The best answers address the question directly, and back up facts with wikilinks and links to sources. Do not edit others' comments and do not give any medical or legal advice.
complete the description of hair by filling in the gaps.the missing words are provided below.
the hair that shows above the skin's surface is ........... it is composed mainly of ............ the same protein hat makes up the ...........
and .............. a hair is made up of 3 layers, the cuticle,the cortex,the medulla.
the ........... is the tough,outer protective layer of the hair.the cells are ............... .
they allow colour from beneath to show through.they form ............., which overlap towards the hair...............
the .............. is the main part of the hair , which contains the colour pigments ...............(brown/black) and ............(yellow/red).
the cells in the ...........contain bundels of ............... The ................,thickness and ......... of the hair is determined by the
way in which the ............ and ............ are held together. ................is formed in this layer. the ............... is the middle
............. of the hair . it is not always present and does not have a significant function.
cells keratin fibres core
dead cortex tip cuticle
pheomelanin scales medulla elasticity
translucent keratin nails melanin
fibres skin strength cortex — Preceding unsigned comment added by Payojana (talk • contribs) 00:42, 28 January 2012 (UTC)[reply]
Clearly hair is the place to start. To be technical, one thing in this exercise is not strictly correct - keratin is not a single protein, but a large family of proteins, and there are slightly different varieties present in each structure - indeed, in each layer of the skin the mix differs. An example of a specific keratin is keratin 14. Note also that type I keratins and type II keratins typically work together in each structure, with one of each type working together as a heterodimer. But it is true that there is a fundamental relationship between all the keratins, tracking back to some single precursor long ago in single celled organisms which evolved into many different specialized forms by duplication and divergence.[1] Also, I would personally prefer to say eumelanin rather than melanin at one point there - to me, pheomelanin is a form of melanin, rather than an alternative to it, and the article we have is written that way also. Wnt (talk) 00:22, 29 January 2012 (UTC)[reply]
General Relativity gives no way for that to happen. It's sort of like asking how a guitar would sound if its strings had folds, or how waves would propagate if the surface of a lake had folds. It really doesn't make sense. Looie496 (talk) 02:34, 28 January 2012 (UTC)[reply]
All that matters to general relativity is the "intrinsic curvature" of spacetime, which affects things like the ratio of a circle's circumference to its diameter. Folding spacetime, in the sense of folding a piece of paper in two, doesn't change the intrinsic curvature, so it's a no-op as far as general relativity is concerned. Pointy bits in the intrinsic curvature are possible, though, and are better known as gravitational singularities. -- BenRG (talk) 05:56, 28 January 2012 (UTC)[reply]
Yes, you can. A massless particle travelling at the speed of light is a source of a gravity shockwave. It is a rather curious construction, and you could say that it is a fold. As a very rough mental analogy, imagine a paper cylinder and think about an edge between the side and the top. The top and the side are flat everywhere (in the strict geometrical sense - they have zero intrinsic curvatures), the edge is unexceptional and there are no singularities, but the whole construct has unusual topology.--Itinerant1 (talk) 01:33, 29 January 2012 (UTC)[reply]
If "Solubility in Water" is 58.2% at 20 °C, what does that mean in practical terms?
Hi there.
I have Potassium Sorbate granules and I need it in liquid form as concentrated as posible.
According to Potassium_sorbate, its "Solubility in Water" is 58.2% at 20°C,
but I'm not sure what that means in practical terms?
(In other words, if I take 100g of Potassium Sorbate, what is the minimum amount of water I will need to dissolve it, and, therefore what strength Potassium Sorbate would that solution be?)
my guess is that it is g/100ml that is meant by the %. To make a saturated solution, why dont you just add a little water to some of the powder, warm, mix and let it stand. The liquid above it will b as satuarted as it can go after a few days of standing.Staticd (talk) 13:31, 28 January 2012 (UTC)[reply]
On a website about unusual Linnaean names I visited a few years back, there was a mention of two Japanese birds of the same genus whose common names in Japanese were mixed up when they were given scientific names. Something like the bird called yosenabe in Japanese was given the scientific name Nipponavis akamichi and the bird called akamichi in Japanese was given the scientific name Nipponavis yosenabe. I can no longer find this page, and searching for "japanese birds" and "mix up" has left me empty-handed. Does anyone know the names of the two bird species who got their names mixed up? Wiwaxia (talk) 17:17, 28 January 2012 (UTC)[reply]
Reminds me of Siebenrockiella leytensis from Palawan, which got mixed up with the more common Cyclemys dentata from Leyte en route from their respective collection sites. This caused the turtle to be classified as Critically Endangered and possibly extinct for years as the zoologists assessing its conservation status were looking for it in the wrong island.
Anyway, where did you get the names Nipponavis akamichi and Nipponavis yosenabe? Did you make those up? Should have put gen. nov., sp. nov. there to avoid them being red herrings. LOL -- Obsidi♠nSoul22:41, 28 January 2012 (UTC)[reply]
Yes, I made up Nipponavis (Japan bird), since I didn't remember the real genus name. akamichi and yosenabe were trying to recall the Japanese names (and I got the aka- part right). I admit I got yosenabe from this Japanese soup. Wiwaxia (talk) 09:35, 29 January 2012 (UTC)[reply]
January 29
Terminology question
Suppose you have a measurable quantity of some kind, such as 123 MWh of energy. This is the same as 123 thousand kWh. The "MWh" and "kWh" bits are called units, but what are the "123" and "123 thousand" bits called? JIP | Talk00:27, 29 January 2012 (UTC)[reply]
But isn't the whole thing called a quantity? I am asking specifically about the bit with the numbers. Changing that bit without also changing the unit would change the overall amount of energy. JIP | Talk01:02, 29 January 2012 (UTC)[reply]
Numerical value. From WP: "the value of a physical quantity q is expressed as the product of a numerical value Nq and a unit of measurement uq" 88.26.74.157 (talk) 01:08, 29 January 2012 (UTC)[reply]
Fitting them would be no problem, but training a horse to roller skate would be difficult, perhaps impossible. You might be able to do it, if you put them on the horse from birth (putting on larger ones as needed).StuRat (talk) 05:35, 29 January 2012 (UTC)[reply]
According to Inline speed skating, rollerblading a "metric mile" is about 50 percent faster than running it would be. Here's the problem, though: rollerblades complement the way humans run, which is on two feet combined with arm-swinging. Horses don't have arms to swing and help them keep their balance. The side-to-side thing would be totally unnatural for a horse. It might be interesting to try, though. ←Baseball BugsWhat's up, Doc?carrots→ 06:33, 29 January 2012 (UTC)[reply]
I googled [horse on roller skates], and a number of things came up, including this somewhat nondescript picture,[2] but I suggest you do some googling and see what you can find. The point being, it's been done. Whether it's faster than running, I couldn't say. But obviously it would have to be done on a paved surface. Roller blades don't usually do well on turf or earth. ←Baseball BugsWhat's up, Doc?carrots→ 06:37, 29 January 2012 (UTC)[reply]
LIFE magazine ends the magazine with a "Miscellanny" picture. The first "Miscellanny" picture was a horse on rollerskates, Jimmy, he appeared in the May 19, 1952 issue. But no-one cares about Jimmy anymore, because now we have Tarra. Even parrots try to imitate Tarra. After a lot of training some cockatoo's can rollerskate pretty quickly. Abused monkeys rollerskate too. If you torture a bear long enough he can skate on ice. I don't think fish rollerskate, they usually prefer skateboarding, just likedogs. Dogs like surfing too. This planet is pretty weird. Did you see this ass called Pinky? Search for "Pinky" on this page, maybe you can find video. Here are the newspaper 1 and newspaper 2. extra info. Pinky was probably painted pink. Von Restorff (talk) 07:22, 29 January 2012 (UTC)[reply]
My chief concern with trying that would be the risk of the horse breaking legs, which usually ends in the death of the horse. Falconusptc15:04, 29 January 2012 (UTC)[reply]
Jimmy! That rolls back memories. Here you can see him horsing around on skates -so to speak. It start just after 6 minutes in. I've Got A Secret - Easter Parade (2/3). It's not the horse but the panel of celebrities that appear to be worried about breaking a leg - their own.--Aspro (talk) 17:01, 29 January 2012 (UTC)[reply]
Anecdotes...
OK, I can't ignore this, too many bad memories...
Much like today's problems involving a spherical cow, when I was in high school Physics, it was guaranteed that on every Mechanics exam, there was one question which began, A horse on frictionless roller skates is moving at [N] m/s..."
It also seems that this piece of "Bumper sticker wisdom" applies: Never try to teach a pig to sing. It wastes your time, and annoys the pig.
