Recent content by Matterwave

Hello and welcome to PF! The concept of white holes has a history in the maximally extended Schwarzschild solution and might be of interest: https://en.wikipedia.org/wiki/Kruskal%E2%80%93Szekeres_coordinates However, we currently have no good candidates (afaik) for potential white holes in...

The figure is just a figure. It doesn't make any assumptions. It just shows you what the experiment is and what happens. I'm unclear on what the highlighting of the pants means. The analogy is about socks. Strictly speaking, Bell's inequalities didn't disprove local hidden variable (LHV)...

Yes, but such a treatment necessarily glosses over a lot of details. Details that you might be referring to when you say the treatments you read are "incomplete or contradictory". This is why @renormalize keeps asking you to provide what statements you find contradictory. What treatments you...

Not everyone would see this as a downside. 😉

Supernovae are quite complex phenomena and are generally only lightly covered at the undergraduate level. You may start to see more comprehensive reviews at the graduate level, in a book like Shapiro and Teukolsky "Black Holes, White Dwarfs, and Neutron Stars" -- the ending chapter 18 has a...

By "independence" here, do you mean statistical independence of measurements? In analyzing an argument such as EPRs, it is best if we stick to clear, well defined, and well scoped terminology. For example, when EPR says "no longer any interaction", they don't mean measurements of the two...

The EPR paper is always worth a (re)read 😉. It is a delightful paper, though it has its faults.

Just the time order of things as the paper presents it. T is not the time of the measurement, it's the final time after which the entanglement is "locked in" so to speak. It is only after some more time, at a time ##t'>T## that the measurement happens. The relevant quote (shortly after...

Not for the EPR state. It is still an entangled state and not a product state. When EPR says (something like) "after T, the two particles no longer interact" they mean something more akin to the Hamiltonian no longer having any interaction terms between the two particles (maybe because they got...

EPR made an implicit assumption in their argument that indeed you can stop the two particles from interacting with each other eventually. If the interaction never stops, their argument (that QM is incomplete) doesn't go through. You could imagine shielding the particles from each other or...

Hmmm, what are you counting as a "single excitation" here? If you hit the state with the number operator, you don't get 2?

Are you reading the EPR paper? It was an implicit assumption of EPR that sufficient spatial separation implies non-interaction. They basically argue that since the entangled particles are far apart from each other, they can not affect each other. This is manifest in special relativity as space...

Not every calculation is physically meaningful. Consider that a light ray emitted from earth at the same time that the spaceship leaves earth will arrive at alpha centauri before the spaceship.

I know a decent number of properties of SO(3) and obviously I can visualize the group action on three space as rotations. But a good visualization of the group itself eludes me. SU(2) is somehow more intuitive to visualize since it simply is ##S^3##. So I just think of a 2-d sphere and say...

How?