:13, 3 August 2014 (UTC)

Very interesting references although hardly applicable to what I have in mind. Nonetheless I appreciate what you posted. Thanks. --AboutFace 22 (talk) 19:30, 3 August 2014 (UTC)

Roget's Thesaurus is based on this sort of classification system - I'm not sure if it has a name, though. You may also want to look at Leibniz' characteristica universalis (or "universal characteristic" if you don't like the Latin) and Aristotle's Categories. Tevildo (talk) 20:28, 3 August 2014 (UTC)

The Suggested Upper Merged Ontology aims at providing such a thing. Note that the example given above is not strictly correct. "Human" is-a subcategory of "Living things that move", but face is not a subcategory of human. Instead, a human has-a face, and a face has-a nose. I am-an incorrigible know-it-all, but at least I have-a sense of humour.  ;-). --Stephan Schulz (talk) 21:50, 3 August 2014 (UTC)

On reading this question, I immediately thought of the semantic web, including its many efforts to standardize a data scheme. You might also find WikiData's knowledge base, which is a collection of structured data in a hybrid MediaWiki / WikiBase format (which is an evolving, amorphous "standard").

For example, you might be looking for OWL - but in order to make use of the OWL language for structuring and defining a data model, you need to understand OWL's context and how it fits into the rest of a semantic environment. Arguably, this kind of data abstraction gets pretty meta: you need a semantic model of your semantic model before you can use it to model your semantics! Nimur (talk) 22:18, 3 August 2014 (UTC)

• My tenth-grade chemistry book had a taxonomy of existence. The first division was between pure and impure substances. Pure substances included elements, particals, and pure molecular chemicals. Impure substances included mixtures and composites. Mixtures included solutions and gross mixtures. Composites included conglomerations (native copper and quartz formation, mountain, planet) and biological entities. Biological enties included organisms, their products, parts remains and artifacts, such as a mollusc's shell, a bird's nest, and a hammer. You might also look up ontology and categories, like Categories (Aristotle). It's also important to remember that what is, is. Our concepts are tools made by humans, not restraints upon nature. μηδείς (talk) 21:46, 3 August 2014 (UTC)

The Oxford Historical Thesaurus, which is unfortunately not public domain, has this kind of classification. "Nose," in the relevant sense, has the classification: the external world > the living world > body > external parts of body > head > face > nose, with further subclassifications. John M Baker (talk) 22:24, 3 August 2014 (UTC)

See Category:Classification systems.—Wavelength (talk) 22:22, 3 August 2014 (UTC)

I really appreciate all contributions, John Baker's especially. I want to emphasize though that chemistry things are beyond the scope of what I need. It is all for visual perception really, so I need to classify things people ogles during their lives. They must be in front our noses visible and available to touch. Thanks --AboutFace 22 (talk) 02:00, 4 August 2014 (UTC)

As a computer programmer (using "object oriented programming") we often have to deal with these kinds of classifications...and it can be quite difficult. One thing that's well-understood in my field is that it's critical not to muddy the concept of "is-a-kind-of" and "is-contained-by". Your initial example ("Living things that move (a category) ==> human (a subcategory) ==> face (subcategory) ==> nose (a subcategory)") makes exactly that mistake. A human is-a-kind-of livingThingThatMoves which is-a-kind-of thingThatMoves which is-a-kind-of thing. But a face is-contained-by a human...it's not a kind of human so you have 'human contains face contains nose'. However, these categories are rarely as strictly hierarchical as you're imagining. After all, a tree is "a thing that doesn't move"...but the category "living thing" is neither a kind of thing-that-moves or a kind of thing-that-doesn't move...so it has to be a kind of thing. Now both trees and humans are living things - and they are also (respectively) things that move and things that don't move. So you don't have a clear-cut unidirectional break-down of everything. It's a web. It's also a tangled web. Mathematics is a kind of set-of-ideas which is a kind of "set" which is a kind of mathematical concept.

Is a human corpse a kind of human? Not really because it's not a living thing or a thing-that-moves. Is Queen Victoria not a human because of that? What about Harry Potter - is a 'fictional human' a kind of human? This gets very difficult. If you decide to split dead objects entirely away from living so that you can keep "human" as a "thing that moves" then you need categories like "Dead Frenchman" alongside "Frenchman"...or do you put Frenchman into both the "Dead Human" or "Human" categories? That's going to become EXCEEDINGLY messy! "Human" can either be both a "living thing" and a "dead thing" but not an "inorganic thing"...which would be fine if you didn't have ikky things like "Queen Victory Action figure" - which is inert plastic but has ought to be in some sub-category of "representations of humans"...and where you'd hope there was some higher level category that contained living human, dead human, unborn human and "representation of human"....

So life isn't going to be quite as simple as you may imagine.

Evidence of this is the Wikipedia category system - where there can be loops (both deliberate and accidental) in the category tree and where almost everything belongs to multiple categories.

SteveBaker (talk) 15:34, 4 August 2014 (UTC)

SteveBaker, thank you. What you said is interesting of course and it is not something that has not been uderstood. Sure, I understand how complex the whole undertaking is. However my goal is to avoid complexity as much as possible. One of the reasons is that classification should result in computer code, so it must be workable. Also as I said it will be limited to the things we see or potentially can see and even touch. Thus (I hope) abstract concepts will be either minimized or completley set aside. The whole thing is for visual perception, this is why I will most likely be able to impose such limitations. --AboutFace 22 (talk) 18:51, 4 August 2014 (UTC)

SteveBaker, did you mean "Queen Victoria Action figure?" --AboutFace 22 (talk) 21:11, 4 August 2014 (UTC)

@AboutFace 22: To help you in your search, it might help to know that you are basically looking for an ontology. Some additional info is at Ontology_(information_science), which is basically the same concept but tied to a specific application. SemanticMantis (talk) 21:32, 4 August 2014 (UTC)

Electric weapons

Have Leyden jars, Tesla coils, etc. ever been used in warfare? 24.5.122.13 (talk) 21:06, 3 August 2014 (UTC)

Ever? It's impossible to know: we can't possibly expect everything that ever happened to be documented! But I am not aware of any famous instances. If you're willing to broaden the definitions of these to mean largely anything similar to a Leyden jar or Tesla coil - like any battery or capacitor, or any coil with a spark-gap - then we can almost certainly say that similar devices were used in early electronics. That would include radios, telegraphs, and so forth - and these technologies were used in support of military activities and warfare.

Leyden jars in particular represent a very primitive type of capacitor. Almost as soon as inventors found practical use for stored charge, large bulky jars were supplanted by more modern forms.

"Tesla coil" is, today, a generic term to refer to a coiled wire with an air-gap for discharging current. Again, if you are willing to suitably generalize this, we could say that Heinrich Hertz's induction coil radio transmitter was built from a Tesla coil - except that Hertz's work predates Nikolai Tesla's!