My chemistry lab instructor would always point out that we shouldn't leave a beaker upside down in a rack to dry as water vapor (H2O at 2(1) + 16 = 18 g/mol) is lighter than air (roughly 80% N2 + 20% O2 at 0.80 (2) 14 + 0.2 (2) 16 = 0.8 * 28 + 0.2 * 32 = 28.8 g/mol). I always figured that there must be an optimum time to leave the beaker upside down so that as much liquid water as possible will drain out before inverting it to air dry the rest of the way; I doubt that such a time would be much more than a minute. The OP may also be interested in reading Density of air#Water vapor which explains why humid air is actually lighter than dryer air, a fact counterintuitive to many who feel hot, heavy air "weighing down on them", but an important fact for pilots as planes have less lift in less dense air and thus need longer takeoff rolls when it is hot, humid, or low pressure (either from weather or, more importantly, altitude). -- ToE14:50, 29 January 2012 (UTC)[reply]
That's a very good point, and explains why the layer of humid air containing the clouds will float. Of course, individual droplets of water that we see (i.e. clouds) are heavier than air, but they fall so slowly due to air resistance that they can't get to the ground - until they join up to be big enough, at which point the rain most assuredly comes down. Wnt (talk) 16:12, 29 January 2012 (UTC)[reply]
That reason for not inverting beakers seems a bit silly, as the natural tendency of water vapor to diffuse will greatly outweigh any density differences, at that scale. I would invert them, both to let water drain out, and to keep dust from settling inside. This is particularly important if they are to be used for biology cultures, as that dust will inevitably contain bacteria. (Of course, the beakers really should be sterilized better than that, and not be allowed to air dry at all, but in a school lab they may not have the expensive equipment to do it properly.) StuRat (talk) 18:18, 29 January 2012 (UTC)[reply]
The chemical term is suspension. (Or, if the water droplets are small enough, an aerosol.) Firstly, due to square-cube effects, as you decrease the size of the droplet, air resistance becomes proportionally much larger when compared to the force of gravity, meaning that small droplets fall slower than larger droplets. Cloud droplets are very small, and thus take much longer to settle out than rain droplets. Also, below a certain size, the random drift of the droplets due to brownian motion is larger in size than the slow settling due to gravity, effectively keeping them "permanently" suspended in still air. But again, air is rarely still, and clouds typically form when warm, moist air rises as a mass, and then cools enough to for the water to condense. This bulk rising also can serve to keep clouds afloat, or even cause them to rise further. -- 67.40.215.173 (talk) 20:08, 29 January 2012 (UTC)[reply]
It won't, actually -- if you tried to do that every day, you would find yourself suffering in the long run. But generally speaking, the relationship between sleep, time of day, light, and alertness is quite complex and far from completely understood. Our article on circadian rhythms contains some useful information, but I won't pretend that it fully answers the question. Looie496 (talk) 18:08, 29 January 2012 (UTC)[reply]
I knew a guy who stayed awake 7 days straight, and was fine after 8 hours of sleep. by constrast, I feel cruddy after sleeping a few hours each of several consecutive nights. Heck froze over (talk) 18:46, 29 January 2012 (UTC)[reply]
Note that they may have only appear to be fine, the long-term consequences of sleep deprivation are fairly well documented. StuRat (talk) 19:23, 29 January 2012 (UTC)[reply]
Feeling awake doesn't mean that you are indeed equally able to perform any task. Self-assessment of your cognitive abilities is tricky, since you are employing your own cognitive abilities, which could be impaired. Do not try to drive under such conditions, since your body could ask you for some microsleep. 88.26.74.157 (talk) 20:01, 29 January 2012 (UTC)[reply]
I work in a 24 hour a day business, and I can tell you that I have most certainly seen the negative effects of long term sleep deprivation with my own eyes. New night shift workers will often try to stay up during the day as well, either to hang out with friends or even to do another job. I've honestly seen people lose their minds doing this, they become extremely irritable and irrational and stop paying attention to details. I even had one guy come up to me several months after I fired him for such behavior and thank me for letting him go because he believed he was on the verge of psychosis caused by sleep deprivation. Beeblebrox (talk) 20:17, 29 January 2012 (UTC)[reply]
If you work out vigorously almost every day, like running fast for half an hour or longer, you will feel the difference between getting a proper amount of sleep at night or just napping for a few hours, already after a few times. Count Iblis (talk) 00:34, 30 January 2012 (UTC)[reply]
In the Incandescent light bulb one of the references says "Edison's research team was aware of the large negative temperature coefficient of resistance of possible lamp filament materials and worked extensively during the period 1878–1879 on devising an automatic regulator or ballast to stabilize current. It wasn't until 1879 that it was realized a self-limiting lamp could be built.". So how come the lamp is self-limiting?, and would the lamp life be extended if the lamp were current controlled? Electron9 (talk) 17:59, 29 January 2012 (UTC)[reply]
As the 'newer' bulb's 'tungsten' filament gets hotter so the resistance goes up (positive coefficient), with say silicon (transistors, glass bottles etc.) and carbon it goes down. This is a poor example on youtube but it was all I could find quickly. [3]. Early Wirelesses often used a bulb to regulate the current because the poor power regulation of mains electricity. Uranium is another element used to regulate current as its resistance go up when too much juice goes through it. The early carbon filaments had a negative coefficient -thus the need to regulate the current.--Aspro (talk) 18:31, 29 January 2012 (UTC)[reply]
This clip demonstrates the negative coefficient of glass which at room temperature is normally a pretty good insulator but heat it up and its resistance goes way down and so starts to absorb microwaves very well . [4]
Hey thanks! An instance of melted Pyrex in the microwave was one of the Great Mysteries - and this provides the explanation. Wnt (talk) 01:35, 30 January 2012 (UTC)[reply]
It wasn't a Great Mystery to the wife – she simply clouted me with a rolling pin. But your support is most welcome.--Aspro (talk) 22:27, 31 January 2012 (UTC) --Aspro (talk) 22:27, 31 January 2012 (UTC)[reply]
“completely' is maybe a bit of a euphemism. This clip is of a torpedo stick and the ship certainly rises some what.[5] A magazine explosion would be worse. Merchant ships carrying munitions have been reported to come out of the water when their cargo explodes but of the footage I can recall, the blast obliterates the ship making it impossible to tell. I would suggest that the bow and stern would blow fore and aft without leaving the water completely. The energy however, would be sufficient to raise it several miles if it was all applied evenly from beneath the keel.--Aspro (talk) 19:14, 29 January 2012 (UTC)[reply]
A Type 45 destroyer has a mass of about 8000 tonnes. Ignoring buoyancy and using the formula E=mgh, we find that it would take 78 Megajoules to lift it one metre. A tonne of TNT releases 4.2 Gigajoules, so could (if all the energy could somehow be used to lift it) lift the destroyer 54 metres. The Father of All Bombs, which is apparently the largest non-nuclear bomb, is equivalent to 44 tonnes of TNT. If you could get all of that energy to lift the ship, it would go 2.4 km (1.5 miles) into the air. Of course, you couldn't actually get all that energy to lift the ship, a lot of it would go down and sideways and a lot of it would go into destroying the ship rather than lifting it. If you really wanted to, you could probably get it to lift a metre of two clear of the water with a perfectly placed explosion. --Tango (talk) 22:52, 29 January 2012 (UTC)[reply]
Depends on the size of the nuke and how close. A Hiroshima-sized nuke could be defended against with little more than a conventional bomb shelter, even at ground zero (directly below the air burst). If you were sitting atop the Tsar Bomba when it was detonated, though, you should kiss your ass goodbye. StuRat (talk) 19:17, 29 January 2012 (UTC)[reply]
I am not sure that a conventional bomb shelter would defend you against being directly below a nuclear detonation. Even if the structure was not crushed by the overpressures (which is not impossible, depending on the construction), the heat and radiation would be extreme. You'd roast. Put another way: a suitable rugged structure, like the Hiroshima Genbaku Dome, might survive such a blast (that building benefited by being directly under the explosion, because the forces on it were primarily vertical, which preserved many of the walls). But nobody inside it would likely survive. You'd need really much more than your conventional bomb shelter to take a direct hit with an atomic bomb of almost any militarily significant size. Even direct hits from conventional bombs can destroy conventional bomb shelters. Fallout shelters were not about surviving direct hits — they were about surviving misses or the effects of bombs some distances off, or avoiding residual radiation. They were meant to save some lucky lives, not all lives. Many of them would have just served as kettles for their occupants, as was the case of shelters used in the firebombings of Dresden. --Mr.98 (talk) 22:23, 29 January 2012 (UTC)[reply]
You don't need to be far underground to be protected from heat and radiation. Air is another problem, though, as you wouldn't be able to get breathable air from above for some time. So, oxygen tanks would be needed, and water. You could likely be rescued before a lack of food would kill you. StuRat (talk) 03:48, 30 January 2012 (UTC)[reply]
It is not that theoretically hard when considering small tactical weapons. As Project Orion discovered, only a few millimetres of a strong shield gets to be eroded by the heat. Next problem: one needs sufficient 'mass' to resist the force to stop the occupants inside from being bounced around to a pulp. Nuclear bunkers are provided with very thick walls of hard zinc cement (like what your dentist uses – if you can afford visit one) reinforced with tungsten rods – all of which weighs many thousands of tons. On the inside, on the upper floors and ceilings, they often apply an epoxy composite layer, of about a foot in thickness. This both stops the concrete spalling off and hitting people, as well as absorbing any neutron radiation that gets through (and prevents some Bremsstrahlung being created as well perhaps). Of course, a poor man's equivalent, is to just use the closest Kelvinator or equivalent - as demonstrated in this clip by Mr. Jones. [6]Don't try this at home kiddies- they don't open from the inside. Hope this helps and are you asking because you’ve heard something on Fox news that we haven't?--Aspro (talk) 20:06, 29 January 2012 (UTC)[reply]
Most modern refrigerators do open from the inside, in that they are only held shut with a magnet, and can be pushed open from the inside easily. It's the old ones with latches that killed kids. StuRat (talk) 20:20, 29 January 2012 (UTC)[reply]
A lot of those fridges are still around in the world (they never brake down) and how is your magnet going to keep the door shut. It wouldn't even happen in the movies ;-) --Aspro (talk) 20:48, 29 January 2012 (UTC)[reply]
They are also angled so gravity holds the door shut, and the magnet doesn't have to do much, just keeps it from bouncing back open when closed (I've had some fridges with weak magnets that do bounce back open). Also, I'd put the brakes on that spelling of "break". :-) StuRat (talk) 22:02, 29 January 2012 (UTC)[reply]
