[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.