Nimur (talk) 22:02, 3 August 2014 (UTC)

There is some speculation that the ark of the covenant may have been an electric weapon. See [3]. My mentioning this is not an endorsement of the idea, but it is at least a well covered one. You can find discussions of the ark in this vein using a simple Google search. --Jayron32 22:43, 3 August 2014 (UTC)

Not sure if this fits the category that you are asking about, but the railgun is "an electrically powered electromagnetic projectile launcher", although a practical weapon is still in development. Alansplodge (talk) 22:55, 3 August 2014 (UTC)

Not quite what I'm asking about -- I was asking specifically about weapons that directly use electric shock for antipersonnel effects, not to launch a projectile or find a target for other weapons. 24.5.122.13 (talk) 23:23, 3 August 2014 (UTC)

Would electric fences, tasers, electrolasers, cattle prods, parrillas, picanas or electric chairs count? InedibleHulk (talk) 00:19, August 4, 2014 (UTC)

Are any of these used on the battlefield (as opposed to domestic law enforcement)? 24.5.122.13 (talk) 05:05, 4 August 2014 (UTC)

The fences and the electrolasers. But the others are often used when the line between "domestic law enforcement" and "war against citizenry" gets really blurry. InedibleHulk (talk) 05:28, August 4, 2014 (UTC)

Note also, many of these have been used on people captured from the battlefield often by people who are much more associated with those on the battlefield than anything which can be considered "domestic law enforcement" (although the lines between the two are often blurry among those who used such things). Nil Einne (talk) 06:03, 4 August 2014 (UTC)

There are electric fences being used as anti-piracy/boarding measures. Google "Secure-ship" for one. --DHeyward (talk) 03:46, 4 August 2014 (UTC)

True, but I was thinking more along the lines of offensive weapons, not obstacles. But yes, electrified barbed-wire fences were used occasionally in World War 1 as anti-infantry obstacles. 24.5.122.13 (talk) 05:07, 4 August 2014 (UTC)

There's Raiden (Mortal Kombat). His existence is dubious, but DARPA has probably at least considered his combat characteristics. InedibleHulk (talk) 10:29, August 4, 2014 (UTC)

Oh, Lord. Why is it that it is so much easier to think up weapons than anything else? I ought to toss this idea out of mind with the others, but I suppose that the agencies who imagine themselves the new Gods would already have arrogated such a power: it strikes me that if a Lightning rocket can bring lightning to the ground for research, then surely the drones that patrol the air must have an option to pass through the most highly charged part of the cloud and shoot a much smaller rocket that crosses the same distance going downward that releases the same payload. Even when lightning strikes from the blue nobody gives it a second thought. Wnt (talk) 23:29, 4 August 2014 (UTC)

Did men really become feminized 50,000 years ago?

Several science articles report without any criticism or scientific analysis a paper published by a Utah graduate student who analyzed a few skulls from tens of thousands of years ago, along with numerous recent skulls, and concluded that mens' testerone levels dropped suddenly, or that receptors for testosterone decreased, 50 thousand years ago, and that as soon as men became thus feminized. great things such as art and technological advances ensued. The reports mention there suddenly occurring "agreeableness and lowered aggression and that, in turn, led to changed faces and more cultural exchange." This is based on the skulls becoming less "masculine" looking 50,000 years ago, in the authors' estimation. I have no access to the original paper, so I would appreciate input and analysis by anyone with access who can evaluate the paper. Has anyone provided alternative explanations of the findings? What on earth would have caused a sudden lowering of testosterone levels in males? Was the paper contrasting Neanderthals, with brow ridges, versus Cro Magnons, without brow ridges? How did they assess the difference in testosterone levels in fossils? By chemical assay or by conjecture and hand waving? Why would women suddenly dig metrosexuals as sex partners 50 thousand years ago, as opposed to the manly men they previously preferred? Edison (talk) 22:47, 3 August 2014 (UTC)

Good old sexual selection for neoteny maybe?-- OBSIDIAN†SOUL 23:26, 3 August 2014 (UTC)

You can't make such far-reaching conclusions from skull shape alone -- this sounds like 18th-century phrenology bullshit, not solid science. 24.5.122.13 (talk) 23:28, 3 August 2014 (UTC)

The original press releases are here. The original paper is paywalled. But as far as I understand it, differences in testosterone lead to differences on skull shape. The authors have measured 1400 skulls and found changes that indicate such a change took place. They speculate that increased population density gave an advantage to less aggressive, more cooperative people. It's not the choice between Chuck Norris and Boy George, it's the choice between Darth Vader and Jean-Luc Picard. --Stephan Schulz (talk) 23:35, 3 August 2014 (UTC)

I haven't read the paper (except the first page on JSTOR), but from what I have read it seems clear that they just looked at skull shapes, that the correlation between skull shape and testosterone is based on modern medical evidence, and that their association of this change with contemporaneous cultural changes is pure guesswork. "Suddenly" probably means over thousands or tens of thousands of years. I have to assume they only looked at human skulls because otherwise the comparison would make no sense. -- BenRG (talk) 23:37, 3 August 2014 (UTC)

(The reason this is showing up in newspapers is that a university PR department wrote a press release about it and the newspapers' science reporters regurgitated the press release. There's nothing to suggest that this paper is scientifically important; a marketer just identified it as likely to generate buzz and free advertising for the university.) -- BenRG (talk) 23:47, 3 August 2014 (UTC)

(ec)The premise that our direct ancestors became "feminized" does not square well with the hypothesis that it was our direct ancestors who extinguished those supposedly more "masculized" Neanderthals. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:39, 3 August 2014 (UTC)

Why not? Do you really think that the Neanderthals were beaten to extinction with clubs? AndyTheGrump (talk) 23:50, 3 August 2014 (UTC)

What do you think they were beaten to extinction with? Feather boas? ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:55, 3 August 2014 (UTC)

I have seen no evidence that they were beaten to extinction at all. In as much as they are extinct (which isn't entirely true, since a significant proportion of the human race has some Neanderthal ancestry), it is almost certainly a result of lower reproductive rates, rather than physical violence. AndyTheGrump (talk) 00:39, 4 August 2014 (UTC)

"Almost certainly"? How CAN you be so certain about what happened a gazillion years ago? 24.5.122.13 (talk) 05:03, 4 August 2014 (UTC)

The normal term is gracilzation, and it is earlier than 50kya. The women lost their brow ridges and heavy bonse structure as well. Men didn't sprout breasts and labia. — Preceding unsigned comment added by Medeis (talk • contribs) 00:03, 4 August 2014 (UTC)

Why would this also have happened to people in Africa and other populations that were isolated from Europeans around that time? Count Iblis (talk) 00:49, 4 August 2014 (UTC)

The arrival of modern humans led to the replacement of Neanderthals. It's true that modern humans show signs of decreased testosterone. Modern humans appear to use intelligence more than brute force, to their advantage. For example, a comparison of spears used by each seems to show that Neanderthal spears were only used for thrusting, which would put them in harms way from the large prey they were trying to kill. Modern humans, on the other hand, developing throwing spears, which put the humans out of range of the dangerous animals they were hunting, particularly when paired with an atlatl. Over time, improved survival rates in modern humans would allow them to spread further, and, when it did come down to a direct fight between the two, throwing spears would again be a distinct advantage. StuRat (talk) 05:18, 4 August 2014 (UTC)

Which is yet another plausible hypothesis why the Neanderthals died out -- the Cro-Magnons were more efficient hunters (due in part to their throwing spears), so in times of food scarcity (such as during the Ice Age), they were less likely to die of starvation than the Neanderthals! 24.5.122.13 (talk) 07:05, 4 August 2014 (UTC)

'mens' testerone levels dropped suddenly'? Did hairs on the head suddenly increased their vulnerability to testosterone too or why do men go bald? I don't notice bald gorillas or chimpanzees. I see no evidence there that men's skulls have changed more than women's, are they saying women used to be more masculine and became more feminine too? Used neanderthal women go bald? I think perhaps this whole idea needs a bit more thought and that the testosterone bit is probably some copy editors invention. They tend to have too much testosterone perhaps. Dmcq (talk) 08:03, 4 August 2014 (UTC)