There are three main effects from the atomic bomb: pressure, heat, and radiation. It's a lot of radiation we're talking about "right next" to the exploding bomb, so a few inches of lead ain't gonna do it. The heat is going to be extreme — millions of degrees celsius. The pressure is quite a lot. So one could imagine being in some sort of container that is going to be blasted into the distance — that's probably your best bet. But you'd still probably die from one thing or another. I think many of the posters above underestimate the amount of energy were talking about here. It's orders of magnitude more than what human beings are used to dealing with. Project Orion is paradoxically misleading on this front. If by "material" you mean, "an elaborately constructed giant spaceship that is designed to translate that energy into thrust," then sure. But that isn't "nuke-proof armor." It's a spaceship. The answer is more or less "no." You can imagine some setups where you could make some sort of container that might help with survival in that it would blast you out of the area once the bomb hit, but that would be pretty dang contrived, and require you to know a lot about the size and location of said bomb ahead of time to have any confidence in it working. In my opinion, the best nukeproof armor you could have would be the live children of whomever has the nukes! --Mr.98 (talk) 22:26, 29 January 2012 (UTC)[reply]
According to our Atomic bombings of Hiroshima and Nagasaki article; "Eizo Nomura (野村 英三, Nomura Eizō?) was the closest known survivor, who was in the basement of a reinforced concrete building (it remained as the Rest House after the war) only 170 m (560 ft) from ground zero (the hypocenter) at the time of the attack" (Hiroshima). He was in a concrete box though, rather than a suit of armour. Also nuclear weapons make a much bigger bang these days. Alansplodge (talk) 00:38, 30 January 2012 (UTC)[reply]
I agree, your best bet is to not try and resist the explosion but to let it throw you clear. You need a sealed sturdy container with something inside to cushion you (some springs, maybe?). --Tango (talk) 00:41, 30 January 2012 (UTC)[reply]
Suppose Tsar Bomba (50 Mton) etc.. is unlikely to be used. But if an B90 nuclear bomb with rating of 200 kton (836.8 TJ) would be used. What level of radioactive exposure in [Sv] (J/kg) will occour?, this essential to calculate any shield. And how much heat energy per area [J/m²] is radiated in order to calculate condensation energy for any wall?, pressure level?, let's assume the distance is 10 meters. Regarding an "blast driven shelter" one still needs to keep the body exposed to less than 50 G in order to not get crushed even with soft cushion. Electron9 (talk) 03:16, 30 January 2012 (UTC)[reply]
It would have help if the OP had given a specific measurable distance and yield. For instance, folks in Washington USA who say they where right next to Mount St. Helens when it blew, really mean they where living 30 miles away, a distance which in little o' Europe is often somewhere in another country where everyone speaks a different language. Yet, let's go though it in more detail. Heat: yes millions of degrees but what does that do ? Just flakes of a little of the outer surface. Its not the temperature that's important. People think that the tower of the Trinity test got vaporised – myth. The Project Orion team scoured the area and found most of it, their just wasn't enough calorific energy in the fireball to vaporize it! Pressure: A direct hit means about 30 psi of over-pressure at ground level. Enough to destroy most structures -which is why the high of burst is chosen to give this figure. It would be a piss poor bunker that could not withstand this and they are often designed to withstand a 1000 psi and more. OK that's air burst. What about ground bust. Well, with an air-burst, one has the advantage, that the shock wave hitting the ground gets reflected back and more or less doubles the over-pressure. With a ground bust however this effect (known as the Mach reflection region -speed of sound relative to temp , density, blah, blah) is much reduced. So you need a at the very lest a contact burst. Also, the concrete is exceedingly resilient. Much the same stuff was used for the WW2 military defences in Europe, they could withstand explosive shells (the pressure of which I forget get but it is something like 25 to 35 bar). Which is why one can still see so many structures in Europe – how can you blow them up without ripping all the roof tiles off the neighbouring houses and shattering the windows in the hamlets round about. Radiation: Just 2.4 inches of concrete halves the transmission of radiation. The thickness of bunker-walls gives nigh on complete protection over 3 months of occupation. Children: This requires attributing the same rationality into the minds of the enemy warlords as on might poses oneself. Did Magda Goebbels accept the offer to have her children passed over to the safety of the Red Cross? History is littered with the children of leaders being less important that the 'great plan'. Just in the last half century there are numerous example of despots refusing to accept the inevitable without regard to their kin.--Aspro (talk) 01:30, 30 January 2012 (UTC)[reply]
That depends on whether you're a high-value target (like a NORAD command facility) or just minding your own business, trying to avoid incidental nuking. It's widely believed that during the Cold War the Soviet Union had a number of ICBMs with very-high-yield warheads designed to incapacitate or destroy hardened U.S. facilities. (In the words of Tom Clancy, "to turn Cheyenne Mountain into Cheyenne Lake".) TenOfAllTrades(talk) 14:50, 30 January 2012 (UTC)[reply]
Remember Tom Clancy had a tendency to write a lot of fiction for his own monetary gain. Cheyenne Lake congers up a picture more in keeping with artistic licence, than anything else. --Aspro (talk) 16:32, 1 February 2012 (UTC)[reply]
Another consideration is that the force of the explosion is sufficient to evacuate the air from the region for a few seconds. The explosive force is followed by an implosive one as the air all rushes back into the space it just left. Combined with the heat and the radiation, the only way to survive the blast is with a self-contained bunker. — The Hand That Feeds You:Bite22:36, 31 January 2012 (UTC)[reply]
...as opposed to snacking continuously all day long (and assuming the same food is consumed either way, in the same quantities). And does the blood sugar spike after a meal actually have a purpose, like the blood pressure spikes during a heartbeat, or is it just a negative consequence of eating meals ? StuRat (talk) 20:15, 29 January 2012 (UTC)[reply]
Part of the reason would be social. For most of the time humans have eaten meals at "fixed" times, it's been with other people. It would be a time for doing many of those things that humans do when they gather in groups, especially involving talking to each other. HiLo48 (talk) 21:38, 29 January 2012 (UTC)[reply]
I've read that in young children, continuous snacking can inhibit the onset of socialism (it is typically hard to learn to socialise with a breadstick in one's mouth), increase the likelihood of choking (because a toddler who is playing might forget that he's also eating), and increase the likelihood of tooth decay (because the toddler has food continuously in her/his mouth for a longer period of time), but I have no information about effects of continuous snacking in anyone else. :S Whoop whoop pull upBitching Betty | Averted crashes21:44, 29 January 2012 (UTC)[reply]
I think you meant "socialization" rather than "socialism", unless you were being funny. :) But I think the answers given here are correct - that a few meals a day, as opposed to a "continuous meal", fits better with agrarian and industrial societies, as compared with hunter-gatherer societies. ←Baseball BugsWhat's up, Doc?carrots→ 23:46, 29 January 2012 (UTC)[reply]
The main benefit from eating fixed meals is that is works well with a sedentary agricultural lifestyle. I'm not sure there's much more supporting it than that (other than habit and culture at this point). Before agriculture — at least, this is my understanding — humans fed more or less continuously through the day. Agriculture and division of labor means you can't do that as easily. --Mr.98 (talk) 22:33, 29 January 2012 (UTC)[reply]
Primates including primitive peoples often eat as they come across food. The only reasons that springs to my mind for three-square-meals-a-day is that it is more convenient for a diet of cooked food, it also allows time to work on other activities, as found in non nomadic societies. The blood sugar spike -if its too high- is not good, but this is less pronounced on say a Paleolithic diet. The spike just means that that sugar is being absorbed by the guts faster that the body can convert it. It serves no purpose, other that to provide pharmaceutical companies with a steady supply new patients to buy their type 2 diabetes treatment products.--Aspro (talk) 22:40, 29 January 2012 (UTC)[reply]
I was fascinated by this research; "In a first-of-its-kind study, Harvard researchers have shown that cooked meat provides more energy than raw meat, a finding that challenges the current food labeling system and suggests humans are evolutionarily adapted to take advantage of the benefits of cooking." The researchers present a hypothesis suggesting that the extra calories provided by cooked food may have allowed developmental changes to early humans 1.9 million years ago. Obviously, if you have to cook food on a fire, it makes sense to do a whole lot together and then sit down with your family and eat it (ie "a meal"). Anyone who has tried cooking food from scratch on a campfire will know that it's a lengthy process. The ability to open a packet of pre-prepared food and bung it in the microwave is a recent luxury. Alansplodge (talk) 00:26, 30 January 2012 (UTC)[reply]
That claim depends on two big and very shaky assumptions: one, that people ate meat in significant quantities 1.9 million years ago; two, that they had enough control over fire to cook that meat. Both of these would, I think, be considered extreme fringe theories in anthropology. There is no evidence of cooking beyond 300 or 400 thousand years before present. There's very little evidence of systematic big-game hunting, and essentially no evidence of serious hunting weapons like bows or throwing spears, before ~100 thousand years BP. By 100 kya, humans had modern-size brains and were in many ways similar to us (there are tribes in Africa whose ancestors split from the rest of the human phylogenetic tree 140 kya ago).
Hunting and cooking certainly played an important role in colonization of Northern Europe and Siberia, but they haven't been with us as long as the authors of that article claim.--Itinerant1 (talk) 07:09, 30 January 2012 (UTC)[reply]
Some of the evidence presented at Control of fire by early humans sounds like more than fringe theories. For some reason, most scientists seem to be dead-set on presenting ancestors' abilities (whether cultural or evolutionary landmarks) as limited only to what has been conclusively proven, even though this by necessity consistently underestimates them. I think you can only read so many silly stories about how the eye is so easy to evolve, so must it evolved independently late in the development of many different lineages, before you just get tired of it. Wnt (talk) 21:26, 30 January 2012 (UTC)[reply]
A lot of the evidence beyond "what has been conclusively proven" is sensation-seeking findings which can be interpreted in many different ways (and the correct way is usually mundane). For example, it has been "conclusively proven" and there are numerous pieces of evidence that humans first made it to the Americas ~13kya. It would be huge to prove that humans were there earlier. Therefore, from time to time some scientist announces a revolutionary discovery of an excavation site with some funny-looking rocks next to some pieces of charcoal which were C14-dated to 50kya (even though the whole setup could have occurred naturally), it gets picked up by the media, and in the end the scientist is feeling bitter and slighted by the "scientific establishment".
