Quatnum Physics - My Limited Understandings

[Dagoth Nereviar 0]

OK, So from what I understand, there is something called the copenhagen interpretation. Anyway theres a closed box and inside it there is a bowl with some unstable particles in it and thats connected to a hammer that's connected to a cat. If one of these particles goes weird the hammer falls and the cat dies. And theres another box with the same stuff in it. Both boxes are closed. In one of the boxes the particles are fine and the cat is alive. In the other it died cos the particles went weird. I think that it's like. The way the electrons move around an atom is totally random. They have no set orbit. And that if they exist in like two ways they could be different.What the heck does that have to do with anything. Random chance does not prove that there is an alternative universe. And apparently the guy who thought of it proved it with maths. How does one prove that with maths? Could someone please clarify this for me because to me it sounds totally silly.

[Saint_Michael 3]

I know what your talking about but I believe it's called Schrodingers Cat that talks about the theory your describing. I believe it has to do with the fact that its neither dead or alive until someone finds out but the paradox is since no one will find out they don't know if its alive or dead. I can't remember if I said that right but it has to do with existence at some level, I learned about this little paradox in one of my favorite computer related books called Wyrm. I would have to say this is my favorite paradox about existence as their are a few others such as what came firs the chicken or the egg?



Some more info about

Article #1

This website puts a little interaction with that paradox

Edited November 30, 2007 by Saint_Michael (see edit history)

[darthvaron 0]

just something about the Schr?dinger Cat I've been thinking about. Tell me where I'm wrong. Because somewhere my argument may fail.This paradox assumes that we know nothing about the inside of the box. But by tunneling "some" information may get outside of the box except if the walls have an "infinity" potential. But a real infinity potential means that somehow the box is not connected to our universe so it's not a physical problem because there is noway to interact with the inside of the box.So, if the box have finit potential walls the "Dead and Alive" state will not really exist for the cat because it wouldn't be a quantic problem (you can nearly commute every magnitude about the cat). But if the box have infinit walls the state wouldn't exist also because it wouldn't be even a physic problem and there will be no chance to know what have happened with the cat.And of course that mean that this paradox is nothing more than an "approximation" to a real phenomenon

Edited December 10, 2007 by darthvaron (see edit history)

[StaticIp 0]

I watched a video on this subject in physics class. When they observe the particles they behave in a certain way. But! when they didn't observe them or watch them, there was a totally different result. Its something extremely hard or impossible to understand. Fine line between them. The two boxes, not the same. of course are going to have two different results.

[salamangkero 0]

This paradox assumes that we know nothing about the inside of the box.

But by tunneling "some" information may get outside of the box except if the walls have an "infinity" potential. But a real infinity potential means that somehow the box is not connected to our universe so it's not a physical problem because there is noway to interact with the inside of the box.

 

...

 

And of course that mean that this paradox is nothing more than an "approximation" to a real phenomenon

Try not to read too much into the analogy. Still, if you want a really accurate description, follow this link to the Wikipedia article. Basically, it's not just any cardboard box through which we can "tunnel" information, but one that will shield the system inside from any outside influences and observation. Simply put, it is a box that is completely opaque to whatever means of measurement one intends to employ in discovering the metabolic state of the cat.

 

The point of Schroedinger's Cat is that, after a while, the cat is both alive and dead. Only by observation, that is opening the box, do we discover whether the cat is alive or dead. Now, the question actually posed by this thought experiment is, "When does the cat stop being both dead and alive, and assumes only one state?" Or more accurately, when does the cat stop being in a mixture of states and become strictly one or the other?

 

The Coppenhagen Interpretation states that the very act of measuring something influences its state. For example, whilst the box is closed, there exist an infinite number of probability fields (or wave functions) inside the box. However, the act of opening the box ("measuring" whether the cat is dead or alive) collapses all these wave functions such that only one remains; we eventually discover that the cat is dead or alive.

 

Allow me to digress a bit and explain more about a phenomenon that seems to prove this theory: the Double Slit Experiment.

 

Note that when light is shone on two (parralel) narrow slits, a distinct diffraction pattern can be seen on the other side. This is caused by the wave nature of light: light passing through one slit interferes with that passing through the other. This is also observable in other experiments involving waves on a medium.

 

Now, the scientists tried another experiment. They bombarded those two slits with electrons, which are, as we know them, particles, not waves. We should expect to see two parallel lines on the other side. However, when the scientists did it, they saw an interference pattern.

 

Working on the idea that, perhaps, the electrons are interfering with each other, the scientists fired electrons one at a time. However, after quite some time and quite a handful of electrons, the same interference pattern was observed.

 

Scientists now placed an observer near each slit. They will now know exactly where an electron passed. Yet, when the electrons were fired, again, one at a time, the pattern on the other side became two parallel lines. It was as if the electrons "knew" they were being observed.

 

Thus, it appears that the very act of measuring something influences the outcome of the scenario. To put it comically, if I put an egg in the fridge, the moment I close the door, the egg could be anywhere in the universe. It could be in the freezer, the chiller, the vegetable crisper, the egg tray, the butter tray, the compressor, the washing machine, the oven, the Pacific, the Antarctic, well, it could very well be outside the Milky Way! Only by observing it, that is, opening the fridge door can I actually confirm that the egg is, actually, in the egg tray where I put it

 

There is, however, another theory. The many worlds interpretation posits that, even with the box still closed, the cat is already either alive or dead. If, it turns out, the cat is already dead, then, it only means that in another universe, the cat is still alive. To put it simply, anything that could have multiple outcomes does end up with all those outcomes happening in different universes.

 

Suppose I tossed a coin. In this universe, I got a head. In another universe, I got a tail. In still another universe, the coin landed on its edge (Whoa!) and in a fourth one, my evil sister punched me in the eye, caught the coin and took it with her that I'll never know what I got, save for a black eye

 

This is rather mind boggling but String Theory does propose that, in the 5th dimension, we have all possibilities happening. This, of course, yields us an almost infinite number of universes, all with the same laws of physics as ours but have vastly different settings.

 

To give another comical example, a physicist went to Vegas and bet twenty thousand dollars on a single roll. People asked him if he was sure and what he'd do if he lost. The physicist replied, "If I lose, then, in another universe, I'd be walking away a rich man"

 

So... what do you guys think? When does the cat cease to be both alive and dead, and becomes strictly either alive or dead?

[Yoji 0]

Hmm if you want to know more about quantum physics I would sugest you the movie/docu: what the bleep do we know, down the rabbithole.Altough it is really heavy material