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March 27

What is the meaning of AKA in the context of the nervous system anatomy?

What is the meaning of the letters AKA in the context of the nervous system anatomy or physiology? (except of "also known as"). 93.126.95.68 (talk) 00:42, 27 March 2016 (UTC)[reply]

AKA is Alcoholic ketoacidosis in the field of endocrinology, fwiw. Do you have any more context, or a pointer to an example?--Tagishsimon (talk) 00:50, 27 March 2016 (UTC)[reply]

To be honest I just heard my teacher say it when he gave us an introduction on the nervous system. He explained something about it but I unfortunately I forgot it. and I don't find where I wrote it, if any. I sent message to my teacher in a request to remind me it. Thank you93.126.95.68 (talk) 01:22, 27 March 2016 (UTC)[reply]

He may have just meant the basic aka - also known as -. Graeme Bartlett (talk) 10:36, 27 March 2016 (UTC)[reply]

This seems the most likely explanation to me; ketoacidosis could come up under the context of the monstrous amounts of glucose consumed by the brain, but it seems like an odd association to draw in an introductory discussion of the nervous system. If there's another neurophysiological usage for AKA, I'm drawing a blank on it, so it seems likely from the context that the OP describes that it was marking a synonymous relationship between two structures, processes, or concepts. Snow ^{let's rap} 08:03, 1 April 2016 (UTC)[reply]

What does it mean "specialized population of neurons"?

What does it mean "specialized population of neurons"? the full context is (from the Campbell textbook): "In all but the simplest animals, specialized populations of neurons handle each stage of information processing. • Sensory neurons, like those in the snail’s siphon, transmit information about external stimuli such as light, touch, or smell, or internal conditions such as blood pressure or muscle tension. • Neurons in the brain or ganglia integrate (analyze and interpret) the sensory input, taking into account the immediate context and the animal’s experience. The vast majority of neurons in the brain are interneurons, which form the local circuits connecting neurons in the brain. • Neurons that extend out of the processing centers trigger output in the form of muscle or gland activity. For example, motor neurons transmit signals to muscle cells, causing them to contract." By the way, Does it say that each acting occurs due to these three stages? If it does, I wonder because when we think about something and then decide to act (e.g. to take something from the table) actually we pass just two stages, because we don't really use sensory neurons for the information processing.93.126.95.68 (talk) 01:42, 27 March 2016 (UTC)[reply]

In this context "population" just means "a distinct group of". Action does arguably involve the three groups mentioned. In your example of taking something from the table, the sensory inputs you ignore might well be sight (you have to see the table and the object, and if you're blind, then touch), but also proprioception - where is your hand, your arm, etc; how well are they responding to actions initiated in support of your objective? --Tagishsimon (talk) 01:47, 27 March 2016 (UTC)[reply]

thank you for your comment, it helped me. I didn't ignore of the sight, because I meant to case that you don't saw it at the same moment. for instance, if you are reading a book and suddenly you feel that you're hungry then you decide to go the kitchen and to open the refrigerator. Does it says that you saw it before? and why does the text limit it to a distinct group of neurons? do exist other types of neurons which don't pass these three stages? 93.126.95.68 (talk) 01:55, 27 March 2016 (UTC)[reply]

In this instance they are probably referring to neurons with different specialized morphology. See retina - two of the figures show the different layers and different types of connectivity in each layer, though I've seen far far better illustrations. However, I think that the statement as written could refer to something else, which is when you have an initially homogeneous set of neurons with the same apparent cellular identity and different ones are recruited to different tasks - like which ones react to a particular word or touch to a particular spot on the body. In that case the connectivity is also different, of course, but the differences may be much more subtle, not morphologically recognizable. Wnt (talk) 02:05, 27 March 2016 (UTC)[reply]

Reading through Nervous tissue may assist you. That article shows a number of different ways of grouping nerve tissue. The list you gave, above, is a functional classification - which must be seen for what it is - a very broad and very simple means of introducing and describing subdivisions of the nervous system. I'm not sure it is very useful to spend time looking for actions which can be performed using only two of the three in the classification system. And, clearly, it is possible to break down the functional classification further, into sub-classifictions. Or to reach for one of the other classifications mentioned in the Nervous tissue article. --Tagishsimon (talk) 02:28, 27 March 2016 (UTC)[reply]

Military applications of wafersats

I was surprised to read a claim [1] that it is possible to send instrument probes to Alpha Centauri and other stars within 10 light years using a laser light sail approach. One thing that they don't seem to discuss at all: the lack of spread of the beam. It isn't that clear to me how long the probe accelerates for before the beam spreads out too much to be caught by the sail, but they seem to describe sails just meters across being beamed at for some appreciable portion of a light year.

If this is true, then these probes seem like the basis of some rather devastating space weapons. For example, the probes - tiny things, grams in weight, probably cubesat material - might be deployed in low Earth orbit, using more rigid reflectors than described. A laser of the type used for probe propulsion can then be bounced off them to set fire to thousands of widely separated remote wilderness sites in a short span of time, or burn right into a giant tank of natural gas (I mean, they talk about a reflector capable of withstanding 10⁵ suns of brightness!), or I suppose to lock onto some VIP caught out in the open. This isn't the first time I've seen hints of such capabilities (the AF 2020 report was another), but I've also seen claims that you can't collimate a laser beam well enough to pull it off. So .... can you? What is the feasibility here, for either application? Wnt (talk) 02:22, 27 March 2016 (UTC)[reply]

Military Industry has been trying to make this work since befor 1984. See Strategic Defense Initiative. Over the years every now and then someone claims to finaly have a working experimental model, presents something alike, but then every time you never read about it again. --Kharon (talk) 11:26, 27 March 2016 (UTC)[reply]

There is a huge difference in range due to air. Air contains dust and perhaps water droplets, both of which spread the beam out and/or absorb it. Space also contains dust, but at a much, much lower density (can somebody put some numbers on this ?). Also, temperature differences in layers of air can defract the beam. This is why stars sometimes appear to "twinkle". StuRat (talk) 13:51, 27 March 2016 (UTC)[reply]

Transparent enough that you can see Deneb right in the middle of the Milky Way through several thousand light years of the galactic disc. 10 light years would be like a 300th root of the Earth to Deneb light transmission percent would it not? Unless the 10 light years are dustier than average but it would still be very very transparent. Sagittarian Milky Way (talk) 16:01, 27 March 2016 (UTC)[reply]

And the Hubble telescope can see objects tens of billions of light years away, which is way past the end of the block ! StuRat (talk) 15:03, 31 March 2016 (UTC)[reply]

Nephron can be considered also as a cell?

I know that the nephron is renal functional unit but I'm asking if we can consider it as a cell? 93.126.95.68 (talk) 03:31, 27 March 2016 (UTC)[reply]

No, a nephron is an assembly of many hundreds or thousands of cells. This page briefly describes the cells found in a nephron. Someguy1221 (talk) 07:55, 27 March 2016 (UTC)[reply]

A simple kidney in small bilaterians consists of a flame cell and tube cell. I think that the collecting aspect of a nephron would hint that the tube cell should be counted as part of its equivalent there, but you could argue the issue. Another question is whether it can be counted as a nephron when there is no loop of Henle (AFAIK). A weirder variant is the nephrocyte - honestly I have no idea what it's doing in the esophagus ( see [2]) but it is said to be homologous to a podocyte. Wnt (talk) 10:33, 27 March 2016 (UTC)[reply]

Effective Strength of a martian "Storm"

Storms on earth can cause many effects - even blow away houses and more. This needs force measured in pressure per square inch. On Mars The resulting mean surface pressure is only 0.6% of that of Earth - so I'd like to know, how much force a martian storm of perhaps 400 km/h can provide at one suare inch (or cm²) to press against objects (and perhaps to move them) - in other words: can such a storm do more that letting a flag flutter? Chiron McAnndra (talk) 14:05, 27 March 2016 (UTC)[reply]

There is a movie showing the Telltale of the Phoenix mars lander moving. I try to find how heavy the thing is but look at the movie first [3] --Stone (talk) 14:31, 27 March 2016 (UTC)[reply]

The small tube with the fibres is in the 10mg range and the length is 2-3 cm. [4] This looks like even on a windy day on Mars you would require a real low weight flag, or do the same cheating like on the moon. --Stone (talk) 14:38, 27 March 2016 (UTC)[reply]

If 400 kph is correct it should be like a 400kph*0.6%**.5 wind on Earth times some adjustment for density (~44 amu vs 29 average particle mass and it's colder so denser) and the force of the wind-driven dust particles. That seems plenty to fly a flag. I don't know how fast the dust moves or how thick it is. When there is no dust storm (which is often) the wind isn't strong enough to pick up any dust by definition so it is pretty weak. Sagittarian Milky Way (talk) 15:47, 27 March 2016 (UTC)[reply]

(ec)Assuming mostly turbulent flow, drag grows quadratically with velocity, but linearly with density. So a 400 km/h storm at 0.6% surface pressure should create roughly the same force as a wind of 30km/h on Earth - that is a "fresh breeze" (Beaufort scale 5 on Earth. Not catastrophic, but certainly noticeable. As a beginner, you don't want to experience that in a Hobie Cat. As a good sailor, its probably where the fun begins ;-). All modulo misunderstanding of the physics and errors in the math.... --Stephan Schulz (talk) 15:52, 27 March 2016 (UTC)[reply]

(ec) Worth noting is that the wind speed in Martian storms is usually vastly overstated. Measured wind speeds on the Red Planet top out around 30 m/s (in round numbers, 60 mph or 100 km/h)— quite a strong wind on Earth, but not extraordinarily so. (Here on Earth, sustained 30 m/s winds would be a tropical storm, not even qualifying as a lowest-grade hurricane.) Note also that wind forces scale with the square of velocity, so cutting the wind speed by three-quarters reduces the force by a factor of 16. TenOfAllTrades(talk) 15:54, 27 March 2016 (UTC)[reply]

Our article on Dynamic pressure can help you get a rough approximation. So at 400km/h or 111m/s and [5] give an air density on Mars of about 0.020 kg/m3. Thus, that gives one q=0.5(0.02)(111)2 = Pa
From there you can get your kg ⋅ m/s2 . So, yes it would feel very windy.--Aspro (talk) 15:56, 27 March 2016 (UTC)[reply]

Such storms would have a much lower impact than what was depicted in The Martian (film). It would also not carry rocks, but only a thin sand that would feel more like smoke. For more details: storms in Mars.--Scicurious (talk) 19:10, 27 March 2016 (UTC)[reply]

Is solder for mechanical joining different from electrical?

Is there a difference in the chemical composition of solder intended for electronics vs mechanical joining of e.g. pipes or other large pieces of metal or are they just different in diameter of wire/pieces? --78.148.107.251 (talk) 16:38, 27 March 2016 (UTC)[reply]

There are different kinds of solder. Please see the Solder article - especially the Solder alloys table. MarnetteD|Talk 16:46, 27 March 2016 (UTC)[reply]

Oh boy! I just want to repair a broken candelabra which I think is bronze plated carbon steel. --78.148.107.251 (talk) 20:33, 27 March 2016 (UTC)[reply]

To solder steel you need to use a silver solder (either silver and lead, or silver and cadmium) and will need a powerful soldering iron as the heat required is much greater than when using tin based solder for electronics. 109.150.174.93 (talk) 13:57, 28 March 2016 (UTC)[reply]

Brazing or welding are more likely to be used on large pipes or pieces of metal. StuRat (talk) 16:50, 27 March 2016 (UTC)[reply]

They have to be different. Solder in electronic components has to conduct electricity. There are further subdivisions by type of alloy or being leadfree (or not) — Preceding unsigned comment added by Scicurious (talk • contribs) 19:01, 27 March 2016 (UTC)[reply]

The flux used differs also. For electrical work, you will want one that does not need washing off, and will not corrode the surfaces. Graeme Bartlett (talk) 21:29, 27 March 2016 (UTC)[reply]

Deep space telescope

This article mentions a "solar lens focus where the Sun acts as a gravitational lens to magnify distant objects". Einstein predicted a 542 AU focal length but it seems difficult to obtain an image through a "lens" whose deflection angle of light decreases away from the axis, and whose center is blinding. Is it sensible to send a radio- or optical Hubble-like telescope all the way out there to take a look? AllBestFaith (talk) 18:53, 27 March 2016 (UTC)[reply]

At least it still magnifies. You should block out the Sun with something like a coronagraph. Thousand Astronomical Units mission gives some idea of what this kind of mission would be like. Sagittarian Milky Way (talk) 20:14, 27 March 2016 (UTC)[reply]

Cats

If cats are solitary creatures, why do they make good pets in large human households? Surely, if there were solitary they wouldn't allow themselves to be domesticated, show affection to people, etc. I'm not sure the argument that we give them convenience flies that well, because they're perfectly able to fend for themselves. Also, in countries where there are large stray cat populations, like Egypt or Turkey, they seem to work together. Is the solitary and aloof quality associated with cats just a myth, are they closet pack animals? --Andrew 19:30, 27 March 2016 (UTC)[reply]

I don't know what you mean by "solitary creatures." They are more independent than dogs, and also have a shorter domestication history behind. But that does not conflicts with the fact that they simply evolved to be around humans. Just because they could live independently out in the wild does not mean that getting food from an old lady is not their first preference. The question is why humans keep them, since they do not provide any service nowadays. Maybe being small non-threatening furry and cute helps their case. At the beginning it might be that they were convenient back then, since they could catch mice, and mice were near us since we are good at producing grain. --Scicurious (talk) 19:38, 27 March 2016 (UTC)[reply]

Wild cats are solitary. Domesticated cats (including ferals) are not. http://icatcare.org/advice/understanding-your-cat/social-structure-cat-life Iapetus (talk) 20:16, 27 March 2016 (UTC)[reply]

The answer is actually quite simple. It depends on food availability. If food is plentiful, domestic cats will readily tolerate each other, even in large groups. Hence the scenes of many feral cats coming together when they are being fed by well-meaning humans, or individuals owning 20+ cats in their homes. Cats can be highly dangerous in aggressive interactions so it is to their benefit to avoid confrontation and aggression. If they have plenty of food, there is no benefit in fighting. Generally, cats, including domestic cats, are considered to be solitary - I think the only exception is lions, although cheetahs will form sibling alliances.DrChrissy ^(talk) 20:27, 27 March 2016 (UTC)[reply]

I would question the "they do not provide any service nowadays" assertion above. A cat provides companionship with less upkeep needed than even a small dog requires, and they eliminate small vermin from residences. --Guy Macon (talk) 22:02, 27 March 2016 (UTC)[reply]

Mine bring the bloody things in! "Hey Dad - look what I brought you!" ;-) DrChrissy ^(talk) 22:08, 27 March 2016 (UTC)[reply]

Are you trying to say that they provide affection in exchange of food? That looks much more like a private association than a service that it's being provided. I'd like to see a cat plowing a field. Scicurious (talk) 23:04, 27 March 2016 (UTC)[reply]

I don't know if there are any clear boundaries and I don't think human boundaries are necessarily applicable to humans. For example an escort, even in a case where they're mostly providing companionship or affection rather than sex will probably be said to be providing a service. This is a lot less common with a kept man or woman (let alone a spouse). If you hire someone to plow your field and they aren't your employee (or to some extent if they are) you may say they are providing a service, if your son or daughter or spouse helps you this is far less common.

