MigL

I know exactly what you mean. Those Nazi Ukrainians, and their jewish President, will stop at nothing in an effort to implicate those innocent Russian victims and make them look bad in the eyes of the World. Those well-intentioned Russians should just leave the Ukraine to their evil ways, and stop trying to help and denazify them.

Is this a belief, or can you suggest a way to prove it ?

But that is exactly what we're dealing with; nothing other than fields on top of fields. Whether scalar ( value at a point ), vector ( value and direction at a point ) or even tensor ( for that pesky gravity field ), QFT is governed by Heisenberg, and so values at a specific point cannot be exact. These small 'ripples' in the quantzed fied values must meet a certain threshold; below that threshold they are 'virtual', and if surpassing the threshold, they are 'real'. It is foor convenience that we treat these field excitations as quantum particles. See the sticky in Quantum Theory "Matter is excitations in a field" It i

Why do I picture your house to look like Dr Emmett Brown's house ( from Back to the Future ), Sensei ?

So, unless the interaction of an entangled particle, with its partner, 'fixes' the particular state of the entangled property, the system has no reason to decohere. It is only when the interaction with the entangled partner results in a defined state ( even if we don't know it ? ) that entanglement is lost. Makes sense; thanks Markus.

And my point is people have to be responsible, and be held accountable, for their actions/decisions. Especially when those actions/decisions result in hundred thousands of deaths and whole countries destroyed through no fault of their own.

That's the thing about quantum particles, we can't determine much about them before detection/interaction; they are simply a mathematical expression of probability distributions. And, upon detection, their properties ( wave-like or particle-like ) depend mostly on the detection mechanism. As a result, we have various models which must be applied to differing circumstances.

The 'wall' was referencing Markus' observation that whereas quantum particles can pass through a wall, as opposed to classical particles which cannot, some of us are thinking 'classically', and nothing is getting through. The question originally posed is, regardless of the mechanism for doing so, can a quantum particle lose coherence by interaction with its entangled partner ? Or does the common wave function alreadytake the interaction into account and simply 'updates' itself ?

We are discussing Russia's invasion of the Ukraine and the ensuing bloodshed and destruction. V Putin was not s'scared' when he launched the invasion; he thought it would be a cake-walk and over in a couple of days. To claim that he is a 'scared little boy' now that the tables have turned is absolving him of the evil decisions he previously made. Should a gambler who bets it all, thinking he'll win big, be given his money back now that he's impoverished ? Tell it to your bookie.

I'm afraid INow might suggest some sci-fi porn ...

Centrifugal force is a fictituous force made apparent by motion in a rotating frame of reference. If you have no access to the external stationary frame, or the motion is slow enough that it is hard to detect, there will be nomotion sickness. IIOW, if you cannot see outside the rotating tube providing artificial gravity, or the stars are far enough away that motion is hardly noticeable, there is no problem.

I don't know how we got on the subject of light cones, and I don't want to re-read to find out. Essentially light cones define which points in space-time have been, are, and will be, in causal contact with an event. Causal contact has a very specific meaning in Physics, and is subject to the speed of light, c .It implies cause and effect, the very things Bangstrom is arguing against, as non-locality requires an 'effect' before information about the 'cause 'can reach that point The 'slope' of the light cone itself is c , and separates time-like ( causal ) from space-like ( non-causal or superluminal ) events in space-time. "Cause and effect, my love" The Merovingian, from The Matrix Reloaded

It may be an example brought to an absurd level, but it illustrates perfectly that QM says there is no reality until an observation/interaction is made. Which side of the wall are you on ? One thing I've always wondered about, and maybe you more learned gentlemen can offer some guidance ... If I produce two entangled particles, and somehow manage to 'steer' them towards each other such that they interact ( only ) with each other, is entanglement lost ?

Old Westerns. Specifically Sergio Leone 'spaghetty' westerns. ( what were you expecting ? )

That 'work together' part would be an excellent start ... after that, sky's the limit.

That may apply when dealing strictly with entanglement. But how does non-locality deal with 'Schroedinger's cat in a box' ? Absence of local realism seems to handle it just fine. Are you suggesting we should use non-locality for one aspect of QM, and absence of local realism for other aspects ?

The absence of local realism is evident in many, if not all, aspects of QM. Non-locality is not needed for entanglement; nor anything else. Relegate it to the dust-bin of history, along with the aether.

No I cannot think of any other example of non-locality. As far as I know, no other effects require that the outcome of an event at a specific point is determined explicitly on what happens at another point, unless there is a transfer of information. And relativity explicitly states that information is constrained to transfer at speeds not exceeding c . So non-locality is not just unproven yet, it is actually not needed; not even for entanglement.

A partial annex this year so we can have peace. In a couple of years V Putin tries again, and Ukraine lets him have another piece to keep the peace. Then a couple of years later ... ( there is no Ukraine left and V Putin moves on to the next country ) I wonder if he would have tried this stunt if Ukraine and the West had stood up to him in 2014 when he annexed Crimea ?

If Studiot and I each pull a coin out of our pockets and palm them, there is a possibility that we pull out heads and tails. That doesn't mean there is an'entanglement' or anti correlation; but if you repeat the process many many times, with the same result, there could be an anti-correlation. Similarly with any two random quantum particles; the two particles may show opposing states, but that doesn't mean there is an entanglement correlation. Further, you have no idea whether the entanglement was lost along the way to your observations, due to some interaction. And particles are indistinguishable, so there is no way to tell if a single particle has an entangled partner, or not. The only way to be sure is to produce the entangled pairs yourself.

It helps those of us who wish to understand entanglement more clearly.

Any one particle does not set a flag, or any other indicator, to let an observer know it is entangled with some other distant partner. You have no way of knowing if any particle you choose to observe/interact with is part of an entangled group, or not. You can only be sure if you produce the entangled pair. I'm not sure if that answers your question; like Studiot, I'm unsure what exactly you are asking.

I remember watching the PBS Space-time video about the Quantum Eraser experiment, and not being particularly thrilled about the conclusions drawn in that video. It would have pleased Bangstrom, I'm sure, because it suggested non-locality lead to the causality violations. Glad to know Sabine and Sean Carroll are not thrilled with it either.

In over 40 years of dealing with computer hardware that use CR2032 batteries to 'hold' set-up information in NVRAM, I have seen many go dead, but have never seen one leak. That doesn't mean it absolutely cannot happen.

You 'look for' particles by detecting, or interacting with, them. You have, then, detrmined the state of its entangled partner; wherever it might be. ( although momentum conservation laws would give an indication of directio of travel ) But, once detectedd, how would you even know you are dealing with a member of an entangled pair ?