[brianush1]

Obligatory "not a quantum physicist," but the only way to observe something is to throw something at it (e.g. a photon) and see what bounces back. The problem is that when you throw something at it, you're interacting with and affecting the ball.

[monktastic1]

This is not quite correct. There are ways to gain information about a quantum state without interacting with it: https://en.m.wikipedia.org/wiki/Interaction-free_measurement

[mrkstu]

Do (non)measurements taken this way 'collapse the wave function' anyway? Or can you only get information that is still open to change during the actual measurement?

[monktastic1]

"Collapse" is just one way to explain how measurements happen. These are "actual" measurements, because they give you actual information.

[Koshkin]

Yeah, this is another popular non-explanation. (It does not explain why the ensuing randomness is subject to strict and perfectly deterministic laws).