May I suggest that the whole idea has had "a bit more thought", at least some of which would be obvious if one reads the full paper, and even more if one acquired the prerequisite training and knowledge to understand the methods and previous state of the art in the field? --Stephan Schulz (talk) 10:08, 4 August 2014 (UTC)

One of the cornerstones of the scientific method is to look for things which might disprove one's hypothesis. It is pretty clear to me that such has not been done in this case - for instance I have pointed out one straightforward indication that what they say is unrelated to testosterone and others have pointed out neoteny as a more likely explanation and as another one can I also point out we don't need such strong muscles in our heads as our ancestors because of cooking. What they have is interesting but their talk about testosterone is just something they have jumped on and is a just so story without something much better being demonstrated. If there was something more convincing than skull measurements I'm sure they'd have said so. Dmcq (talk) 12:00, 4 August 2014 (UTC)

Neoteny may be achieved by reduced testosterone levels, so those are not incompatible. StuRat (talk) 13:28, 4 August 2014 (UTC)

Regarding lowered testosterone in women, yes, that would likely also be the case. As for other primates going bald, this does happen, but the longer lifespan of modern humans presumably explains why a larger percentage of modern humans go bald. It is also possible that humans are more genetically susceptible to balding, too. After all, the tendency toward baldness is an inherited trait, so it could vary in a population over time, if there was an advantage to being bald (perhaps the bald were revered as elders, and thus treated better, increasing their odds of survival and passing on their genes). StuRat (talk) 13:34, 4 August 2014 (UTC)

Well I just had a look up on the subject and it seems human adult male testosterone levels are pretty similar to those of adult male chimpanzees. Really all this looks to me like people grabbing headlines with no basis in science. Dmcq (talk) 13:56, 4 August 2014 (UTC)

Not that that's impossible, especially the headline part, but are you sure that you are more qualified to judge this than the editors and reviewers of Current Anthropology? I wouldn't expect an anthropologist to understand model construction using transfinite induction, or how to use SAT solvers to handle the travelling salesman problem, or even why NFAs and DFAs are equivalent. I try to assume I'm similarly handicapped in assessing anthropological research, or in performing brain surgery, or in translating first century Aramaic texts... --Stephan Schulz (talk) 16:08, 4 August 2014 (UTC)

I think I'll stick with my assessment that their conjecture about testosterone is BS. I intend to keep hold of my critical faculties and not automatically accept as gospel everything every scientist says. If it becomes more mainstream then fine I'll accede I was wrong but I'll be surprised. Dmcq (talk) 16:32, 4 August 2014 (UTC)

• Anatomically modern human in Africa, well before 50kya. μηδείς (talk) 16:53, 4 August 2014 (UTC)

Are people here commenting on the paper or the PR? If it's the later, I'm not sure that's particularly useful on the science desk, except in a manner similar to StS's PHDComics link.

For example, I'm not sure the usefulness of all this comment on anatomically modern humans 50 kya ago. It's not like they don't know that. They said

This 100–150,000 year gap between the emergence of modern human morphology and the consistent expression of symbolic behavior is often referred to as the “problem of behavioral modernity” and has generated heated debate about the cognitive and cultural capacities of the earliest modern humans

.

And from what I can tell (as somewhat hinted by their abstract) they're discussing what they think are gradual changes from sometime in the "Middle Pleistocene to recent times" (I think 200,000 is roughly their starting point). I'm not saying 50,000 BP is irrelevant, they consider it important for various reasons but if I'm understanding them correctly, they're not saying that these cranio-facial changes happened suddenly at 50,000 or stopped then.

They don't seem to mention gracilization in the paper, but do mention it in their reply. From what I understand they're not sure that the changes they observed are a part of gracilization and in any case, gracilization seems to have happened to several different species but they're not sure that it's the same for their observed changes. (Although one of the respondents believes it is.)

Similarly while they don't mention neoteny per se (although one of their cites is "Heterochrony in human evolution: the case for neoteny reconsidered"), they do mention

Support for a link between reduced aggression and craniofacial feminization again comes from the breeding experiment conducted with the silver foxes. In addition to the behavioral and physiological changes that were evident after 20–40 generations of selection for tameness, the morphology of foxes changed relative to the wild type. These changes included decreased sexual dimorphism in canine size, coat depigmentation and piebald coloration, reduced cranial capacity, and feminized craniofacial skeletons, with later generations of male foxes possessing skulls significantly shorter and wider (and thus more like female foxes) than the wild type

and also:

Finally, the more socially tolerant bonobo exhibits reduced craniofacial sexual dimorphism relative to common chimpanzees (Cramer 1977; Fenart and Deblock 1972, 1973, 1974; Shea 1989), as well as a degree of paedomorphosis in cranial ontogeny

(And a bunch of other stuff that may be relevant that I didn't include.) So whatever you may think of the data they're using and resulting conclusions, it seems likely that they consider this feminisation part of what most would call neoteny. (And it also seems clear they're saying the changes in androgen reactivity have lead to reduced sexual diamorphism, so it's not they haven't considered females either.)

They also mention why they think the brow ridges changes are "temperamental variation" and not because of "masticatory mechanics". And analysed differences between "foragers" and "agriculturalists".

And why do people keep discussing testorene levels anyway? Again even the abstract mentions it could be levels or receptor sensitivity (they use the term "androgen reactivity to include both).

I'm not saying the paper is right by any means, not am I saying that they didn't miss anything or weren't too quick to make conclusions or whatever. Instead, while I mostly agree with StS, I do think if people are going to criticise it, they should at least try to read it (even if as StS suggested, they have difficulty understanding it) rather than coming up with random stuff based on their own presumptions. This is the science desk not your personal blog or usenet after all. And personally, I find Sheela Athreya's, Trenton W. Holliday's, Teresa E. Steele and Timothy D. Weaver's + Richard Wrangham's criticism much more compelling than anything here, even though I'm pretty sure I don't understand all they're saying. (Not saying there's anything wrong with April Nowell's comment, simply that it doesn't particularly relate to that discussed here except I guess the last comment. Although I forgot about BB's stuff.)

Nil Einne (talk) 18:21, 4 August 2014 (UTC)

I have an unusual liking for "Lamarckist" notions (even if Darwin expressed the ideas more cogently and Michurin pioneered the practical aspects). So I can't help but note that certain social circumstances, such as competition, can affect testosterone. [4] It looked like in a few papers testosterone wasn't actually shown to change on a transgenerational basis, but other factors can, accounting for the qualities of domestication. [5] I would suggest investigating the possibility that the humans showed less testosterone-affected types not due to lower testosterone, but due to other epigenetic factors that might have changed on a transgenerational basis to cause a similar reduction in the visible "masculinity" of the domesticated humans. But this is absolutely just a wild speculation! Wnt (talk) 01:02, 5 August 2014 (UTC)

Thermolysis

Is it possible to predict the rate of thermal atomisation of gas into its elements under ideal conditions, as a function of temperature. Primarily, the conditions include a pressure and concentration approaching values of zero, so as to minimise particle interaction. The enthalpy of atomisation, as well as the activation energy are known. Plasmic Physics (talk) 23:58, 3 August 2014 (UTC)

The Saha ionization equation can be used to describe the process of dissociation as well as ionization. Application of the equation to dissociation of molecular hydrogen is described here. --Mark viking (talk) 01:13, 4 August 2014 (UTC)

August 4

Are Mathematical Dimensions incorrect?

This is probably not the best place to debate or question the validity of the current mathematical dimensions up to 4-dimensional, but I was trying to imagine some spacetime concepts last week, and reading up on the mathematical 4D, it seems that some people like to refer to the fourth dimension as "Time".