But as said, I don't know if these boundaries are that useful.

BTW this all seems to be besides the point, since the issue of concern was whether "question is why humans keep them, since they do not provide any service nowadays" is meaningful. If you now recognise you should not have said only service but should have said ".... do not provide any service or private association nowadays" then we can discuss that instead. If you decide instead that these can be called service, it's the same thing. The statement "question is why humans keep them, since they do not provide any service nowadays even though they do provide a private association in the form of affection or companionship" doesn't make much sense.

Nil Einne (talk) 00:02, 28 March 2016 (UTC)[reply]

From a human perspective, maybe the line is to be drawn between what you like and what you need. You like the cat's affection, but you need them to catch mice, in the same way that you need the protection a dog can provide against other animals. The question is why do we like cats, and why we are affectionate towards non-humans, although we could quite well survive without them. --Scicurious (talk) 00:06, 28 March 2016 (UTC)[reply]

There are many things we don't definitely need including often the services or private affection/companionship of other humans, so part of your question doesn't make much sense. Also your boundaries are flawed mostly because boundaries are nearly always fussy. If you live in a fairly urban environment, having a cat to catch the odd mouse may be slightly useful, but actually it's often far less useful than the companionship. Particularly for someone who lacks sufficient human companionship for whatever reason. (And human companionship isn't automatically superior than non human animal depending on many factors.) To put it differently, the companionship/affect may very well have a far bigger effect on your lifespan or wellbeing than the mouse catching bit. If you live in a farm, it may be something very useful to have, but depending on the specific circumstance may not be essential. I.E. It's not guaranteed you're not going to survive without it. Nil Einne (talk) 00:54, 28 March 2016 (UTC)[reply]

Almost all wild cats are solitary. Only Lions typically live in groups. However most other cats are known to build bonds with others sometimes despite usually being solitary. All domesticated animals are breed races pretty much like domesticated plants. The feral and solitary instinct in cats was breed out or genetically sorted out over many generations. Looking at domesticated plants you can see the huge changes breeding has achieved since it became a profession in the earliest civilisations. So in comparrison its not such a big wonder when housecats today are so very different from wild cats nomatter they are biologically still close enough to proliferate.

What makes cats "good" pets is clearly their exessive grace and majestic nature. We humans simply love them for that. Almost any palace in the world has some stone cats as guard nomatter no civilisation ever used "guardcats". Palaces should have stone dogs but who wants that if he can have majestic stone cats? So are they really our pets or are we theirs? --Kharon (talk) 00:29, 28 March 2016 (UTC)[reply]

Scicurious says "I'd like to see a cat plowing a field." Here you go:

--Guy Macon (talk) 00:45, 28 March 2016 (UTC)[reply]

I would point out that I don't think comparing to random other species of Felidae is necessarily useful anyway. If all cats except all of the closest descendants of the house cat, were solitary; but all of the closest descendants live in groups (and perhaps we even have reason to think the most recent common ancestor lived in groups), the all cats bit is likely to be mostly irrelevant. On the other hand, if all cats except all of the closest descendants of the house cat, live in groups; but all of the closests descendants live solitary (and perhaps we even have reason to think the most recent common ancestor was solitary), the all cats bit is also normally going to be largely irrelevant. (Undomesticated wild cats which are in some ways the same species are solitary, which is what you should be mostly looking at although as said, with domesticated animals you have to take great care considering how quick certain changes can happen. There may be some limited utility of considering whether the solitary bit is related to specific evolutionary adaptions which haven't significantly changed even in the group ones including related to whatever possibly related niche they fill. As well as whether adapting to solitary existance or group may be slightly easier in evolutionary terms. But ultimately looking at the other relatives is only likely to be slightly useful.) Nil Einne (talk) 01:09, 28 March 2016 (UTC)[reply]

1) When we say cats are naturally solitary, we mean except for the mother cat raising the kittens until they can fend for themselves. There are some animals that don't do this, and those are truly solitary.

2) Domestic cats have been (intentionally or unintentionally) bred for the characteristics we like. The result of this process is that we bred them for neoteny, which means the adults still behave much like kittens. That is, they play and treat their owners (even men) as if they are the mom cat, going to them for food and grooming. Note that this is different from dogs, which treat their owners as the pack leader. You can challenge a pack leader and try to become the new pack leader, but you can't challenge "mom" and try to become the new mom.

3) As far as what service cats provide, they seem to lower our stress levels and blood pressure, with all the health benefits those bring. I imagine medication to do the same would cost quite a bit, and have serious side effects. StuRat (talk) 02:31, 28 March 2016 (UTC)[reply]

Two points: 1) The very "neoteny" to which StuRat refers, and which we have selectively bred into our domestic cats which we keep as pets (we want them to be kittens for life), may have a "side effect" of making them more accommodating towards each other, just like kittens of the same litter rarely get into serious brawls (playfighting is a different story).

2)The OP may find our article on the evolutionary processes of Self-domestication to be of interest. At some point, cosying up to a human, who in turn provides you with food and shelter in return for some affection, makes evolutionary sense, and the cats which do this will outlive those which don't, or form their own distinct self-sustaining population. I daresay cats are not committed solitary creatures. They can cope with solitude, but if manipulating a human with a show of affection will get them food, they're more than happy to oblige. Even (some) strays are known to attempt to "befriend" humans, so the self-domestication trait remains. Cats seem to have developed a masterful sense of how to manipulate us humans, and most cat owners will happily admit this fact. Eliyohub (talk) 14:11, 28 March 2016 (UTC)[reply]

I don't agree with the idea that they manipulate people, if you mean they don't really like us but just pretend that they do. For one, deception like this requires more intelligence than they have, specifically it requires the theory of mind. That is, they would need to know what you are thinking and how their behavior would affect your thoughts. I believe they genuinely like being petted, as it removes loose fur they might otherwise swallow, provides warmth, etc. Again, they don't think all this through, but cats that enjoyed being petted were more likely to survive to pass on this gene to others. StuRat (talk) 16:17, 28 March 2016 (UTC)[reply]

Yes, I agree. Many of these behaviours are simply Associative learning. Cats mark their territory with glands on their cheeks, around their mouths and at the base of their tails. Somewhere along the line, humans liked being "marked" (rubbed) by cats and rewarded this with food. Humans would then have artificially selected cats, or otherwise increased their biological fitness by e.g. targeted feeding, which have a greater propensity for rubbing against humans. This relationship is completely due to the humans mistaking cat's natural marking behaviour as an indication of affection. Similarly, the kneading behaviour which many cats show: they have scent glands in their paws. The ability of humans to change cat behaviour can be great. Most cats meoww to us, especially for food. But cats do not meow at each other. This appears to be a behaviour which is directed uniquely to humans. Again, it can be explained as associative learning, perhaps followed by artificial selection. DrChrissy ^(talk) 16:38, 28 March 2016 (UTC)[reply]

You can take this as OR if you like but it is very evident from observation. Man may have domesticated the dog but cats domesticated themselves symbiotically. When Man started to form semi-permanent settlements it was because they stored food of a nature that attracted rodents. The higher rodent population attracted cats to the area. Out of every littler of cats, one proves more bold and adventurous than the rest and one proves more docile. Neither attribute is good for survival in the wild. Yet, during the times when the cats natural pray is scarce and starvation threatens, those cats that have modified their behaviours (the various traits combining to be compatible to how human live)., and not to snare and claw at any human (and more importantly -any human child) will be better tolerated and feed by the village community, because the community appreciated that the cats eat rodents, which in turn, ate the villages food supplies. When, the cats natural food supply becomes more plentiful, they go back hunting for that. Cats prefer a freshly caught rodent above what humans can feed them. Cats are lone hunters but in a village, they congregate for protection against bigger critters. One only has to see how a domestic cat reacts to the presence of a nearby fox. Its strength in numbers. Also they don't have to be biologically related to the litters that they watch over – because if they come to have a litter, the same protection will be afforded to theirs. Lets go back to food. A human settlement provides an opportunity to occasionally get a rat. That takes some three days to fully digest and so they don't need to sit with the other cats nor hunt again during that time. Somewhere quiet for digestion may be afforded in a humans hut, in a spot that is away from drafts from the entrance and somewhere warm at night (a full belly switches off the need of nocturnal behaviour). Repeated visits to a particular home and comfortable place may make the cat want to make this resting space its own. i.e. if it returns to find a human sitting their already. It never the less tries (and often succeeds) to occupy the same space. Just like ones own moggie. I has is favourite chair before the fire and if after its meal it finds a human sitting their already, it will leap upon their lap, because that-is-their-preferred-resting-place. Survival fitness (in this particular ecological niche) means that after several generations, cats that can do this (from their own selective breeding) and tolerate the house family’s little Jane or John Doe from stroking him/her and muttering “Hallow little pussy” much like the kittens in the commune group do, affording them a much better chance of survival in the long term, than their cousins in the wild. So, the trait of self domestication perpetuates itself. --Aspro (talk) 14:13, 28 March 2016 (UTC)[reply]

While I agree that most of cat breeding was accidental, there was also some intentional breeding, such as the Sphynx cat. StuRat (talk) 16:25, 28 March 2016 (UTC)[reply]

We may have domesticated and keep cats for other reasons which are not immediately obvious. One hypothesis about why cats purr is that this heals their bones (see the Purr article. It is possible that purring is a low energy mechanism that stimulates muscles and bones. The frequency of their purr is also consistent with bone healing in humans. Perhaps we domesticated cats partly for this. The other word which seems to be missing in our discussions above is "entertainment". Perhaps editors have been using the word "affection" in a way which includes entertainment, but the two can be separate; keeping a goldfish is entertainment (providing a service), but I struggle to think of them as providing affection. DrChrissy ^(talk) 14:32, 28 March 2016 (UTC)[reply]

Kittens are often separate from their mother as soon as they have been weaned. But they have still not developed independence. So of-cause they look at their new providers of food and shelter thus showing affection. - its instinctive (Imprinting (psychology) and all that). Also, why separate entertainment. A new born into the family provides a lot of entertainment (in between diaper changes) because it is part of the bonding system we form with others around us -that is hardwired into our genes. As for keeping cats for other reasons which are not immediately obvious. My cat often walks across my computer key board and corrects my coding errors but I put that down to rare chance occurrences. She is more than probably, trying to remind me that she wants her nice bit of Coley that she has trained me to buy for her – by showing me great affection when she gets a whiff of it in the shopping basket (cats are not very good at sailing fishing boats or visiting the supermarket). Cats may have physical small brains but they are wired up in such away that they can fool us into thinking that we only possess the power of will and control over our actions. Oh, got to brake off here as she's now meowing at me because I've forgotten to add a few drops of vanilla essence to her dish of milk (and it has to be full cream not semi-skimmed). It was cats that domesticated man, so that we could provided them with a continuous supply of food shelter and warmth; not the other way around --Aspro (talk) 21:23, 28 March 2016 (UTC)[reply]

"of-cause" = "of course" ? StuRat (talk) 21:41, 28 March 2016 (UTC)[reply]

Well of course, watt did u think I ment? :¬) --Aspro (talk) 21:47, 28 March 2016 (UTC)[reply]

Less intelligent animals and even plants are able to fool us into thinking they are smarter than they are, by evolving instincts (in the case of animals) which accomplish the same things we need to use our intelligence to accomplish. For example, if a plant loses one water source, it has a way of growing it's roots towards another. In humans, finding a new water source requires intelligence, with one notable exception. StuRat (talk) 22:15, 28 March 2016 (UTC)[reply]

@Aspro - the feeding of milk to cats is purely because humans have learned that cats like it and get a sense of "being kind" by giving it to them. In nature, adult cats do not drink milk. Animals, including humans, do not always consume food or drink that is necessarily good for them. I strongly suggest you stop feeding your cat milk - it can be harmful. Water is perfectly fine. DrChrissy ^(talk) 23:22, 28 March 2016 (UTC)[reply]

Water? Try convincing my moggy of that. On second thoughts don't – she may may hide the key to my store of single malt whiskey until I repent. Cats are natural Carnivore#Obligate_carnivores and will turn up their noses at anything unhealthy – unless they live in the city and have no choice but eating supermarket 'cat food,' which is a euphonium for cheap and nasty. Which in turn leads to high vet bills when they eventually ail from being offered only a poor diet. Not all cats are lactose intolerant – she may be intolerant to my young nephew swing her round by the tail -but not milk. Let them choose their own food and they will reciprocate by correcting ones coding errors, retexture one's upholstery with their claws and purr away, oblivious to any sneezes around them due cat dander allergy. Which face it. Is a human immune problem anyway and not the cats fault at all. If this allergy of ours did bother cats, they would have selective bred this malady out of their slaves long ago.--Aspro (talk) 00:29, 29 March 2016 (UTC)[reply]

"euphonium" = "euthemism" ? AllBestFaith (talk) 14:04, 29 March 2016 (UTC)[reply]

Unless the cat plays the euphonium, I suspect he meant euphemism. StuRat (talk) 15:07, 29 March 2016 (UTC) [reply]

Cue more hilarious videos from @User Guy Macon: I hope ;-) DrChrissy ^(talk) 15:17, 29 March 2016 (UTC)[reply]

See wikt:euphonious - the definition fits for that. Personally, I reserve an absolute right to make up English words I want as I go along, but not being a native speaker of Greek I'm more hesitant with that ... but I think most people are the reverse, so I'll say fair ball. Wnt (talk) 23:11, 29 March 2016 (UTC)[reply]

Lactose tolerance in adult cats

The above discussion makes me wonder if a large portion of cats, like humans, have developed tolerance for lactose as adults. Since cats have been living with humans who herd domesticated animals, some have probably been given milk, or poached some which was left out. Those who could tolerate it were more likely to survive and pass on this gene. And there may have been more cat generations since they were domesticated than human generations since herding began, therefore it seems quite possible some may have developed lactose tolerance, at least in areas where milk was available. So, do we have a situation mirroring lactose toleration in humans, where some populations are largely exhibit lactose intolerance, and others don't ? StuRat (talk) 01:18, 29 March 2016 (UTC)[reply]

Adult cats are normally lactose-intolerant[6]. The undigested lactose passes through the intestinal tract, drawing water with it. Bacteria in the colon also ferment the undigested sugars, producing volatile fatty acids. This may induce vomiting and the most common symptom of lactose intolerance in cats is diarrhea. And there is an old Russian saying: The cat with cream on his whiskers had better find good excuses. - Ninotschka (Greta Grabo, 1939). AllBestFaith (talk) 15:04, 29 March 2016 (UTC)[reply]

What does "non-Gaussian AO situations" mean?

