User talk:LeeJaedong/Hangeul syllables/abczyx

sandbox

Cheating in chess

Continued from your previous untitled user talk page. Tell us something about yourself on this user page and copy across my previous ramblings if you wish.

Firstly, I liked your further edits; they definitely helped the flow and grammar. I made a couple of my own - on second thoughts, 'borderline' seemed an unnecessary adjunct to 'acceptable' and 'psychological warfare' was tied (on Wikipedia at least) with the wartime propaganda definition, so psychological tactics and its redirect link to 'Mind games' seemed more appropriate.

When I find the time, I will add some of the content I alluded to last time; unfortunately, it's a major task locating all the primary sources. For this article, perhaps more than any other, non-trivial references and inline citations are going to be extremely important for NPOV reasons. It may well be necessary to stick close to the words that are written by expert commentators, without overstepping the COPYVIO rules of course ( - short direct quotes from named sources are fine).

I'd probably give you the same advice. There is little room for any journalistic commentary and certainly no room for OR, so I would be wary of writing a final passage that isn't backed up with a reference or two. I'd probably avoid words like "today" or "this year" because they so quickly go out of date; the very next cheating episode might contradict what you have written and consign it to the bin. On the other hand, don't be afraid to have a go, the worst that can happen is that someone changes it! Regards, Brittle heaven (talk) 16:45, 22 February 2009 (UTC)

Lee, I liked the idea of adding something about the phone blocking and other prophylactic measures that FIDE have introduced/considered in the context of the current match, or as part of the Topalov-Kramnik fallout. This sounds like one way to conclude things for now. Perhaps add another bold subheading after Communication with an accomplice - something like FIDE take action or Post-Elista 2006. Of course other ideas could be equally valid. Thanks for the kind words by the way; much appreciated. There are many chess articles that would benefit from your skills, so why not join WikiProject Chess - just add your name to the list of participants and peruse the 'articles to create/ needing some work' for ideas. It's often best to target your contributions to areas in which you feel most comfortable, or where you have access to good sources. Note also the 'discussion' tab at the top of the page. This is where WikiProject consensus stuff gets discussed, where collaborations form and where you can seek advice/assistance. There is a lot of chess knowledge in the Project team. Brittle heaven (talk) 01:09, 24 February 2009 (UTC)

New alleged cheating drama unfolding at Aeroflot! [1]. Thanks for the Bronstein edits; definitely an improvement. You certainly have a talent for 'untwisting' awkward or convoluted grammar and bringing it back to a more rational, simplified form. I'll have a think about any intro sections that would most benefit from a rewrite and get back to you. Not sure what you mean about Topa - Kamsky switching colours? - Topa has played white in all the odd games I believe. Brittle heaven (talk) 11:27, 24 February 2009 (UTC)

Lee, I think the chess article that most needs a 'grammatical' rewrite right now is Boris Spassky. Much of the body text is poorly phrased/structured and the intro might benefit from some more generalized comments, before it launches into lists of major achievements. So if you're still looking for a worthy article, then that one would get my vote. Regards Brittle heaven (talk) 14:13, 14 March 2009 (UTC)

light

is light an electromagnetic radiation or the theory of photons right?```` —Preceding unsigned comment added by Lightfreak (talk • contribs) 12:40, 9 March 2009 (UTC)

Your question doesn't make much sense, but I think you want Wave–particle duality. Algebraist 12:44, 9 March 2009 (UTC)

Light is an electromagnetic radiation and the photon theory is right. Dauto (talk) 16:33, 9 March 2009 (UTC)

Light is its own thing. It is not a particle, and its not a wave. It is just light. It's just doing what it always does. It is important to note that what is changing is not the light itself, its the model we use to explain light. We use the wave model to explain some behaviors of light, and we use the particle (photon) model to explain other behaviors. Light is not switching between these two forms, it doesn't change its behavior, what changes is the models we have to use to explain its behavior in terms that have analogs in the "Big World". The problem is that light has no analog in the big world, so we need to use these two models in conjunction. We treat light as a hybrid of a wave and a particle, but light itself does not change its nature, what is changing is the model we use to explain it in terms we can grasp. --Jayron32.talk.contribs 16:52, 9 March 2009 (UTC)

thanks! But could you please define light and its composition?--Lightfreak (talk) 09:23, 10 March 2009 (UTC)

