[ajuc]

It seems to me that one of these positions makes much more sense because it assumes the least unproven behaviour.

We measure the wave collapsed as if the cat died in minute 3 of being in the box (we can calculate that from the amount of CO2 and other methods). You say "we don't know if it really collapsed in minute 3, or collapsed now and retroactively made every measurable fact look like it happened in minute 3".

To me it sounds like "Earth can be 6000 years old - God simply made it look like it has billions of years". Sure I cannot experimentally distinguish between these options, but one is much simpler.

I guess with QM at least we "caught God doing the retroactive stuff" for small things, but we had no proof it had anything to do with consciousness, and it never seems to happen for macroscopic stuff.

It's like I see street lamp goes black when I'm near it and assume it's because I was close to it. It's easy illusion to get into, because you never see the lamps that go black when you're not around. But there's no justification that you/consciousness is needed.

[stale2002]

You are once against picking a specific time as to when exactly collapse happens.

I would argue the opposite to you, actually, and instead say that the whole world is entangled, and the wave never collapses.

We can't even prove that collapse happens in the first place.

So, assuming that things never collapsed is actually the situation with the least amount of unproven assumptions, and it literally is not assuming that the collapse ever happens.

That's much better than saying that the wave function collapses at exactly the atomic level or something.

All of these points in time are arbitrary.

> retroactive stuff

There is nothing retroactive about any of this. Before collapse, it exists in a state of it not happening and happening at the same time. That's not retroactive.

[ajuc]

> You are once against picking a specific time as to when exactly collapse happens.

Well Many Worlds assumes multiple universes that's kinda big assumption too. But I agree it's the most elegant interpretation.

> All of these points in time are arbitrary.

If we exclude Many Worlds then collapse happens. We have to conclude it can happen for microscopic objects at least.

What I cannot understand is how people then jump to assume it's consciousness that is the important distinction. What's the reasoning here? We can't even define it, we don't know if we have it, we don't know if it's important, why put it it physics?

> There is nothing retroactive about any of this. Before collapse, it exists in a state of it not happening and happening at the same time. That's not retroactive.

Ok, if you don't go back and recreate everything that happened when I observe it then you have to remember all the possible paths and chooses one of them when I look at it.

If I had to code the universe I wouldn't write it in such a way that it needs to remember everything that could happen but was never observed by a player :) Seems like a huge waste of resources if I could just as well cull the statetree early.

We even have an interaction that AFAIK cannot be isolated (gravity) - how's that working with the cat in a box? When it falls dead it curves spacetime outside of the box differently after all.

[stale2002]

> AFAIK cannot be isolated (gravity) - how's that working with the cat in a box?

If you want to argue that the gravitation effect of something, causes the act to be "observed" by the person, that's fine. But that's still an observation.

That is still the person "observing" the effect, because they are now effected by it. And you have no way of knowing when exactly the wave function collapsed.

It could have collapsed at any time.

So back to your original example, it would not be the camera recording it that collapses it, it would be the gravity waves being "observed", or whatever.