Within the context of statistics and control theory I found this sentence:

"produces estimates that are quite good approximations to the exact conditional mean in non-Gaussian AO situations"

What does "AO" mean? source Ferrofield (talk) 22:10, 27 March 2016 (UTC)[reply]

Or another source, Masreliez’s theorem. Appears to mean "additive outlier". Which tells me nothing except that I can look stuff up. --jpgordon^{::==( o )} 22:32, 27 March 2016 (UTC)[reply]

~~Maybe Adaptive Optics [7]~~ Loraof (talk) 00:02, 28 March 2016 (UTC)[reply]

I found the answer on page 1046 of the link provided by the OP: A section is entitled "IO+AO", and the first sentence contains the phrase "innovations and additive outliers". Loraof (talk) 00:14, 28 March 2016 (UTC)[reply]

March 28

64-hour days

This BBC article has a photograph of a clock (manufactured by the New England Clock Company - see History of Connecticut industry) where the face is divided both into the conventional twelve hours, and 32 smaller units. Does this time system have a name, and is there any more information out there about it? The Hexadecimal time system of John W. Nystrom divided the day into 16 hours, so the numbers read from the clock in question are four times the Nystrom value - it's therefore probably not an implementation of that system. Tevildo (talk) 00:10, 28 March 2016 (UTC)[reply]

Date. --jpgordon^{::==( o )} 00:24, 28 March 2016 (UTC)[reply]

Yeah, I agree, it looks like a day of month indicator. For one thing, it's dividing the clock into 31 intervals, not 32. And it wouldn't really make sense for it to be 1/64th (much less 1/62nd) of a day even if there were such a time system, because there's no fourth hand to indicate smaller divisions of that interval, and 22.5 minutes is an inconveniently long amount of time to be the smallest interval that a (modern) clock can measure. CodeTalker (talk) 01:02, 28 March 2016 (UTC)[reply]

Here is a picture of just such a clock face. --jpgordon^{::==( o )} 01:08, 28 March 2016 (UTC)[reply]

That would make sense - so the red hand isn't a second hand, it rotates once a month instead. Is there a name for this type of display? Tevildo (talk) 09:22, 28 March 2016 (UTC)[reply]

Complication (horology) mentions a "calendar watch", so maybe it's called a calendar clock? Try searching for information about watch complications. Perhaps there is a more specific name. --Guy Macon (talk) 11:29, 28 March 2016 (UTC)[reply]

Does this clock need to be manually corrected at the end of every month that does not have 31 days? Or is there some automatic/mechanical method built in to do so? Deli nk (talk) 13:11, 28 March 2016 (UTC)[reply]

I have no idea about that specific clock, but many clocks with date features use Perpetual_calendar technology to get the date correct automatically. SemanticMantis (talk) 16:22, 28 March 2016 (UTC)[reply]

See "THE CALENDAR WATCH, EXPLAINED" for the different types of calendar clocks.--TMCk (talk) 16:38, 28 March 2016 (UTC)[reply]

And, yes, every month short of 31 requires you advance the hand manually. It's not a huge deal; if you have one of these clocks, you are winding it probably every week, anyway. --jpgordon^{::==( o )}

I found Waterbury Niagara Oak Calendar Shelf Clock, ca. 1911 and 1890's Oak Jewelers Advertising Regulator Calendar Clock, or you can build your own Schoolhouse Calendar Clock with the aid of a kit. So "calender clock" is indeed what it is called. Alansplodge (talk) 21:46, 28 March 2016 (UTC)[reply]

Crossing the Bering Strait

If we ignore diplomatic issues, is it possible to drive from the Alaskan mainland (whether Cape Prince of Wales or somewhere else) to the Russian mainland (again, either Cape Dezhnev or somewhere else)? Bering Strait crossing talks only about proposals to build a road or railroad that crosses the strait completely; I'm wondering whether the winter ice is typically thick enough and consistent enough that one could drive a land vehicle such as a truck or snowmobile, or whether one would be restricted to using a boat or aircraft. Nyttend (talk) 01:13, 28 March 2016 (UTC)[reply]

Here is one site that indicates that using a land vehicle would not be possible. That is backed up by the last paragraph here Bering Strait crossing#Technical challenges. MarnetteD|Talk 01:21, 28 March 2016 (UTC)[reply]

The goggle title for this had me fooled for a moment but the pic shows that, even though it is a Land Rover that made the trip, it didn't "drive" the whole way :-) MarnetteD|Talk 01:25, 28 March 2016 (UTC)[reply]

FWIW, Bering Strait#Expeditions says

In March 1913, Captain Max Gottschalk (German) crossed from the east cape of Siberia to Shishmaref, Alaska, on dogsled via Little and Big Diomede islands. He was the first documented modern voyager to cross from Russia to North America without the use of a boat.[7]

and mentions other crossings on skis and on foot. Loraof (talk) 01:30, 28 March 2016 (UTC)[reply]

Initial planning of the 1908 New York to Paris Race contemplated motor cars racing across on the winter ice. This proved impractical. Jim.henderson (talk) 01:31, 28 March 2016 (UTC)[reply]

They were only supposed to race across the ice of Alaska, from Valdez to Nome. This is what proved impractical. The one car that made it to Valdez returned by boat to San Francisco, and its time was adjusted to compensate for the side trip. Then all the cars went by boat to Russia from there, instead of from Nome. See Hard Driving (1991) by Dermot Cole, ISBN 1-55778-360-8. --69.159.61.172 (talk) 09:52, 28 March 2016 (UTC)[reply]

It would certainly not be reliable, this comment "Although there are no icebergs in the Bering Strait, ice floes up to 1.8 metres (6 ft) thick are in constant motion during certain seasons, which could produce forces on the order of 44,000 kilonewtons (9,900,000 pounds-force) on a pier.[13]" comes from the article you linked to. μηδείς (talk) 01:34, 28 March 2016 (UTC)[reply]

I'd taken that as a reference to summer weather, conditions that would threaten the bridge piers, rather than as a winter-weather situation. Nyttend (talk) 02:49, 28 March 2016 (UTC)[reply]

I think it's reasonable to assume that one can say, it is possible under the right conditions to cross using a vehicle with luck, but it is not possible to say there is a set route that is always crossable in the same way at the same time each year. Keep in mind, also, that these floes are not flat. The Hudson and Delaware freeze over at NYC and Philly on occasion, but people don't attempt to drive across. μηδείς (talk) 17:28, 28 March 2016 (UTC)[reply]

I suppose there is less ice nowadays than 100 years ago. so, no crossign without a boat.Scicurious (talk) 01:45, 28 March 2016 (UTC)[reply]

No, Winter ice maximums in the arctic are relatively unchanged. Summer minimums are lower.

Normal to have one nostril always blocked?

One of my nostrils is always blocked, it switches but it's constantly either one of the other. Is that normal? 2.103.12.92 (talk) 03:49, 28 March 2016 (UTC)[reply]

It depends on your specific situation. Giving you a useful answer would require us to make a solid medical diagnosis, and we can't do that over the Internet. Please ring up your local doctor's surgery and get an opinion from an NHS professional. Nyttend (talk) 04:02, 28 March 2016 (UTC)[reply]

Yeah, after googling causes of it I was thinking of going to the doctor's to get an allergy test but according to this video it's perfectly normal so I don't know what to believe - https://www.youtube.com/watch?v=BGACvb3Mm60 I'm not asking you to diagnose me, but is that video right? 2.103.12.92 (talk) 04:12, 28 March 2016 (UTC)[reply]

An internet video does not necessarily apply to your particular situation. If you're concerned, see your doctor. ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:19, 28 March 2016 (UTC)[reply]

Any question that asks about whether or not some health condition you have is normal requires a medical diagnosis. Such a thing should only be performed by a medical professional. See Wikipedia:Medical disclaimer. Wikipedia does have an article titled nasal congestion, but how that applies to your situation, we cannot say. --Jayron 32 12:19, 28 March 2016 (UTC)[reply]

I strongly disagree with that. Saying that humans normally have two arms, not three, is by no means a medical diagnosis. And neither is saying that both nostrils are normally open. Saying what specific medical condition the OP has or doesn't have, now that would be a medical diagnosis. StuRat (talk) 16:47, 28 March 2016 (UTC)[reply]

You may find our article nasal cycle enlightening. SemanticMantis (talk) 13:49, 28 March 2016 (UTC)[reply]

And there was light. Thank you ;) --TMCk (talk) 16:45, 28 March 2016 (UTC)[reply]

Note that the article says "partial congestion", not "total blockage". StuRat (talk) 16:50, 28 March 2016 (UTC)[reply]

This is worth noting. The nasal cycle is merely a back-and-forth shift between the tumefaction of one nasal passage, resulting in disparate airflow nasal respiration, but if one closes off the presently "dominant" nostril, airflow through the other nostril is rarely restricted to a noticeable degree (as evidenced by the fact that many people go through life never recognizing the nasal cycle is a physiological reality in their respiration). However, what the OP seems to be referencing is outright blockage. The propensity of this blockage to switch may or may not be related to the nasal cycle, and I join the other editors here in urging that the OP consult a medical professional if this is a cause for concern. Snow ^{let's rap} 07:55, 1 April 2016 (UTC)[reply]

How many types of neuron cells do exist?

How many types of neuron cells do exist? I'm confused because According to the BRS gross anatomy (8th edition, p.6) there are three types (1. unipolar, also pseudo-unipolar. 2. bi-polar. 3. multi-polar) while according to the Moore anatomy book (7th edition. p.46) there are 2 types of neurons (multipolar and pseudounipolar) 93.126.95.68 (talk) 03:49, 28 March 2016 (UTC)[reply]

Neuron#Classification covers various types of neuron cells. The answer to the question "how many..." depends first on the answer to the questions "what constitutes a "type"..." which is not always a straightforward thing to answer, and over which many recognized experts will disagree. --Jayron 32 12:17, 28 March 2016 (UTC)[reply]

There are hundreds of named types of neurons. One of the ongoing projects in modern neuroscience is to come up with a principled way of dividing neurons into types -- probably the ultimate answer will be based on gene expression patterns. Looie496 (talk) 14:03, 28 March 2016 (UTC)[reply]

There are as many different neurons as there are neuroscientists studying them. A slightly flippant answer, but not far of the truth. Nobody agrees. The terms you mention refer to gross morphology of the neurons, but there are many more kinds than just those you mention. Then, do you want to look at electrical properties? Neurotransmitters? (Many more of those than mentioned in the link provide above by Stu) Biochemical/genomic profiling? Anatomical location? Any of the above? You could make a case that each neuron is a different type, it just depends on how fine-grained you want to be. Conceptually similar to coastline paradox really. Fgf10 (talk) 23:01, 28 March 2016 (UTC)[reply]

Special relativity. Derivation of $t'$ formula

Question	Remark
According Null result of Michelson–Morley experiment extrapolation we can write: $BC'^{2}=CC'^{2}+BC^{2}$ ; $(ct_{to\ upper})^{2}=(ut_{to\ upper})^{2}+(ct_{self})^{2}$ ; $t_{self}^{2}=t_{to\ upper}^{2}{\tfrac {c^{2}-u^{2}}{c^{2}}}$ ; $t_{self}^{2}=t_{to\ upper}^{2}(1-u^{2}/c^{2})$ ; $t_{self}^{2}=t_{to\ upper}^{2}{\tfrac {(1-u^{2}/c^{2})^{2}}{1-u^{2}/c^{2}}}$ ; $t_{self}=t_{to\ upper}{\tfrac {1-u^{2}/c^{2}}{\sqrt {1-u^{2}/c^{2}}}}$ ; $t_{self}={\tfrac {t_{to\ upper}-t_{to\ upper}u\cdot u/c^{2}}{\sqrt {1-u^{2}/c^{2}}}}$ ; $x=t_{to\ upper}u\Rightarrow t_{self}={\tfrac {t_{to\ upper}-ux/c^{2}}{\sqrt {1-u^{2}/c^{2}}}}$ . Is derivation correct? $t_{to\ upper}$ — time needed light spherical wave to reach upper mirror ( moving with speed $\mathbf {u}$ ) in point C' in Sun frame (observer on Sun, at rest). Sun frame is not rotating. $t_{self}$ — time needed light spherical wave to reach upper mirror in frame of interferometer , $t_{self}\sec <t_{to\ upper}\sec$ . $t'$ — time seen in interferometer frame from Sun frame. $t$ — time seen in Sun frame. $t'=t_{self}$ as we can consider vertical arm of interferometer as primitive clock ticking when light is reflected. $t=t_{to\ upper}$ . $t'$ is slower than $t$ . Is it correct?	http://www.feynmanlectures.caltech.edu/I_15.html#Ch15-F2 , Fig. 15–2; https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&oldid=711458491 Light path analysis and consequences https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&oldid=711808143 Null result of Michelson–Morley experiment extrapolation

193.238.36.135 (talk) 09:24, 28 March 2016 (UTC)[reply]

I think it's correct. -- BenRG (talk) 23:23, 28 March 2016 (UTC)[reply]

biotin crosslinking with streptavidin

I'm on a commercial R&D team where most of my colleagues are skeptical of any experimental process that is too "academic" -- still, we really want to increase average** particle size after magnetic particles linked to streptavidin bind to protein-functionalized-biotin conjugates, which doesn't appear to be really affected by pH (we have to stay within pH 5 to 9), and gets worse (smaller) with increasing ionic strength. So currently we're running optimization experiments by changing the temperature of the buffer during the biotin-streptavidin binding process.

To me, the obvious thing to do would be to obtain "double biotin" -- a covalent linker with biotin on both ends. We would only have to dope at around 0.1 to 2% ratio (per equivalent of "mono" functionalized and free biotin we're using) to get controlled increases in particle size, so the cost increase would be marginal. When I look up "dual biotin" I keep getting double biotin that is attached to some sort of nucleotide, which is pointlessly expensive because we have no use for the nucleotide. What is the right keyword to get a double biotin linker that *doesn't* have any nucleotide in it? Basically, if I can find a double linker that's cheap enough, then I might persuade my team (always bottom-line-minded) to try my idea.

** I really think we should be using the median as a useful marker of particle size to account for outliers, based on my previous experience with population statistics, but my team still thinks the mean is just good but sigh

Yanping Nora Soong (talk) 16:50, 28 March 2016 (UTC)[reply]

Have you tried this Google search ?

"double biotin" "covalent linker" -nucleotide

Also, is the term "dual biotin" ever used ? StuRat (talk) 20:29, 28 March 2016 (UTC)[reply]

I don't really understand this: "dope at around 0.1 to 2% ratio (per equivalent of "mono" functionalized and free biotin we're using)" If you are reacting the protein with variable amounts of something with biotin that covalently binds to various random spots on the protein, then adding a bit more should be the same as using "double-headed biotin" ... shouldn't it? And if you have somehow engineered specific sites into the protein (which is at least possible) then you could engineer more with a similar effect. What am I missing here?

I'm assuming there are strept?avidin beads like this being bound to biotinylated protein with varying numbers of moieties attached. The way you describe the size of the complex makes me think you are trying to get multiple beads to bind per protein and multiple proteins per bead for big aggregates, though I didn't think this was necessary in routine protocols?

A concern I would have with double-headed biotin is that a) if the linker between the two biotins is really short, then I don't know how likely it would be for a free biotin chained to a huge (I assume) magnetic bead to be able to get access to another one, and b) if the linker is long, then I don't know if the two biotins can access multiple avidins bound to the same magnetic bead.

