Entangled Photons with no shared Past

[JesseM]

Do you recall a reference where someone used that as coming from Einstein?

According to http://www-groups.dcs.st-and.ac.uk/~history/Quotations/Einstein.html, the "common sense is the collection of prejudices..." quote from Einstein can be found in E. T. Bell's Mathematics, Queen and Servant of the Sciences, 1952. A google book search shows this book which says the quote can be found on p. 42 of Bell's book, so someone could look up the context if they're interested.

 

[RandallB]

According to ...the "common sense is the collection of prejudices..." quote from Einstein can be found in E. T. Bell's Mathematics, Queen and Servant of the Sciences, 1952.

Thanks, “The Expanded Quotable Einstein” (2000) by Calaprice
lists the quote as ‘Probably Not by Einstein’ on page 319

I always wondered by who or where, the potential misquote might have started. I’ll try to find the E. T. Bell book
----
I see windscar is no longer with us.
So DrC doesn’t have to defend entanglement, which should be a given for the issue in this thread.

 

[DrChinese]

1. Now, the electron's position in the PDC crystal A might be influenced by the field of the electrons/quarks in the PDC B.

2. A neutron is a complex system containing three charged particles (quarks). The electron that is generated in this way will depend on how these quarks are positioned, and this in turn depends on the surrounding fields. Therefore your electron would not be in a pristine state.

3. Please then specify what exactly the "normal" use of a common past is for you.

I know that the photons originated in some charged particles, and I know that those particles interacted as a consequence of them being charged. This qualifies as a "common past" for me.

1. This is qualifies as hypothesis, as there is not the slightest evidence of any such effect - either by experiment or accepted theory. So if your hypothesis is accepted (which I would not grant), then you have identified a previously hidden variable. However, even in this case, the photons still do not share a common past even if the electrons do. The photons were created in environments that are still local to them and are most certainly not identical.

2. This also is qualifies as hypothesis, as there is not the slightest evidence of any such effect - either by experiment or accepted theory. If your hypothesis is accepted, then you have identified a previously hidden variable.

3. A common past requires 2 particles to have been in the same place at the same time at some point in their lives.

The problem with this discussion is that it pulls us away from looking at the true issue with this fascinating experiment. Clearly, the entanglement of A2 & B2 occurs because of something that happens AFTER they are created! This is the variable in the equation that is most interesting, because the normal light cones for causality are thrown into disarray. It would be possible, in principle, to construct a version of this experiment in which A2 & B2 have never had the chance to be in causal contact. This is different from regular PDC entanglement, in which the two photons were "born" together.

 

[RandallB]

According to http://www-groups.dcs.st-and.ac.uk/~history/Quotations/Einstein.html, the "common sense is the collection of prejudices..." quote from Einstein can be found in E. T. Bell's Mathematics, Queen and Servant of the Sciences, 1952. A google book search shows this book which says the quote can be found on p. 42 of Bell's book, so someone could look up the context if they're interested.

Attached is a copy of page 42 to put his use of the quote in context – which I find rather pointless. Got lucky and found an old first edition (I doubt there is a second edition beyond). I doubt the author just made it up – but the book gives no reference and my guess he only heard it through the grapevine from a verbal source that did make it up.

I agree with “The Expanded Quotable Einstein” (2000) by Calaprice
Einstein almost certainly never actually said this about commonsense.

 

[Demystifier]

Even the free Schrodinger equation describing non-interacting particles contains entangled solutions. So, I do not understand what is so strange about entangled particles not sharing the common past?

 

[DrChinese]

Even the free Schrodinger equation describing non-interacting particles contains entangled solutions. So, I do not understand what is so strange about entangled particles not sharing the common past?

Nothing is strange about it at all unless you harbor underlying ideas about local realism. There must be all kinds of entanglement around us in our everyday world.