How does "Schroedinger's Cat" work?

Question

As the theory goes, if you place a cat in a box with a radioactive particle, and said particle decays, the cat is then neither alive nor dead until someone observes the cat to determine it's state. How exactly does this theory work? Please be thorough. I'm certainly no expert on quantum mechanics.

Answer 1

You've actually explained it very well. Unless the box is opened, there is no way to know whether the cat has died or not. Thus, the cat is potentially both alive and dead.

When you open the box to determine the cat's state, the wave function collapses into a single point - living or dead.

Answer 2

It come from the the Heisenberg Uncertainty Principle. This says that the uncertainty in position of a particle (or wave) times the uncertainty in it's momentum is greater than or equal to a constant, Planck's constant divided by 2*PI. Think of it this way, the particle is a wave that may, or not, exist at a given point. There is an inherent uncertainty in it's position. From this principle we find that the more we know of the particles position, the less we know of the particles momenta, it's mass and velocity.

So, this concept of particles being nothing more than waves of probability led Ernst Shcroedinger to propose a thought experiment that showed an inherent paradox in this approach to understanding what is going on. This is the Schroedingers Cat experiment. What Schroedinger proposed (and never actually did) was to put a Cat in a large box with a vial of deadly poison. The poison is released when a radioactive substance, nearby, decays and hits a trigger mechanism. Now, radioactive decay is totally random. When we put the Cat in the box with the poison and seal the box we can not see what is going on. At any time the Cat could be dead or it could be alive. Which is to say there is an uncertainty in its position, or state. We could write a wave equation that describes the state of the Cat. We find, from this approach of waves being probability waves that the cat is both dead and alive at the same time due to an inherent uncertainty in it's state.

Now comes the clever bit. A day later, say, we open the box to see of the Cat is Dead or Alive. In doing so the cat stops being in an "indeterminate" state and is found to be dead or alive, a discrete state. What we have just done is changed the Cat's state. Before it was neither dead or alive, now it is dead, or alive. We say that the Cat's wave function has collapsed or decomposed (a bad pun)

If we apply this to Quantum Mechanics, we see that a particle before it is observed can be any allowed state. By observing the particle we change it's state to the one we see, only one possible state out of many allowed ones. This is an apparent paradox, particles can exist in any state possible before we measure them. In measuring them we have altered them.

Answer 3

right it incredibly is a miles less dramatic way of restating the Cat Paradox. in case you have one thousand bins, each and each with a cat interior, the QM equations will inform you that approximately 500 of those bins might have stay cats interior them, and approximately 500 might have lifeless cats interior them. As to which field has which cat, nicely, you need to open up each and each field to ascertain. the real heart of the anomaly isn't any remember in case you assign some actual which means to the wavefunction until eventually now length. if so, you have each and each cat interior the field that's the two alive and lifeless on the comparable time. in spite of the incontrovertible fact that, measurements do no longer use uncooked wavefunctions (that are complicated) yet only truthfully the cost of the wave function (it incredibly is genuine valued), and it relatively is which you bodily see. And once you're coping with probabilities, you could in basic terms relatively meaningfully communicate approximately great communities of issues, no longer guy or woman issues. To me, that isn't the wierd part of QM. The wierd part of QM is the EPR paradox, the place it sounds as though like pairs of debris are talking with one yet another swifter than gentle. I say sounds like, by way of fact until eventually you degree the pairs, you do no longer likely comprehend what exceeded off in between.

Answer 4

The process of observing changes the outcome. If you don't open the box, there's a universe where the cat is alive and a universe where the cat is dead. If you don't know, the cat is simultaneously both.
It's similar to wondering if our surroundings exist without us. If there is no one in the forest when the tree falls, does it make a sound? Or is it the act of hearing it, which gives the sound existence?

Answer 5

Supposedly, the observer influences the outcome in quantum physics. And there can be multiple realities occurring at the same time.

Answer 6

You can look this question up here, as it has already been answered a few times.

Answer 7

You don't have it quite right. Read about it at Wikipedia.