But the biggest worry I'd have would be bureaucratic. Using a different reagent to interact with the bead sounds like a patentable invention. Problem is, this is a fairly mature process - I would worry there could be some patent out already that would interfere with your product as revised. Also, telling us too much about your invention might interfere with patenting it in many jurisdictions... Wnt (talk) 22:14, 28 March 2016 (UTC)[reply]

If I'm reading your question correctly, you want to bind multiple proteins to a single bead in this order: bead+streptavidin=biotinilated protein=double headed streptavidin=biotinilated protein etc? You're going to need a long flexible linker for that, otherwise the biotinilated sites on new proteins aren't going to be able to bind to the exposed streptavidin due to steric interactions. Undergrad organic chemistry is a long time ago, but the obvious candidate for that would be a long alkane. However, with those you're going to get significant problems with hydrophobicity of your linkers. Fgf10 (talk) 22:55, 28 March 2016 (UTC)[reply]

Nay, he said two biotins with some covalent linker. I had assumed this had to be linked to the protein somehow. Otherwise they would just aggregate the beads on their own with no protein needed (though maybe not as much? Or maybe what counts is how much protein gets pulled down regardless of how?) I would have thought that aggregating beads on their own in any quantity would cut the particle size rather than raise it, by creating more nuclei, though I suppose you could add it after the protein to try to get any wallflower beads to stick on to something. Still... this feels too complex, too finicky. If you want bigger complexes, couldn't you just use bigger beads? Wnt (talk) 14:08, 29 March 2016 (UTC)[reply]

Medicine price in the US: wholesale $5-7, monthly $100-$200

According to budesonide: "The wholesale price for an inhaler containing 200 doses is about 5 to 7 USD as of 2014.[11] As of 2015 the cost for a typical month of medication in the United States is 100 to 200 USD"

Where do the $95-$193 go to? Couldn't a lab just offer it for $9.5-$19.30? Wouldn't US resident who need this medicine for treating a chronicle condition be better off traveling abroad to buy it? --Llaanngg (talk) 23:34, 28 March 2016 (UTC)[reply]

Please provide a link to where it says that. Offhand, I'm thinking that they charge $5-7 for the inhaler, but you must pay additional for the meds it contains. StuRat (talk) 00:00, 29 March 2016 (UTC)[reply]

It is in the third paragraph of the linked article. You assumption is not right. It says one inhaler with 200 doses. That implies inhaler and medicine together. --Llaanngg (talk) 00:04, 29 March 2016 (UTC)[reply]

The source for the first sentence is available online, but the source for the 2nd line doesn't appear to be. This makes it difficult to know exactly what they said. StuRat (talk) 00:24, 29 March 2016 (UTC)[reply]

probably very misleading statements, at best....the fed govt via medicare/Medicaid has an upper limit on allowable markup (their formula for determining price is likely several thousand pages long...but that much markup would not be allowed)...private insurance negotiates price too, in an incredibly complicated and opaque manner as well....the "retail" price might be the price that very, very few people actually pay (ie no insurance, not on medicare/Medicaid) and this price varies from region to region, drug store to drug store...point is, these claims in the Wikipedia article are largely meaningless...68.48.241.158 (talk) 00:15, 29 March 2016 (UTC)[reply]

My guess is that there is a confusion between inhaled budesonide and oral budesonide. The oral tablets are used differently than the inhaled treatments and typically contain 10-20 times higher doses, which could explain a much higher cost if the second price is actually referring to the oral treatments. Dragons flight (talk) 00:18, 29 March 2016 (UTC)[reply]

In answer to the ~~later~~last question, while this isn't legal advice the answer is "probably not" even if the stated costs were accurate. See this page for the FDA's guidance on importation [8]. Note that the general guideline is 3 months. While this isn't a limit, consider the wording on when more than 3 months may be allowed. Also the fact the guidelines aren't intended for cases when a person is importing drugs available in the US which are cheaper elsewhere (except where the patient needed to fill the prescription while overseas) anyway.

So while again this isn't legal advice, if you're lucky you may be allowed to import 3 months when coming back. Perhaps you'll even be allowed to import 3 months every 3 months. Even with usage 2 times a day, this will probably only be a single inhaler. If you need more than 2 doses a day, perhaps you'll get away with 2. So at most perhaps you're saying around $380. More likely $190.

If you live right next to the Canadian or Mexican border (and Mexican may bring additional safety concerns) perhaps it'll be worth the cost including your time spent (maybe a passport if you wouldn't have one otherwise). If you live far and need to either drive long distance or fly, it's unlikely to be worth it. And you have to hope you'd really be allowed to do it regularly, particularly if you were only gone for an hour or two. Even more so if you're trying to import 2 regardless of whether you use enough for this to be 3 months supply.

Nil Einne (talk) 03:37, 29 March 2016 (UTC)[reply]

Pharmaceuticals are subject to all kinds of absurd patent, exclusivity, and just plain ridiculous regulation. From what I've, heard, the American locations (with foreign owners) that make them are shrines of bureaucracy, where it costs them $5,000 to go over their records if somebody scribbles out a number, and they fire a whole shift if someone draws a smiley face on a box. (So to make things extra secure, they hire almost entirely immigrants and work them long hours on swing shifts) So their costs are "actually" higher than the costs for people quoting drug prices FOB Nairobi, as in the first source listed. That said, drug imports to the U.S. can be around 55% cheaper, according to this WebMD article, which definitely makes mail order "against" the law sound very mainstream indeed. There's an online pharmacy article here. However, note that the TPP and its fellow international overlords are expected to lay waste to health care everywhere, leaving Canada and Mexico in the same sorry boat as Americans - see [9] [USER WAS BOMBED FOR THAT POST, some say] Wnt (talk) 13:13, 29 March 2016 (UTC)[reply]

March 29

bird ID

What bird is this? The file id's it as a Javan hawk-eagle but I think it looks more like a black eagle. Said to be photographed in Mount Halimun Salak National Park on Java where 10 Javan hawk-eagles are said to have been found. Rmhermen (talk) 01:51, 29 March 2016 (UTC)[reply]

Yes, it does look more like the black eagle. While the black eagle isn't listed as being native to Java, it does extend down to the Malay Peninsula. I wonder if that would put them close enough to be within flight distance (they could stop off at Sumatra on the way). StuRat (talk) 03:37, 29 March 2016 (UTC)[reply]

It does look more like the black eagle (not a terribly high bar as the pictured bird is pretty clearly not a Javan hawk-eagle), but I'm not so sure that's what it is; the barring on the tail is rather distinctly different. Note: I'm no expert; that could easily be due to normal variation. Matt Deres (talk) 15:20, 30 March 2016 (UTC)[reply]

In fact indeed do exist a real uni-polar neuron?

According to the article on Wikipedia, do exist real uni-polar neuron ans this is in contrast (apparently) to what I saw in the books that I read that there are three is only pseoudo-unipolar neuron. So in fact indeed do exist a real uni-polar neuron? 93.126.95.68 (talk) 02:32, 29 March 2016 (UTC)[reply]

Yes, there are real unipolar neurons. They are very common in insects and other invertebrates but also exist in vertebrates. If you are asking anything more, I can't understand it. Looie496 (talk) 00:58, 30 March 2016 (UTC)[reply]

I'm not even sure why they is asking, as in order to link us that picture, they had to have seen the article explaining that they are real and what they are. --OuroborosCobra (talk) 01:49, 30 March 2016 (UTC)[reply]

Special relativity. Simultaneity

Question	Remark
As BenRG (talk) 17:39, 20 March 2016 (UTC) said here https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&oldid=711808143, digital displays cannot lie. But as we know from Special relativity , clocks in moving reference frame are not synchronized. E.g. our clock shows $t\sec$ from Big Bang (or from any other moment). Another frame passing us with speed $\mathbf {u}$ has 3 clocks: front-end, hind-end and middle clock. When middle clock passing our clock , our clock and middle clock are synchronized manually. Man in moving frame synchronizes front-end and hind-end clocks with middle manually. Then we see from our frame:[reply] our clock shows $t\sec$ ; middle clock shows $t\sec$ ; front-end clock shows $t-4\sec$ ; hind-end clock shows $t+4\sec$ . When moving reference frame will stop instantly ( $a=-\infty$ ), what will we see on front-end and hind-end clocks and why?	https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Science&action=edit&oldid=711808143 Null result of Michelson–Morley experiment extrapolation https://archive.org/download/PhysicsForTheEnquiringMind/Rogers-PhysicsForTheEnquiringMind.djvu , page 492

37.53.235.112 (talk) 05:04, 29 March 2016 (UTC)[reply]

You've specified that the moving clocks differ by 4 seconds when measured simultaneously wrt the lab frame, and I'll assume that they all stop simultaneously wrt the lab frame. Then after stopping they will still differ by 4 seconds wrt the lab frame, because acceleration doesn't affect ideal clocks; their reading doesn't jump forward or backward at the moment of the acceleration, they just keep ticking. This is an example of ideal clocks losing their synchronization when accelerated, which happens in special relativity but not in Newtonian physics. (Another example is the twin paradox/effect: the twins' initially synchronized ages are desynchronized when they meet again.) -- BenRG (talk) 05:59, 29 March 2016 (UTC)[reply]

When moving ref. frame stops, it merges with ours. Man from moving frame saw clocks sinchronized. An when his frame will stop he will see difference, or what? But digital display can't do such things.37.53.235.112 (talk) 10:30, 29 March 2016 (UTC)[reply]

The clocks are just clocks. They aren't aware of each other, they just follow their own local laws. If they end up not Einstein-synchronized, and you still want to call them a reference frame, that's fine as long as you're willing to accept the consequences (more complicated-looking physical laws), but the universe doesn't care one way or another what you use as a reference frame. -- BenRG (talk) 19:58, 29 March 2016 (UTC)[reply]

Could someone clearly and simply state what's being asked here? I can't figure it out...but find the topic interesting so would like to understand what's being discussed...68.48.241.158 (talk) 15:26, 29 March 2016 (UTC)[reply]

I think you need first check links in Remark column. Don't worry, 99% of people don't understand special relativity.37.53.235.112 (talk) 16:47, 29 March 2016 (UTC)[reply]

I think the question is simply whether, if you accelerate a bunch of comoving Einstein-synchronized clocks, they will still be Einstein-synchronized afterwards. The answer is no in general (yes in special cases, but the question wasn't about one of those cases). -- BenRG (talk) 19:58, 29 March 2016 (UTC)[reply]

Question	Remark
Another question. Suppose we have 2 observers ε (at rest) and ε' (moving) in 2 coaches as on Fig. 31-39 : https://upload.wikimedia.org/wikipedia/commons/1/17/160329155625UTC.png Observer ε has 1 clock, it shows time in frame ε: at start $0$ , when ligth raeches hind end of ε' coach $\tau _{1}$ , when ligth raeches front end of ε' coach $\tau _{2}$ . Also observer ε can see ε' clocks (ε' has 3 clocks hind, middle, front) from frame ε: at start ε' clocks shows $\theta _{0}^{[}$ ([ means hind end), $0$ (at start observers sinchronized clocks manually), $\theta _{0}^{]}$ (] means front end), when ligth raeches hind end of ε' coach $\theta _{1}^{[}$ , $\theta _{1}$ , $\theta _{1}^{]}$ , when ligth raeches front end of ε' coach $\theta _{2}^{[}$ , $\theta _{2}$ , $\theta _{2}^{]}$ . First let us find $\tau _{1}$ and $\tau _{2}$ : $\tau _{1}={\tfrac {L/2}{c+u}};\tau _{2}={\tfrac {L/2}{c-u}}$ . Then , suppose $\theta _{1}^{[}=\theta _{2}^{]}$ . We have: $\theta _{1}^{[}=\theta _{0}^{[}+\tau _{1}{\sqrt {1-u^{2}/c^{2}}}$ , $\theta _{2}^{]}=\theta _{0}^{]}+\tau _{2}{\sqrt {1-u^{2}/c^{2}}}$ , so $\theta _{0}^{[}+\tau _{1}{\sqrt {1-u^{2}/c^{2}}}=\theta _{0}^{]}+\tau _{2}{\sqrt {1-u^{2}/c^{2}}}$ ; $\theta _{0}^{[}-\theta _{0}^{]}=\tau _{2}{\sqrt {1-u^{2}/c^{2}}}-\tau _{1}{\sqrt {1-u^{2}/c^{2}}}$ $={\sqrt {1-u^{2}/c^{2}}}(\tau _{2}-\tau _{1})$ $={\sqrt {1-u^{2}/c^{2}}}({\tfrac {L/2}{c-u}}-{\tfrac {L/2}{c+u}})$ $={\sqrt {1-u^{2}/c^{2}}}{\tfrac {Lu/c^{2}}{1-u^{2}/c^{2}}}$ $={\tfrac {Lu/c^{2}}{\sqrt {1-u^{2}/c^{2}}}}={\tfrac {(x^{]}-x^{[})u/c^{2}}{\sqrt {1-u^{2}/c^{2}}}}$ . First , why do we suppose $\theta _{1}^{[}=\theta _{2}^{]}$ ? These times do match only in ε' frame as observer ε' sinchronized all his clocks. $\theta _{0,self}^{[}=\theta _{0,self}=\theta _{0,self}^{]}=0$ . When light reaches walls in frame ε': $\theta _{self}^{[}=\theta _{self}=\theta _{self}^{]}={\tfrac {L/2}{c}}$ . https://upload.wikimedia.org/wikipedia/commons/4/49/160329181132UTC.PNG Second. $\theta _{1}$ and $\theta _{2}$ are not used, but are next eq. correct $\theta _{1}=\tau _{1}{\sqrt {1-u^{2}/c^{2}}}$ , $\theta _{2}=\tau _{2}{\sqrt {1-u^{2}/c^{2}}}$ ? Should we not make correction for coordinate term $ux/c^{2}$ ? Third. What actually is $t'$ from Lorentz transformations ? Time interval or moment time or what? $t'={\tfrac {t-ux/c^{2}}{\sqrt {1-u^{2}/c^{2}}}}$ If $x=0$ then $t'={\tfrac {t}{\sqrt {1-u^{2}/c^{2}}}}$ . So $t'>t$ , as ${\sqrt {1-u^{2}/c^{2}}}<1$ and so ${\tfrac {1}{\sqrt {1-u^{2}/c^{2}}}}>1$ . But we know that time goes slower in moving frame, so we always have $t'\sec <t\sec$ .	https://archive.org/download/PhysicsForTheEnquiringMind/Rogers-PhysicsForTheEnquiringMind.djvu , page 493, Fig. 31-39. http://www.feynmanlectures.caltech.edu/I_15.html#Ch15-S6

37.53.235.112 (talk) 16:47, 29 March 2016 (UTC)[reply]

Is the observer actually "seeing"/detecting light from three clocks that (at the moment) displays +4, 0, -4? Or are there three observers that happen to be beside the three moving clocks, at rest relative to one another, who at the same moment (from their perspective) see these readings and later communicate them? In the second case, instantaneous deceleration should not much affect the clock reading as said above. But in the first case, light emitted by the clocks will continue to tick forward after the deceleration, showing them keeping time at a different rate due to time dilation; once the deceleration happens they tick at normal speed. But exactly when the deceleration occurs, there's a bit of a mystery; bear in mind that if the three clocks decelerate at the same time in your frame of reference, that's a different time in theirs, which is why the Lorentz contraction becomes a real crunching together in space (as it must for the Lorentz contracted object all to stop at the same time as you see it). Wnt (talk) 18:14, 29 March 2016 (UTC)[reply]

Is the observer actually "seeing"/detecting light from three clocks that (at the moment) displays +4, 0, -4? Or are there three observers that happen to be beside the three moving clocks -- As in E.Rogers book [page 493, note 19], I think observer at rest allows for time-delay of seeing a clock that is far away. To do that he can use 2 helpers or put 2 additional clocks, yes. But question isn't with observer at rest, but with both observers. Before stop moving observer sees 0, 0, 0. Observer at rest sees +4, 0, -4. After stop observer at rest still sees +4, 0, -4. Stoped observer sees ... what? also +4, 0, -4? 37.53.235.112 (talk) 18:39, 29 March 2016 (UTC)[reply]

The stopped observer sees one clock stop at -4, then he keeps going on for a while and stops later, then the last clock keeps moving at him and then stops at +4. Note that the actual difference in time is generally small and the distance large - you would never see a timelike slice of someone else's light cone in normal space at any speed - so there is always enough distance for the clocks to tick that far before they change speed. Wnt (talk) 10:18, 30 March 2016 (UTC)[reply]

I urge you to forget about "observers". The experiment here consists of the train car, the light, and the clocks. There needs to be an experimenter looking at the digital readouts of the clocks, but that person doesn't need to be moving in any particular way, doesn't need to look only at certain clocks and ignore others, etc.