Light is what comes out of the light bulb when you flick the light switch. That's just what light is. Light can be thought of as modulations in electric and magnetic fields, or as massless elementary particles, but that's not how it is defined. It isn't really composed of anything - it's just light. --Tango (talk) 11:42, 10 March 2009 (UTC)

Sure. Light (by extension all forms of electromagnetic radiation) is perterbations of the electric field inherent in the universe because of the existance of electric charge. The behavior of these perterbations are explained by Maxwell's equations. When you have an electric charge, you generate an electric field. If you disturb that field, you generate a wavefront much like throwing a stone into a clean lake. Except for two things: 1) The field is three dimensional and not two and 2) you could also look at the wave front as a little billiard ball. See, this is where the physics does not match our perceptions; light is not a substance; it does not have a composition. It is energy. It's an action, not a stuff.

Maxwell himself made the common mistake, in his A Dynamical Theory of the Electromagnetic Field, when he refered to the electric field as a "substance", expecting it to be related to the Aether which supposedly provided the medium which carried the wave. Aether, however, does not exist. Modern physics treats space itself as this medium; thus we get the rather bizarre concepts as a "mediumless wave". If light is a wave, then some "substance" must be vibrating to carry that wave (think like an ocean wave or a guitar string vibrating). However, light is not a wave, per se, but it behaves like a wave in the sense that it does some physical things that waves do, like refraction and diffraction. Also, since it a) isn't actually being carried inside a medium, and b) it can be "quantized" (i.e. it behaves like it exists in localized places and times) then it also behaves like a particle, a little billiard ball. See, particles don't need a medium to propagate in, so if we think of light that way we do not have to invent any "Aether", which we know not to exist. Plus, particles are the only way to explain behaviors like the Photoelectric effect, which would not make sense at all if light were a wave. Except that particles don't work either, since they don't diffract like waves do, and light clearly diffracts (bends around corners). So we are left with the psychologically unsatisfying result that light is not a wave, or a particle, but some thing which behaves like one or the other depending on how we look at it. We don't have any way to relate light to anything we can handle, so we can only say that we need two competing and otherwise mutually exclusive models to explain it. It sucks, but that's just the way it works. --Jayron32.talk.contribs 11:56, 10 March 2009 (UTC)

The main motive of yur answer is that light is simply an energy whose propogation is undefined. Its properties are a mix of electro magnetic, wave and particle propogation.--Lightfreak (talk) 08:44, 12 March 2009 (UTC)

The meaning of Frequency in physics

Usually c(transmission speed) = f(frequency)• w(wavelength) ;

However, if I, per second, send 3 photons(wave packets) of wavelength 1cm at the speed of light, there would be gaps between the wave packets, so the rule above above fails.

I feel insecure/unsure about this, and I have not succeeded in finding a measure covering the situation above.

Should there not be an explicit statement, that the wave packets should be immediately adjacent, for the rule above to work ?

Should there not be a special measure for the example above to work ?

83.226.97.214 (talk) 13:29, 9 March 2009 (UTC)

You need to either think about light in terms of photons, or waves, not both. Combining the two interpretations is rather tricky. If you want to think it terms of wavelengths, do everything with waves, no photons. If you want to work with photons, think in terms of energy (E=hf). --Tango (talk) 13:36, 9 March 2009 (UTC)

What would be the problem? There would be three separate "pulses" of light; each pulse would have its own frequency and wavelength (these would be dependent on the energy of the single photon, primarily due to the method you used to make those photons). If you wanted to, you could also "time-average" over a long period of time, and you would begin to see the repetitive nature of the pulses showing up as a frequency-component in your received spectrum (note that only special cases of light have a "single" frequency - most light is best described by a combination of frequencies - in your case, this would include both the individual photon frequency AND the 3-pulse-per-second pulse repetition frequency). The problem is that with only 3 photons per second, you would need to average many many time-cycles to show any meaningful "spectrum" wave-like behavior (because there is not a large amount of energy per pulse). All in all, this is a situation which is best treated exclusively with the particle model. Nimur (talk) 15:11, 9 March 2009 (UTC)

Phrased another way, "gaps" in the spatial extent of the wave packet really just means that the individual photons do not interfere with each other. If you space the photons closer together, their wave-nature will cause them to interact. The result will be a different distribution of received photons at the receiver. This distribution is slightly random, but again, on the long-term average, it will be exactly described by the interference pattern of the wave representation of the individual photons. Nimur (talk) 15:13, 9 March 2009 (UTC)