With regard to fire and cooking, I think that the wiki article gives too much credence to alternative theories. Here's what other anthropologists have to say:
The consensus among many paleoanthropologists is that unequivocal evidence for the use of fire dates to the beginning of the Middle Paleolithic, ca. 200-300 ka. Even during this period, however, evidence of fire is sporadic. ... Extensive sequences of burnt remains and control of fire are clearly observed in Middle Paleolithic contexts younger than 200 ka. These Middle Paleolithic cases present many indications that social activities centered around hearths.
Where we would expect habitual use of fire in the Paleolithic, i.e., the northern latitudes, we do not see any clear traces of it at all until the second half of the Middle Pleistocene. Cave sequences spanning the later part of the Early Pleistocene and the earlier part of the Middle Pleistocene in Europe do not have convincing evidence of fire. The number and quality of these early sites are significant, and this absence of evidence cannot be ignored. The simplest explanation is that there was no habitual use of fire before ca. 300–400 ka and therefore that fire was not an essential component of the behavior of the first occupants of the northern latitudes of the Old World.
Thanks! Your response is very nearly persuasive, but I still have a little skepticism focusing on the "you would expect" bit. What if ancient humans invented fire, but at first they couldn't stand it? Maybe they had an uncontrollable terror of it, or the smell repulsed them or something? And maybe they didn't need it in the same way as modern populations either - better immunity against meat pathogens, better heat regulation in the cold. I can picture that it might have been hundreds of thousands of years until natural selection made them more tolerant of fire, or so far gone in their addiction to it that they brought it into their homes despite the gruesome deaths they must have witnessed. Of course, that's not evidence ... just, I'm still not totally convinced. Wnt (talk) 22:57, 1 February 2012 (UTC)[reply]
Eating the food as you find it is meaningful if you cannot protect it from others. Eating meals is meaningful when it comes to time management. 88.26.74.157 (talk) 15:41, 30 January 2012 (UTC)[reply]
I almost agree with you. I can't cruse by the fridge without dipping in, because if I don't, I know someone else will raid it, for those bit left over from the night before. As to time management. Whilst I'm walking by it takes no time at all to open the door ... Oh, I see what you mean - I don't have to wast time sitting down. Note: it is also a well known proven fact, that food eaten straight from from a fridge contains no calories whats-so-ever and thus don't need to be counted on any dietary weight loss plan .--Aspro (talk) 22:52, 31 January 2012 (UTC)[reply]
Collapsed an offtopic discussion. This issue was discussed at the talk page.
No, of course not. The bible is full of claims that are not true, because the people who wrote and rewrote and edited and censored and translated the bible were often incorrect. Read this. Von Restorff (talk) 09:24, 30 January 2012 (UTC)[reply]
N.B. the actual Parable of the Mustard Seed is prone to various translations. [10] Many say the smallest seed on "the earth", but is that the earth you're planting it in, or the Earth as a planet? Anyway, I've moved this under the collapse because it is also irrelevant. Wnt (talk) 18:06, 30 January 2012 (UTC)[reply]
I assume you were probably not aware that this is a religious issue and not a simple scientific question but it is. I wish it wasn't, and I assume you do too. It is 2012, people should've stopped believing this kind of nonsense a long time ago. Von Restorff (talk) 11:10, 30 January 2012 (UTC)[reply]
I am fully aware of the origin of the mistaken idea that the mustard seed is the smallest. I am questioning the propriety of turning the question into an opportunity to post links to ranty pages about religion. Just answer the question with unembellished facts. OK, 'nuff said. Roger (talk) 11:37, 30 January 2012 (UTC)[reply]
Well, the unembellished fact is that this one of the many incorrect claims made in the bible. Are you claiming I posted "links to ranty pages about religion" here? I posted 3 links here. 1 is a link to a cartoon, not a "ranty page about religion". 1 link points to our article Ignosticism; if you are saying that page is "ranty" I will reply with {{sofixit}}. The third link is to a blogpost, EverGreg used the same link, and if you truly believe that page is "ranty" you and I have different ideas of what the word "ranty" means. If you are claiming I posted links to "ranty pages about religion" here would you please be so kind to point them out? Von Restorff #talk# 11:48, 30 January 2012 #UTC#
(ec)The point is is is not necessary to refer to religion at all #particularly in a way apparently intended to belittle or insult another editors presumed beliefs# when answering a botanical question. This is the Science Refdesk, not Religion or Mythology Refdesk. Doing so is simply gratuitously trying to provoke controversy. Can we please take this to the Talk page if you feel it's necessary to continue the discussion. Roger (talk) 12:05, 30 January 2012 (UTC)[reply]
Of course you did not answer my question. You still claim this was a botanical question; I am not sure why you still want to pretend it is even though you said you are aware of the origin of the mistaken idea that the mustard seed is the smallest. Was it my intention to belittle or insult another editors presumed beliefs? Thanks for letting me know! I was under the impression my intention was to help a misinformed person who believed an unreliable source, but obviously I am sometimes not aware of my own intentions, thanks for correcting me. Maybe we can both spend our time better than having this metadiscussion. Von Restorff (talk) 12:18, 30 January 2012 (UTC)[reply]
Von Restorff—the question asks if mustard seeds are the smallest seeds. Your first two posts reference the Bible, God, and atheism. It is just my opinion, but I think your response strays from that which is strictly asked. Bus stop (talk) 12:15, 30 January 2012 (UTC)[reply]
These tiny orchid seeds have no endosperm and contain underdeveloped embryos. As EverGreg says, that's 1/15th the size of a mustard seed, but volume scales as length cubed, meaning that those orchid seeds have less than 1/3000th the volume!
This would seem to be a common question, and that information should be in either our mustard seed or parable of the mustard seed article. While the link appears to give reliable information, as a blog it does not satisfy WP:RS. We certainly should be able to find these seed sizes sourced elsewhere. -- ToE14:19, 30 January 2012 (UTC)[reply]
While I am no expert on flowers, those really-really small seeds strike me as being not so likely to have been native to the Middle East. So a question more to the point might be, "Would the people of the Biblical region of Palestine likely have been aware of any seed smaller than the mustard seed?" ←Baseball BugsWhat's up, Doc?carrots→ 02:28, 31 January 2012 (UTC)[reply]
Yes, they would have. Many species of orchids are found natively in Palestine. Jesus was not well informed about scientific issues, even compared to the intellectuals of his time. --140.180.15.97 (talk) 05:18, 31 January 2012 (UTC)[reply]
Since the smaller seeds are decorative flowers, and probably not many people were doing intensive agriculture with decorative flowers back then, it's entirely possible that nobody ever figured out how small those seeds were. Also keep in mind that they wouldn't have known that all flowering plants even have seeds. StuRat (talk) 05:32, 31 January 2012 (UTC)[reply]
Seeds of many fruits are small. Figs come to mind, and my impression is that they were part of that culture. Berries like raspberries and blackberries have tiny seeds. HiLo48 (talk) 03:31, 31 January 2012 (UTC)[reply]
ToE: As for a reputable source on seed size, I think the Science report "A brief history of seed size" (DOI: 10.1126/science.1104863) would be sufficient. The supporting online material (found at [12]) contain an impressive wealth of data on seed size. While the authors study seed mass, they also find that mass and volume is approximately proportional for all species, with seed mass (mg) = 1.1 * seed volume(mm^3)^0.96. Quoting the paper:
Present-day species have seed masses ranging over 11.5 orders of magnitude, from the dust-like seeds of orchids (some of which weigh just 0.0001 mg) to the 20-kg seeds of the double coconut.
this implies a smallest seed volume of 0.000062 cubic milimetres. Assuming a spherical shape, that gives a diameter of 0.049 millimetres, or about 1/500th of an inch. (about 1/600 if you assume a cube). Half their raw data came from the Kew gardens seed database [13] which could also be consulted. Meanwhile, "Global patterns in seed size" (Moles et.al.) find that seeds are a lot bigger in the tropics. It's really the story of how seed size relate to evolutionary strategies that's the big story here. — Preceding unsigned comment added by EverGreg (talk • contribs) 15:50, 31 January 2012 (UTC)[reply]
The lapse rate article, while correct, is an unusually hard read for a wikipedia article. It's about a meteorological term and the physics is only mentioned in passing. To summarize, the article makes two points:
The sun heats the ground and the air closest to the ground absorb this heat, the air further up do not
Pressure decreases with height. As hot air rises, it therefore expands. With reference to the ideal gas law, its temperature must then decrease. Therefore, the air is not mixed to equal temperature but maintains a temperature gradient.
