swansont

Our physics descriptions are valid back to about 10^-43 sec. Not to zero.

Depends on the temperature difference. Which is why it becomes less efficient with each stage of trying to recover energy.

I used to teach the folks running the reactor. If you actually knew more your son would be in violation of national security laws for having divulged classified material to you, and he’d lose his clearance, and probably his job and pension. You don’t need to separate them; most are irrelevant. They would be thermal photons that don’t trigger the photodetectors. If these are near-visible or visible wavelength photons being entangled and you’re worried about contamination, there are wavelength filters and also the very technologically sophisticated step of turning the room lights off during the experiment. There’s also the coincidence measurement I mentioned, which is a filter in the time domain.

Why do you need to separate the photon? How does this relate to the scenario under discussion?

Yes, that was the revelation of Einstein’s relativity, back in 1905. We perceive length visually, geometrically. Time, not so much. There’s no physics that describes time standing still and contracting length to zero. The equations fail under that scenario. Before the big bang is another thing that physics can’t describe.

Again, your idea of what’s going on isn’t how the experiment is run. It’s done under controlled conditions so there’s virtually no other candidate photons, and you do coincidence measurement to screen out extraneous signals. If you do e.g. spontaneous parametric down-conversion, the entangled pairs are emitted in a particular direction. The bottom line is the folks doing these experiments understand what’s going on, as opposed to some hecklers in the peanut gallery. Declaring that “this can’t work” and the insinuation that you know more than the scientist who have performed the experiments isn’t a good look in light of the fact that this does work.

Length changes, too, under those circumstances

Or perhaps you just don’t know how any of this works. It doesn’t fit with your mental model of what’s going on, but it’s your model that’s wrong, not the experiment. (iow this is argument from incredulity, which is a fallacy; things aren’t wrong simply because you don’t undertand) The light passes through the cube. Straight through for one polarization, at 90 degrees for the other. Which path it takes tells you the polarization. All you have to do is put a photodetector at each path to tell you where the photon went.

So does USNO, via GPS. Time from USNO and NIST typically agree to better than 100ns (often much better); there’s a memorandum of understanding that dictates how well. How is this different from other base unit standards, like length, which is defined in terms of how far light travels in a second? They’re all conventions.

Directional charge? Charge is a scalar. ! Moderator Note Piling nonsense on top of nonsense, and repeating assertions instead of addressing issues. A hand-wave is not a model. We’re done here. Don’t bring this up again.

! Moderator Note The next step needs to be addressing the many problems that have been pointed out, rather than building on top of a flawed foundation

! Moderator Note Stock discussion is decidedly not quantum theory.

But without the BH, there is no appreciable gravity. Certainly not enough to do what you claim. And: a dipole? What would the electric dipole moment be?

Depends on the experiment, but you know where the photons are coming from and the wavelengths, so it’s not difficult to do. It’s a cube, 1/2” or 1” on a side. Exactly. And that’s why you need statistics of several photons, as you pointed out.

You’d probably send the light through an optical fiber, which can be coiled up, and the measurement takes much less than a second. Because you entangled the photons. As you’ve been told, if it’s just a random photon there’s no way to tell if it’s entangled Again, as you’ve been told, you need multiple photons to do this. You really need to read the replies in the thread.

Because that’s trivially known, if you’re familiar with atomic physics. Your tone suggests that you think it hasn’t been done. I’ve done it. One way is to send it through a polarizing beam-splitter cube. If the polarization is in one direction it goes straight through. If it’s orthogonal it gets reflected. Knowing which way it goes tells you the polarization I have no idea of the context of this question, but spacetime means you’re talking about relativity, and entanglement is a quantum effect. So you need to explain the connection.

The issue that’s all to common is that interested amateurs watch a video but it’s not saying what they think it’s saying. Saying that the whole lecture is fascination isn’t the issue here - what is in the video that pertains to this particular discussion. It’s unlikely that all 50 minutes are.

It’s unreasonable for you to expect anyone to watch a 50 min video and sort through the arguments, which is why we have a rule against it to add to this: measuring one photon doesn’t even tell you it’s entangled It could possibly rule out entanglement, since the correlation could come out wrong. But that’s it

You can ask questions of the original poster as long as it’s on-topic

Entanglement can’t be used for faster than light communication, which is the usual proposal

The first two responses gave some details of what cosmology says on the matter

! Moderator Note And you have a thread for that, so we won’t be discussing it here

That’s just silly Source: me, who worked for ~25 years at the US Naval Observatory in the precise time department

But why would they stay in orbit if there is no longer a black hole? They tend to go in straight lines. LOL no. There have been experiments that yield a much smaller value

I prefer Rb-87, but that’s a personal bias. Some former colleagues like calcium and strontium How does this differ from length?