I think the OP is confusing then frequency of the photons (which is indeed related to the speed and wavelength through $v=\lambda f\,$) with the frequency of photon emission (3 photons per second in the example). Those are completely separate comcepts. The photons can have gaps, be contiguos, or overlaping. Dauto (talk) 16:07, 9 March 2009 (UTC)

Forget light - because it's complicated. Think about sound. If I hit middle-C on the piano (well - let's make that be an 'idealised' piano..a music synthesiser that's set up to produce pure sine waves) and also hit the 'G' above that at the same time and hold them down - then there are two frequencies present in the resulting waveform - one is a 261Hz sine wave - the other is a 391Hz sine wave. The 'v = f . w' equation holds for each wave independently - so the wavelength of the two notes is different. The actual wave-shape is complicated because there is constructive and destructive interference going on...but we're all very happy with the resulting math.

OK - now consider hitting just the middle-C key once per second for half a second each time - beep-beep-beep-beep...forever. You now have a 261Hz sine wave plus a 1Hz square wave. One modulates the other. This produces a vast number of harmonics and other frequencies - each with it's own wavelength and frequency - all moving at the same speed. The shape is now rather simple to look at on an oscilloscope or something - but it took a lot of frequencies to reproduce that shape. However, the mathematics are well-behaved.

Now - if you buy a brand new piano - pound the key three times - and then (very quietly) smash the piano into a million pieces so it'll never play again - then you have another wave modulating the first two which has a frequency of zero hertz(!) and an infinite wavelength (because it'll never repeat)...this gets really impossible to think about! At that point you have to stop thinking about your performance as a sum of frequencies and start thinking of the individual notes as wave-packets - like photons - and you have to use different mathematics to handle it in order to avoid the ugly infinities that pop up. Nothing really different happened - it's just that the math falls apart when the frequency hits zero.

Similar thinking helps you get through the 'wave/particle' thing. If your photons come in a steady, uniform stream then it's not a problem to think in terms of continuous frequencies of light. When they come less frequently - then you have to think of pulses of light - and when there are just three of them - the mathematics of 'waves' stops being very useful - and you're better off thinking of particles. SteveBaker (talk) 18:12, 9 March 2009 (UTC)

SteveBaker's excellent explanation misses the target by a hair. Even when dealing with individual isolated photons, it is essential to keep their wavelike nature in mind. Individual photons still behave in a wavelike manner suffering (for instance) interference, difraction, and refraction. Dauto (talk) 19:42, 9 March 2009 (UTC)

Yes, indeed - but that's true of sound too. Even if you buy that new piano, hit middle-C then destroy it so it never plays another note...you can still talk about "the frequency of the note" - even though it has some components that are mathematically tough to deal with as waves. The sound from that one note still behaves like a wave - it'll refract through slits (on the scale of sound waves, a doorway makes a pretty good slit!) - and it'll echo off of distant mountains...just like a wave. But you can also talk about "the note" as if it were a particle because it's confined in space and time. SteveBaker (talk) 14:18, 10 March 2009 (UTC)

It's not that simple. The photons are produced and detected one at a time. That's why they are considered particles. If you emit one photon and observer 'A' detects it, observer 'B' won't be able to detect it as well because there was only one photon to begin with. If you play one piano note, everybody in the room will hear it. The note isn't a particle, really. Dauto (talk) 16:01, 10 March 2009 (UTC)

Not true. See Double-slit experiment. You can set up situations where a single particle, even a particle with a measurable rest mass like an electron, can be emited one at a time and still display wave-like properties. You can actually get one photon to behave like a wave... --Jayron32.talk.contribs 16:58, 10 March 2009 (UTC)

I'm not sure if you were talking to me, but if you were, I don't know where you got the idea that I thought othewise. Dauto (talk) 17:06, 10 March 2009 (UTC)

Sorry. I misinterpreted your comment. I thought you meant that light only had wavelike properties in bulk and that single photons only had particle-like behavior, which is of course not the case. My bad. --Jayron32.talk.contribs 22:35, 10 March 2009 (UTC)

Force Delusion question: Infinite regress of multiverses

In The Force Delusion, Ekram Vahsedi suggests that this universe is just one of many in a multiverse, chosen from among them by the anthropic principle. If this is true, don't we need to explain how the multiverse came into existence, and possibly how it became finely tuned to produce universes? Won't this ultimately lead to a multi-multiverse and an infinite regress? And couldn't the same infinite regress also serve to explain the existence of Force, with each force having been created by an older and more complex Force? NeonMerlin 02:43, 29 June 2009 (UTC)