I'd like to take a moment to define three dimensional space and somehow propose that 4D is not explicitly "time" in the way it is currently understood. In 3D, much like 2D, there are just points on planes; but with the added Z plane to the established XY planes, right? But the thing about analyzing depth is that it already inherently requires a factor of time to be aware of it. From a static view from any static point in an XYZ 3D Graph, all other points and their lines would just appear flat. The main reason depth can be analyzed at all is because either the points can move at a speed, or the entire 3D graphical presentation can be moved and manipulated to display different angles, and movement is a factor of time.

This has lead to problems with visualizing 4D Shapes using the current time-related Fourth Dimensional view because of this apparent overlooking of "time" having already been implicitly established in the Third Dimension view. I have proposals for a restructred dimensional understanding from 1D to 4D, But again i'm not sure this is the place to best deliver the idea.

So really i'm just wondering if any mathematicians out there doubt the established order and definitions of Mathematical Dimensions? Fbushnik (talk) 02:52, 4 August 2014 (UTC)

Before you advance your proposals in a more appropriate forum (Wikipedia isn't such a forum), it would probably help for you to read Dimension (mathematics and physics). RomanSpa (talk) 04:34, 4 August 2014 (UTC)

It's not a question of doubting it. Euclidean 4-space is as self-consistent a mathematical system as Euclidean 3-space. But we know for a fact that neither of them describes the physical world correctly. To see an abstract mathematical model of relativistic space-time, check out Minkowski space. AlexTiefling (talk) 04:43, 4 August 2014 (UTC)

Treating time as "The Fourth Dimension" is a mathematical convenience. It doesn't mean that it is literally "the fourth dimension of space" in terms of physics...that's not even a particularly reasonable presumption. There are plenty of scientific theories ("String theory" being the most prominent) that actually require there to be more than three "spatial" dimensions. It's then necessary to question why we can only perceive three of them...but there are ways to do that.

This question about extra spatial dimensions comes up quite a bit - and I like to point out that we do not in fact "see" the world in three dimensions in the first place. Our retinas are two dimensional imaging devices, just like cameras or an artist's canvas. We see the world in TWO dimensions and attempt to infer the third from the way that the 2D image changes as we move around - from the fact that we have two, slightly different 2D images to compare - from the fact that we have to adjust the focal length of the lenses in our eyes to bring nearby objects into clear focus...that kind of thing.

An analogy with how a computer draws 3D objects in computer games and such is worth explaining here. The third dimension is basically used only indirectly. It's used to reduce the size of objects as they get further away (perspective) and to hide distant objects behind nearer ones (hidden-surface elimination). However, we can change that...it's easy enough to toss out the perspective thing and draw an "orthographic" display. Lots of "god games" like SimCity do that, and we have no problems with it. You can also draw just the outlines of objects, making them transparent - and still, we can recognize 3D objects. So simply ignoring the 3rd dimension doesn't seriously impact our ability to see. We can use the third dimension in other ways...modifying the color of objects as they get further away allows you to simulate fog...which actually improves depth perception quite a bit if used subtly. Mixing in a bit of blue creates the effect of Raleigh and Mie scattering...same deal.

You can also do what doctors do with MRI machines - they photograph a bunch of slices of an object and change them over time. That's using time as the THIRD dimension...which is another kind of projection.

So-called "3D displays" like in movie theatres basically use the third dimension to produce a spatial shift between two images where the amount of shift varies with range...since our visual system naturally does that in the real world, it works reasonably well.

You could (theoretically) make a display where the blurriness of the image varied according to the third dimension to allow your eye's focussing mechanism to be used to get us that extra dimension.

In mathematical terms, these are all kinds of "projection" - how do you project three dimensions into two? And things like perspective, orthographic, fog and hidden-surface are all ways to drop that extra dimension.

So to view a 4D world, it's just a matter of deciding how you're going to deal with the extra two dimensions. You could, for example, use one of the extra dimensions to do a perspective projection and the other dimension to produce color shifts like fog or spatial shifts or whatever.

The most common way to try to help people see in 4D is to use the third dimension as perspective and the fourth as time...but it's certainly not the only choice.

The observation that we're ALREADY missing one of the three dimensions because of our two-dimensional retinas is a useful one. There is nothing magical about having extra dimensions - it's just a matter of how you discard them in order to produce an effect that our 2D retinas can cope with.

SteveBaker (talk) 15:12, 4 August 2014 (UTC)

It is very much of a shorthand, and a somewhat misleading one, to label time as Dimension 4 along with the three known spatial dimensions. Another treatment is to use a Minkowski treatment that views time as Dimension -1 as being time-like rather than space-like. (In a black hole, of course, things are different.) Robert McClenon (talk) 17:10, 4 August 2014 (UTC)

• Doesn't gravitational lensing count as a directly visible spatially fourth-dimensional phenomenon?

• Is there any possibility of "exposure" being a dimension in itself?

For example, hubble deep field images. We have the telescopic power to look immense distances to recognize extremely distant galaxies; but only with the factor of exposure. IIRC the eXtreme Deep Field took upwards of 20 hours of exposure. The way i see it; real 3D points are static even with regard to changing an outside viewing angle of their 3D graph, and only with movement do they become "4D", which would fully envelope our universal existence and the way we perceive motion in our evermoving universe. But although those distant galactic sources of light are always sending their light to us at a relatively constant rate, it takes an extra dimension of recorded time in "exposure" to actually view them. Imagine light photons on the Edge surface of a wheel, and this wheel will roll along the the line-of-sight from the focal point (xtreme deep field), to our point of observation (hubble). We normally cant see the distant galactic objects (imagined by the edge surface of the wheel not intersecting our point of observation), but if we set exposure, it allows that wheel to "roll" towards us and eventually the edge will intersect our point of observation, to which after having recorded for 20 hours we now get a visible image. Something we cannot experience "right now", but can experience over a length of time. Fbushnik (talk) 19:41, 4 August 2014 (UTC)

Effects of faking muteness

I recently saw a Chinese TV series where one particular character had faked being mute at the request of her mother. This charade lasted for several years until she saw an urgent situation involving a couple of other characters and suddenly spoke again (and the words came out flawlessly), much to the surprise of the other two characters that were with her. I wonder how realistic this scenario would be in real life: if someone actually faked being mute for years and the suddenly decided to start speaking again, wouldn't that person initially have trouble speaking coherently and thus require therapy/training in order to regain his/her formerly coherent speech? 69.120.134.125 (talk) 03:26, 4 August 2014 (UTC)

I wouldn't think so, since they would still be thinking the words all that time, perhaps even forming them with the mouth but not sounding them. This would keep them in practice. StuRat (talk) 05:23, 4 August 2014 (UTC)

There are cases of people being genuinely mute or voluntarily choosing not to speak for decades and suddenly being able to speak again...it does seem to be something you don't forget. SteveBaker (talk) 14:50, 4 August 2014 (UTC)

One famous example is Maya Angelou, who was mute for five years as a child. Ghmyrtle (talk) 16:25, 4 August 2014 (UTC)

Yes I was also wondering about those who took a long term vow of silence although they're generally much older. However I didn't find anything about what it's like when they speak again. Nil Einne (talk) 18:39, 4 August 2014 (UTC)

Selective mutism. --TammyMoet (talk) 18:09, 4 August 2014 (UTC)

I don't know if that's particularly relevant. (Selective mutism could cause problems like [6]) but if the person is still speaking then it probably won't have the same effect on their ability to speak as someone who never speaks, presuming there is an effect.)