if a scientist takes some HIV (no matter what type of HIV) infected blood, and puts it in a sterile Petri-dish that contains Chlorhexidine (or pure alcohol), will it kill the Virus?, if not, what similar preparation could in fact do so?, interesting indeed. thanks. — Preceding unsigned comment added by 79.182.45.12 (talk) 13:09, 30 January 2012 (UTC)[reply]
If you are actually in a situation where you might need to handle or dispose of HIV-contaminated blood or blood products (or blood and blood products of unknown HIV or other infectious disease status), then you should consult with your school or workplace's health and safety or infectious disease control staff. The US EPA has produced a list of commercial antimicrobial agents that are – when used properly – effective against HIV: [14]. TenOfAllTrades(talk) 14:29, 30 January 2012 (UTC)[reply]
I'm glad I looked this up. It does indeed look like HIV can survive in dried blood for days, even weeks. [15][16] I have to say, I didn't know this, and there is evidence that even large forum discussions of people online don't know this either! [17] This may be a point where a little public awareness would go a long way. Diluted bleach will kill HIV, but some other products that "kill HIV" are labelled to do so with an unrealistic 10-minute exposure. [18] An interesting "Primary Surgery Wiki" describes chlorhexidine as ineffective, though the 70% ethanol in which it is usually made up might be effective - anything less than 70% apparently is not. [19] They sound skeptical of all methods of chemical disinfection due to the chance that the blood will kill the disinfectant rather than the other way around. And they say 10 minutes. Wnt (talk) 18:35, 30 January 2012 (UTC)[reply]
Skepticism and learning
how can a student who is in the process of learning be "skeptic" about what he/she is being taught by his/her professors? It may seem stupid at first, but when do students exactly learn to think in a skeptical way?--Irrational number (talk) 15:23, 30 January 2012 (UTC)[reply]
Salam chetori :) (the OP speaks Farsi). You might be interested in critical thinking, which explains the process in general. As for self-teaching skepticism, my only advice is that if you choose to think for yourself, you are well on your way. I don't think there's any special time when this happens, but I learnt more when I had to fend for myself, when I realised my life wasn't going to be as cosy as I had expected. You learn a lot by realising you are kind of on your own, so you have to learn to think for yourself. IBE (talk) 16:38, 30 January 2012 (UTC)[reply]
Skepticism has many definitions. When most people use it, it generally means refusing to believe in anything without evidence--such as paranormal phenomena or religion. Philosophical skepticism is the refusal to assert that it's possible to have any certain truths about the world. Usually, skepticism doesn't mean refusing to believe your calculus professor when he proves the mean value theorem, or refusing to believe your history professor when he says WWI started in 1914. --140.180.15.97 (talk) 20:03, 30 January 2012 (UTC)[reply]
Actually, skepticism can be useful even in math or especially in history.
A high school math teacher of mine said that if you tossed a coin five times and it came up heads every time, then you were likely to get more tails than heads during the next five tosses. The same teacher told the class that it was apparently impossible to integrate x-1 dx, because it would result in a division by 0 if you use the formula for integrating xn dx. Math teachers are sometimes wrong.
And skepticism can be very important when learning history. As a general rule, in whatever country you're learning history in, the history books in that country are at risk for having a bias towards describing historical events from a perspective that makes the country you're learning history in, and its current leadership, look good. As an example, when I was young, I was taught that Christopher Columbus was a heroic explorer who "discovered" the Americas, rather than being taught that he essentially was the beginning of a European invasion into a continent that had some fairly large civilizations for the time already living there, who arguably had more of a right to be there than did the invading newcomers. Red Act (talk) 22:34, 30 January 2012 (UTC)[reply]
I don't believe they need to learn specifically to be skeptical. They learn by doing and by example being in the company of other people. If you spend time with people with an inquisitive mind, you'll end up being inquisitive. The same applies for religious people.88.26.74.157 (talk) 21:39, 30 January 2012 (UTC)[reply]
One caution: While I encourage you to be skeptical, it's not always wise to voice that skepticism. For example, some teachers will get mad and retaliate if you question them. The same is true of bosses and friends, spouses, etc. So, be sure you are prepared for the consequences, before you decide to announce your skepticism. StuRat (talk) 00:48, 31 January 2012 (UTC)[reply]
There are also some people who never become skeptics, so I don't think that there is a "usual age" when most people become skeptics. --Lgriot (talk) 11:01, 31 January 2012 (UTC)[reply]
The OP might be confusing "skepticism" with "critical thinking". And Stu makes an important point. It's funny how often those who overtly express skepticism get angry when their own comments are viewed with skepticism. ←Baseball BugsWhat's up, Doc?carrots→ 13:31, 31 January 2012 (UTC)[reply]
Compass points South instead of North
Whenever I go near a compass, it switches polarity and points South instead of North, and generally won't return to pointing North. Why is this so? 122.149.61.46 (talk) 15:56, 30 January 2012 (UTC)[reply]
On these occasions, do you have about your person any significant pieces of metal (e.g. a belt buckle) or electronic equipment containing magnets (such as a cassette recorder or headphones) that might be overpowering the relatively weak terrestrial magnetic field? This would explain temporary deflections (see Compass#Using_a_compass, last paragraph), though not a permanent change in a compass needle's polarity, which would however be possible with stronger magnets or electric circuitry. {The poster formerly known as 87.81.230.195} 90.197.66.38 (talk) 16:19, 30 January 2012 (UTC)[reply]
The answer is no. This has occurred since childhood. I first noticed it when I buggered up my grandfather's compass just by holding it. Since then I have affected many compasses and now warn people to keep them away from me. Most recently today! Somebody let a compass near me and it started to turn South! They took it away and it went back to North. I'm just wondering why this would happen. 122.149.61.46 (talk) 16:42, 30 January 2012 (UTC)[reply]
Our Uri Geller article describes him similarly moving a compass; perhaps you can be The Next Uri Geller! What you are describing does sounds like a paranormal phenomenon. If you are not pulling our collective legs (and unless someone else here offers a more mundane explanation) then you should present yourself to a physics professor at a local university. Please let us know when something gets published. -- ToE17:34, 30 January 2012 (UTC)[reply]
We do have Bioelectromagnetism and Biomagnetism articles but they do not describe your particular power. The latter states, "The present scientific definition took form in the 1970s, when an increasing number of researchers began to measure the magnetic fields produced by the human body. The first valid measurement was actually made in 1963, but the field began to expand only after a low-noise technique was developed in 1970." These magnetic fields are presumably much less than what would be necessary to swing your average compass. -- ToE17:53, 30 January 2012 (UTC)[reply]
This claim is definitely extraordinary, and you'll face some skepticism. If it is true, it is worth documenting in detail. First, unless you happen to have been struck with a magnetic monopole (not inconceivable, but again, extraordinary), the compass should not simply point "south" no matter how you hold it - at any given time you should have a north pole and a south pole. (Humorously we all have a south pole, and you might need an understanding fellow researcher to read the compass there!) A normal magnetic field might conceivably be explainable by some kind of lost magnetic surgical implement, an encysted swallowed magnet, even a biochemical abnormality that would somehow allow some magnetic substance to precipitate in your tissues with a biologically ordered domain orientation. But all of those things are, again, truly bizarre - it's hard to get a field strong enough.
Realistically, until proven otherwise, I'm going to assume either hoax or something the matter with the compass. But again, if you're telling the truth, keep up your investigation. Who knows what you might come up with. Wnt (talk) 18:02, 30 January 2012 (UTC)[reply]
Wouldn't it be pointing toward the IP user, not simply toward the south? That in itself doesn't readily make sense to me. – Kerαunoςcopia◁galaxies18:07, 30 January 2012 (UTC)[reply]
Anecdotally, I used to sit next to a girl who made my wind-up wristwatch run fast. We could sit and watch the second hand whizz round while she was holding the watch! I wonder if this is a similar phenomenon? --TammyMoet (talk) 20:33, 30 January 2012 (UTC)[reply]
I used to sit next to a girl who made time fly as well, though I assumed it was simply a matter of perception, and you seem to be describing the second hand actually moving faster. A long long time ago I owned either a wind-up wristwatch or stopwatch (can't remember) which would do the same thing when it was shaken very rapidly, and I assumed it was the watch mechanism's escapement slipping. The shaking I would do was at a very low amplitude -- almost more inducing a vibration than displacing the watch back and forth any significant distance -- but the shaking action would still have been visible to an observer. Perhaps your friend either had a more practiced hand, or was able to put pressure on the case in such a way that caused the escapement to similarly slip. -- ToE00:52, 31 January 2012 (UTC)[reply]
No I actually noticed the phenomenon when sitting next to her in class with the watch on my wrist. It got worse when she held the watch. And I'm not sure why time would seem to fly when a straight girl sits next to another straight girl... --TammyMoet (talk) 12:09, 31 January 2012 (UTC)[reply]
Assuming the OP is not pulling our ref desk leg, this is different from the usualj alleged "paranormal" occurrence, in that it's something that can easily be tested with scientific rigor. Maybe contact Mythbusters, or failing that, your high school science teacher. ←Baseball BugsWhat's up, Doc?carrots→ 02:26, 31 January 2012 (UTC)[reply]
It's interesting that the OP geolocates to Australia. From my reading, compasses that are designed for the northern hemisphere don't work very well in the southern hemisphere, because of the inclination of the magnetic field lines relative to the surface of the earth. Therefore there are special southern hemisphere compasses, which point south rather than north. Looie496 (talk) 02:34, 31 January 2012 (UTC)[reply]
OP: If you have a macbook or other laptop with a built-in camera, point it so that you can see a table with a compass on it, with the compass clearly visible, and the background. Start recordering, move away from the compass (wearing as little clothing as decent) and then move close to it. Upload this video somewhere where we can see, such as http://www.mediafire.com/. It should take you seconds to set up making the video, and another 3-5 minutes to make and uplload it. If you're on windows you might start with downloading some free software to make a video using the built-in web cam. Let us know if you need any more help, and we look forward to seeing the effect!! 188.6.73.215 (talk) 09:24, 31 January 2012 (UTC)[reply]
Culm power
I approve of many of the Occupy movement's sentiments, but after looking at one of their latest cluster fucks I'm thinking it would be nice to have a more responsible organization that would find abandoned buildings to administer with the consent of local authorities. To do this, they'd have to bring something to the table, and heat is such a gift - both to preserve the building from humidity etc., and to fight the Occupiers' frosty nemesis. As it happens, Pennsylvania is littered with piles of "culm", a sort of fine-grained coal residue, and/or other spoil tip material. Sometimes large piles, sometimes very small, often in lands that are since abandoned or even turned into state forests and gamelands. While the smaller deposits might not yet have become economical for any company to exploit, I wonder if a few people with a pickup truck and a plan could do something with it.