To answer your third question first,

t'

is a coordinate. You're probably familiar with Cartesian coordinates from Euclidean geometry, and you know that the transformation between different coordinate systems (with a common origin) looks like

x'=x\cos \theta -y\sin \theta

y'=y\sin \theta +x\cos \theta

where

\theta

is the angle between (say) the x axes. There's no reason we have to use the angle; we could instead use the slope of one x axis with respect to the other coordinate system. Call the slope

v

. Then

\theta =tan^{-1}v

, and plugging that in and doing some trig substitutions gives you

x'=\gamma (x-vy)

y'=\gamma (y+vx/c^{2})

where

\gamma =1/{\sqrt {1+v^{2}/c^{2}}}

and

c=1

. The reason this looks almost the same as the Lorentz transform is that they are almost the same thing. The similarity is hidden by the completely arbitrary way in which special relativity has always been taught. By convention, we use the slope

v

between the coordinate systems instead of the angle

\alpha

. By convention, we use different units for distance and time intervals, which necessitates adding in some factors of

c

. None of this accomplishes anything; the universe doesn't care. Time is actually just another dimension, and the Lorentz transformation is just a coordinate transformation.

When you transform Cartesian coordinates, you plug in the coordinates of a point (x,y), and get new coordinates of the same point, (x',y'). Either pair of coordinates, by itself, identifies the point. You don't need both pairs. You don't need to pick the coordinate system that the point is "in". All points are "in" all coordinate systems. You should pick the coordinate system that's most convenient for the problem you're trying to solve. Any coordinate system will work, because they're equivalent descriptions of the same geometry.

Coordinate pairs like (x,y) or (x',y') must always be kept together because the components are meaningless by themselves. An equation like x=3 can define a line, but if you want to transform that equation into a different coordinate system, you can't just plug the x coordinate into the transformation equations and get an x'. The line doesn't have an equation of the form x'=anything. You can, for example, write the line parametrically as x(q) = 3, y(q) = q, or better as (x,y)(q) = (3,q), and plug the pairs (3,q) into the coordinate transformation, and get a correct parametric equation for the line in terms of the other coordinates. Likewise, pairs like (x,t) and (x',t') must be kept together. You can't just transform time. You must always use both (or all four) of the Lorentz transformation equations together, otherwise you will get nonsensical results (unless you really understand what you're doing).

In your problem, say the light is emitted at (0,0) (in either coordinate system). It reaches the walls at

(x',t')=(\pm L/2,L/2c)

, or equivalently

(x,t)=({\tfrac {\pm Lc}{2(c\pm u)}},{\tfrac {L}{2(c\pm u)}})

. Your first clock has the parametric equation (x,t)(τ) = (0,τ), which you can plug into the Lorentz transformation to find (x',t')(τ). To find the digital reading of that clock at a particular (x,t) or (x',t'), you just solve for τ. Your other three clocks have the parametric equations (x',t')(θ) = (0, θ) and (x',t')(θ^[]) = (±L/2, θ^[]), and you can plug those into the Lorentz transformation to find (x,t)(θ^whatever). Any question you have about what someone sees at a given (place,time) can be answered in this way. They are simple questions about coordinate geometry. -- BenRG (talk) 19:58, 29 March 2016 (UTC)[reply]

Last Sunday, March 27, 2016 we had to put our beloved cat to sleep. She was 21 and sick for a year. She weighed only 4 pounds with her premorbid weight of 12 pounds, skin and bones. She could not eat at all for the last week or so. She lived with us for 18 years. Two weeks before she died our long-functioning wall clock stopped and it seems we must throw it out. On Monday I found out to my surprise that it is a common belief that if your clock stopped, somebody will die in your family and this cat was a true family member. It is a true story. Read this Daily Mail article. Is it a Special Relativity or what? --AboutFace 22 (talk) 22:11, 29 March 2016 (UTC)[reply]

Question	Quote
So $(x',t')(\tau )$ are space-time coordinates of 1st clock in rest frame seen from moving frame, right? $(x',t')(\tau )=({\tfrac {x-ut}{\sqrt {1-u^{2}/c^{2}}}};{\tfrac {t-ux/c^{2}}{\sqrt {1-u^{2}/c^{2}}}})$ $(x',t')(\tau )=({\tfrac {0-u\tau }{\sqrt {1-u^{2}/c^{2}}}};{\tfrac {\tau -0}{\sqrt {1-u^{2}/c^{2}}}})$ At time $\tau _{1}$ 1st clock will show $(x',t')(\tau _{1})=({\tfrac {-u\tau _{1}}{\sqrt {1-u^{2}/c^{2}}}};{\tfrac {\tau _{1}}{\sqrt {1-u^{2}/c^{2}}}})$ , seen from moving ε' frame. Is it correct? Thank you. But I will study Special relativity as rotatings next month. Now I must understand all without coordinates, angles, etc. I follow Feynman Lectures and chapters 15-1...15-6 don't use rotatings.	In your problem, say the light is emitted at (0,0) (in either coordinate system). It reaches the walls at $(x',t')=(\pm L/2,L/2c)$ , or equivalently $(x,t)=({\tfrac {\pm Lc}{2(c\pm u)}},{\tfrac {L}{2(c\pm u)}})$ . Your first clock has the parametric equation (x,t)(τ) = (0,τ), which you can plug into the Lorentz transformation to find (x',t')(τ). To find the digital reading of that clock at a particular (x,t) or (x',t'), you just solve for τ.

37.53.235.112 (talk) 09:05, 30 March 2016 (UTC)[reply]

So

(x',t')(\tau )

are space-time coordinates of 1st clock in rest frame seen from moving frame, right? –

(x,t)(\tau )

is where the clock actually is, and

(x',t')(\tau )

is also where the clock actually is, just expressed in a different way. To figure out what people see, you need to trace light from the clock to someone's eye (and you can use either coordinate system to do that, and get the same result, since they describe the same world).

At time

\tau _{1}

1st clock will show

(x',t')(\tau _{1})=({\tfrac {-u\tau _{1}}{\sqrt {1-u^{2}/c^{2}}}};{\tfrac {\tau _{1}}{\sqrt {1-u^{2}/c^{2}}}})

, seen from moving ε' frame. Is it correct? – I think the algebra is right, but the description is sort of backwards. The clock shows

\tau _{1}

on its face when it's at

(x',t')=({\tfrac {-u\tau _{1}}{\sqrt {1-u^{2}/c^{2}}}},{\tfrac {\tau _{1}}{\sqrt {1-u^{2}/c^{2}}}})

. -- BenRG (talk) 17:20, 31 March 2016 (UTC)[reply]

Kinetic energy of charged particles

What is the expression of the kinetic energy of moving charged particles?--5.2.200.163 (talk) 15:38, 29 March 2016 (UTC)[reply]

You'll need to provide more context. In many cases, the classical formula - the one you probably know as

KE=1/2mv^{2}

- is good enough for the job. In Griffith's book, he advances the definition to account for special relativity, using the formuka

E_{kin}=mc^{2}({\frac {1}{\sqrt {1-{\frac {u^{2}}{c^{2}}}}}}-1)

for relativistic velocity u. In Bittencourt's book, which makes extensive use of energy analysis for charged particles, the author uses a more statistical approach, defining an energy density just for kinetic energy:

W_{\alpha }=1/2\rho _{m\alpha }u_{\alpha }^{2}+1/2\rho _{m\alpha }<c_{\alpha }^{2}>

for the mean kinetic energy density of particles of species α, mass density ρ, with velocity u and peculiar velocity c (representing sort of "Brownian motion" separately from bulk particle transport velocity). The author proceeds to analyze other statistical measures of the kinetic energy distribution - there's more information than just the average value! In a sense, this is a classical treatment: so if you wanted to deal with something awful, like a multi-species, hot, dense, relativistic plasma, with each charged specie interacting with every other charged specie - say, modeling the charged particles inside the sun or inside a nuclear bomb - you'd have to synthesize a corrected total energy and total kinetic energy equation that combines a lot more terms and forms!

Many times, especially in quantum mechanics, kinetic energy is defined as an operator, and is usually expressed in relation to the momentum (not the mass and velocity). This is particularly helpful when laboratory measurement of mass or velocity is muddied by technical difficulties: for example, it is often easier to measure the energy of a charged particle than to measure its mass, charge, or velocity: we have lots of machines that can directly measure electron energy, like an electron spectrometer or an electron energy loss spectrum analyzer.

The point is, lots of advanced physics just builds on top of the basic physics you already know, and adds complications one step at a time.

Nimur (talk) 16:01, 29 March 2016 (UTC)[reply]

More context would be connected to what the article momentum#Electromagnetism#Particle in field says and the relation between kinetic energy and momentum within electromagnetism.--5.2.200.163 (talk) 16:39, 29 March 2016 (UTC)[reply]

If you look closely at the subsection you linked, you can see that the first row of the first column contains a classical kinetic energy term, in vector coordinates. The next column applies a Lorentz transform to that equation. The trick to extract the kinetic energy term is to carefully observe and recognize its general form. If you make simplifying assumptions, the equation is exactly the same as the one you learn in basic physics. You can go very far with Newtonian-style equations - and unless you like making extra work for yourself, in many cases you should use the simplest form of the equation.

But, the authors of the section you linked are being very cautious in order to be generally correct. For example, they write

{\frac {m}{2}}\mathbf {\dot {r}} \cdot \mathbf {\dot {r}}

instead of

{\frac {m}{2}}v^{2}

. Why have they written it in this way?

Can you think of any condition in which the time derivative of the position vector is not the strict velocity vector? Or, more likely: where would the inner product of the time derivative of the position vector, multipled by itself, not be equal to the square of the scalar velocity?

I can think of a case: a non-scleronomous coordinate system - like the swinging arm of a double pendulum (or, in electrodynamics: a charged particle orbiting an accelerating charged particle - like we might see in the electron of a nearly-ionized hydrogen atom traveling in the van Allen belt)! We don't even have to dive deep into relativistic physics or quantum physics - just classical cases - where the general form of the equation is more correct. Throw in the effects of relativity, or the wacky nonsense called "quantum mechanics," and the equations just get more and more complicated. Yet, this allows us to solve equations of motion - and conserve energy, and so forth - even in non-inertial reference frames, or in cases of non-conservative forces, and so forth.

Nimur (talk) 17:47, 29 March 2016 (UTC)[reply]

Hey @Nimur: are you saying that for a pendulum whose pivot undergoes simple harmonic oscillation, the equation

{\frac {m}{2}}v^{2}

does not yield the right answer for kinetic energy, but the r-dot form does (assuming both the v and r are with respect to the same non-moving frame in which the pivot oscillates)? Also, is "non-scleronomous" just a synonym for "rheonomous" in this case (or in general)? Both those articles could use some improvement... SemanticMantis (talk) 18:34, 29 March 2016 (UTC)[reply]

The point is that a double pendulum provides an easy-to-visualize case of a complicated non-inertial reference frame. If you are not very careful about the definition of the position (and therefore, the velocity), you end up computing very strange (incorrect!) quantities of energy. For example: you can fully treat the double pendulum as a two-dimensional system; you may, therefore, represent the position of the end-effector as either Cartesian (x,y) pair, or you may use the angular position of each hinge (θ₁, θ₂). Both representations are of equal rank, so they fully describe all the degrees of freedom; but if you use the x, y, position of the second segment of the arm, you are probably forgetting to account for the mass, momentum, and energy carried by the first segment of the arm - or you're setting yourself up for some terrible algebraic transforms! One representation provides a much more natural way to represent and compute the kinetic energy.

Yes, rheonomous and scleronomous coordinate systems are opposites. These terms show up in robotics, physics, and so on. These terms refer to whether your generalized coordinates are time-invariant.

You might also find holonomic and non-holonomic coordinates, especially in the contexts of robotics. These terms refer to whether your generalized coordinates are orthogonal and whether they inherently depend on the time-history.

Nimur (talk) 20:21, 29 March 2016 (UTC)[reply]

Most abundant species?

[10] and [11] makes the following claims:

(Cracked is not a reliable source for anything but bad jokes, but they are right surprisingly often.)

The Antarctic krill is the most abundant animal species, with a population of 500 trillion. I would have guessed nematodes or one of the bacteria.
Cows are the animal species with the highest total weight -- 170 million tons. I would have guessed one of the ant species.