Although it could be. One thing that isn't clear from the OP's post is whether the person was truly mute. It seems easily possible they spoke to their mother when alone, perhaps when she gave permission. Or alternatively secretly to a friend or even to herself. There are also other factors that may come in to play, e.g. what age was she when she stopped speaking and what was her level of speech? Of course, may be the story didn't go in to such details.

Nil Einne (talk) 18:39, 4 August 2014 (UTC)

Can a person get Ebola if they have sex

Can a human being contract Ebola if they have sex with someone with the Ebola virus? If so, should the person be wearing a condom to protect themselves? 202.177.218.59 (talk) 03:51, 4 August 2014 (UTC)

Actually, I think this is one case where a gendered pronoun might work better than singular they. :) Though I might still take some flack from trannies for being politically incorrect. :) Wnt (talk) 20:12, 4 August 2014 (UTC)

(I'll assume that this is a hypothetical question, rather than a request for medical advice) If you know your partner has Ebola, you shouldn't be getting that close anyway. It is usually transmitted through "direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people" [7] While a condom might provide some protection, it certainly wouldn't be enough to make it safe. Abstinence in such circumstances would seem sensible... AndyTheGrump (talk) 04:06, 4 August 2014 (UTC)

I rather doubt that anyone suffering from Ebola would be in any condition to engage in sexual activity. Roger (Dodger67) (talk) 07:15, 4 August 2014 (UTC)

Apparently, there's a week or so at the start where you're not a "sufferer" yet. Looking normal and feeling normal leads to normal sex. InedibleHulk (talk) 08:12, August 4, 2014 (UTC)

I've just been reading an article based on the diary of a doctor working with the World Health Organisation in Africa at the heart of the ebola outbreak. For reference it's here but you need a subscription to read it all. He says that ebola has a 21 day incubation period when people are infected but symptom free and that the virus has been isolated from almost every body fluid including sweat, semen, blood, urine, oral secretions and tears. Doctors and nurses caring for the patients wear full body protection, like space suits, and yet a number of them have contracted the disease and died. A condom would provide little protection in this situation as you would still be exposed to bodily fluids other than semen. Richerman (talk) 18:04, 4 August 2014 (UTC)

While I don't disagree that a condom is unlikely to do much, how infectious are people during the period they are symptom free, particularly the early part? While I'm not sure if anyone knows for sure, it seems easily possible many of the infections of medical workers are coming from caring for patients with symptoms rather than patients who are currently symptom free. Particularly in the early stage of infection (amongst other things, it seems unlikely many of these are patients, actually I think that's a big part of the problem). Nil Einne (talk)

Many of the media reports have been reassuring us that people aren't infectious until they show symptoms. Then again, these are the same media reports that reassured us that Ebola could only spread through backward African customs of washing the dead and so Americans in Liberia would be at no risk of catching it. So I tend to think somebody is trying to quell panic, and might be making broader generalizations than what is known of the biology of the virus can really support. On the other extreme there's Richard Preston in The Hot Zone claiming that Ebola Reston passaged in a few generations to become a sort of "Ebola flu" being passed through ventilation shafts from room to room. The virus is new to humans, still getting accustomed to its new surroundings, so I wouldn't hastily rule out such a thing, but it still is a pretty extraordinary claim. Bottom line: when the virus is ready, it will let us know... Wnt (talk) 20:09, 4 August 2014 (UTC)

Sounds unlikely as symptomless carriers like bats transfer the virus just fine. Viruses that kill too quickly before patient death don't last long. The most lethal viruses are transferrable for a long period when the host is alive. --DHeyward (talk) 12:09, 5 August 2014 (UTC)

Men who have recovered from the disease can still transmit the virus through their semen for up to 7 weeks after recovery from illness. Count Iblis (talk) 21:22, 4 August 2014 (UTC)

Exercise and immune system

In what ways does exercise help the immune system? And does this include all exercise? (Cardio, muscle strength training, walking etc) — Preceding unsigned comment added by 82.132.216.37 (talk) 13:11, 4 August 2014 (UTC)

Here is a quick overview from the National Institutes of Health, a U.S. Government agency. It's got references too, if you want to follow up for more details. --Jayron32 23:43, 4 August 2014 (UTC)

Objects hitting the Moon?

I don't know if this has already been addressed, but what about the claims of objects hitting the Moon in this video? Bubba73 ^{You talkin' to me?} 19:59, 4 August 2014 (UTC)

I'm not going to watch that whole video, but things hit the moon quite frequently. It has a minimal atmosphere so nothing "burns up" as it does in the earth; any time we have a meteor shower on earth, all those streaks you see are little rocks that, on the moon, strike the ground. See Moon#Impact_craters. Here is a page at NASA.com discussing a 2006 impact on the moon which was watched from Earth; it discusses lunar impacts in some detail as well. --Jayron32 20:35, 4 August 2014 (UTC)

I didn't watch the whole thing, because 19 minutes is way too long to spend watching a UFO conspiracy theorist's video. But at one point of the skipping around that I did, it looked like the guy was being amazed by what to me just looked like some compression artifacts. Red Act (talk) 20:51, 4 August 2014 (UTC)

I didn't watch the whole thing, but about 8 minutes in he shows what he is talking about. In two of them I could see a dark streak going across. I didn't see the crater he was talking about. Could the dark streak be a compression artifact? Bubba73 ^{You talkin' to me?} 21:47, 4 August 2014 (UTC)

Yes. It looks to me like a meteor or some other object passed in between the telescope and the moon, without touching the moon. Some of the pixels in the image along the line where the object passes aren't the same color after the object passes over as they were before the object passes over, and the guy interprets that as indicating an object skipping across the moon, leaving craters in its wake. My presumption is that those changed pixels are compression artifacts. When a video is compressed, most of the frames of the video aren't compressed completely independently of other frames, because that would be too inefficient. Instead, only infrequent I-frames are encoded completely independently of previous frames. All other frames are either P-frames, which are encoded in terms of data from past frames, or B-frames, which are encoded in terms of data in both past and future frames. The result of that inter-frame data dependence can result in a tiny object flying across the image leaving some "ghost" pixels behind it where the object's image used to be in recent frames. Red Act (talk) 22:57, 4 August 2014 (UTC).

It's tough to know what's a compression artifact - or some consequence of amateur "enhancement" tricks that actually make exciting images from nothing at all. Before anyone should give an opinion here, we need to see the most original image available. The narrator says "the only change made is adding that reference marker"...yeah - but to add that marker, they had to decompress the video images and then recompress them again. These compress/decompress cycles are "lossy" - so ANYTHING you do to an image with lossy encoding and decoding can obliterate valuable evidence and introduce spurious artifacts - and that's more than enough to create all kinds of junk in the picture.

For a rock to be visible at that scale, it would either have to be VERY close to the camera (ie, not hitting the moon) - or absolutely freaking ungodly huge...in which case we'd have heard about it because anything the size of a large mountain entering inside the moon's orbit would be a major event.

Back in 2009, I showed how this kind of thing happens. I start with a screenshot of the Wikipedia science reference desk (what could be more innocuous?!). I look at a single period ("." character) from that page, I convert between file formats, zoom in, do "enhancement" and wind up with a clear picture of an alien city, hiding inside that period! Here are the stages...

Here is another example where I grab a picture of the moon and "enhance" it to reveal clear signs of an alien rocket attack!

