Wikipedia:Reference desk/Archives/Science/2015 June 8

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June 8

Plant identification from photo.

Hi, I would like to get a plant identified from my photos. Could someone please tell me how to upload the photo to appear in my question? Is this the best place to post it? Thankyou 49.197.174.35 (talk) 06:20, 8 June 2015 (UTC)

Go here and in the menu on the left you will see an "Upload file". click on that and follow the instructions.Richard Avery (talk) 07:30, 8 June 2015 (UTC)

You have to create an account, as far I know you can't upload just from an IP address. Ariel. (talk) 07:36, 8 June 2015 (UTC)

You don't have to use Wikimedia Commons. Though using a Wikimedia sister site is the only way to get the photo to show up here in your thread. There are numerous photo sharing sites on the internet. You can use any of them and then just post a link to the photo here. Two that I've used in the past are Photobucket and Imgur. Dismas|^(talk) 12:28, 8 June 2015 (UTC)

You must be an autoconfirmed user to upload image file for that you should at least have 10 edits in wiki(go to ur preferences tab) + 4 days of account.sidsandyy (talk) 14:13, 8 June 2015 (UTC)

Imgur is probably the easiest to use and has least clutter from the viewing end. If/when you come back to post, here's a few tips: Include a close-up and distance shot if possible. Tell us where in the world and what time of year the photo was taken if you can. Any additional info on the situation will help, descriptive words are sometimes better than the photo itself. SemanticMantis (talk) 14:27, 8 June 2015 (UTC)

@Dismas, Sidsandyy, and SemanticMantis: I think JustPaste.It is a pretty easy site - no logins needed, but you can save a link to reedit your page if you want, and you can even give it an easy to remember custom URL. Hey, we have to try not to fall too far behind ISIS in our tech resources! Wnt (talk) 22:40, 12 June 2015 (UTC)

Chilli chaser

I can easily handle my liquor, but when I follow a meal that contains an exceptional amount of chilies with a shot of tequila, I instantaneously suffer from long-lasting and debilitating nausea. How does alcohol and capsaicin interact to produce such a pronounced effect, that they don't do alone? Plasmic Physics (talk) 12:25, 8 June 2015 (UTC)

I can't find any report of such an effect, so any answer has to be speculative. It is interesting to note that capsaicin has very little solubility in water but is highly soluble in alcohol, so it seems possible that the alcohol is moving the capsaicin around in your digestive system, or is carrying a large bolus from your mouth into your stomach. Looie496 (talk) 13:41, 8 June 2015 (UTC)

You might also want to mention this to your doctor, since alcohol and chilies can aggravate ulcers and other conditions, but had Looie496 not already mentioned it, I would have brought up that capsaicin is alcohol soluble. μηδείς (talk) 18:55, 8 June 2015 (UTC)

I'm quite certain that it is not a case of aggravating preexisting conditions, I have clean bill of health in that regard. Plasmic Physics (talk) 20:41, 8 June 2015 (UTC)

I'd not be so sure, Plasmic Physics. What I thought was a peptic ulcer in my late twenties and a bladder infection in my early 30's ended up being a rather severe case of diverticulitis in my early 30's, which resulted in having 2/3 of my colon out. I was literally within a cm of having a colostomy bag for life, or dying. I'd still go to a gastroenterologist ASAP had I known then what I know now. μηδείς (talk) 22:48, 8 June 2015 (UTC)

Not so sure about what, my doctor's assessment? I think that the given explanation of increased motility given by Looie is entirely plausible. Although, I do think that it very strange for there to be a lack of research on the interaction. Plasmic Physics (talk) 12:20, 9 June 2015 (UTC)

LOL. You should see the talk page, where I can't get some of these people to admit it would be wrong to tell someone "to see a doctor ASAP" who asks if he could have caught rabies after being scratched by his girlfriend. But here someone's trying to second-guess your doctor. Well, on Wikipedia YMMV. :) Wnt (talk) 22:43, 11 June 2015 (UTC)

I'm wondering about the universality of such a response among the general populace. It would make for a comical, if somewhat cruel, practical joke. Say for instance, if one would sneak a quantity of cayenne pepper into a morsel to be taken by a subject, and then appear to offer relief, by feigning to provide a glass of water, only for it to be a glass of vodka or a similarly strong spirit. Or perhaps it could be used as some insidious rite of passage? Plasmic Physics (talk) 22:37, 8 June 2015 (UTC)

So, PP, you want advice on intentionally poisoning people? That's probably covered by the medical advice disclaimer. μηδείς (talk) 22:41, 8 June 2015 (UTC)

Not quite. That is just a hypothetical aside, hence the small post. In either case, it is quite harmless under normal circumstances. Plasmic Physics (talk) 00:13, 9 June 2015 (UTC)

Since it involves substituting alcohol, I suggest we suggest it for ISIS members. That way it's only veterinary advice. Wnt (talk) 22:43, 11 June 2015 (UTC)

Encrypt and decrypt a photon?

