Jump to content

Recommended Posts

Posted
It is particles which have spin.

 

Yea that's a mistype, thanks for the correction. You have the wrong person listed as the quote though somehow.

Posted
So what is mysterious about that ?

I have a stick with one end painted in red and the other painted in blue.

I have two box' date=' I close my eyes, break the stick in two and put one piece in each box that I close. I send you one of the box and the other too an other person. When you will open the box and see that you received the blue end. Instantanly you will know that the other received the red end ! HUU fantastic that's magic :D:eek:[/quote']

 

I think this is an oversimplication (therefore wrong "in theory" although Einstein would have agreed with you).

 

I will offer an oversimplified explanation (therefore probably wrong "in theory" but I will offer it as an analogy and hope someone will correct us both in a way that we can understand):

 

You could have opened the box testing for green vs yellow which is independant of the red vs blue or turquoise vs orange which is partially dependant on the red/blueness and the green/yellowness.

 

By carefully selecting the "colours" of the test you can effect the odds of a subsequent test to the opposite particle even though it had not been "tampered with", at least not locally. Of course it would take a number of particle pair tests to prove this changing of the odds of the opposite particle.

 

I hope the above is perfectly confusing. If not, it is probably "not even wrong" and should be ignored. :D

Posted
I hope the above is perfectly confusing.

Yes completely confusing. Why test for a color I know will never happen ?

The photon are polarised to the left or to the right. If I mesure one to be left, I am sure the other is rigth polarised. I think that the confusion come from the supposition that the photon before mesurement is in both state at the same time (left and rigth polarised) something I don't accept...

Posted
supposition that the photon before mesurement is in both state at the same time (left and rigth polarised) something I don't accept

I thought superposition was that it could be either one state or another we say it "posses" both states, but in reality it only has one state, but we don't know it.

 

Schrödinger's cat wasn't dead and alive, it was in an unknown state, represented as saying it was in "both" but something can't be one and the other. When you observe it you find out which state it is in, before that it is in a superposition, we do not know what state it is in.

Posted

That's what I also think but I think that physicist say superposition is both state at the same time... Can a real physicist give is opinion on that ??

Posted
superposition is both state at the same time

It is not literally in both states, a particle cannot have 2 different spins, however we say or refer to it as having both states. A mathematical referrence to something and reality is not always identical.

 

The reason I was picking up on this is because you said "something I don't accept" and I seemed to have made the assumption it was because you don't think e.g. a particle can have an up and a down spin at the same time.

Posted

That is what I think that we don't know which state it is but it have only one state

Thanks for your answers. I was under the impression that physicist where realy thinking that it was in the 2 state at the same time. I think that some physicist mixup reality and mathematic ;)

Posted
I thought superposition was that it could be either one state or another we say it "posses" both states' date=' but in reality it only has one state, but we don't know it.[/b']

Schrödinger's cat wasn't dead and alive, it was in an unknown state, represented as saying it was in "both" but something can't be one and the other. When you observe it you find out which state it is in, before that it is in a superposition, we do not know what state it is in.

 

I think this interpretation has been consistently on the losing end of the argument for the last 70 years, at least in the eyes of most physicists.

Posted
Yes completely confusing. Why test for a color I know will never happen ? The photon are polarised to the left or to the right. If I mesure one to be left, I am sure the other is rigth polarised[/b']. I think that the confusion come from the supposition that the photon before mesurement is in both state at the same time (left and rigth polarised) something I don't accept...

 

But don't you have to choose an axis about which to test the polarisation? Are you not "forcing" a 100% left or 100% right choice on the photon?

Posted
I thought superposition was that it could be either one state or another we say it "posses" both states, but in reality it only has one state, but we don't know it.

 

No, that's exactly what superposition doesn't say.

 

Superposition states that a state function is made up of a linear combination of all (orthonormal) eigenstates. It does not say it is one eigenstate and you don't know which.

Posted
I think this is an oversimplication (therefore wrong "in theory" although Einstein would have agreed with you).

 

I will offer an oversimplified explanation (therefore probably wrong "in theory" but I will offer it as an analogy and hope someone will correct us both in a way that we can understand):

 

You could have opened the box testing for green vs yellow which is independant of the red vs blue or turquoise vs orange which is partially dependant on the red/blueness and the green/yellowness.

 

By carefully selecting the "colours" of the test you can effect the odds of a subsequent test to the opposite particle even though it had not been "tampered with"' date=' at least not locally. Of course it would take a number of particle pair tests to prove this changing of the odds of the opposite particle.

 

I hope the above is perfectly confusing. If not, it is probably "not even wrong" and should be ignored. :D[/quote']

 

That's basically right.

 

The limitation of saying the two photons will always have orthogonal polarizations is that you have neglected to say how you measure it: you have to choose an axis to be | vs ---. So while you know the other photon's polarization instantly, you can't communicate how you measured it to anyone else faster than c, to give them access to the same information.

Posted
I think this interpretation has been consistently on the losing end of the argument for the last 70 years, at least in the eyes of most physicists.

 

Yes. The Bell's Inequality measurements point toward there not being local hidden variables.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.