Now a full century ago, using culm for heat was a hot topic [20] - apparently its main problem was that as finely ground carbon it could create too much heat for any known fire brick to survive. (Other samples were much less pure, however, producing much more ash) Apparently though the Wooten firebox was such a way. In more modern times some plants have been built to burn the stuff, e.g. [21][22]. There was also a much-vaunted proposal by Ed Rendell to use culm to produce synthetic liquid fuel, which has produced a now-venerable sign proclaiming the future site of the plant on scenic route 61. Something about this is explained at [23]. There are a lot of things up about a "smokeless culm gasification furnace" from China, e.g. [24], which I think must be smaller and less complex - not sure.
Anyway, what I'm wondering is, is it conceivable for a progressive group to set up a practical, safe, and acceptably clean way to burn small amounts of culm for local heating purposes? Wnt (talk) 19:59, 30 January 2012 (UTC)[reply]
Generically, an organisation that uses profit-making for social ends is called a social enterprise. It's possible that such an entity would be able to do this.
I'm completely unclear as to what the progressive group has to do with anything. Are you just asking if burning culm is a good idea? That seems like a hard enough question in and of itself to think about whether progressive protest groups would think it is a good idea. (It certainly has nothing to do with the purpose of their protest. It may even be quite poor from the point of view of CO2 emissions). In any case, I would do a little more research before trusting Glenn Beck's account of anything the Occupy movement allegedly does — the guy is a total loon and his take on things is always slanted if not totally made up. --Mr.98 (talk) 01:40, 31 January 2012 (UTC)[reply]
I was trying to frame the parameters; I know, after all, that culm can be burned at an industrial scale. True, the political thing was a distraction... Wnt (talk) 02:14, 31 January 2012 (UTC)[reply]
An apropos: While the material in Spoil tips are combustible, a discussion on processing may confuse this 'coal dust' with activated carbon (produced in e.g. the Kværner-process) or even with carbon black. The activated carbon can be burned profitably and cleanly, but these materials are more interesting as storage mediums for hydrocarbons or uses unrelated to combustion. EverGreg (talk) 10:28, 31 January 2012 (UTC)[reply]
Why is there a lot of soot in most diesel exhaust but not a lot in most gasoline exhaust?
I read diesel exhaust, didn't find anything about why it produces soot in the first place, or rather why diesel produces more than gasoline. ScienceApe (talk) 21:24, 30 January 2012 (UTC)[reply]
This page says (in slightly fractured English): "The fuel in diesel engine is ignited by the heat of the compressed air. It results in that fact that fuel had no time to fully mix with the air and it produces CH, NOX and carbon black during the combustion process. The carbon black is particularly visible then it colors the exhaust in black."Alansplodge (talk) 22:00, 30 January 2012 (UTC)[reply]
In the US, at least, they recently switched to a cleaner diesel, and we no longer see black clouds pouring out of trucks as a result. So, apparently, use of low quality fuel is also an important factor. StuRat (talk) 00:38, 31 January 2012 (UTC)[reply]
The phenomena are unrelated. The diesel standard adopted across the United States in 2007 was for ultra-low-sulfur diesel; it's 'cleaner' because of the very low sulfur content (resulting in reduced emissions of sulfur oxides), not because it's less sooty. Reduced soot is due to the increasing use of diesel particulate filters in modern vehicles, encouraged by more stringent regulation of particulate emissions. TenOfAllTrades(talk) 01:49, 31 January 2012 (UTC)[reply]
The causes of soot (carbon particles) in diesel exhaust is not completely understood, as physical chemists have yet to produce complete data on reaction rates for the multitude of chemical reactions taking place simulataneously within the cylinder. So we can't yet do an accurate computer simulation. However, the following is clear:-
It is NOT because of combustion less complete than in gasoline engines - generally, diesel engines have more complete combustion.
Gasoline engines do not (unless maladjusted) produce soot because they operate stoichiometrically - there is always just enough air to burn the fuel - this keeps combustion temperature high throughout the throttle range and even when idling. Gasoline is easily vaporised - why this matters is explained below.
Diesel engines always draw in a full quantity of air, well above stoichiometric level, regardless of throttle position - so combustion temperature is low, particularly at part thottle settings. It takes high temperatures to avoid precipitating out carbon, and diesel combustion temperatures are not much above this temperature.
Diesel engines tend to produce vsisbile soot when starting up from cold, because the cold cylinder temperatures pull the combustion below the soot limit temperature.
Diesel engines may produce visible soot at full load thottle settings because the volume of fuel injected may be above the capacity of the injectors to handle while "atomising/misting" the fuel. If the fuel particles are too large, the liquid in each particle holds local combustion temperature below the soot limit. This often occurs with cheap fuel and/or worn injectors. In other words, injector capacity sets an upper throttle limit to operating without soot. It doesen't happen with petrol engines because gasoline is easily vaporised.
Even if injector capacity is increased, a diesel engine will still produce soot at a (still higher) power setting. I've been trying to figure out why this is.
1 & 5 and so on. The fuel -as you say- is not taken into the cylinder as a vapour. The injector 'squirts' out a liquid – which hopefully mists – but at high delivery rates, it goes in as a jet. Note: Some oil compression engines have an over-fueling setting for starting. Fuel from the injector relies on the 'swirl' (created by the funny shape on top of the piston ) to mix it with the compressed charge of air. This means that there are areas of compressed air, that are very rich in fuel, which in a petrol engine doesn't exist. The oxygen in these areas get depleted faster than gaseous diffusion can bring in more oxygen to combust the remaining fuel. So, just like an Oxyacetylene torch with the oxygen off – the incomplete combustion produces shoot. When the engine is cold, the compression cycle looses too much of its heat to the cold surfaces of piston, cylinders wall and head, thus preventing the completely combust the fuel because much the heat from the compression is lost. This is now understood, because a well maintain 'modern' compression ignition engines are designed (regardless of if they used fuel oil or 'diesel' spec fuel) to forgo the clouds of smoke. Lastly, no modern engines use the Diesel Cycle any more- WP need up dating badly on this point to make this clear. There are engines that run on gasoline/petrol, oil (of various sec's), diesel grade, kerosene/paraffin, vegetable oil, methane, etc., but non are Diesel Cycle Engines which WP articles seems to suggest. --Aspro (talk) 21:52, 31 January 2012 (UTC)[reply]
January 31
Running and Coughing up Greyish Matter
Sorry, but Wikipedia cannot give medical advice as a matter of policy.
The following discussion has been closed. Please do not modify it.
I have been an intermittent smoker for the last 5 years. Not cigarettes, however--one common "herb" for the entire time, and hookah for the middle 3 of those years. For the two years before I started smoking, I ran regularly, and after running I would often cough up clear phlegm and sometimes get a phlegm feeling in my throat. The coughing up of phlegm was most common when I'd be in a steamy shower afterword.
I recently started running again after the 5 years of hookah/herbal smoking. I get the same symptom: in the few hours after running, I'll cough up some phlegm a few times, especially in a steamy shower. However, what is different is that now there are some grayish particles in the phlegm. I assume this is tar/ash/etc. from smoking.
Is that correct? If so, is this normal? Is it good to cough up the possibly carcinogenic grayish stuff? If it is good, can I do anything (besides steamy showers) to encourage it to all come out?
I am afraid that we cannot give medical advice, per our policy, and will have to close this question. Please take your question to a qualified professional who is in a better position to answer your questions. I apologize, and wish you the best of luck. Falconusptc00:26, 31 January 2012 (UTC)[reply]
Bad invention idea ?
The Sift and Toss litter box system seems like a bad idea, to me. It's a mesh you place under the kitty litter, then lift to separate the "clumps" from the rest. This will no doubt create a cloud of cat feces dust, which will then be inhaled. So, can this cause toxoplasmosis, or any other disease ? StuRat (talk) 00:58, 31 January 2012 (UTC)[reply]
Seeing as toxoplasmosis is rarely a serious disease, and that if you have a cat at home and regularly clean its litter box then you are likely immune, it would seem that other factors are more important than the probability of toxoplasmosis infection. Whoop whoop pull upBitching Betty | Averted crashes01:10, 31 January 2012 (UTC)[reply]
I don't think that assessment jibes at all with our article on the subject. I don't know why you'd assume people were immune. I don't think StuRat's talking about the acute version of it, but the latent version and its potential connection to psychiatric disorders. --Mr.98 (talk) 01:12, 31 January 2012 (UTC)[reply]
What makes you think this is any worse than using those little scoopers to do the trick? Or the activity created by emptying litter in general? My experience with cat feces, some years old now, is that it does not turn to "dust". You get lots of dust from the litter itself but it seems like the feces itself stays pretty solid. --Mr.98 (talk) 01:10, 31 January 2012 (UTC)[reply]
Depending on how slowly you lift the mesh, airborne dust can probably be minimized. Slow lifting I would think would create less dust due to lesser air currents and a lesser height from which particulate matter "falls" back into the box. Bus stop (talk) 01:16, 31 January 2012 (UTC)[reply]
With any organic pet, as opposed to a plush toy, this is going to be a factor. Not the cheapest thing around, but one very effective approach is a litter box with an automatic rake, which somehow detects when the cat has just been there, and drags a metal "comb" through the litter and dumps the clumps into a collection pan with a lid that opens just long enough to admit the clumps. Obviously, it still has to be cleaned regularly. But much neater than the old slotted-scooper method, and very little dust. ←Baseball BugsWhat's up, Doc?carrots→ 02:12, 31 January 2012 (UTC)[reply]
Web of Trustflagged that link, something about malware, viruses, fake goods, and other such goodies. Therefore I have removed it, and recommend against accessing that website. If you feel that this was in error, feel free to undo, but I would still leave some kind of warning message. Falconusptc10:10, 31 January 2012 (UTC)[reply]
The Wikipedia article Fuchsia indicates that there are a large number of plants which are classified as fuchsia so it may be quite difficult to make a blanket statement regarding such characteristics. You may have more luck looking for information on specific species. --Jayron3203:56, 31 January 2012 (UTC)[reply]
Our article says "the fruit is a small (5–25 mm) dark reddish green, deep red, or deep purple, edible berry, containing numerous very small seeds. Many people describe the fruit as having a subtle grape flavor spiced with black pepper." Looie496 (talk) 04:42, 31 January 2012 (UTC)[reply]
But maybe people that discovered that not all fuschias were necessarily edible might possibly not have had the opportunity to describe the taste afterwards... AndyTheGrump (talk) 04:47, 31 January 2012 (UTC)[reply]
Here's a clip that talks about the edibility of fuchsia berries. He says he's eaten them and he still seems alive. I have eaten them on several occasions and my advice from a culinary point of view is 'don't bother'. Googling "eating fuchsia flowers" gives several sites which endorse this practice. Richard Avery (talk) 08:29, 31 January 2012 (UTC)[reply]
Why use a mechanical shutter to determine exposure time?
