Does quantum physics invalidates causality and reality

[dracului]

If according to the recent discoveries of quantum physics the small parts of atoms are in an infinite number of states, than this would suggest that there is an infinite number of realities (multivers theory ) and they only appear in one state if observed than reality is created by the observer after my understanding, please correct me if I am wrong.
If one now takes the meaning of the word small and puts it into the grand picture of the universe, or the one we create by observing it, than we are also small particles compared to this, like a quantum.
So if we or for the sake of the argument I am a "quatum" made up of many little quantums, than the number of realities of my existence is infinite.
So can I choose my own? or which is my own? and is there a possibility to that all might interact?
Would be glad if some one could give me a science based advise, not looking to discuss SiFi.

[jake-the-peg]

I've tried to answer this 3 times now and have ended up starting again each time.

You've got quite a number of concepts all jumbled up here.

Firstly subatomic particles themselves aren't in an infinite number of quantum states. In fact the whole concept of quantum mechanics is that such objects only have a limited number of states that they can occupy.

The Many Worlds Interpretation (and there are others such as the Copenhagen Interpretation) says that the universe splits whenever a quantum choice occurs which leads to an almost infinite (but not actually infinite) number of slightly different Universes.

You are not a quantum object - because of your size. You cannot suddenly disappear on one side of a wall and reappear on the other like an electron can.

We have no actual evidence for many worlds it's just a way of interpreting what we see. Stories of travelling between universes are really just stories I'm afraid.

There is a really good interactive site that goes through the physics behind some of this complete with Java applet experiments that are quite fun.

I strongly suggest you spend some time on it if you're really interested in this stuff:

http://www.colorado.edu/physics/2000/index.pl

personally I'd start with this bit:
http://www.colorado.edu/physics/2000/schroedin ger/index.html

[dracului]

Thanks for your answer, and apologies if what I wrote was not clearly expressed.
I am aware that there are a limited number of quantum states as if memory serves correct there is spin up or spin down as a state and so called paired ones behave reverse or if observation of one turns out to be up spin the other is down spin etc. other wise one could not calculate with a quantum computer from what I can imagine, and I have to point out that I am not deeply familiar with the subject.
And I also only scratched the surface of the Copenhagen theory. But since I am made up out of atoms and small particles forming this atoms ? So does quantum mechanics not also takes effect in the human them self?
I admit my main reason for writing the question is triggered by recent discovery of the Copenhagen theory for my self and the question which implications could or has it if its right? Or is it just a nice theory proving a certain state of the universum or multiversum so to speak.

[jake-the-peg]

No quantum mechanics does not generally scale up to large objects, and normally such effects cancel out.

I say normally because large scale events can be dependent on quantum states. The classic example is "Schroedinger's cat".

Just on the off chance you've never come across it. Erwin Schroedinger devised it to illustrate how nonsensical quantum mechanics is. Ironically it's now used as a prime example of quantum mechanics.

A cat is in a sealed box with a flask of poison which is trigered to break if a radioactive source decays in a certain time period.

The Copenhagen interpretations says that the experimenter observing the event influences whether the source decays or not and that decision is not actually made until it is observed. So until the box is opened the cat is both alive and dead at the same time.

In the many worlds interpretation the universe splits and in one the cat is alive and in the other the cat is dead.

The Copenhagen interpretation is a bit like "If a tree falls in a forest and nobody hears does it make a sound?"

However I come from an experimental rather than theoretical tradition of science and as far as I'm aware nobody has ever come up with an experiment to distinguish the two.

So for my money until that happens these are just the things that mathematicians and theoretical physicists come up with in pubs when they think there are no experimentalists around.