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May 13

Does a photon have any chance of crossing a metal plate?

If a metal plate is opaque (say, it's 5 mm thick), could a photon still have a tiny probability of crossing through it? --Llaanngg (talk) 00:25, 13 May 2016 (UTC)[reply]

Yes in theory. You will have to qualify what kinds of photons you are talking about. For gold you can make it thin and transparent, see Gold#Characteristics. For light, although there may be a tiny tiny tiny chance, perhaps 1:10⁻²⁰⁰⁰, the practical answer is no. For gamma rays the chance of penetration is high. But it depends on how much guarantee you need there will no photons. There may be a chance of corrosion, or damage due to people drilling holes in it, or perhaps the photon can get around the edge of your metal plate, that is diffraction. For radio wave photons diffraction becomes much easier. Graeme Bartlett (talk) 00:50, 13 May 2016 (UTC)[reply]

Radiation_protection#Electromagnetic_radiation states "X-ray and gamma radiation are best absorbed by atoms with heavy nuclei; the heavier the nucleus, the better the absorption. In some special applications, depleted uranium or thorium[7] are used, but lead is much more common; several centimeters are often required." Several centimeters is greater than 5 mm. --Jayron 32 01:06, 13 May 2016 (UTC)[reply]

At sufficiently low frequencies (less than 100Hz say), there is a fair chance of a photon getting through without being absorbed - see skin depth. However, even at very low frequencies, most photons will be reflected rather than absorbed or transmitted to the other side, and only about ~~1 in 10⁸~~ 1 in 10¹⁶ will get through. --catslash (talk) 14:37, 13 May 2016 (UTC)[reply]

Well, the OP never specified which energy photon. Really, the difference we're talking about here can be the difference between firing a bullet from a gun versus lightly tossing one underhand. Exactly what the photon would penetrate would depend entirely on how much energy it has. --Jayron 32 14:44, 13 May 2016 (UTC)[reply]

Yes. They aren't stopped instantly, their intensity falls off exponentially with distance in. The proportions of this curve depend on materials behaviour and substantially on the photon energy. So for visible light and higher frequencies there's a "thin film" distance where a metal foil (or more usually a layer deposited on something else) can still allow an appreciable fraction through. These thin films are quite important to all manner of devices. Andy Dingley (talk) 14:49, 13 May 2016 (UTC)[reply]

Virtual photons may have a much better chance of getting though even thick copper. This may be why, NASA are getting promising results from their absolutely-impossible -to-believe RF resonant cavity thruster experiments.--Aspro (talk) 19:01, 13 May 2016 (UTC)[reply]

I'm not sure I would call it "promising." More likely they are looking for normal explanations to explain margin of error. --DHeyward (talk) 00:45, 14 May 2016 (UTC)[reply]

And to that end, the results are look promising. --Aspro (talk) 16:33, 17 May 2016 (UTC)[reply]

Photons can also tunnel through metals via QM [1]. Spin Hall Effect article touches on it with few sources, though. I seem to recall a very precise gyroscope being built using this but can't find it. :( --DHeyward (talk) 00:45, 14 May 2016 (UTC)[reply]

What is the reason that the fox was considered always as the cleverest or smartest among the other mammals?

93.126.95.68 (talk) 03:41, 13 May 2016 (UTC)[reply]

Um, was it? Can't really answer this question without proof of the premise... --OuroborosCobra (talk) 03:46, 13 May 2016 (UTC)[reply]

Well, in folklore, sure, "as cunning as a fox". But this is barely a "science" question, maybe more humanities? Vespine (talk) 04:45, 13 May 2016 (UTC)[reply]

Anecdotally, i live in an area where there are wild foxes, I've seen them in my own back yard. They are elusive and they are harder to trap than a lot of other animals. It's not easy to lure them with a simple bait trap, it takes more effort to set up a trap that will catch a fox. The main reason might be because they are also very good at getting into chicken hutches, they are much stronger than a cat and about as smart as a dog making them a formidable predator. Vespine (talk) 04:52, 13 May 2016 (UTC)[reply]

The reason I wrote this question here is because I would like to ensure it with science. Is it right scientifically that the fox is such cleaver? 93.126.95.68 (talk) 04:54, 13 May 2016 (UTC)[reply]

Don't predators in general seem to be "smarter" than their prey? Prey are better known for being prolific than for being smart. The average cat might be smarter than the average mouse, but there are a lot more mice. ←Baseball Bugs ^{What's up, Doc?} carrots→ 07:06, 13 May 2016 (UTC)[reply]

As the Kzinti say, "How much intelligence does it take to sneak up on a leaf?" {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 14:04, 13 May 2016 (UTC)[reply]