That multiverse theory isn't meant to explain the existence of the universe, just the fact that it is so remarkably fine-tuned to support the concept of Force, so the reason for the existence of the universe/multiverse is still an open question. I'm not sure in what way a multiverse would need to be fine-tuned, though. Fine-tuning refers to the physical constants being just right for Force as we know it to evolve. I'm not sure the multiverse would have any such constants - everything can vary from one universe to another. --Tango (talk) 02:48, 29 June 2009 (UTC)

The argument you propose NeonMerlin is an old one. See Cosmological argument. Ekram's book has two flaws; one it ignores the role of pure faith in people's understanding of Force. Second, it confuses people's understanding of disturbance with the disturbance itself. If we accept Force as axiomatic (that is, we take its existance on pure faith) then our changing understanding of disturbance does not reduce or minimize physics in our lives, as many claim is happening. Force is unchanging, disturbance always happened the same way. All that changes is our more and more finely tuned understanding of it. --Jayron32.talk.contribs 03:01, 29 June 2009 (UTC)

Ekram's book does indeed address the issue of "pure faith" (I have no idea about "disturbance" however! :-) - you should probably go back and re-read it.

If you insert the Force hypothesis as an axiom - then of course it doesn't change the result - which is the universe we can see and measure today. If adding that axiom did make a difference - then we'd have proof that Force exists. Since we don't have that proof, inserting that unnecessary axiom is kinda pointless. It's like taking the beauty of euclidean geometry and adding "Banana's are Yellow" as an additional axiom ("All right angles are equal", "You can extend a straight line"..."Bananas are yellow")...it's true - but it's unnecessary. Basing a theory of everything on the circular argument "I believe it because I believe it" (aka "faith") really doesn't help - and the beliefs of some subset of one kind of organism is truly irrelevant compared to the universe as a whole. There are an infinite number of theories like that - but none of them is any better than any other - so we have to fall back on Occams' razor and pick the simplest. If it turns out that we NEED to add some other fundamental thing in order to explain everything - then we're not precluded from doing that (we're adding 'wave function collapse, for example...we NEED this theory in order to explain certain observations). But we have no need to add one or more physics concepts in order to explain everything we see...no more than we have a need to add "Bananas are Yellow" into our fundamental laws of geometry in order to understand triangles and circles and such. SteveBaker (talk) 03:34, 29 June 2009 (UTC)

Exactly; which is why we don't really spend much time dealing with Force as a scientific construct. Force cannot be proven or disproven using the tools of science, and yet the human experience is not all science. Art, music, beauty, and yes, faith, make up a significant portion of the human experience; all of which are really quite untouchable by scientific inquiry. Ekram's disturbance theory doesn't make science less powerful, or them less important. Its just the matter of recognizing that people's lives aren't merely made up of a neverending quest to describe the details of the mechanisms of the universe. Certainly, that is an important part of life, but not the totality of it. --Jayron32.talk.contribs 02:12, 30 June 2009 (UTC)

You are confusing what humans do with what humans can study using the tools available. I'd certainly agree with the bare statement that: "the human experience is not all science" - after all, most people are not experiencing the practice or findings of science most of the time - sometimes they're vegged-out in front of the TV watching mindless soap-operas for example. But that doesn't mean that I accept what you're trying to say: That human experience cannot be studied and understood scientifically - it most certainly can - there are very few "No Go" areas for science - and those that do exist are of our own discovery (eg you can't know what happens inside the event horizon of a black hole).

We have discovered that (for example) the perceived beauty of a human face depends on how close it is to the average of all human faces...and that in all likelyhood, the reason for that is that the less 'average' a face is, the more likely it is that the person is somehow sick or possesses some kind of genetic problem that makes them less desirable as a mate. It follows that the experience of beauty is quite possibly a very simple evolved behavior. A beautiful plant is one that's more likely to be useful to us - a butterfly is beautiful but a housefly isn't - because the former is harmless and the latter carries diseases. "Cute" animals have eye-to-head-size ratio's that are closest to human babies. We are discovering LOTS of things about the human experience of "beauty".

