swansont

If it’s with light and you’re observing the interference pattern, you’re destroying the photons.

Yes. If it has enough energy in the rest frame of the other particle, it has enough energy in any frame.

! Moderator Note We aren’t going to entertain such questions, regardless of your assurance.

I don’t understand. Something takes part in the interaction. You’ve had two of us state that.

Rigor, please. Model, predictions, data.

You can quantify it. You can’t get to the right answer without properly accounting for each. Yes. 45 microseconds a day vs 7. But if the 7 is ignored, that’s more than 2 km of positioning error building up each day. I think we’d notice

No. You need something else around to recoil a tiny bit so that momentum is conserved.

Mass x velocity. p=mv (nonrelativistic formula) You need to know both. Talking about the momentum in an orbital is usually nonsensical. The whole atom has momentum, but you can't really assign a value to individual particles. They do not follow a classical trajectory. The energy used to create the photon is the energy difference between the electron states. That tells you its energy. There not used to make the photon (i.e. there's no waste involved). The only other energy would be the atomic recoil, and that's tiny for one photon — visible-energy photons cause a recoil of order 1 cm/s. The actual value depends on the exact energy and the atom's mass. (But scatter a few thousand photons and the effects are definitely noticeable)

This seems to me to be a problem with reporting, and possibly funding, than with scientists.

Momentum, like mass, is a property of a particle. They would not be properties of each other. A photon has momentum. An electron that's moving has momentum. And electron also has mass. 0 mass particles are never at rest. They always move at c. Since energy and frequency are related, you can glean a certain amount of information by measuring one or the other. A photon at 1420 MHz probably came from a hyperfine transition in hydrogen, and if it's shifted a little from that, you could conclude that the source was moving relative to you. All atoms have characteristic spectra that are used this way.

If there is a way to do that conversion, as with matter-antimatter annihilation, yes. e.g. an electron and positron annihilating will convert their 1.022 MeV of rest mass into that amount of photon energy (two or more photons, in order to conserve momentum) If you have a photon of sufficient energy you can create a particle/antiparticle pair. One problem is knowing how much energy you start with. It could be zero. We typically only measure changes (or differences) in energy.

You can put slits where you would expect an interference maximum to occur, so light going through must have interfered to get there.

They always have a wave function. The collapse is a loss of superposition of states, not the loss of having a wave function. You can send particles through multiple sets of slits and you will have interference, as long as you create a new superposition.

In the way we keep the books, energy due to center-of-mass motion does not contribute to mass. Other energy does. A spinning top has more mass than when it is not rotating, and a hot cup of soup has more mass than an otherwise identical cold cup of soup. If you excite an atom or nucleus, its mass increases — this last effect has been experimentally confirmed.

Except we don't. Gerrymandering skews representation, and voter suppression means that our representation (the rule) is not representative of the people. To some extent we rule by consensus of representation. But people have rights that can't be abrogated by this consensus. It's one reason Trump has often been a loser in court after trying to implement policy based on GOP "consensus"

Ethan's article is quite correct: we need independent confirmation, with a different method and from some other group. That's more or less understood, though. Important points not mentioned in the original article include the existing kind of experiment which should have seen this, if it were real, and did not ("Lepton colliders producing electron-positron collisions at these relevant energies should have seen evidence for this particle; they have not") and that this group has made new particle claims before which have not panned out.

You are free to come up with examples of the application of the negative root in this kind of problem. You realize the fact that it's not a vector and uses scalars works against your position, right? OK, now do the problem where Alice is starting at the distant star and moving toward Bob. Her length is still contracted the same amount and her speed is the same. How can her time not be dilated the same?

#5 — without an acceleration, there is no deviation. It's not the source of time dilation, but it is the reason for the asymmetry in the effects. #6 is correct, and verified, making #7 wrong (not the part about it being what you think, but the physics). Take the Hafele-Keating experiment. Time dilation depended on movement of East vs West, which boils down to faster or slower as compared to an inertial frame. Not moving toward or moving away, as they spent half of their time doing each, with respect to the clocks on the ground.

What's the evidence of this?

Not for length contraction or time dilation. The sign wouldn't matter.

The wave function does not depend on the detector. That's an experimental detail. Much like spin, the polarization is another factor you have to include; it's not part of the basic wave function of the Schrödinger equation.

That's the wrong approach. There's nothing that says that it is. You have to assume something extra to put directionality into it. The directionality of the doppler effect comes into play with the sign of v. The Lorentz factor uses v^2, so the sign goes away. (edit: and now I see Janus has given a more complete answer than my short summary)

That doesn't jibe with "positing something different"

Physics doesn't try to describe reality. It tries to describe how nature behaves. IOW, behind the curtain, nature nature might be very different from what physics says, but that is not something we can currently test. What we can observe limits us to describing things that can be confirmed (or disproven) by we can observe. Our models are mathematical because the best models quantify things. Maybe someone can come up with a non-mathematical model that can be tested precisely, but until they do, math is what we have. Yes, sorry. I fixed it. Physics deals with time measurement and quantifiable effects. The issue is similar to to asking "what is energy?" Once you get much past "the capacity to do work" you're typically deep in the heart of metaphysics.

That's much more in the realm of metaphysics (i.e. philosophy), rather than physics. edit: xpost with Strange