Mechanical shutters fail and have a lifetime-- why not just configure the image-gathering device to collect an image between two set points of time? That's how video DSLRs work, yes? Video DSLRs rely on a "digital shutter" so to speak-- so why not use this for still images? I also worked in a very expensive government lab using very expensive super-high-resolution subdiffraction-limit optical cameras for very expensive microscopes (there were ways of "cheating") ...and I don't remember mechanical shutters being used at all. 199.111.169.54 (talk) 08:55, 31 January 2012 (UTC)[reply]
There's various reasons. According to Steve's Digicams an electronic shutter (where the sensor starts and stops capture) requires more complex electronics on the sensor, increasing noise and reducing image quality; a mechanical shutter is cheaper than the additional electronics. On a DSLR or other camera which has removable lenses the mechanical shutter may protect the sensor from dust, etc. Electronic shutters are bad for rolling shutter due to the fact that it takes time to read data from the sensor particularly with cheaper sensors (though you can get this with a mechanical shutter too). Additionally, in a DSLR removing the shutter won't give silent operation because you still have to move the mirror. Mechanical shutter mechanisms have been made for decades and are now reliable and well-understood by manufacturers. Shutter (photography) is the WP article. (Of course there are disadvantages as well, particularly in non-SLR designs.) --Colapeninsula (talk) 10:39, 31 January 2012 (UTC)[reply]
If the image sensor chip is on and exposed to light for a prolonged period, it suffers a temperature increase and becomes more noisy. Using a mechanical shutter may therefore increase image quality. EverGreg (talk) 10:42, 31 January 2012 (UTC)[reply]
This is a known problem with DSLR sensors in video or long exposure mode, and with the recent ability of DSLRs to do video, videographers are routinely warned that DSLR sensors can develop hot pixels which may or may not go away when the camera is cooled down: this is part of the reason why a Canon EOS 5D (meant mostly for still images with a mechanical shutter) costs $2500, but a Canon C300 (a DSLR designed for video use) will set you back $16,000: better cooling and a sensor that is better optimized for video use (i.e., an electronic shutter). Consumer-grade mechanical shutters have a lifetime of about 50,000 exposures, while professional-grade shutters go for 100,000 or 200,000 exposures, by which time you want the camera to be overhauled (or it's obsolescent) anyway. Shutter noises are insignificant compared to mirror noise. Acroterion(talk)19:56, 31 January 2012 (UTC)[reply]
Also note that, as with electric cars, silent operation isn't necessarily desirable. Having an audio indication that a picture has been snapped can be useful. There's the privacy issue, of people not wanting their pictures taken without their knowledge (like the dreaded "upskirt photos"), but, also, when taking a picture of a model, say, without a flash, it is useful to the model to know when a frame was snapped, so she can then move on to the next pose. StuRat (talk) 20:18, 31 January 2012 (UTC)[reply]
Cycling over hills vs cycling arouund them
Suppose a cyclist has two routes from A to B, which are at the same elevation. Route 1 goes over a large hill and down the other side, whereas route 2 is flat and goes around the hill. If both routes were the same length, it seems (intuitively) that it's easier to go round, but is this true? I guess that all the energy the cyclist uses in ascending is not restored to the cyclist on descending, so how much further does the route around have to be in order to make it better to go over the hill? I guess that this in turn depends upon the size of the hill... Any thoughts, anybody? Chris (talk) 09:51, 31 January 2012 (UTC)[reply]
Probably not easily resolved on the Science desk as a lot of the decision process is psychology.
For me the crux of the issue will be the motivation for why one is cycling. In any given circumstance two different cyclists may make different decisions, or even a single cyclist making a different decision when on different bikes.
Indeed, it depends a lot on the bike and your level of fitness, as well as the size of the hill and the state (and length) of the roads. No doubt one could come up with a formula taking all those variables into consideration. If you check out a cycling forum I bet someone will have done the math(s). My 1947 roadster (weighing in at around 50lb) doesn't do hills, so it's an easy decision for me. As a general rule I'd say as long as it's a good road surface it usually costs less energy to go around any sizeable hill.--Shantavira|feed me13:01, 31 January 2012 (UTC)[reply]
When going uphill you expend energy. When going downhill this energy is returned to the cycle/rider system. However you may not be able to take advantage of the returned energy and be forced to burn it off in the brakes. Also the losses in the cycle/rider system are likely to vary with speed.
As for how much longer the route round would have to be to make it better to go over there are just too many paramerters to give a general answer. Plugwash (talk) 13:17, 31 January 2012 (UTC)[reply]
You're into "effective" use of the energy, and I have a feeling that a flat route would be more effective as power delivery is smoother, not subject to those expending/ recovering transitions.
Having re-read the question it does seem that it's restricted to energy usage, and in theory there is no difference, although the effects of power consumption are different in each case. Even from a training perspective a hilly route gives a different training effect to a flat route.
There are a number of ways to approach this problem. If we start with the spherical cow approximation and for simplicity assume no rolling resistance or aerodynamic drag, then it actually takes no energy input to travel the flat path; you could coast indefinitely at constant speed once started. On the other hand, climbing the hill requires an input of energy (more energy and much more instantaneous power if one wants to maintain the same forward speed all the way up, a little bit less if you're content to come nearly to rest as you crest the hill); you must burn calories to buy that gravitational potential energy, even though you'll get that energy back as velocity on the other side. In this simplest scenario, the rider doesn't lose any energy either way – the hill climber's gravitational potential is converted back into speed (kinetic energy) on the way back downhill – but the rider following the flat path wasn't forced to burn any calories in the first place.
We can start adding bells and whistles to that model, and see where it takes us. Rolling resistance (to a very simple first approximation) can be modelled as a flat energy expenditure per mile of road covered. If route 1 over the mountain is significantly shorter than route 2 around the mountain, then our rider may burn fewer calories on the mountain route just because he isn't leaving quite so much energy on the road (warming up the asphalt and his tires, mostly). If the two routes are the same length over the same type of surface, this consideration is moot.
Aerodynamic drag puts another wrinkle into it. The power needed to overcome drag goes up as roughly the cube of velocity, so the energy cost per mile goes up with the square of velocity. That velocity-squared relationship means that your high-speed downhill leg puts a big dent in your energy budget, even if you were just crawling on the uphill portion. Once again, a much-longer flat route can offset the drag costs of a high-speed downhill run.
And finally there are the safety questions. In actual practice, would you want to convert all your hilltop gravitational potential energy into velocity, even if you could? How straight is the road, how good is the surface, and how far is it to the next traffic light? Most of the energy that doesn't get lost to rolling resistance and aerodynamic drag is going to end up warming your brake pads. TenOfAllTrades(talk) 16:32, 31 January 2012 (UTC)[reply]
1) Gearing. If you don't have adequate gearing on your bicycle, you will end up expanding far more energy on the hill, as pretty much any bicycle will be geared appropriately for level ground. This is particularly true if you end up walking up the hill, pushing the bicycle as you go.