Is it possible to encrypt a photon?The main problem in long range communication is it takes lot of time.Really a lot of time.If we somehow managed to encrypt the photon and decrypt it with some kind of transmitter and receiver system by making slight or no change in its properties that will become easiest way to communicate cause we all know,FOR NOW, nothing travels faster than light.So at long range,communication will be much easier.sidsandyy (talk) 14:07, 8 June 2015 (UTC)

Short answer? No. But we can encode (not encrypt) digital data in modulated pulses of light, which is absolutely a means of sending data via photons in bulk at light speed. It's almost certainly a part of the process by which you are reading these words. — Lomn 14:20, 8 June 2015 (UTC)

A photon can be a transmission medium, but it is not a message in itself, so it cannot be encrypted. Physical properties of an individual photon can be modulated; so an encrypted message could be used to select modulation parameters; but that's the sort of work done in laboratory experiments. In current real-world telecommunications technologies, we don't usually work at the abstraction of individual particles. Instead, we treat signals as waveforms - bulk electromagnetic radiation made of individual photons - and we modulate properties of the ensemble (like the waveform amplitude, frequency, and phase). Nimur (talk) 14:23, 8 June 2015 (UTC)

Note that Nimur's last point is an important one and perhaps not properly mentioned in this thread yet. It's not really clear what you mean by "long range" and "lot of time". Presuming by long range you mean in to space, then pretty much any current communication system will have the same speeds over most of the travel time. I'm not sure there if there is some confusion on your part, but remember that c, the speed of light in vacuum, refers to the speed for all electromagnetic radiation edit: including radio waves for example, not just the portion of the spectrum we call light. In a medium (instead of vacuum) and particularly if you are relying on refraction and other such phenomena (as mentioned in radio propagation for example), things get a little trickier. That said, AFAIK for a lot of communication on earth, when it comes to latency it isn't the transmission speed itself is slow. But the fact that your probably not going direct but through several hops. (Satellite communication is different, but in that case again, it doesn't matter ?much if you're using light, radiowaves or whatever.) As for "lot of time", well in addition to my earlier comments, consider that even at the speed of light Mars is still 4 - 20 minutes away from earth. Alpha Centauri, the closest star system to our solar system is 4.37 light years. Nil Einne (talk) 15:19, 8 June 2015 (UTC)

You might be interested in Quantum_cryptography. By manipulating the polarization properties of photons, very secure communication is possible. "In principle, this method can be used for continuous, unbreakable encryption of data if single photons are used" - so no: no single photon can be encrypted; that doesn't even really make sense. However, single photons can be used as the basis for strong encryption that is essentially unbreakable, based on quantum mechanical theory. As far as I know QC has not been implemented in any large-scale real-world application, but it is a fairly active research area, and it may well become available in a usable way to governments or individuals. Some people are already thinking of post-quantum cryptography, which is about how to design secure encryption schemes that will can resist cryptanalysis from quantum computers. I'm not entirely sure, but I think quantum encryption would remain secure in a world of ubiquitous quantum computers. SemanticMantis (talk) 14:38, 8 June 2015 (UTC)

Nope.There has to be some way to encrypt it otherwise its almost impossible to communicate with our satellites far outside of our galaxy?and one more thing is, Is there any way to control qantum entanglement?so that 1part will be with us.and other will be at the edge of universe.and we could somehow send the messages through them it doesnt matter even if it lasts for few milliseconds?

sidsandyy (talk) 15:20, 8 June 2015 (UTC)

You can encrypt a signal sent via photons, but you're not really encrypting a single photon. I think you're tripping up on the terminology. SemanticMantis (talk) 15:31, 8 June 2015 (UTC)