Animal intelligence is fiendishly hard to quantify (indeed, even human intelligence is fiendishly hard to quantify...) Wikipedia does have an article titled Animal cognition which gives a nice overview of the science. Perhaps starting there will lead you interesting directions for your research. --Jayron 32 12:10, 13 May 2016 (UTC)[reply]

Once an animal becomes the symbol of some particular anthropomorphism, that tends to continue even if science might cast doubt on it. The idea that the fox is cunning goes back over 2000 years (the first literary reference is Aesop) so was probably based on popular observation, rather than on what we could consider scientific study. 81.132.106.10 (talk) 12:15, 13 May 2016 (UTC)[reply]

It is worth noting that it isn't just Western culture. Foxes have long been regarded as highly intelligent tricksters in the cultures of China and Japan as well (e.g. kitsune, huli jing). Dragons flight (talk) 12:31, 13 May 2016 (UTC)[reply]

As far as tricksters go, "Living Sideways: Tricksters in American Indian Oral Traditions" says "Coyote is no doubt the best known of the animal tricksters, but there are many others: Raven, Mink, Fox, Blue Jay, Skunk, Coon, Spider, Dragonfly, Turtle, Mud Hen, Wolf, Rabbit, Canada Jay, and Wolverine". The book goes on to discuss some theories about why those animals were chosen, but it appears that no one knows. I'll also point out that Genesis 3:1 says that the serpent is the craftiest of the animals. So there may be nothing special about foxes. -- BenRG (talk) 19:50, 13 May 2016 (UTC)[reply]

Humans consider the Fox a pest for his opportunistic attacks on poultry and rabbits, resistance (usually) to domestication and wiliness at concealment that makes him difficult to track and hunt. In the Lotka–Volterra equations that model predator-prey species interaction the variable y is typically the number of foxes. This article discusses Foxes in popular culture. As early as 600 BCE Aesop told a story about a dishonest greedy fox. Machiavelli wrote that the successful prince must have the traits of both the lion and the fox. In English dictionaries we find:

FOX (noun) someone who is clever at tricking people, a shifty deceptive person

TO FOX (verb) to make you confused and be impossible for you to understand or solve. Etymology from 1660s is "to delude" implied in Old English verbal noun foxung "fox-like wile, craftiness;" and Middle English had foxerie "wiliness, trickery, deceit."

SHENANIGAN (a deceitful confidence trick, or mischief) is considered to be derived from the Irish expression sionnachuighim, meaning "I play the fox." AllBestFaith (talk) 12:40, 13 May 2016 (UTC)[reply]

I think BenRG is correct above. I'll add that there can be different animals for different kinds of cleverness, such as the distinction between the clever conniving predatory fox and the clever stealthy resourceful respectable coon. This is kind of hinted at in one of Melville's wierder works [2] but I think it is also a broad part of early American culture; part of this I think is also based on a point that I'm still not sure about that the red fox was believed to be (and was it??) of foreign origin, whereas the coon was an American native. So you can see old political cartoons of the Whigs, and especially Abraham Lincoln, who was Whig before he started his own descendant party, drawn as coons - their opposition to slavery eventually led to "coon" being used as a perjorative term for blacks, though one, given its original positive meaning and the sort of skills that their communities needed to develop to survive injustice, was oddly apt, though I would not nonetheless expect to get a favorable reaction anywhere in the country if using it! But I fear that in modern America there is much too much singing of the praises of foxes, and not so much of coons, in any sense at all. Wnt (talk) 22:35, 13 May 2016 (UTC)[reply]

Let's compare foxes with other similar-sized mammalian predators. There are cats and dogs, both thought to be fairly intelligent, but those living with people may have less need to be clever to survive (would you really kill you dog if he can't learn any tricks ?). Wolves live in packs, so may have less need for a certain type of cleverness needed by a solitary hunter. Coyotes are also thought of as clever, and also tend to live solitary lives. Then there was the popularity of the fox hunt, which no doubt led hunters to exaggerate the skill of their quarry in order to boost their own standing. StuRat (talk) 23:01, 13 May 2016 (UTC)[reply]

This claim about the fox hunt seems sketchy. It seems like all the skill of tracking and cornering the quarry is that of the dogs, and the rich English guy rides along behind them to claim credit for their work after the fact, much as in his business enterprises. Wnt (talk) 02:49, 14 May 2016 (UTC)[reply]

Whose prejudices are showing now? It's not only rich people that hunted foxes - many less well off country people got involved too. In the Lake district they traditionally hunted on foot so you didn't even need to own a horse. Richerman (talk) 08:56, 14 May 2016 (UTC)[reply]

