[graycat]

Issues:

(1) With Itself:

Consider Young's double slit experiment: So, have plane with two slits and some distance away a parallel plane with detectors. (A) Several times, shoot a photon at the slit. Observe that the detection locations form parallel lines, i.e., fringes. (B) Cover one slit, repeat, and observe that the detection locations from a smooth hill without fringes.

So, from (A) we conclude that the something about the photon went through both slits and interacted with itself to form the fringes, the ones we didn't see from (B).

Q. Between the two planes, where was the energy?

(2) Mass and Charge

Set aside (1) with its photons and two planes.

Now one at a time shoot electrons, i.e., with not just energy but also mass and charge. And shoot the electrons at a beam splitter, i.e., a plane, partially transparent to the electrons, and at 45 degrees to the path of the electrons.

Some electrons pass through the plane with no change in direction and some get deflected 90 degrees.

On the paths after the plane, have some very sensitive detectors for mass and charge. These detectors are distant enough that what they do cannot affect the electron, i.e., the electron does not know about the detectors.

Q. What do the detectors read? For each of the two paths, whole mass and charge, half, or something else?

[evanb]

You're very close to understanding to quantum eraser experiment / the even more upsetting delayed-choice quantum eraser.

Even though it sounds as though your arguments are gotchas that prove quantum mechanics to be nonsense, it turns out the world really is that way.

https://en.wikipedia.org/wiki/Delayed-choice_quantum_eraser

[graycat]

Gee, I'm not the first to make this mistake about quantum mechanics!

[scotty79]

You can't detect without affecting.

My idea for resolving this is that electron is never a point-like particle. It's always a cloud, just larger or smaller. When it's detected it gets reshaped to be narrower. Mass, energy, momentum and such are a quantities ascribed to the whole cloud and exchanged only on the moment of interaction.

Think about diffraction. Photon or electron that passes through a small hole had it's moment messed up proportionally. It becomes large again.

Interesting question is where's the gravity in all of this. There are various ideas how to match quantum uncertainty to shape of space-time.

[graycat]

> You can't detect without affecting.

"These detectors are distant enough that what they do cannot affect the electron, i.e., the electron does not know about the detectors."

We detect gravitational waves without "affecting".

The electron mass and charge send out signals. Have the detectors sufficiently far away that they can't affect the particle yet. Get the detection and then know where the particle was and its mass and charge then. Have the particle reflected by some mirrors and then know the current path of the particle and its mass and charge, all without affecting the particle.

[scotty79]

> The electron mass and charge send out signals.

This affects them.

[graycat]

So LIGO detects a gravitational wave. Optical telescope data indicates that the wave was generated 10 billion light years away from two neutron stars. So, then, LIGO today affected the two neutron stars 10 billion years ago? Affected them today?

[oezi]

Absolutely. But this not a causal effect, but it collapses the probabilities of what has occurred.

[tzs]

> You can't detect without affecting

What about interaction-free measurements, such as in the Elitzur–Vaidman bomb-tester thought experiment [1], which was later shown experimentally to be correct?

[1] https://en.wikipedia.org/wiki/Elitzur%E2%80%93Vaidman_bomb_t...