Bottom line, "enhancement" tools are dangerous weapons in the hands of the idiots. SteveBaker (talk) 23:13, 4 August 2014 (UTC)

And you didn't point out the "force fields" around Earth and Moon. With that amount of geometic regularity, they HAVE to be of alien origin! OTOH, the lines look "genuine" but I'd blame scratches or smears on the window rather than missiles.

Introducing said JPEG/MPEG artifacts before enhancement is the high-tech equivalent of rounding intermediate results. That's one of the reasons why popular video formats are not used in scientific imaging: they tend to have a very low data rate but discard useful information. In essence, they try to discard "information the human eye isn't likely to see anyway", while image enhancement can be defined as "enhancing information the human eye isn't likely to see anyway"! It's not hard to see what happens if one compresses and then enhances what's left of the origial data. - ¡Ouch! (^{hurt me} / _{more pain}) 07:20, 5 August 2014 (UTC)

Actually, rather than a meteor, my bet is that the object going across the image is a satellite. Comparing the field of view of the image to a full picture of the moon, it looks like the object is travelling at an angular velocity relative to the Earth such that it subtends the same angle that the moon's diameter does in about 8 seconds. The angular diameter of the moon as seen from the Earth is about 30 arcminutes, so an object in Earth orbit would have that angular velocity if its orbital period is about 96 minutes. Given that 96 minutes is in the range of orbital periods that satellites in low Earth orbit have (88-127 minutes), and given that the large majority of satellites out there are in low Earth orbit, it seems like it'd be too much of a coincidentally correct speed for the object to not be a satellite. If someone wanted to, it should be possible to take the time of the observation and the latitude and longitude of the telescope, and figure out exactly which satellite would be appearing to cross the moon at that time from that location.

Although I have a theoretical interest in astronomy, I'm not a star-gazer at all, so I don't know if typical satellites are as easily visible as in that video (although I'm guessing not). If not, then I'm thinking the observed object was the ISS, which is an unusually visible object among the objects in low Earth orbit. The orbital period of the ISS is 92.88 minutes, which is very close to the 96 minute orbital period that I came up with as an approximation. Red Act (talk) 02:04, 5 August 2014 (UTC)

I am a star gazer and while the ISS is especially bright, there are other many satellites which are also very bright, Some can be even brighter when the angle is right. Vespine (talk) 03:39, 5 August 2014 (UTC)

I am a former star gazer, and in my experience they wouldn't even have to be visible to the naked eye. It's not uncommon while looking at a telescopic view of something to see, in a 20 minute period, 2 or 3 satellites that (by comparison to the stars in the field) must be well under magnitude 6. {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 13:23, 5 August 2014 (UTC)

August 5

Quantum vacuum plasma thruster

There has been some discussion of the quantum vacuum plasma thruster, where it was reported at a NASA conference that it worked - producing thrust without propellant. However, according to the article it is not a reactionless drive because it acts against virtual particles in the vacuum. So.... virtual particles are short-lived "errors in bookkeeping", not a permanent receptacle for energy or momentum, right? So far as I know, anything that can be written as virtual particles can be written as some other exercise in uncertainty, can't it? So my assumption is that the energy and momentum of the photon somehow manages to pass out of the chamber, but ... it still has to end up as a photon on the far end, doesn't it? Which gets to the basic hard fact I don't know, namely how much energy it takes to get how much thrust with a QVPT, and whether that is any better than simply powering a laser and relying on the light pressure. That little NASA blurb I saw doesn't give the power used. On the other hand, I suppose a virtual antiparticle could, in concept, go out through the chamber, find a real matter particle to annihilate with somewhere... it'd be like the transactional interpretation with the advanced wave from the outer air or whatever pushing on matter in the chamber. Temporal mechanics... But then again, I don't understand what kind of virtual vacuum particle can make it through a resonant microwave chamber. If the virtual particles stay trapped in the chamber until they self annihilate how can they carry away any momentum?

I know, this concept is probably bogus and my stream of consciousness is running particularly muddy today... throw me a clue? Thanks. :) Wnt (talk) 01:30, 5 August 2014 (UTC)

My impression is that regardless of what the article says, a QVPT would violate the conservation of momentum, and as such is just as complete and utter nonsense as the perpetual motion devices that are intended to violate the conservation of energy. I made an edit to the article last Thursday. The version of the article right before I made that edit[8] was so badly biased that there wasn't a single sentence in it that would detract a reader from getting the impression that a QVPT is based on unquestioned physical theory, that's now been experimentally verified, and we just need to wait a couple years for the technology to be scaled up and start being used in spacecraft. I tried to help move the article at least a little closer to giving a balanced perspective, and I see that William M. Connolley has also made a half dozen edits today to try to help push the article toward a more balanced perspective, but it's still rather badly biased. For an article on basically the same exact thing that isn't quite as biased, see EmDrive. Red Act (talk) 02:54, 5 August 2014 (UTC)

A few comments:

1. Foremost, I have a pdf copy of the paper, anyone can feel free to contact me via the 'email me' link on my user page and I will send it off. I know a lot of us don't have access to it, and this will surely aid in discussion.
2. Said paper clearly states in the abstract "This paper will not address the physics of the quantum vacuum plasma thruster (QVPT), but instead will describe the recent test campaign."(bolding is mine) -- so even the authors are not confident enough in their understanding of the physical mechanisms at play to attempt to publish an explanation at present.
3. As for light pressure, the calculations I've seen seem to indicate that this small force is indeed greater than would be accomplished through using photovoltaic panels to power lasers on satellites. Turn it around: if solar powered lasers were a good way to accomplish positional thrusters on satellites, wouldn't we be doing that already? I won't link to the source because it's not reliable, but there are extended discussions of this work on metafilter and reddit that you might want to peruse.
4. Many people seem to think this must be observational error, because thrust was also recorded on the 'null test' engine, which was not thought to provide thrust. However, the true control was an RF load with no mechanism, and there was a true zero thrust for that test. I've pasted a key table of results below, if anyone wants to prettify it I'm sure it would be appreciated.
5. (Many of the key figures are screen grabs and I am personally disappointed that none of the authors could be bothered to put out a nice vector graphic to illustrate the potentially valuable findings.)
6. some people say it would violate conservation of momentum, but it's not quite so clear to me that that must be the case. I imagine there's all kinds of physics of virtual particles and different relativistic frames that might explain the apparent paradox. (These are mentioned and referenced in the Emdrive article.)
7. This paper is a record of conference proceedings I am not a physicist, but in most of the sciences that I am aware of, this kind of thing goes through minimal if any peer review, compared to a 'real' journal article.
8. I don't think anyone is really an expert on this stuff yet, so most of us will have to be content to wait for a bit and see what shakes out...