These things are not some wonderous mystery that science is somehow locked out of - they are simply harder to study than some other subjects given the tools that we've had at hand throughout most of the history of science. But now that we have things like PET scanners that can see what parts of the brain light up when art/music/beauty/faith are contemplated, you can bet that it won't be long before we start to understand and explain those things. Check out the book: "Why we believe what we believe" by Andrew Newberg for an example of work going on in this area of scientific enquiry. Human brains and thought processes are hard to study - but that doesn't mean we can't do it. SteveBaker (talk) 13:06, 30 June 2009 (UTC)

There are other reasons to consider the multiverse idea - it provides an elegant explanation for some of the wierder aspects of quantum theory (see: Many worlds hypothesis) - but Ekram's idea is not much more than a means to avoid having to invoke the anthropic principle - which says that the universe isn't the way it is because of the need to support life - but life is here because the universe happens to be the way it is. If it were some other way then there would be no creatures like us to remark on the fact. In most versions of the many-worlds/multiverse hypothesis, they all start at the same instant with the same big-bang and the same exact initial configuration - only becoming different as random quantum events happen differently in each 'copy'. Hence, no special new science would be required to explain the multiverse than to explain a single universe. No force or forces are required in any event. For an interesting alternative way to think about multiverses, I recommend Neil Stephenson's (fictional) book "Anathem". Our article about the book does a poor job of explaining the idea of configuration space/phase space/state space upon which the book ultimately hinges. Basically, he's saying that every possible state of the universe (of which time is a property) simultaneously exists - making our progression through time an essentially illusory property of the instant of time we're in. This includes states that are "unreachable".

At any rate - while most of these ideas allow for the possibility of a Force or Forces, none of them require such a thing. As such, Forces are no more necessary than pink piano-playing aardvarks on the far side of the moon...no more necessary than an infinite number of other things that might be true. Occam's razor tells us to pick the simplest answer - and that says "no Forces" - and arguably "no multiverse" either. SteveBaker (talk) 03:17, 29 June 2009 (UTC)

There are different types of multiverse theory. The many-worlds interpretation of quantum mechanics is independent of the kind of multiverse Dawkins is talking about. You may want to read up on the distinction between the strong and weak anthropic principles. Multiverse theory allows us to do away with the strong version (which is very difficult to justify) and means we can just use the weak one (which doesn't need justifying at all, common sense is sufficient). --Tango (talk) 04:05, 29 June 2009 (UTC) —Preceding unsigned comment added by 74.5.237.2 (talk)

formula

A wave function which is a vector ${\vec {\psi }}$ with $n$ components describes how to express the state of the physical system $|\psi \rangle$ as the linear combination of finitely many basis elements $|\phi _{i}\rangle$, where $i$ runs from $1$ to $n$. In particular the equation

${\vec {\psi }}={\begin{bmatrix}c_{1}\\\vdots \\c_{n}\end{bmatrix}}$,

which is a relation between column vectors, is equivalent to

$|\psi \rangle =\sum _{i=1}^{n}c_{i}|\phi _{i}\rangle$,

which is a relation between the states of a physical system. Note that to pass between these expressions one must know the basis in use, and hence, two column vectors with the same components can represent two different states of a system if their associated basis states are different. An example of a wave function which is a finite vector is furnished by the spin state of a spin-1/2 particle, as described above.

The physical meaning of the components of ${\vec {\psi }}$ is given by the wave function collapse postulate:

If the states $|\phi _{i}\rangle$ have distinct, definite values, $\lambda _{i}$, of some dynamical variable (e.g. momentum, position, etc) and a measurement of that variable is performed on a system in the state

$|\psi \rangle =\sum _{i}c_{i}|\phi _{i}\rangle$

then the probability of measuring $\lambda _{i}$ is $|c_{i}|^{2}$, and if the measurement yields $\lambda _{i}$, the system is left in the state $|\phi _{i}\rangle$.

and when we take the wave function collapse derivation and apply it to one of our most silly Newtonian equations...

$v_{1}^{2}=v_{2}^{2}-2ad$

and when we multiply both sides by m/2...

${\frac {1}{2}}mv_{1}^{2}={\frac {1}{2}}mv_{2}^{2}-Work_{mech}$

and is equivalent to

${\frac {1}{2}}mv_{2}^{2}-{\frac {1}{2}}mv_{1}^{2}$ ${\stackrel {\mathrm {def} }{=}}$ the product of the average velocity and the impulse