(EC) I'm not sure if you quite understand what "encrypt" means (like the purpose, and what it entails). In any case, the limitations on communication with distance objects aren't related to a inability to encrypt the signal, or anything relating to modulation limitations really, but transmission power (and reception requirements). Of course it's a moot point. We don't have anything we know of to communicate with. We don't have satellites or space probes far outside our galaxy. Even Voyager 1 only just recently left the solar system heliosphere (not galaxy, or even solar system!). Also, the No-communication theorem, and to a lesser extent Faster-than-light and Quantum entanglement explain why quantum entaglement can't be used for faster than light communication. Nil Einne (talk) 15:34, 8 June 2015 (UTC)

BTW you may want to read my reply you above (between Nimur and SemanticMantis) that you accidently deleted twice, as it definitely sounds like you're confused about a lot of stuff, some of which it addresses. Voyager 1, is actually a good example to look at in response to some of you'reyour confusion. It's already 18 light hours away and it's likely it will have insufficient power to communicate with us (or use any instruments) by 2025. Also I should also mention that there may be some reasons why light in particular instead of other EM would be advantageous for some forms of interstellar communication, but speed isn't one of them. Nil Einne (talk) 15:50, 8 June 2015 (UTC)

One is tempted to refer the OP to Powder of sympathy... Tevildo (talk) 20:53, 8 June 2015 (UTC)

Is there any way to control particles entanglement?

Both particles has to behave opposite to one another.By recording the changes in 1 particle can we judge the behaviour of another particle and one day the universe?

See my answer above to the related question. Nil Einne (talk) 15:37, 8 June 2015 (UTC)

This is apparently based on a misunderstanding of quantum entanglement. I have heard it stated, many times by different people, that with quantum entanglement, you can have to particles that always behave in the opposite way. So, you can put one at the edge of the solar system and the other on earth. If you twist the one on Earth clockwise, the one on the edge of the solar system will magically twist counter-clockwise. If you accept this definition of quantum entanglement, you can have faster-than-light communication. However, that is not how entangled particles work. You don't have one particle that you can mess with and another that you can watch. Still incorrect, but a better simplification, is that you have two particles that you can watch. If you measure one of the particles and you get a value, such as "left", you know that the other particle will MOST LIKELY give you the opposite value. No faster-than-light communication is available to the observer in this case. I've heard it simplified even further to be like putting a right glove in one briefcase and a left glove in the other. You give a man one suitcase at random and he flies far far away. When he gets very far away, he opens his briefcase and finds a right glove. He instantly knows that the left glove is back where he started his trip. It isn't faster-than-light communication. It is, at best, faster-than-light assumption. 199.15.144.250 (talk) 19:47, 8 June 2015 (UTC)

It is a lot stranger than that. What you described with the gloves is a hidden variable theory, and following on Bell's theorem and the experiments showing quantum effects don't follow that the hidden variables theory is practically definitely wrong. It seems we do have to accept some sort of version of faster than light communication - except we can't transmit information at a faster than light speed using it. Dmcq (talk) 20:27, 8 June 2015 (UTC)

I thought the act of measuring it contributed to the solution. I thought it was the Hallmark "problem" with the uncertainty principle was whether it was inherently a fundamental property of the universe or whether it was the inability to determine the impact of measuring a property and the property itself. One is immutable, the other is a limit to what we can know about quantum states. I thought the best way to explain it was still with wave interference vs. particle. The pair interferes with each other until it's localized and then it's by nature the particle version of the interference. Localizing the particle imparts properties that still must support interference and the act of "knowing" changes it. I didn't think this was a way to impart information but a way to know it. Like phase velocity (favorite example is large pair of scissors - closing the scissors and measuring the velocity of the point where the blades meet from the handle to the tip can exceed the speed of light - an infinitely long scissor moves an infinitessimally small amount at the tips and the closing speed is near infinite. ) , it imparts no information from one side to the other, though, even though "open" and "closed" are measurable states. --DHeyward (talk) 22:39, 8 June 2015 (UTC)

If someone always wears one black and one white sock, and you see the sock on one of his feet, do you immediately know the color of the other sock? Yes. Can you send information from one foot to the other using sock color? No, because you don't control the color of either sock.