2) Basal metabolic rate. You burn quite a few calories when not doing anything, especially if it's cold and you burn some to keep warm. So, if the level path takes longer, then more calories will be burned this way. However, one could also argue that you should compare the total energy of a 20 minute bike ride on level ground with the 10 minute bike ride over the hill plus 10 minutes resting. StuRat (talk) 20:10, 31 January 2012 (UTC)[reply]
According to our article, Fletcher's Ice Island "drifted throughout the central Arctic Ocean in a clockwise direction". This would be due to ocean currents, with perhaps some impact from the Coriolis effect. The ice would tend to melt a bit in summer and rebuild in winter, possibly becoming landlocked or part of a larger ice sheet at that time. The Arctic may be the only place this is possible, as ice shelves which break off Antarctica quickly drift into warmer waters and melt. The difference is that the Arctic is surrounded mostly by land, which makes "escape" more difficult. StuRat (talk) 19:55, 31 January 2012 (UTC)[reply]
frequency limit
Is there a limit for the frequency(or wavelength) of mechanical (I'm mostly interested in sound) waves in each medium?Also, does anything special happen if the wavelength of a sound wave is equal to the mean free path of the gas molecules(or less) in a gas or when the wavelength is equal(or less) to the distance between the atoms in a solid, or the amplitude of the solid atoms vibrations in thermal motions?--Irrational number (talk) 13:14, 31 January 2012 (UTC)[reply]
Our article on Nonlinear acoustics states that higher frequencies are more attenuated. So yes, there is a limit. This is apparantly an important consideration for ultrasound through biological tissue. Also, because the high-pressure phase of the oscillation travels faster than the throughs, the sinusoidal pattern is distorted. EverGreg (talk) 16:01, 31 January 2012 (UTC)[reply]
Big legs through running or jumping
Okay so many of my mates have quite muscley legs and most of them are in the basketbal team. I have quite skinny legs so because I thought that they gain their muscle mass through all the running they do, I started to work out on a running mill. However now one of my friends said it would probably not be useful for building muscle mass. He said he reckons the most muscle mass he has is due to all the jumping he does. So now I've started jumping on a trampoline. Is that more likely to help build muscle mass or should i be doing a mix of both. — Preceding unsigned comment added by 91.49.33.124 (talk) 14:01, 31 January 2012 (UTC)[reply]
Speaking personally, my thighs were large and muscular when I used to climb 4 flights of stairs 4 times a day at a college! My hubby also tells me that cycling is good for developing muscles. I think it's the resistance that's the important factor. Maybe try incorporating some resistance training into your routine will help. --TammyMoet (talk) 18:29, 31 January 2012 (UTC)[reply]
Any use of your legs will build muscles, although which specific muscles may vary a bit. For overall health, you want low impact aerobic exercise, such as jogging. I'm guessing you are male, but if female be sure to get a sports bra before taking up jogging. An alternative, but without the aerobic component, is walking. This does have the advantage of being more socially acceptable, say, at work. I would walk around the building periodically just to get exercise. While a half hour of walking isn't going to develop muscles as quickly as a half hour of strenuous exercise, you can walk a lot more each day. Park your car far from the entrance instead of close to it, for example, as I do. StuRat (talk) 19:41, 31 January 2012 (UTC)[reply]
My intuition would be that, if you specifically want big legs and want the shortest path to that goal, you need to do weight lifting with your legs. These other suggestions may work too, and may have other benefits, but what really causes muscle hypertrophy tends to be heavy resistance. At least that's my prejudice; I'm no expert and could certainly be wrong. See strength training. --Trovatore (talk) 20:00, 31 January 2012 (UTC)[reply]
The saltiness of Sodium chloride(NaCl) is not a property of the molecule. It's more like a property of your tongue. Also see Saltiness. The salt can't be tasted unless the molecule dissolves into free ions, which it does in a polar liquid. If you sprinkle salt in cooking oil, the salt won't dissolve. So as a gimmick, you could say that salt can't be salty without water. EverGreg (talk) 16:11, 31 January 2012 (UTC)[reply]
It could if it weren't pure salt. Before there were effective means of purifying salt, ancients would often mine "salt" which may have had a considerable amount of impurities, including things like insoluble silicates and stuff like that. A supply of salt could, if it got wet, have all of the sodium chloride leach out of it, leaving behind the less soluble (and not salty) components. The resulting pile of leftover stuff would be worthless as an aside, Edison is clearly reading WT:RD and testing the limits of if people will answer the scientific question without bringing up the obvious bible passage. Nice try. --Jayron3216:38, 31 January 2012 (UTC)[reply]
Depends whether the mustard seeds were scattered on stony ground or good earth. Tangentially, I've seen it argued that Yesua's recorded parables, if authentic and representative, corroborate that he was raised in a fishing rather than a farming community because his marine and piscatorial allusions generally make sense while his agricultural ones often don't. {The poster formerly known as 87.81.230.195} 90.193.78.57 (talk) 19:36, 31 January 2012 (UTC)[reply]
It is hard to envision people deliberately seasoning meat or other food with "salt" which contained a preponderance of sand, rocks, or dirt. If the salt content of such a product were so slight that its saltiness could be washed or leached out while leaving even half or the original mass behind, I can't envision it being added as a flavoring to food which one planned to eat. Salt with mineral inclusions might have been useful for preserving meat, since salted cured meat (country ham, for instance) is generally boiled or simmered to wash out the salt before eating. Sodium chloride is easily extracted from rock salt or sea water by evaporation and crystallization, and the the salt is typically transported. It does not make sense that someone would transport "salt " consisting mostly of mud, sand, or other minerals when the relatively pure product is so easily extracted. Edison (talk) 17:36, 31 January 2012 (UTC)[reply]
In Matthew 5:13, Jesus is saying that just as salt prevents meat from going bad so too can Christian people help humanity from going bad, and that if Christians fail to fulfill that mission, that their purpose on Earth was so-to-speak being squandered. That seems to be the significance of the Bible passage reading: "You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled underfoot."Bus stop (talk) 17:53, 31 January 2012 (UTC)[reply]
Bus stop is exactly correct here. The whole point, and the entire point of that passage is to note that if a substance with one purpose (salt's purpose is to be salty) loses that purpose, then it has no use anymore. Thus, when Christians lose the property that makes them Christian, they have no use anymore. If Edison has problem understanding this, then the correct article to read is metaphor. Jesus isn't trying to teach his disciples how to preserve meat. He's trying to teach them how to be better people by using the metaphor of meat preservation. --Jayron3218:08, 31 January 2012 (UTC)[reply]
To answer the OP's question also in bible form but with an historical explanation: No, it would not be sodium chloride. Salt was (is) obtained by evaporating sea water. The 'cheapest' was the whole evaporate. That contained other stuff. . Middlemen, in order to produces a better product for resale in distant lands, refined the salt evaporate by skimming off the surface crystals (rich in sodium chlorite) from brine. This left precipitates (lost its essence) which had lost its "savour" compared to the original first sea-water precipitate. It is easier to understand if you read the original Koine Greek New Testament. New wine into old bottles also makes more sense when one realises that it is actually a reference to 'wine skins' made form animal skins, which of course degrade unlike glass bottles. --Aspro (talk) 19:40, 31 January 2012 (UTC)[reply]
Don't some people (perhaps from reading the Bible passage brought up above) believe that salt can somehow remain physically whitish crystals, but due to moisture, exposure to sunlight, or simple aging, lose its saltiness, so that it is "unsalty salt? The "saltiness" would be a transient and removable property of the material, like saltines lose their crispness and freshness, or like flowers wither and lose their aroma. This seems to be a popular belief. I've still not seen a good explanation of what substance or compound "unsalty salt" would be. It seems unlikely that someone would transport or purchase a mixture of sodium chloride and some mineral or adulterant. I have seen salt absorb moisture from the air and become moist, but if exposed to heat the brine recrystallizes into salt just as salty as it started. Nor have I found prolonged exposure to sunlight to have any effect on the saltiness of salt. I have done crystal growing experiments with salt, and the 'saltiness" of the crystals formed out of the brine solution did not seem to vary from the first crystals formed to the last. Edison (talk) 22:43, 31 January 2012 (UTC)[reply]
I have read in the past and even have a book from the library on the subject right now, but is some good further reading in wikipedia and elsewhere about how the mind works around maintaining a factual belief (flat world, hollow earth, and other disproved ideas) even in the face of overwhelming proof to the opposite.
I'm thinking studies or pop science books on how the mind or brain works or the thought processes involved in working out that contradiction. Thanks. I want to be clear on this, though: I'm not interested in religious beliefs, just secular science. Mingmingla (talk) 18:19, 31 January 2012 (UTC)[reply]
If you want a website, Badscience.net is pretty good, they also have a series of books. This is still happening: my son's teachers recently taught (to my kindergartener) the Taste map. I thought we'd long ago learned how much bullshit that was. --Jayron3218:46, 31 January 2012 (UTC)[reply]
Sure, but that's due to religion, which the OP (for some reason) wants to exclude. If we include incorrect factual beliefs due to religion, the number of such beliefs multiplies dramatically. Start with young-Earth creationism, and proceed from there. --140.180.15.97 (talk) 23:16, 31 January 2012 (UTC)[reply]
Hang one above your bed. If you don't like what you see reflected in it when you wake up – go back to sleep – repeat as often as necessary.--Aspro (talk) 20:32, 31 January 2012 (UTC)[reply]
I have a question that has been bugging me for quite some time. I know that eyes have two distinct motions for focusing - convergence, and divergence. After some training I can point one eye at my nose while the other looks straight ahead, but despite all my efforts I cannot get one eye to look AWAY from the nose while the other looks straight ahead. I have noticed that the eyes never diverge beyond parallel, but after doing research on the muscles of the eye I find no connection from one eye to the other that would "hold" them together to make this impossible. Both eyes can obviously move completely away from the nose with no problem, but they can't both do it at once. The reason I think this is possible is because I've seen people do it (although that was a long time ago, my memory is hazy).
So my questions are simple. What the heck is keeping the eyes from diverging beyond parallel? Is it mental or physical? And is it possible to voluntarily extend this divergence beyond normal? Chris16447 (talk) 20:52, 31 January 2012 (UTC)[reply]
When I was in high school, I experimented with stereoscopic vision and stereoscopic photography, and through practice acquired the ability to diverge the lines of sight of the two eyes, to be able to combine two different photo images into a 3D view. It became easy to diverge the views of the two eyes and combine two stereo images side by side, or to diverge the two eyes and suppress attention to either eye, voluntarily, when not viewing stereo images. There is not much need for voluntary strabismus outside experiments in visual optics, or other than being a comic actor like the aforementioned Feldman, or his predecessor, Ben Turpin shown here in a Youtube silent movie clip. Not medical advice, but be careful wishing for strabismus, or working to achieve it. I believe that the practice has interfered with the natural and automatic convergence of the eyes, Edison (talk) 22:23, 31 January 2012 (UTC)[reply]
