User talk:LeeJaedong/Hangeul syllables

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? Neon Merlin  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. Isaac Newton (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. Isaac Newton (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. Isaac Newton (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)

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