This is similar to quantum entanglement. In the quantum case you have a choice of mutually incompatible (noncommuting) measurements that you can make, but you still can't choose the outcome of the measurement and you still can't send a message. -- BenRG (talk) 05:41, 9 June 2015 (UTC)

@BenRG: I think that explanation is a little dangerous because it is a hidden variable theory; you don't know which sock but there really is a black and white assignment ahead of time. The QM version, as I'm sure you know, is stranger: as I understand it you can check one entangled photon with a polarized filter at a certain orientation, and now the other one at the other polarized filter is perfectly predictable at that orientation, but not at one 45 degrees off from it... no matter what orientation you first pick! Wnt (talk) 11:46, 9 June 2015 (UTC)

Well in fact you get a higher correlation of about 0.7 at 45 degrees than can be explained using any classical physics theory based on hidden variables which gives at best 0.5. The lack of correlation happens at 90 degrees. Dmcq (talk) 13:05, 9 June 2015 (UTC)

Quantum entanglement is (in a precise sense) the quantum version of correlation. Correlation doesn't mean "when you change one thing, the other one instantly changes too, no matter where it is", and neither does entanglement. That's the thing people seem to most often get wrong about entanglement, and the socks illustrate what's wrong with it (in the classical case). Once you've gotten past that mistake, you still don't know what entanglement (or correlation) actually is, but it's a start. -- BenRG (talk) 16:01, 9 June 2015 (UTC)

As stated above, the difference between the hidden variable theory and quantum entanglement is that the values in hidden variable theory are constant. They do not change once set. In quantum mechanics, particle properties can (and do) change. So, we discuss correlation. From a simplistic point of view, particles are created in pairs with opposite values (be it spin or direction or whatever). If they are not affected by anything, they should maintain the opposite states. Therefore, if you filter one and get a measurement of, say, right, then you should be able to measure the other one in the same way and get an opposite result. Because the particles are affected by things, it isn't perfect. The study of exactly how particles interact with each other at a quantum level is where the cool stuff happens. At the quantum entanglement level, it isn't all that interesting. It is mostly dealing with people who make claims based on a complete misunderstanding of quantum entanglement. 209.149.113.240 (talk) 19:21, 9 June 2015 (UTC)

Values in hidden variables theories are not constant. They can evolve according to any classical dynamical rules. -- BenRG (talk) 20:11, 9 June 2015 (UTC)

A common problem caused by discussing science without using formal language. We are simply using two different definitions of constant. I am referring to a lack of uncertainty. You are referring to a static state, I believe. A semantic argument will go nowhere. 75.139.70.50 (talk) 02:28, 10 June 2015 (UTC)

Hidden variable theories don't have to be deterministic. Bell's theorem doesn't assume determinism, or that the system is in a definite state before or after measurement, or that measurement doesn't affect the system. It works even if the two particles are people, and a measurement consists of asking them a question which they are free to answer however they want, and they're allowed to consult a hardware RNG, and they answer with the goal of behaving like quantum particles. The only restriction is that they can't communicate with each other between hearing the question and answering (locality). -- BenRG (talk) 03:25, 10 June 2015 (UTC)

That isn't what I took the Bell inequality to mean, though I admit I'm at or beyond the limit of my understanding. If I ask Alice "North or South?", Bob always gives the other answer. If I ask Alice "North or South?", Bob can answer "East or West?" randomly and I'm none the wiser. But if I ask Bob "Northeast or Southwest?", his answer will agree with hers quite often, as will it if I ask "Northwest or Southeast?" My impression is that Bob's answers turn out to agree with Alice more often than any pseudo-random number generator could arrange in that situation. Wnt (talk) 11:43, 10 June 2015 (UTC)

It's not really fair to John Stewart Bell that everybody reinterprets his statement and attributes his name to any reinterpretation. If we go to source material, cited in our article on Bell's theorem, what he actually said was:

“ ...the statistical predictions of quantum mechanics are incompatible with separable predetermination. ” — Bell, J. S. (1964). "On the Einstein Podolsky Rosen Paradox". Physics 1 (3): 195–200.

That's not the same as saying particles are entangled, or that hidden variables are forbidden. It's saying that if you read his paper, then either formula 2 is wrong, or formula 22 is wrong, because they are provably incompatible. If you try to stretch this technical fact into a plain-english sentence or generalize it beyond what Bell generalized in his section called "Generalization," ... then you are performing synthesis, which is original research and probably doesn't belong on Wikipedia's science reference desk. There is no shortage of commentary on this paper; it was quite famous, and many people wrote analyses, rebuttals, and confirmations. Our article does a great job of summarizing the most historically important responses.

If reading physics publications isn't your cup of tea, and you want an analysis independent of Wikipedia, the Plato Encyclopedia from Stanford has an extensive article available at no cost: Bell's Theorem at the Stanford Encyclopedia of Philosophy.

Nimur (talk) 14:07, 10 June 2015 (UTC)