Table of results
Configuration Test Article Thrust Direction Thrust Range (μN) Mean Thrust (μN) Number of Test Runs 1A Slotted Forward 31.7 – 45.3 40.0 5 1B Slotted Reverse 48.5 48.5 1 2A Unslotted Forward 35.3 – 50.1 40.7 4 2B Unslotted Reverse 22.5 22.5 1 RF Load 50Ω Load N/A 0.0 0.0 2

So, no real answers, but interesting stuff! SemanticMantis (talk) 03:08, 5 August 2014 (UTC) (ETA: table now displays properly)

My understanding of this thing is that it's just a photon drive which has been known to work (but produce pitiful thrust) for a long time now. 1 ScienceApe (talk) 04:51, 5 August 2014 (UTC)

No, photon-based systems are different. Instead, White believes he's going to get thrust by pushing quantum vacuum fluctuations. In White's words, "How does a Q-thruster work? A Q-thruster uses the same principles and equations of motion that a conventional plasma thruster would use, namely Magnetohydrodynamics (MHD), to predict propellant behavior. The virtual plasma is exposed to a crossed E and B-field which induces a plasma drift of the entire plasma in the ExB direction which is orthogonal to the applied fields. The difference arises in the fact that a Q-thruster uses quantum vacuum fluctuations as the fuel source eliminating the need to carry propellant."[9] Red Act (talk) 06:57, 5 August 2014 (UTC)

I think they still consume energy. Wouldn't that make it similar to an engine that expels massless photons but different from a plasma drive that expels mass particles? The measure of newtons per kilowatt leads me to believe they are creating a nonrecoverable energy outflow that would look similar to photon propulsion. --DHeyward (talk) 08:17, 5 August 2014 (UTC)

No, it's different. Although a photon has a zero rest mass and hence according to Newtonian mechanics it should have zero momentum, relativistically it does carry a tiny bit of momentum; see Photon#Physical properties. So a spacecraft accelerating itself forward a bit by emitting a laser beam out the back is still obeying conservation of momentum. But a spacecraft that somehow pushes on quantum fluctuations isn't leaving a beam of particles behind it carrying momentum in the opposite direction (virtual particles don't exist for macroscopic periods of time), so if the spacecraft is accelerating, momentum isn't being conserved. Quantum fluctuations can indeed carry momentum, as per the uncertainty principle, but only for very short distances (momentum and position are conjugate variables). A vacuum containing no (nonvirtual) particles or macroscopic fields doesn't carry any momentum macroscopically. Red Act (talk) 11:07, 5 August 2014 (UTC)

So where is the energy they express in N/kW going? --DHeyward (talk) 11:40, 5 August 2014 (UTC)

The energy they put into the test device during the testing process got turned into heat.

Here is a critique of the experiment, that was posted by John Baez, a somewhat famous physicist and mathematician. To me, the most damning thing about the experimental results is that the device that was designed to be similar to the "working" device, but was specifically designed not to work, produced just as much measured thrust as the device that was intended to work. If the "working" device doesn't produce any more force than the "dummy" device that just exists for the express purpose of measuring how much measured force you get from just experimental error, then what should be the obvious conclusion is that the "working" device doesn't produce any force at all that can't be attributed to experimental error.

Here is another post by John Baez, which talks about how the "quantum vacuum virtual plasma" that's the crucial ingredient that enables the device to function, isn't even something that actually exists![10] Quantum vacuum fluctuations exist, but they don't form a plasma, so you can't push them like you can push a plasma. Red Act (talk) 14:50, 5 August 2014 (UTC)

I'm not going to debate the physics, and I too remain very skeptical of this device. Still, your "most damning thing" does not make sense to me. The paper discusses two control-type items. The fact that the 'unslotted' engine still produced thrust doesn't necessarily mean that the measurement was experimental error. Logically, it could also be the case that they simply didn't understand the function well enough to disable it. To my reading they just removed one piece. refrained from carving out slots at the end of the gizmo. The much better control item, the real null test, is referred to as "RF load" which did indeed come out to zero thrust with their measurement system. It is possible that something went wrong in the measurements between the RF load tests and the 'unslotted' tests, but the fact that the RF load came out to zero does give some evidence against measurement error. SemanticMantis (talk) 15:21, 5 August 2014 (UTC)

Indeed, the more damning thing would appear to be Baez's second point, that while they conducted the experiment in a vacuum chamber with the door closed, they left it at ambient atmospheric pressure because their RF amplifier contained electrolytic capacitors which can't withstand a vacuum. -- ToE 23:12, 5 August 2014 (UTC)

This is certainly outside my training, but I've done some study in the history of science in the 18th and 19th century. When some surprising effect has come up in science in the last couple of centuries (and failure to conserve momentum is certainly "surprising," just like the recent "faster than light particles" which were debunked) even before someone finds a good mathematical and theoretical basis for it, good researchers will try not just to duplicate the effect but to actually eliminate it by controlling for possible confounds or measurement errors. Faraday was well known to find some small surprising electromagnetic effect, and then to work diligently until he was able to eliminate it by controlling some minor flaw in the (then very crude but ingenious) equipment. It is encouraging that he effect was replicated to some extent in a NASA lab and not just at the lab of the first discoverers, or even at the lab in China. A robust effect should show up when tested with apparatus built by different parties and used in a different lab by different researchers, One looks for control experiments to work, so that the effect is there when it should be and gone in a well selected control experiment, but apparently it did not go away in the control experiment. Extremely sensitive apparatus was used to measure the thrust; how far is the thrust above the limit of detectabiity or the noise level of the instrument? Were the NASA researchers "true believers" or skeptics? Edison (talk) 18:23, 5 August 2014 (UTC)

I appreciate your comments, but this experiment was well controlled. Twice now I've posted above about how there were two different types of "control" tests reported on. The simplest control with no mechanism was measured as providing zero thrust. The apparatus used was a "Scientech SA 210 precision weighing balance (resolution to one micronewton)." The highest thrust recorded was 48.5 micronewtons. The "zero" thrust should I suppose be reported as "0+/- 0.5 micronewtons". The table above now displays properly, and has all the results. SemanticMantis (talk)

Tey pump 28 watts into a metal enclosure in a test chamber, it heats up, there are certainly convection currents, and they get a resulting unexplained force of micronewtons, like the weight of a few milligrams? If they'd put a propellor over it it would have spun from the convection currents. It could be rising like a hot air balloon, or from the air streaming around it due to convective heating. They need to do the high vacuum testing and report back. Edison (talk) 23:49, 5 August 2014 (UTC)

Cooking with car exhaust

Let's say you hook up your exhaust pipe on your car to a contraption that allows you to heat up food. Would the contaminants in the car exhaust, also contaminate your food and make it unfit for consumption? ScienceApe (talk) 04:47, 5 August 2014 (UTC)

Not if the system is well designed. The thermal conductivity of a metal barrier is high, but the mass diffusivity is low; see the mention of metals in Permeation#Description.

Similar to your idea, in the "Food fables" episode of Mythbusters they cooked a Thanksgiving dinner using the heat produced by a car engine. However, they placed the food within the engine compartment, instead of using a contraption attached to the exhaust system. Red Act (talk) 05:29, 5 August 2014 (UTC)

Top Gear did that years before Mythbusters. 131.251.254.110 (talk) 12:14, 5 August 2014 (UTC)

Manifold Destiny beat them by a decade or so. See, we used to read these things called "books" printed on some sort of tree product before the interwebs were as popular... DMacks (talk) 15:29, 5 August 2014 (UTC)

During World War 2 and other conflicts, didn't the troops sometimes cook their rations by placing them atop a tank's engine compartment? 24.5.122.13 (talk) 05:50, 5 August 2014 (UTC)

You just wrap it in aluminium foil - see: Engine Cooking and How to cook food on you car engine. Richerman (talk) 06:42, 5 August 2014 (UTC)

Ah, there's nothing quite like the taste of incomplete-combustion-smoked barbecue. ←Baseball Bugs ^{What's up, Doc?} carrots→ 08:15, 5 August 2014 (UTC)

In the 1980s I spent a lot of time touring Australia on motorbikes, and I met a bloke on the side of the road, who had a little water boiler, which slipped over the header pipes. It held just enough water to make a cup of coffee and was a lot more convenient than getting the Primus stove out. My grandfather once told me when the family were out picnicking on the motorbikes in the 1950s, he used to put the teapot on one of the cylinders of his flat-twin to keep it warm. I never quite believed him... --TrogWoolley (talk) 12:42, 5 August 2014 (UTC)

