Entangled Photons with no shared Past

[DrChinese]

If you commit the "sin" of assuming light is at rest, space-time would contract to zero, and time would slow down indefinetly. So, light would observe itself as being everywhere it was, is, and will be at the same time! It would be as though it was everywhere along it's world line at once. Then the photons would see themselves as being A1 and B1 or A2 and B2 at the same time they are just A1, A2, B1, and B2. This is because when the wavelengths match up, they amplify their intensity as if they joined into one particle. So from the photons frame of reference, they are the same particle at the same time they are not. To the photon, time has no meaning, and it is as there is no time that the particle passes through. So then the particles could share histories that are completely independent from each other...

I am not sure what any of this actually means, but...

If two particles exist only during a period in which they are causally disconnected, I don't see how they can have a shared history. This is essentially true by definition - and regardless of how they experience time.

 

[RandallB]

...entanglement... is something that can only be explained using the Special Theory of Relativity.

If you commit the "sin" of assuming light is at rest, ...
I am not surprised at all by these result, and find it has further confirmation of one of my theories.

OH PLEASE windscar
Don’t dump trash like this on DrC..

Your “sin” matchs the "science" of Zeno & Parmenides around the Fifth Century BC

You they and your photons agree with Zeno's paradoxes and therefore “know” that nothing in our universe actually moves at all.

It’s all just a sophist dream of some kind;
we just don’t know that we are not real.

You may need to test some of your theory’s (How many ?) in the philosophy forum.

 

[ueit]

I don't need to "prove" particles don't carry a history with them any more than I need to prove that Santa Claus does not exist. It is a fact that no known history is present in any particle beyond a few basic observables (position, momentum, etc.). No such history has ever been observed! You cannot distinguish a photon created 5 minutes ago with one creates 5 billion years ago as far as anyone knows.

By "history" I understand the conditions regarding the emission process, not a "list " containing all past interactions. That, I agree with you, would be ridiculous. So, a photon's spin along a certain axis may depend on electron's position in the atom (true, QM doesn't distinguish between atoms in the same state, but Bohmian interpretation proves that it is possible to make such a distinction without contradicting known experimental evidence). Now, the electron's position in the PDC crystal A might be influenced by the field of the electrons/quarks in the PDC B.

As to how an electron is created: this can be done in particle accelerators and can be done by decay of a neutron. Where do you think these new electrons were "hiding" before their creation?

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.

Of course A2 and B2 do not share a common past, as the term is normally used.

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.

 

[Hootenanny]

You can't use common sense to understand theoretical physics, but you must develop a new type of uncommon sense. Er, it went something like that, and was said by Einstein

Perhaps not common sense, but mathematics certainly, perhaps you would care to show us how these 'results' verify your theory before this thread gets locked, which would be a shame since you've hijacked the Doc's thread. And the actual quote if I remember correctly goes as follows;

"Common sense is the collection of prejudices acquired by age eighteen."
​

 

[RandallB]

And the actual quote if I remember correctly goes as follows;

"Common sense is the collection of prejudices acquired by age eighteen."
​

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

It doesn’t sound like him when you see him say things like:

“. . . science is nothing more than the
refinement of everyday thinking”
A. Einstein
(from; Journal of the Franklin Institute 1936)​

 

[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.