Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: rgiuly on 25/03/2010 21:57:40

Title: How can Schrodinger's cat be dead and alive at the same time?
Post by: rgiuly on 25/03/2010 21:57:40

Referring to the cat in the box experiment, where the cat either lives or dies based on whether a radioactive atom has decayed or not:
I don't think that two cats exist at once in both the dead and alive state. I don't think that experiences the sickness and death while at the same time the other one experiences normal health. I do believe that when you run a physics *simulation* you will need to keep track or of both possibilities happening at the same time to ultimately get the "right" answer - but I just don't think both possibilities happen.

I've heard teachers say the cat exists in both states until it's observed. I don't buy that. The only thing people have proven is that our mathematical/computational models need to keep track of multiple states to get the answers right. But, because the answers themselves do not involve multiple things at the same time (cats dead and alive), I would argue that nature does *not* necessarily allow the cat to exist in both states at once.

The real question I'm thinking about here is are many versions of everything existing - and I'm guessing no. (Unless somebody can really prove it.)


-rick

Title: Re: How can Schrodinger's cat be dead and alive at the same time?
Post by: BenV on 26/03/2010 00:34:30

It's a confusing experiment, because it uses classical scale things (a cat) to describe a quantum situation.

Title: Re: How can Schrodinger's cat be dead and alive at the same time?
Post by: Geezer on 26/03/2010 07:12:25

On the other hand, cat in the hat is a well known field in science.

http://en.wikipedia.org/wiki/The_Cat_in_the_Hat

Title: How can Schrodinger's cat be dead and alive at the same time?
Post by: graham.d on 26/03/2010 09:54:26

I don't think Schrodinger ever intended his thought experiment to be taken seriously. The only way it could be so is really if there was absolutely no way of detecting the state of the cat in the box. In practice there would be some interaction with the outside that the state of the cat would affect in some way. Just because the experimenter does not know the state does not mean that it is unknown. It is not a practical idea but an absurd extrapolation to show that macro events could (in theory) be in two states, however it was a joke.

The multiverse concept appears in a good deal of scifi books/films/tv programmes and is based on the idea that the universe diverges at every quantum event. This is more of a guess than a theory as we can't easily prove or disprove it. However I think that someone showed that it was unlikely because of the total energy requirement. I don't know the details - this is just a vague recollection.

Title: How can Schrodinger's cat be dead and alive at the same time?
Post by: JP on 26/03/2010 11:46:42

I think the original idea was to show that the usual (Copenhagen) interpretation of quantum mechanics (QM) could lead to absurd results for macroscopic objects.  Whether you believe the Copenhagen interpretation or one of the other equally valid alternatives such as the many-worlds interpretation is a matter of choice, really.  No one has come up with an experiment that can tell them apart.