It's a common way to cook in cold, snowy climates. Wrap it in foil, tuck it into your snowmobile's exhaust headers, and when you get to where you're going, the food is done. Justin15w (talk) 15:16, 5 August 2014 (UTC)

If you shove something in an exhaust pipe, it will clog it, and result in carbon monoxide spilling into the passenger compartment, killing everyone inside. Not a very good way to cook stuff. 108.170.113.22 (talk) 16:11, 5 August 2014 (UTC)

Only if it can withstand the pressure of the engine exhaust stroke and the exhaust system itself is weak/leaky.[11] DMacks (talk) 16:18, 5 August 2014 (UTC)

The main thing here is to separate the food from the actual exhaust fumes...foil should suffice for that. The temperatures you'll get would be higher up by the engine's exhaust manifold - and I think that's where most engine cooking is done. I've known a few real experts at it - and they use the water outlet to get temperatures around 100 degC and the exhaust manifold for higher temps. I've had eggs boiled in the top of the radiator too. I'm told that it's possible to fry bacon on disk brakes after a long downhill section...but that seems like an "advanced" technique! SteveBaker (talk) 19:50, 5 August 2014 (UTC)

• It's curious whether science ape is still alive? (Not so much that I actually want an answer.) μηδείς (talk) 22:32, 5 August 2014 (UTC)

Energy and momentum of refracted light

A ray of light passes into a container with a high refractive index containing fluid with the same high refractive index. Presumably, energy and momentum is transferred to the container before an opaque object inside is struck with the light pressure. But what's really going to bake your noodle is what happens if the light is emitted rather than absorbed by the object along this path. Wnt (talk) 16:31, 5 August 2014 (UTC)

This is actually based on the question about quantum vacuum plasma thrusters above, but here let's stick to known physics of plain old refraction. As I understand it, light travels both more slowly and in a different direction when it enters an object with a high refractive index. I assume this means that it has both a different momentum, and different energy. Otherwise, for example, an object in the water struck by a photon would be propelled according to the original heading of the photon before it was refracted, and therefore not directly opposite to the photon at the point of impact!

• What is the momentum and energy of a refracted photon?

• Is the momentum delivered at the surface of a refracting object parallel perpendicular to the surface?

• What is the momentum delivered to, precisely? In terms of which particle?

• Now suppose light is produced within the high refractive index material, speeding up to full c when it reaches the surface and changing direction. Does it extract energy and momentum from the boundary of the material?

• Does the ratio of momentum / energy vary depending on the refractive index of the material in which the light is produced?

• Does this allow for a potential interpretation that the quantum vacuum plasma thruster is equivalent to siting your microwave emitter within material of some unusual refractive index, and if so what? Wnt (talk) 16:31, 5 August 2014 (UTC)

Refraction is a special case of conservation of momentum. Snell's law is a special case of refraction. Deriving Snell's law from conservation of momentum is a common homework problem in an advanced physics class. The math is on our article, and it's really easy algebra ... but suffice to say, if you're not already pretty quick with the mathematical physics, then "it's going to take a while to explain..." Do you want help tracking down reference material on this topic? Nimur (talk) 18:26, 5 August 2014 (UTC)

Ach! You're right... somehow I misremembered and had the arrow pointing 90 degrees off here. The momentum is indeed conserved in the directions parallel to the surface. But surely the slower-moving light doesn't retain its full momentum in the perpendicular direction? And... oh phooey, I'm trying to recall how it can be that light can keep its full transverse momentum, yet be moving both more slowly and at less of an angle relative to the surface while doing so. Wnt (talk) 19:03, 5 August 2014 (UTC)

Oh, are you kidding me? I went searching to figure out how momentum was conserved, arriving at stackexchange which highlights the Abraham–Minkowski controversy, i.e. that there has actually been disagreement on what the momentum is in the dielectric medium. The rival forms were

• The Minkowski version: $p={\frac {nh\nu }{c}}$
• The Abraham version: $p={\frac {h\nu }{nc}}$

And... the article says that this has been proposed as the basis of a reactionless drive! So I may not remember half of the optics I learned in physics class, but maybe I'm on the right track anyway. :) It all comes down to a paper said to reconcile the differences: [12] Now maybe if I learn what a polariton is I can figure out if you can have virtual polaritons... :) Wnt (talk) 19:17, 5 August 2014 (UTC)

Lots of things have been "proposed as the basis of a reactionless drive". For example, you could put a strong guy in a sealed chamber and have him repeatedly punch one of the walls really hard. That idea has now been proposed at least once. That should be enough (evidently) to get funding from NASA for an experimental test. If I conduct the test on Earth instead of in deep space, and use a sufficiently imprecise accelerometer, I'm sure I'll detect some effect.

With that off my chest, I'll try to answer your refraction questions. Just considering the 1-dimensional case, you can handwavingly think of the slower speed in a medium as being due to the light being repeatedly absorbed by the medium and re-emitted after a delay. The absorption transfers momentum to the medium, giving it a kick forward, and the re-emission gives it an equal kick backward. The net effect is that the medium returns to its initial velocity, but in the mean time it moved somewhat in the direction of the light.

If you put a light source in the medium, it will be pushed backward when it emits the light, and the light will give an additional net backward kick to the medium as it leaves. This leaves you with light moving in one direction, and the light source and medium moving in the opposite direction, with equal and opposite momenta. This is not a reactionless drive but a photon rocket.

I don't think you can explain Snell's law in this handwavy particle picture, but I'm not sure it's relevant anyway. -- BenRG (talk) 20:20, 5 August 2014 (UTC)

Yawning pulling muscle

What is it called when you yawn really wide, and pull a muscle out of alignment in fleshy part of your jaw and it hurts tremendously until it becomes situated like it's supposed to be. Is that a hernia? 108.170.113.22 (talk) 16:43, 5 August 2014 (UTC)

That's a cramp. Here's a hernia. InedibleHulk (talk) 16:50, August 5, 2014 (UTC)

Also possibly a subluxation. InedibleHulk (talk) 16:56, August 5, 2014 (UTC)

It's also called yawning too hard and getting a cramp. μηδείς (talk) 22:29, 5 August 2014 (UTC)

Temporomandibular joint dysfunction may be an interesting read. --Jayron32 01:52, 6 August 2014 (UTC)

Lithops plant withering

I recently bought a Lithops plant which has just now become very withered (picture). Google turns up some conflicting advice on whether it requires more water or less. I should note that I live in Southern California, and we have recently had some extremely humid weather. So what should I do? 75.4.20.212 (talk) 17:29, 5 August 2014 (UTC)

(WP:OR ahead, my advice based on ~15 years experience, never lost a succulent) I wouldn't add water unless the dirt is bone dry, and it hadn't had water for a few weeks. Your specimen actually looks fine to me. Check the dirt by sticking a toothpick down in an inch or so, leave it for a minute, then check for any moisture. If you can detect any moisture, don't water yet. If it's very dry, just give it a small splash of water. If that's what it wanted, it should 'fill up' and lose some wrinkles within a day or two. But really, that plant can live off of a few drops of water a year. Generally, succulents are easier to kill by over watering than under watering. Even if badly dessicated, they can spring back once water is added. But, if water logged, they will completely die rather quickly. Make sense? SemanticMantis (talk) 18:38, 5 August 2014 (UTC)

The soil is actually a tiny bit damp near the surface, so I'll just monitor my plant and use the toothpick test. Thanks for the input. 75.4.20.212 (talk) 18:46, 5 August 2014 (UTC)