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You are not logged in. #1 20070605 04:59:45
Basic Quantum PhysicsI told somebody (I can't remember who) that I'd post some stuff on quantum physics here. "Knowledge is directly proportional to the amount of equipment ruined." "This woman painted a picture of me; she was clearly a psychopath" #2 20070605 05:06:28
Re: Basic Quantum PhysicsI'm not sure as to the details of this part, but I think it's something like this: "Knowledge is directly proportional to the amount of equipment ruined." "This woman painted a picture of me; she was clearly a psychopath" #3 20070605 05:39:33
Re: Basic Quantum Physics
No, it has to be a monochromatic light.
For anyone who is thinking of trying this at home, these slits must be very small, precise, and a short distance apart. Furthermore, there must be a way to allow no other light sources from entering these slits.
Where to start? It's not the uncertainty principle. It's simply the wavelike properties of a wave. They have nothing to do with each other to my knowledge. But as for the Uncertainty Principle, it is simply that you can't know velocity and momentum of an electron at one time. The more you know of one, the less you know of the other. This is partially because the only way we know how to measure electrons is by bombarding them with other electrons. But I am also told that it is not just an effect of how we measure, that we can never know both no matter what measurement technique we use. I don't fully believe this, but I take it a bit on faith since quantum physistics typically know what they are talking about.
Both of these misconceptions are the result of quantum physicists and their like for science fiction. They are simple "what if..." scenarios and not meant to be taken seriously. We know that quantum properties don't apply to macroscopic matter, such as a cat.
I've never heard of anything like this, do you have a source for it? "In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..." #4 20070605 05:55:41
Re: Basic Quantum Physics
I read up a bit more on this and I think I have a better understanding now. We use photons (not electrons... sheesh) to measure the position of electrons, bombarding them like a blind mind would throw tennis balls to see where a car is. If it travels in the expect path and hits the ground... no car there. If it bounces off of something, then we found it (assuming nothing else is around). "In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..." #5 20070605 07:40:55
Re: Basic Quantum Physics
And this tells me that the method has problems (and I would look for another method), but physicists say that the whole world has this problem and call it the Uncertainty Principle. "The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  Leon M. Lederman #6 20070605 13:19:06
Re: Basic Quantum PhysicsI don't understand the one photon at one time experiment. Really weird. The Photon splits into two parts of itself before it sees two slits?? Really weird. X'(yXβ)=0 #7 20070605 14:08:11
Re: Basic Quantum Physics
No body really understands, even quantum physicists. Sure, we can represent it mathematically and make incredibly accurate predictions, as well as analogies as to why, but to say what is really going on is beyond us. It's simply because the quantum world is nothing like our macrsopic world that we can't even begin to picture how things work. "In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..." #8 20070605 14:11:13
Re: Basic Quantum Physics
Perhaps I was wrong on this point. I can't seem to find any source saying the limit of the distance of the slits. But I would imagine once the slits are far enough apart that the effect would be nonexistent. "In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..." #9 20070605 14:39:56
Re: Basic Quantum PhysicsErr, I like the cancelling out theory. X'(yXβ)=0 #10 20070606 01:27:09
Re: Basic Quantum PhysicsLike you said, Ricky, noone really gets this, not even those who claim to be specialists in the matter. (no pun intended) "Knowledge is directly proportional to the amount of equipment ruined." "This woman painted a picture of me; she was clearly a psychopath" #11 20070606 01:39:45
Re: Basic Quantum PhysicsThe main thing you've gotta understand is that we can't be absolutely sure of anything. Last edited by Laterally Speaking (20070606 02:03:05) "Knowledge is directly proportional to the amount of equipment ruined." "This woman painted a picture of me; she was clearly a psychopath" #12 20070606 02:01:54
Re: Basic Quantum PhysicsSorry, that's not really quantum physics, but it's not the clearest thing to see either. If I'm not mistaken, that's Chaos Theory, which is loosely related to the quantum world, though slightly easier to understand. "Knowledge is directly proportional to the amount of equipment ruined." "This woman painted a picture of me; she was clearly a psychopath" #13 20070606 02:35:08
Re: Basic Quantum Physics
That's classical physics thinking. On the another hand, quantum physics says you can take two exact (and I mean exact) same systems and end up with entirely different results, since the results are based not only upon what's in the system, but chance as well. "In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..." #14 20070606 08:23:24
Re: Basic Quantum PhysicsAnd I would argue that without chance the universe is fully predictable, and so would (in a sense) be static. "The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  Leon M. Lederman #15 20070606 09:15:17
Re: Basic Quantum Physics
Predicable and static are two completely different things. Static implies that nothing changes, predictable just means that you know what's going to change and how it's going to change. "In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..." #16 20070606 12:03:58
Re: Basic Quantum PhysicsI know it is a funny thing to say, and I can't think of the right way of saying it, but if you treat time as (say) the words in a book, then the book is a static thing, even though you can dynamically read it. "The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  Leon M. Lederman #17 20070606 12:06:15
Re: Basic Quantum PhysicsBy static, are you trying to say that some jerk flipped to the end of the book and told you how it ends? "In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..." #18 20070606 21:50:48
Re: Basic Quantum PhysicsI think I should have named the thread something like "Debates about stuff nobody really understands"... "Knowledge is directly proportional to the amount of equipment ruined." "This woman painted a picture of me; she was clearly a psychopath" #19 20070606 22:15:32
Re: Basic Quantum PhysicsWhen you are firing the photon at the screen, doesn't it matter in which direction you fire it? Or are you talking about the case where the photon is fired directly at the space between the two slits? #20 20070606 23:17:19
Re: Basic Quantum Physics
I think a better comparison would be to get inside the author's mind and “know” the story for yourself. #21 20070607 00:46:23
Re: Basic Quantum Physics
That's ludicrous Jane. How would you fit? I mean, maybe if you're a midget and the author has a really really big head, just maybe. But otherwise, that's crazy.
I don't believe photon firing is an exact science (heh), and we don't have precise control over what direction the photon goes in. "In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..." #22 20070607 01:42:06
Re: Basic Quantum PhysicsRichard P. Feynman used to go out to a bar when he got a chance to leave Los Alamos for an evening and he would write Physics on napkins in the bar. He also drummed for fun. He also could compute answers faster than calculators of the day! igloo myrtilles fourmis #23 20070607 02:58:22
Re: Basic Quantum Physics
I doubt that. "In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..." #24 20070614 04:46:27
Re: Basic Quantum PhysicsWell, actually, the exact phrasing would be " he could calculate stuff faster than people could enter it into a calculator at the time". "Knowledge is directly proportional to the amount of equipment ruined." "This woman painted a picture of me; she was clearly a psychopath" 