The only remotely academic reference that I could find was Friendly foxes are cleverer: Domesticated foxes show evolution of social intelligence by Emma Marris, which seems to refute StuRat's assertion above that "those living with people may have less need to be clever". Alansplodge (talk) 00:18, 15 May 2016 (UTC)[reply]

I was talking about evolution, which takes many generations, so unless foxes have been domesticated as long as cats and dogs, and to the same degree, there will have been little evolutionary change to them. Also note that social intelligence is just one type. It's quite possible that their ability to hunt and evade being hunted goes down at the same time their social intelligence goes up. StuRat (talk) 01:00, 15 May 2016 (UTC)[reply]

If anyone suspects one is unintelligent, one has a choice between remaining silent or opening one's mouth to prove it. So let's ask What does the fox say? (video) AllBestFaith (talk) 11:16, 15 May 2016 (UTC)[reply]

Going back to the original question, I thought that it was another mammal species that was always considered to be the smartest or cleverest...i.e. Homo sapiens. DrChrissy ^(talk) 13:54, 16 May 2016 (UTC)[reply]

It wasn't about "another mammal species". It was about the other mammal species. I guess that excludes us. It's not just mammals that are smart. Recent studies have shown that birds are pretty intelligent, despite their small brain size. Although they don't have a cerebral cortex, their alternative wiring is just as effective. 80.44.167.65 (talk) 15:00, 16 May 2016 (UTC)[reply]

I guess that depends on the way you read it. My interpretation is that because the question did not specifically exclude humans, and we are undeniably mammals, we are among the "other mammals". I agree with you totally about birds and their intelligence, particularly the corvids. I have recently created Theory of mind in animals where birds feature heavily and the Mirror test is also rather revealing. DrChrissy ^(talk) 15:31, 16 May 2016 (UTC)[reply]

How being a veterinary work?

How being a veterinary works?
I mean to take care of humans you need do to medicine to be a doctor, thats an entire course to deal with just one single specific living being, the homo sapiens sapiens (and doctors dont deal with ALL areas of human medicine, they have their specific areas), but a veterinary have to deal with every single other specie that exist on this entire earth.201.79.54.252 (talk) 12:44, 13 May 2016 (UTC)[reply]

Veterinary physician has an overview. Veterinarians often specialize in certain disciplines, such as can be seen at Veterinary physician#Focus of practice. No veterinarian would be expected to treat every single kind of animal, and instead specialize by category. --Jayron 32 12:48, 13 May 2016 (UTC)[reply]

Bear in mind also that vets do not have the same pressure to try and save the patient's life at any cost: if the condition is too serious, or the treatment too expensive for the owner, a lethal injection is an option that no doctor would have when treating a human patient. 81.132.106.10 (talk) 13:44, 13 May 2016 (UTC)[reply]

Adding to what Jayron32 has said, sometimes doctors and other (human medical specialists) are called in to assist with procedures particularly on apes but also other non humans mammals see e.g. [3] [4] [5]. However these are the exception, in normal cases it is veterinarian although as Jayron32 and the article say, it's not true that all vets normally treat all animals or all types of problems, there are specialisations based on type of animal and procedure. Besides our article, see e.g. [6]. Nil Einne (talk) 17:07, 13 May 2016 (UTC)[reply]

All veterinarians are competent over a large range of animals (including humans..your typical vet could work in an emergency room during a disaster etc), like an internist...but there are all kinds of specialists too (ie horses, marine animals etc)..68.48.241.158 (talk) 13:49, 13 May 2016 (UTC)[reply]

(Personal anecdote) I've had pet rats for over 10 years. I have found that many veterinarians won't treat rats. I assume the same is true for other exotic pets. It took a while to find a vet who was both willing to treat rats and was knowledgeable about them. A vet once told me that there's a joke among veterinarians: "doctors are veterinarians who only treat one kind of animal." CodeTalker (talk) 19:08, 13 May 2016 (UTC)[reply]

as a kid the vet we took our dog to never had a problem looking at my hamster or iguana..prescribed something for an eye infection iguana had...they understand animals like this quite well...these are knowledgeable scientists with a lot of schooling...of course 90% are dealing with cats/dogs/horses/farm animals/cattle regularly..68.48.241.158 (talk) 20:12, 13 May 2016 (UTC)[reply]

Someone with no feeling below the ~diaphragm (because of a spine injury) remarked that he might do better going to a vet, because they're accustomed to not being able to ask the patient how something feels. —Tamfang (talk) 23:39, 15 May 2016 (UTC)[reply]

This article will give you a good idea of what is required to become a qualified veterinary surgeon in the UK. Richerman (talk) 09:19, 14 May 2016 (UTC)[reply]