Has anyone made an educated guess as to the most abundant species by number of individuals or by total weight? --Guy Macon (talk) 21:26, 29 March 2016 (UTC)[reply]

if google 'total weight all ants' a bunch of articles will come up...apparently there's no scientific consensus as to how many ants there are on earth (like not even a good guess)...only that there are a lot....obviously too bacteria and such are not considered animals..68.48.241.158 (talk) 21:36, 29 March 2016 (UTC)[reply]

What you are looking for is the animal with the largest biomass, the article has a list. Vespine (talk) 00:05, 30 March 2016 (UTC)[reply]

Actually, the list is at Biomass (ecology) - the Biomass article is about plant crops used as a source of fuel. 217.44.50.87 (talk) 09:32, 30 March 2016 (UTC)[reply]

Ants are commonly estimated to be roughly equal to human biomass. E.O. Wilson claims this in his book The Insect Societies, and here is a nice discussion of the claim, with further citations, and it also addresses the krill, with additional citation. Wilson and Holldobler have additionally estimated 10,000 trillion individual ants alive at a time, which would far surpass the krill. But maybe we're not making the right comparisons. The simple reason ants cannot be the most massive species is because their are many, many (>10k) species of ant; the Formicidae are a family. In contrast, we could probably claim that all the breeds of cattle still constitute a single species, and thus the cattle would out mass any single species of ant. Back to the krill, keep in mind they live in a much thicker layer than any other candidates on the list. Sure there are arboreal ants, and the nematodes go down a few feet maybe, but that's nothing compared the zone Antarctic krill inhabit, which is up to 3 km deep. Anyway, if you want to restrict to single species, a specific ant is probably not going to hold any records. If you want to compete all ranks, clades, and unranked groups then all the records are going to be set by one of the three domains. SemanticMantis (talk) 13:37, 30 March 2016 (UTC)[reply]

It's also worth noting that it is often claimed that 1/4th of all living things are beetles. (like here) However, that claim is usually based on the fact that about 1/4th of all identified species are beetle species, which is yet another way to count living things. About 1/4th of all species are species we classify as beetle species. Some will confuse this with the above definitions of "most", so while "ants" as a classification contain more individuals than "beetles" would, there are more different kinds of beetles than there are kinds of ants. --Jayron 32 14:38, 30 March 2016 (UTC)[reply]

And just to emphasize it again, that's only described species. Amateur and semi-professional collecting of beetles goes back more than a century and the differences between beetles are rather easier to discern with the naked eye. In other words, more attention was historically paid to describing and cataloging beetles than ants, which skews the numbers. Matt Deres (talk) 15:25, 30 March 2016 (UTC)[reply]

There is also the question of whether it is fair to lump multiple species of ants or beetles together when determining "most individuals" or "largest biomass". Even the "individual" bit is somewhat ambiguous. Is the "largest organism" listed at Clonal colony#Record colonies one individual or thousands? Is a Volvox one individual or many? See Slime mold#Behavior for a colony that is "no more than a bag of amoebae encased in a thin slime sheath, yet they manage to have various behaviours that are equal to those of animals who possess muscles and nerves with ganglia – that is, simple brains." Also see: Largest organisms. --Guy Macon (talk) 15:46, 30 March 2016 (UTC)[reply]

Even, to add to the excellent points you are making, the species problem. --Jayron 32 18:41, 30 March 2016 (UTC)[reply]

Note that bacteria aren't animals, so even if they are more numerous, they wouldn't count for the original stat. Iapetus (talk) 16:12, 31 March 2016 (UTC)[reply]

March 30

Rumination Syndrome Weight Loss

Hey, I have rumination syndrome and I was recently reading the article on it. I am a bit underweight, and I was surprised that this might be due to a RS symptom occurring in 42.2% of people "at an average loss of 9.6 kilograms, and is more common in cases where the disorder has gone undiagnosed for a longer period of time, though this may be expected of the nutrition deficiencies that often accompany the disorder as a consequence of its symptoms". 1) How do the symptoms cause nutrition deficiencies? 2) Which symptoms in particular? 3) What effect does nutrition deficiencies have on weight? 4) Why is this so drastic (9.6 kilos average!!!)? Thanks JoshMuirWikipedia (talk) 11:14, 30 March 2016 (UTC)[reply]

I can't help you much right now, but I want to stress that you asked four very specific questions about a named syndrome, and we can in principle provide references that may address those questions. I have numbered them for our convenience. The fact that you may or may not have this syndrome is irrelevant. I will personally be watching this thread, and removing any responses that give (or appear to give) medical advice. For 3) you might start at Malnutrition#Diseases, which discusses how certain disorders can cause malnutrition and weight loss in general, though it does not say anything about Rumination Syndrome in particular. SemanticMantis (talk) 14:00, 30 March 2016 (UTC)[reply]

I was just about to offer the standard "we cannot provide medical advice" response, but I think SemanticMantis is correct that we can provide links to sources. But honestly, for serious conditions like this, isn't it better to trust your treating professional rather than "doctor google"? Eliyohub (talk) 14:02, 30 March 2016 (UTC)[reply]

Sure, I'll tell OP right now to go see a doctor. But I'm pretty sure he already knows he can see a doctor. He's probably already seen a doctor. And none of that really matters, because these are just questions about a medical condition, and OP is clearly not seeking any diagnosis, prognosis, or treatment. But sometimes people just want to know information. And most doctors won't do literature searches and summary for you on the spot. Sometimes we do :) SemanticMantis (talk) 14:08, 30 March 2016 (UTC)[reply]

Also here [12] is a link to the abstract of the article that is cited by our WP article to support the quote you gave. It says " Weight loss was described by 42.2% (median: 7 kg)". Now our article may be reporting a mean that is higher than the median, but the 7kg median is a little more reasonable (perhaps there was one high-loss outlier). I also note that the sample was a bit small, only 147 patients. Finally "Outcome data (at median follow-up 10 months) were available for 54 patients. Symptoms resolved in 16 (30%) and improved in 30 (56%)." If you would like full access to that article, you can ask at WP:REX, or contact me at my talk page. SemanticMantis (talk) 14:08, 30 March 2016 (UTC)[reply]

What is the substance which makes the yellow color of the urine?

93.126.95.68 (talk) 14:37, 30 March 2016 (UTC)[reply]

Urochrome. If instead of coming here and waiting for someone to answer it, you had typed your exact question into Google, you'd have gotten your answer faster. In general, questions can often be answered faster just by typing what you would ask here directly into Google and reading a few links. If that doesn't work, THEN come here and ask. --Jayron 32 14:40, 30 March 2016 (UTC)[reply]

Yeah but then you would have nothing to do, would you??--178.101.224.162 (talk) 00:03, 31 March 2016 (UTC)[reply]

You forgot to put that joke in small print. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:36, 31 March 2016 (UTC)[reply]

...unless your question is "What is the TRUTH about black helicopters?". The links Google returns for that question are...interesting. :) --Guy Macon (talk) 15:53, 30 March 2016 (UTC)[reply]

I don't believe urochrome has anything to do with why helicopters may be black. I believe that is because of black paint. It may take a bit more research to look into which pigments are commonly used in black paint. But entirely irrelevant to answering the posed question, because the OP asked only about yellow urine. --Jayron 32 16:27, 30 March 2016 (UTC)[reply]

Ah. I had not realized that your advice above was only for someone asking about the color of urine. It looked a lot like general advice for all sorts of questions. --Guy Macon (talk) 16:36, 30 March 2016 (UTC)[reply]

I feel a song coming on... "Urachro...oh...ohm, gives us that nice, yellow color, makes us feel all the world's a sunny day...ay...ay". StuRat (talk) 17:15, 30 March 2016 (UTC) [reply]

When I think back to all the piss I learned in high school, it's a wonder I can think at all....--Jayron 32 18:39, 30 March 2016 (UTC)[reply]

Or "...it's a wonder I can tinkle at all". StuRat (talk) 19:46, 30 March 2016 (UTC) [reply]

Yellow lamppost, what'cha knowin'?
I come to ask: "What was that flowin'
In the staggering drunk-guy's pee?
Oh, oh! Uro-chrome streaks on theeeee."

-- DMacks (talk) 21:15, 30 March 2016 (UTC)[reply]

Is there a species that comes in at least 3 very saturated and very different colors?

Like red, green, and blue or violet. Sagittarian Milky Way (talk) 16:42, 30 March 2016 (UTC)[reply]

Scarlet Macaw? They are a bright, saturated red, blue, and yellow. --Jayron 32 16:57, 30 March 2016 (UTC)[reply]

(ec) Do you mean one individual has all those colors at once ? If so, some types of parrot may qualify, or a mandrill (red, blue and cyan). Since many species have brightly colored eyes, that may count as the third color in many cases. If you mean a species which has multiple color phases, each with one distinct bright color, that may be harder to find. StuRat (talk) 16:59, 30 March 2016 (UTC)[reply]

(ec) A number of fish species, take e.g. the Siamese fighting fish that you can find in red, purple, blue, orange etc. - Lindert (talk) 17:01, 30 March 2016 (UTC)[reply]

(ec) Do you mean a single individual of a species that has three colours? The Mandrill would be a contender for this. If you mean individuals that are a single colour only, but this differs within species, this is rather unlikely because individuals within a species all evolve to have a similar appearance for communication purposes. This breaks down for animals we have artificially selected and we can find a wide range of colours in these (e.g. cats, dogs, guinea pigs), but the colour blue is quite rare in mammals. DrChrissy ^(talk) 17:04, 30 March 2016 (UTC)[reply]

You might also consider animals that can change their colors, like the cuttlefish. (Chameleons can change to bright green, but not sure if any other colors they can manage would qualify as "saturated"). StuRat (talk) 17:11, 30 March 2016 (UTC)[reply]

One place to start understanding colours is Biological pigmentation. DrChrissy ^(talk) 17:10, 30 March 2016 (UTC)[reply]

Wow! Take a look here[13] I have never seen a red budgie before! Follow-up. This site claims the photo of the red budgie is a fake.[14]DrChrissy ^(talk) 17:20, 30 March 2016 (UTC)[reply]

@DrChrissy: That hypersaturated image could be fake, but there are others on the web, and I found this video of a partially red budgie which seemed pretty convincing. Nothing is impossible in biology, but changing structural color should be significantly more possible than usual, because making it red just means putting the ridges further apart. So the claim that it can't be true because of a "color palette" is entirely baseless, AFAIK. Wnt (talk) 00:49, 1 April 2016 (UTC)[reply]

@Wnt: Thanks very much for that. Much more convincing. The budgie is a myriad of apparent colours! Did you notice the blue beak (not just the cere) and the apparently green legs! DrChrissy ^(talk) 13:11, 1 April 2016 (UTC)[reply]

I think you're probably looking for a certain type of Polymorphism_(biology). That article has many examples you can go through, but one that fits pretty well is the famous Common_side-blotched_lizard, whose three primary male morphs participate in a very interesting paper-rock-scissors mating competition. Their color schemes are orange, blue, and yellow [15]. SemanticMantis (talk) 17:36, 30 March 2016 (UTC)[reply]

Yes, I was looking for polymorphism. I guess there are species like that then. That's a cool lizard. God must've sprinkled extra interesting powder on it while designing.. Now I'm wondering if there's any bioluminescent species of jellyfish or something that come in different "glow races". Sagittarian Milky Way (talk) 18:03, 30 March 2016 (UTC)[reply]

ASK and ye shall receive :) Three colors of glow in this [16] beetle, from green to yellow to orange, similar deal with male polymorphism seemingly related to mating strategies/courtship behavior. They say it's the only known example of color polymorphism of bioluminescence. Here's some of the published research on it [17] [18], and because it's so cool, here is a figure from the PNAS paper that shows some of the colors both on the beetles and cloned alleles expressed by E. Coli in petri dishes. SemanticMantis (talk) 18:29, 30 March 2016 (UTC)[reply]

It'd be a shame if an asteroid barely exterminated the beetles in a 147 mile circle and Jamaica was inside. Sagittarian Milky Way (talk) 01:41, 31 March 2016 (UTC)[reply]

I assume you mean animal species? Because there are hundreds of plant species that have flowering bodies and folliage in various colors. EvergreenFir (talk) Please {{re}} 18:43, 30 March 2016 (UTC)[reply]

We humans have quite a few different hair, eye and skin colors...admittedly not "very saturated" colors - but it demonstrates that evolution allows multiple colors to remain in a population. SteveBaker (talk) 19:47, 30 March 2016 (UTC)[reply]

Maybe a person with bright red hair and two different color eyes might qualify ? StuRat (talk) 19:52, 30 March 2016 (UTC)[reply]

That will be the much missed David Bowie as Ziggie Stardust [19] DrChrissy ^(talk) 20:17, 30 March 2016 (UTC)[reply]

It's actually a very common misconception that David Bowie had different colored eyes, his eyes were both blue, but he had a condition called anisocoria which makes the iris enlarged only giving the appearance that one eye is much darker than the other. Vespine (talk) 00:19, 31 March 2016 (UTC)[reply]

Further, I know some birds have already been mentioned, here are a couple more that might qualify which i have seen in my own back yard, rainbow lorikeet and Eastern rosella. Vespine (talk) 00:22, 31 March 2016 (UTC)[reply]

I was aware that some tropical birds have many colors but I was wondering about something like Siamese fighting fish. I didn't know what they looked like but know I know (red or orange or yellow or green or turquoise or blue or purple or black or white or albino or blue+purple or..., depending on genes) . Sagittarian Milky Way (talk) 01:15, 31 March 2016 (UTC)[reply]

Can anyone name a legal compound of Bromphiramine X, where X is an expectorrant, but not considered a "cough medicine"?

Basically, I have been told that Brompheniramine is now illegal as a capsular antihistamine (In the US), although it is still available as an out-of-pocket liquid anti-cough compound. The problem is that the compound runs $40 for a 4 day dose. I am curious if there is a cheaper formulation that has a monthly dose of brompheniramine, which I took as an antihistamine for two decades, until it was outlawed after someone watched Breaking Bad. Thanks. μηδείς (talk) 21:47, 30 March 2016 (UTC)[reply]

If you want to ping User:Yanping Nora Soong, you should just do it, and if you want the question to be for him alone, you should post it to his talk page. That said, I would suspect chicanery, since it does not take much for greedy medical industry officials to ban a generic in favor of something patented, exclusive, or otherwise monopolized. I see some evidence the product is "discontinued" here, but that doesn't say when or why. Their entry on the U.S. code seems to treat it as legitimate. [20] The news mentions a ban on OTC cough products for kids under 2 as of 2008 or so, but I don't see anything recent. I see concerns about dementia but they seem to skew over to chlorpheniramine when checked - not sure this has been identified for this drug, let alone that it's the reason. Searching Walmart's site for it comes up with some cough elixirs containing it... all marketed at children, oddly enough, though presumably older than two. Now compounding pharmacies are sort of the kung fu heroes of American culture, and it does look like some hits come up that way [21]. I remain almost entirely ignorant of this issue, and if you can post your original point of contact with the "Breaking Bad" story I'd like to see it. It doesn't look much like methamphetamine, but it might cause a false-positive on a test. [22] Wnt (talk) 00:03, 31 March 2016 (UTC)[reply]

Yes, I just wanted attention from someone who might be a little better at reading the relevant literature than I. Putting the name in the header is not good for a few reasons, so I have edited it, thanks. μηδείς (talk) 18:53, 31 March 2016 (UTC)[reply]

If you have been taking it for two decades you may only think you need it, because being an ephedrine your body may have down rated production of your natural ephedrine. So I am not even going to mention even one of the cheap herbal alternatives. Go to you GP, give him your history and listen to what he advises. If you live in the US where doctors are money hungry and don't tend to give impartial advice seek out a trust worthy medically qualified relative. Normally it is bad practice to seek medical advice from a relative but he may be able to point you in the right direction to get proper effective treatment.--Aspro (talk) 00:43, 31 March 2016 (UTC)[reply]

@Aspro: Our article does not call the drug an "ephedrine", but an anticholinergic and possibly antimuscarinic. Ephedrine is a sympathomimetic. It isn't very close to ephedrine physically - for example, note the nitrogen is three rather than two carbons from the phenyl ring and the crucial alpha methyl group of ephedrine and methamphetamine is missing from brompheniramine. If it cross-reacts on a test I'd guess this just means it's a lousy test that will give a positive with practically any alkaloid.

Also, I think you're wandering into medical advice territory when all that was asked was where/whether the drug was available. We should keep our eye on the ball and figure out what happened regarding its availability. Wnt (talk) 11:33, 31 March 2016 (UTC)[reply]

This seller of one capsular product containing brompheniramine [23] says it's unavailable due to manufacturing problems not that it's been discontinued. [24] doesn't even mention supply problems. There are also various info pages like [25] [26] (for some reason I can't access these pages unless I use a US proxy) although the later is a tablet not a capsule and I'm not certain these are still sold.

As with Wnt, I don't see why you think this whatever has happened has something to do with Breaking Bad, as I can't see any info suggesting Brompheniramine is use for illicit drug manufacturing. Since you want an expectorant, perhaps you're confused. I see many formulations with brompheniramine also have pseudoephedrine as a decongestant. It's possible some of these formulations have been banned or restricted (or discontinued because even licit sales have dropped off too much due to the restrictions), but that would likely be because of the pseudoephedrine not because of the brompheniramine.

I also doubt it has anything to do with Breaking Bad even if it did happen. Pseudoephedrine restrictions mostly predated Breaking Bad or at least were well discussed before then. E.g. Combat Methamphetamine Epidemic Act of 2005 as you may guess from the title in the US was before Breaking Bad. In NZ, the most significant (and controversial particularly due to questions over whether phenylephrine is actually effective) restrictions only came after it had started. But the diversion of pseudoephedrine in to making P (meth) was discussed well before Breaking Bad and some restrictions had already been put in place. There was little mention of Breaking Bad in the restrictions and IMO it's fairly unlikely it was much of a factor. (Now a lot of the pseudoephedrine is illegal imported from China.)

Actually [27] while after the first season of Breaking Bad suggests the restrictions actually resulted in an increase in products which just had brompheniramine, and again since we're talking about the US here, there's surely little doubt that these restrictions had little to do with Breaking Bad.

[28], [29] and [30] has some discussion on the historic discontinuation of some products containing brompheniramine, the reasons stated don't seem to suggest it has anything to do with illicit drug manufacturing or Breaking Bad. Incidentally, there's some recent discussion on page 2 of that first link, but it doesn't seem to be a recent change [31] so I presume it's not the reason for the possible current supply limitations of that particular brompheniramine containing product. Dexbrompheniramine/pseudoephedrine mentions another antihistamine (dexbrompheniramine instead of brompheniramine) which was historically removed from the US market for unclear reasons but possibly not anything to do with illicit drug manufacturing and unlikely anything to do with Breaking Bad.

P.S. I can't help with specific marketing definitions of these drugs which I guess is related to insurance, as it's not something I have to deal with or have any desire to learn to deal with. Suffice it to say, if it's true you can't find the drug you want, it seems very unlikely it's anything to do with concerns over brompheniramine being used for illicit drug manufacturing and particularly not concerns that arose from Breaking Bad. There's a slight chance the removal of the drug you want is due to illicit drug concerns (but probably still not Breaking Bad) most likely pseudoephedrine if it contained that.

But since I presume you're talking about something very recent i.e. in the past year or so (as said, the pseudoephedrine issues are fairly historic now), for once I think Wnt's conspiracy theories may be the more likely reason. It's either FDA requirements unrelated to illicit drug concerns, or simple the manufacturing wanting to only sell more modern antihistamine they can charge more for. (There is a possibility restrictions imposed have dropped licit drug sales enough that when combined with other more recent issues, the manufacturer decided it was no longer profitable i.e. it was a contributing factor even if not the final nail.)

P.P.S. Let's not forget Breaking Bad dissed pseudoephedrine meth manufacturing anyway.

P.P.P.S. While this isn't medical advice, if it was a medical professional who told you Breaking Bad or at least illicit drug manufacturing is the reason and they aren't able to offer good evidence for this, perhaps it's time to seek an alternative to more than the specific medication you're looking for.

Nil Einne (talk) 13:56, 31 March 2016 (UTC)[reply]

From those last references it is now clear that this is part of the Unapproved Drugs Initiative, which is most famous for its first feat of seizing colchicine from gout patients. Even after manufacturing is restored the medicine will not be affordable - possibly for a limited term, though I expect that some evergreening tactic or other will keep it unaffordable indefinitely. It is indeed all about money, and so what remains is a straightforward exercise of smuggling vital medicines past the officials of a corrupt regime. Wnt (talk) 14:12, 31 March 2016 (UTC)[reply]

Thanks for all the help above. I'll have to follow all the links. The allusion to Breaking Bad was just shorthand for the Methamphetamine act, which took a lot of drugs off market. I always have had very bad allergies, and am currently taking a first-generation antihistamine QID, which works quite well. But I had been taking Bromfed, as needed, for about 25 years. I only very rarely took two pills a day, and often might only take 4 or 5 pills a week, even during allergy season.

At one point I lost my insurance, during which time I used benadryl, about 8-12 a day. When I got coverage back, I asked the doctor to put me back on Bromfed. Two pharmacies told me they couldn't find it anywhere, and then on my third try, the pharmacist said it had been discontinued in pill form due to the law mentioned above. I have an appointment with a specialist tomorrow, so I will have this at hand when i go in. Thanks. μηδείς (talk) 18:53, 31 March 2016 (UTC)[reply]

Damn, this is not easy. I looked up a document by some dog owners looking to get colchicine for some misguided breed of dog they like. The document dated 10/2014 listed four places that sold colchicine, all of which appear to still have the product listed, though you may have to chop off the subpage on the URLs (though until you get to the final transaction screen you never know if they'll say no wait...). These were www.universaldrugstore.com, www.canadadrugs.com, alldaychemist.com, and (to veterinarians) wedgewoodpetrx.com. But none of the four had a listing for brompheniramine! Wnt (talk) 21:30, 31 March 2016 (UTC)[reply]

Allergens in mushrooms

Are they destroyed by cooking? This is not a medical question. I am just wondering about the nature of the allergen. I read somewhere that it is a protein and elsewhere that it is spores. Thank you kindly. Anna Frodesiak (talk) 23:59, 30 March 2016 (UTC)[reply]

probably not: http://www.eufic.org/page/en/page/FAQ/faqid/does-heating-affect-food-allergens/ 68.48.241.158 (talk) 00:40, 31 March 2016 (UTC)[reply]

Do you really mean allergens, or just toxins as in the deathcap mushroom ? The toxins survive cooking (that is, they exhibit thermostability). StuRat (talk) 01:37, 31 March 2016 (UTC)[reply]

I mean like for food allergy people. Whatever they are allergic to. Anna Frodesiak (talk) 02:25, 31 March 2016 (UTC)[reply]

Wouldn't that depend on exactly which compounds in the mushroom they are allergic to? Different compounds will have different responses to different cooking conditions. If you can name specific allergans within mushrooms, perhaps we could research how cooking affects them. --Jayron 32 02:30, 31 March 2016 (UTC)[reply]

Oh, dear. I didn't think of that. I just thought there would be one allergen. And I don't even know the name of any allergen in mushrooms. Anna Frodesiak (talk) 04:55, 31 March 2016 (UTC)[reply]

Since the article doesn't say, is there any proven safe way to de-toxify a mushroom? I'm thinking of a film I saw in high school, which showed some native American women preparing acorns to be consumable, by a process where they grind them into a flour and then use water repeatedly to leach out the tannic acid. ←Baseball Bugs ^{What's up, Doc?} carrots→ 11:53, 31 March 2016 (UTC)[reply]

See Mushroom allergy - it seems that a lot more people are allergic to breathing spores than to eating them, but "nobody knows" probably sums it up fairly well. Alansplodge (talk) 12:23, 31 March 2016 (UTC)[reply]

I'm talking about the deadly toxins in certain mushrooms, not allergens. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:15, 31 March 2016 (UTC)[reply]

There are lots of factors in play here. Many things are detoxified by cooking. Acorns are not exactly detoxified -- they contain high levels of tannins, which are water-soluble and can be washed out by grinding them up and soaking them in water. The same treatment is also often used, for the same reason, with olives. Regarding allergies, they are most commonly caused by proteins, which are usually denatured by cooking. Denaturing a protein greatly reduces the allergenic potential of a protein but may not eliminate it -- it depends on details of the shape of the protein. Looie496 (talk) 14:37, 31 March 2016 (UTC)[reply]

Fly agaric can apparently be detoxified by appropriate cooking methods. Note that that does not necessarily apply to any other fungus. Iapetus (talk) 16:18, 31 March 2016 (UTC)[reply]

That's interesting, I was only familiar with the users who preferred to eat it with the toxins intact- Berserker#Theories. SemanticMantis (talk) 16:25, 31 March 2016 (UTC)[reply]

Thank you everyone! :) Anna Frodesiak (talk) 04:43, 1 April 2016 (UTC)[reply]

March 31

When did the Moon become tidally locked to the Earth ?

Can we put a date on it ? StuRat (talk) 02:14, 31 March 2016 (UTC)[reply]

This has some calculations and comes up with an answer for you. --Jayron 32 02:29, 31 March 2016 (UTC)[reply]

That page in turn cites this one, which states that such estimates can be very far off. --69.159.61.172 (talk) 05:58, 31 March 2016 (UTC)[reply]

It's tidally locked everyday. :) --DHeyward (talk) 08:51, 31 March 2016 (UTC)[reply]

Is it easier for a tornado to make a cow fly or a car or a mobile home/trailer?

The car is several times heavier but it's several times less dense. The trailer might be less dense than the car no? At least when empty. Since it has no engine and more volume to area. It is less aerodynamic and more easily toppled than an SUV. It semi-traps the wind under it as long as the trailer doesn't leave the ground and then increases the area facing the wind (up to a point) as the trapped air effect decreases which should give it some rotational momentum on the long axis for the wind to accelerate. So maybe a mobile home is the easiest of all?

Could a tornado suck up a tank? (high weight, high density). Sagittarian Milky Way (talk) 18:00, 31 March 2016 (UTC)[reply]

Tanknado? Now that's scary. You think baseball-sized hail is bad, try HE shells! But why the shells you ask? Because A-Team is coming in for a landing!Wnt (talk) 18:18, 31 March 2016 (UTC)[reply]

I believe you have the right ideas, that density matters more than weight, and that the shape also matters quite a bit. The hardest thing to lift is something dense and flat to the ground and attached to it, like pavement. If the pavement is ripped from the ground, you have had a massive tornado. A trailer with no engine would be low density, so would be blown around easily, if not properly anchored to the ground. Cars and trucks would be next, and the cow would be after that, then the tank would be hardest of all to lift. StuRat (talk) 02:02, 1 April 2016 (UTC)[reply]

Certainly trailer parks here in Texas are commonly described as "Tornado magnets" - that's because they frequently figure in the news when there are tornadoes touching down. People assume that tornadoes more frequently hit trailer parks - but in truth it's just that they are vastly more likely to be damaged than more substantial (ie denser) structures. The goal when designing such structures is often to enclose the maximum amount of living space with the least amount of material - so they do tend to have low densities when compared to cars and cows. SteveBaker (talk) 13:17, 1 April 2016 (UTC)[reply]

Self-driving cars and drafting

I've read that theoretically, a person driving right behind a semi rig can cut gas consumption by as much as half - but he'd have to drive in a suicidal position, within a meter of the back of the rig, and of course it could brake at any time.

However, it strikes me that the self-driving cars being produced should have many advantages - they should have real-time machine-to-machine communication that allows them to coordinate drafting maneuvers from both ends. Do they have enough control via their interfaces to literally dock a specialized fitting to securely link them as a "train"? (Besides reducing the risk of jarring mismatches in position, this would allow the rear cars to deliver their fair share of the energy, so that the front car is not paying full freight when everyone else gets half off) Does the car in front have enough lead time when it sees a hazardous situation that the ones behind can either unhook and evade or else just brake in synchrony?

Has anyone tested anything like this? I'd imagine that you could link any number of self-driving cars together in a train, essentially without limit since each provides its own power. Ideally they should have some kind of specialized structure (maybe even just a set of streamers, or perhaps something more solid) that would make them "one" so that the wind would flow past as if they were a single vehicle. But they'd need some kind of common, manufacturer-independent protocol for communication, docking, and connecting to reduce air resistance, probably other things. Is there any such protocol? Wnt (talk) 18:30, 31 March 2016 (UTC)[reply]

I should note I've found some mentions, not very detailed, of "flocking" of self-driving cars [32] but this still implies considerable distance between them. Wnt (talk) 18:38, 31 March 2016 (UTC)[reply]

About a month ago, a self driving car found itself unable to avoid hitting a bus when both were traveling at very low speeds: [33]. Given that, I'm not sure the technology exists now to safely allow for self-driving cars to try the maneuvers you are describing. Of course, in the future, who knows? --Jayron 32 18:45, 31 March 2016 (UTC)[reply]

This was a report about testing self-driving lorries, which would lock into a convoy with just a few feet between vehicles: http://www.bbc.co.uk/news/technology-28834774 217.44.50.87 (talk) 19:24, 31 March 2016 (UTC)[reply]

Lockheed Martin has worked on convoys of autonomous vehicles. For example, this 2014 press release, U.S. Army and Lockheed Martin Complete Advanced Autonomous Convoy Demonstration, describes technology for convoys of self-driving military vehicles. I'm pretty sure I've seen presentations from Lockheed Martin and others that describe fuel economies, although wind resistance is not the only advantage. Here's a decent starting place: a 2015 review presentation of interesting technologies investigated by the Army's TARDEC Tank and Automotive Research, Development, and Engineering Center. Fuel economies of modular autonomous vehicles are described. Nimur (talk) 19:28, 31 March 2016 (UTC)[reply]

That picture in the first (Lockheed Martin) link shows vehicles quite widely spaced - the convoy doesn't really look like it's worried about fuel, but rather is reducing the number of people exposed to (presumably) potential hostile action. Even the BBC link in the response above that presumes vehicles meant to work together in advance. But what would really seem to make sense is that the car comes onto the freeway, finds a line of other autonomous cars of all descriptions, and they all roll down as one big unit until the next exit where a subset might break off. For which a more universal standardization would be needed. Still -- these are pretty good finds, thanks. Wnt (talk) 21:07, 31 March 2016 (UTC)[reply]

They don't have to be self-driving cars. They only have to be self-braking and have some form of communication.Llaanngg (talk) 00:09, 1 April 2016 (UTC)[reply]

Well, to physically hitch them I'd expect you'd want robust computer-controlled steering, so that going over a pothole at the wrong time doesn't scratch your pretty chrome bumper (or worse) when you're trying to link up. Wnt (talk) 01:10, 1 April 2016 (UTC)[reply]

I'm rather surprised that nobody has mentioned the Mythbusters episode where they figured out that you have to be incredibly close to see any sort of real fuel savings. Dismas|^(talk) 01:23, 1 April 2016 (UTC)[reply]

@Dismas: In a way this question was inspired by that episode - I think I remember them getting close to 50% savings at that ridiculously close distance. That's why I was suggesting a physical connection (and even some kind of shell to keep air from getting into the remaining space between vehicles) rather than just a "flock". Wnt (talk) 17:20, 1 April 2016 (UTC)[reply]

See also slipstreaming wch cites "a 10% increase in efficiency of certain hybrid vehicles".--Shantavira|^{feed me} 06:52, 1 April 2016 (UTC)[reply]

It's worth mentioning that the lead vehicle gets benefits from slipstreaming as well as the one at the rear - but the largest gains are in the middle of the pack.

With intelligent vehicles (even if they aren't 100% self-driving), the communications lag should be a vanishingly small percentage of the time for braking - where mechanical parts have to move. I don't think it would make much difference to stopping distances for all of the vehicles to spend a millisecond be informed by the one in the lead of the intent to brake (or turn, or accelerate, etc) so that it happens at the exact same time. My concern would be about the degree of maintenance of these vehicles. If someone in the middle of the pack has worn brake pads and bald tires - then the possibilities for disaster become rather severe. SteveBaker (talk) 13:09, 1 April 2016 (UTC)[reply]

Well, the self-driving car ought to know if it has those mechanical problems, and know whether it can compensate to match the other cars with its current status or not. And the case of the abrupt failure is one of the reasons I suggested a linkage, so that the other cars would physically help the damaged one keep going at the same speed - while, of course, collaborating as a unit to brake it safely as it would with its own self-driving algorithm, even as those not adjacent peel off and reform, until they can leave it safely alongside the road and go on. Wnt (talk) 17:24, 1 April 2016 (UTC)[reply]

Perhaps some of this belongs in Platoon (automobile). Jim.henderson (talk) 17:11, 1 April 2016 (UTC)[reply]

Now that is a relevant keyword. (though I thought men joined platoons and vehicles joined convoys...) Wnt (talk) 17:27, 1 April 2016 (UTC)[reply]

Anti-wart vaccines

Is there a vaccine that prevents one from getting "ordinary" warts on the skin, e.g. plantar warts or the ones pictured in File:Wart ASA animated.gif? Wart#Prevention only really addresses genital warts, ignoring everything else except for a single unsourced statement saying that ordinary anti-genital-wart vaccines don't affect plantar warts. HPV vaccines appears to concern itself entirely with the genital-wart types of viri. Not surprisingly, I can't find anything else on Google. Nyttend (talk) 19:24, 31 March 2016 (UTC)[reply]

The Plantar wart article indicates there is no vaccine. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:34, 31 March 2016 (UTC)[reply]

See Plural form of words ending in -us#Virus, incidentally. "Viri" is attested - that doesn't mean it's correct. Tevildo (talk) 19:49, 31 March 2016 (UTC)[reply]

Hm. I thought all warts were caused by HPV, and wart supports that. But there are hundreds of strains of HPV, so this becomes a very detail-oriented question about how and if vaccines against viral infections have any cross efficacy to closely related strains. There is also the matter that we would never expect a vaccine to do anything much to a current infection. So of course an HPV vaccine will not affect a plantar wart, but it conceptually might still be able to decrease chances of new infection. I'll do more searching of the academic literature to see if I can find any clarification. SemanticMantis (talk) 19:54, 31 March 2016 (UTC)[reply]

Here [34] is a research paper that discusses a bit about vaccine development strategies and a little about what works for what. SemanticMantis (talk) 20:20, 31 March 2016 (UTC)[reply]

Our entry on Gardasil says it is up to a 9-valent vaccine, i.e. it is a mixture of vaccines against HPV 6, 11, 16, 18, 31, 33, 45, 52, and 58. The bad news is that our wart article blames common warts on "2 and 4 (most common); also types 1, 3, 26, 29, and 57 and others", and plantar warts on "HPV type 1 (most common); also types 2, 3, 4, 27, 28, and 58" - which means that only one (58) is shared with the vaccine. The good news of course is that the vaccine does largely prevent genital warts and cervical cancer caused by them. Which means that it is reasonably likely that a similar 7-valent vaccine could target common warts, or a 10-valent vaccine could target common + plantar warts, and actually provide protection. Wnt (talk) 01:06, 1 April 2016 (UTC)[reply]

are we inside a black hole?

the schwarzschild radius of the observable universe is like 13 billion light years. there's a lot of dark matter too, could we be inside a huge black hole? if we were though, wouldn't one side of the universe (the side facing the center of mass) be completely black to us?— Preceding unsigned comment added by 203.213.116.10 (talk • contribs)

You appear to have answered your own question. Beyond that, all we could do is provide you with references (if they exist) that suggest we're in a black hole or attempt to explain why there wouldn't be a huge black spot. We can't really answer questions, just repeat answers that already exist. Ian.thomson (talk) 02:03, 1 April 2016 (UTC)[reply]

Sort of like a black hole does. Shock Brigade Harvester Boris (talk) 02:04, 1 April 2016 (UTC)[reply]

Well, I think the best evidence that we aren't inside a black hole is that the universe appears not to be contracting, but expanding, and not only expanding, but the rate of expansion is increasing. Secondly, I'm not sure you could explain the Cosmic microwave background from inside a black hole. Vespine (talk) 04:06, 1 April 2016 (UTC)[reply]

I think it is possible to have a standard cosmological spacetime with a finite total volume and mass, surrounded by an infinite Schwarzschild vacuum. Possibly if the matter recollapses, then it's inside the Schwarzschild radius, but I may be misremembering. This is sort of like a "universe inside a black hole", but I don't know what sort of process would produce it, and the evidence doesn't support a recollapsing universe anyway.

One side of the universe wouldn't be completely black. It would look almost the same as the actual world (including the CMB), and it would be almost the same, unless we were close to the edge of the matter region (and if the matter region is large enough, the chance of that is negligible).

In a recollapsing universe, you eventually hit a curvature singularity no matter what you do. The collapse is sometimes described as a "union of black holes." If you can't avoid ending up in a black hole, then by definition you're already in it. So maybe recollapsing universes are "inside a black hole" by definition, even without the surrounding Schwarzschild vacuum. -- BenRG (talk) 07:33, 1 April 2016 (UTC)[reply]

As said above we don't seem to be in one because the rate of expansion is increasing. I don't know what being inside a white hole would be like but perhaps this is it. Dmcq (talk) 11:51, 1 April 2016 (UTC)[reply]

Hearing loss from music performance

(Professional advice disclaimer noted.)

http://www.bbc.co.uk/news/entertainment-arts-35938704

"A renowned viola player is suing the Royal Opera House for ruining his hearing and his career during rehearsals of Wagner's Die Walkure."

Does anyone here know of any papers on what the type of injury is likely to be? ShakespeareFan00 (talk) 10:21, 1 April 2016 (UTC)[reply]

The news report you linked to says Acoustic shock. Our article doesn't include any papers but a search should find ones like [35] [36] [37] [38] [39] [40] [41]. These in turn link to other research. Stuff like [42] may also be relevant. Nil Einne (talk) 12:11, 1 April 2016 (UTC)[reply]

The thread title is far different from the specific question. The Royal Opera House musician claimed that loud music during one set of rehearsals for one piece had caused this "acoustic shock" similar to a syndrome experienced by call center personnel in India whose headphones had squeals or were generally loud. This is despite his having been provided with hearing protection which reduced the sound pressure level by 28 dB, which is close to the best protection obtainable via earplugs or over-ear protectors. The claimed syndrome rather than rendering him unable to hear soft noises caused him to have psychological trauma when he heard a variety of sounds, such as his infant, or random household noises. The more common manifestation of actual "hearing LOSS from musical performance" is that the 130dB or whatever from combined percussion and brass in an orchestra or band causes lower hearing sensitivity at some frequencies, or causes tinnitus which interferes with hearing, as reported in a study from Michigan State University, which reported 71% of the Chicago Symphony musicians had experienced hearing loss. Some classical or popular musicians use special earplugs by companies such as Etymotic Research mentioned in a journal article which are supposed to let them hear the ensemble better than standard industrial hearing protection. Even in high school bands, having a number of trumpets playing a few feet behind one is painful and likely damaging to hearing. Studies with rats show that loud noise literally destroys permanently the "hair cells" in the cochlea which are the sensory receptors for sound. Edison (talk) 17:07, 1 April 2016 (UTC)[reply]

Nuclear renewable energy

What is the relation between the nuclear energy and renewable energy?--5.2.200.163 (talk) 15:06, 1 April 2016 (UTC)[reply]

They both contain the word "energy". --Jayron 32 15:09, 1 April 2016 (UTC)[reply]

Thats a pretty fececious remark J. Below your station I suggest. Why not try to be helpful?--178.101.224.162 (talk) 23:57, 1 April 2016 (UTC)[reply]

Nuclear energy is in no way "renewable". The fuels that it uses (uranium, for example) are mined and will eventually run out just like coal and oil. Even fusion power requires materials like Deuterium that are not "renewable" (at least not rapidly).

The closest relationship I could imagine between nuclear power and true renewables (such as wind, wave and solar power) is that nuclear energy could provide a stop-gap measure as we phase out hydrocarbon fuels and phase in those true renewables.

Nuclear fission reactors cannot be a long-term solution to mankind's energy needs.

SteveBaker (talk) 15:44, 1 April 2016 (UTC)[reply]

I'm not deliberately trying to be facetious, by why are wind, wave, and solar power "renewable"? They depend on a unidirectional flow of solar energy. Over a sufficiently long time, the sun will consume all of its hydrogen, and that's a one-way trip. It will take billions and billions and billions of years before a new cluster of hydrogen coalesces under its own gravity, collapses into a core, and reaches critical mass-density to sustain hydrogen fusion inside a new sun. Eventually, over the timescales of tens or hundreds of billions of years, the universe will run out of free hydrogen from which we can form more stars.

Meanwhile, fossil fuels only take a few million years to collect a large quantity of biological kerogen, and then a few more million years to cook into useful petroleum, gas, and other fossil fuel. On geological timescales, fossil fuels form really fast. We can renew our fossil fuel resources much faster timescales than we can renew the hydrogen-resources that fuel our sun. The only downside is that nobody in present company will survive long enough to wait for the next batch to come out of the proverbial geological oven.

The terminology "renewable resource" refers to a renewal process that happens within a specific timeframe. Most of the time, that timescale is compared to the characteristic life-cycle of a human, or a group of humans.

Depending on how far out you're thinking, though, no energy source is renewable: our universe is on a steady march governed by the laws of thermodynamics, paraphrased thusly (1) You can't win; (2) you can't break even; (3) you're guaranteed to lose.

If we're speaking purely in terms of physics, solar energy (and wind energy, and so on) are not renewable. Their actual advantage has nothing to do with the fact that they're renewable. They really have advantages because they are (potentially) low cost; (potentially) low-polluting; (potentially) low ecological impact; and because to first order approximation, they provide an "approximately" infinity-sized hot-bath reservoir for the enormous Carnot engine that is human society. None of those advantages have anything to do with "renewability." Don't get me wrong - I'm a huge fan of hydroelectric power generation, wind power generation, and so forth ... but I think we should be pitching for these excellent alternative sources of energy on their real merits, not their illusory merits.

Nimur (talk) 16:46, 1 April 2016 (UTC)[reply]

1) Nuclear energy could last us for a very long time before we run out of uranium. That's not technically "renewable", but what we really care about is having an energy supply that lasts so long we don't need to worry about it running out, and it qualifies in that case. According to our peak uranium article "The identified resource at the start of 2013 was enough to supply reactors at current consumption rates for more than 120 years, even if no additional uranium deposits are discovered in the meantime." And, of course, there are many undiscovered reserves and even the possibility of extracting it from sea water at some point in the future. As with most natural resources, the higher the price goes, the more can be produced, since the less accessible reserves can then be accessed, at higher costs. However, unlike other natural resources, the price of uranium has little to do with the cost of the energy produced by it. That's because a huge amount of energy is produced by a very small amount or uranium, and most of the cost of the energy is due to the construction and maintenance cost of the reactor, transmission costs, etc.

2) Breeder reactors may possibly be used to make fuel for nuclear reactors, from other radioactive materials. Of course, those radioactive materials might themselves eventually be used up.

3) Nuclear fusion reactors should one day provide even more energy.

So, by combining these, we have centuries of nuclear energy available. It may, ironically, last longer than some actual renewable energy sources, like wood. This is because, if we were all to burn wood to provide energy, we would use it up faster than we could grow new wood. Then there would also be massive pollution created by burning all that wood. StuRat (talk) 16:32, 1 April 2016 (UTC)[reply]

How about radioisotope thermoelectric generators, how do they fit in in this context? And also isotope and elements regeneration by neutron capture and beta decay?--5.2.200.163 (talk) 16:39, 1 April 2016 (UTC)[reply]

Reply to first first question: Doesn't really fit in at all. Those portable devices are comparable to a can of Sterno used for camping. That is, the amount of energy produced by them is totally insignificant in the overall picture. (We could in theory each have a portable nuclear generator, but the risk or accidents and terrorism is just too high to do that.) StuRat (talk) 16:47, 1 April 2016 (UTC)[reply]

Radium mixed with uranium

If radium is mixed with uranium in a container, is the halflife of the uranium decreased? By a lot, or hardly measurably?Eva M. Kahn (talk) 20:01, 1 April 2016 (UTC)[reply]

Outside of certain unusual environments such as the interior of stars, nothing changes the halflife of any element. --Guy Macon (talk) 20:05, 1 April 2016 (UTC)[reply]

(ec)No, radioactive decay, to an excellent approximation, is completely unaffected by external chemical or physical processes. There are some possible quibbles (especially for unusual decay modes like K-capture, which doesn't apply to uranium), but at any level you're likely to care about, the decay of the uranium is unaffected. --Trovatore (talk)

I was just about to correct myself. See Radioactive decay#Changing decay rates. --Guy Macon (talk) 20:09, 1 April 2016 (UTC)[reply]

I suspect you are confusing two different things. The half-life refers to it's tendency to decay all on it's own. You can, however, cause it to undergo nuclear reactions quicker than that, by exposing it to various forms of radiation. A nuclear explosion is the ultimate example of this. StuRat (talk) 20:16, 1 April 2016 (UTC)[reply]

True or false? "Winter ice maximums in the arctic are relatively unchanged. Summer minimums are lower."

Is it true that "Winter ice maximums in the arctic are relatively unchanged. Summer minimums are lower." (according to User:DHeyward above). If there is some source of this, it could be interesting to update some articles. --Scicurious (talk) 22:28, 1 April 2016 (UTC)[reply]

https://nsidc.org/data/bist/bist.pl?annot=1&legend=1&scale=75&tab_cols=2&tab_rows=2&config=seaice_extent_trends&submit=Refresh&hemis0=N&img0=trnd&hemis1=N&img1=plot&mo0=03&year0=2016&mo1=09&year1=2016 Maximum extent is in March. Min extent is in September. Rate of loss is roughly an order of magnitude difference between max and min. Not sure what articles you think need updating. --DHeyward (talk) 23:16, 1 April 2016 (UTC)[reply]

I suppose Polar_ice_cap#North_Pole and Arctic sea ice decline could benefit from this information.--Scicurious (talk) 23:24, 1 April 2016 (UTC)[reply]

Just to be pedantic: its minima and maxima. Still, not everyone had the experience of Latin in school.--178.101.224.162 (talk) 00:00, 2 April 2016 (UTC)[reply]

Just to be pedantic: (1) it's it's; and (2) both plurals are correct for those nouns. This is English, not Latin. --69.159.61.172 (talk) 08:00, 2 April 2016 (UTC)[reply]

The American Heritage dictionary confirms: Its is the possessive form of the pronoun it and is correctly written without an apostrophe: The cat licked its paws. The contraction it's (for it is or it has) should always have an apostrophe: It's the funniest show I've seen in years. TearsOfaClone (talk) 12:00, 2 April 2016 (UTC)[reply]

The time series graph on this NSIDC page is probably useful in answering the question. --Tagishsimon (talk) 00:11, 2 April 2016 (UTC)[reply]