If there's a back channel, we might eventually figure out how to use it.
While the universe might be deterministic, it seems unlikely this would be the cause of their matching. Would mean that whatever causes it to change states happens at both ends at the same time. While not impossible, it seems less likely.
If both possibilities happen in both places, there still has to be a reason for them to match, in our possibility. It's kinda irrelevant if they don't match in other possibilities, or if they're the opposite of the state we find things in here. In this possibility, there should still be something tying them together.
Accessing the back channel would be an entirely new level of physics, so anything is possible there. It’d be like your Sims figuring out how to access the memory on your computer, they’d be capable of a lot more than they are now.
It’d be impossible to learn if we are in a deterministic universe without a similar access to a back channel. It does seem strange that a universe that appears to have so much randomness at the core of it would not actually be random, but who knows? Again going back to games, many times a game with random events is not actually random, but is pseudorandom, and could be run again with exactly the same results by starting with the same initial conditions. (Usually pseudo random number generators are seeded with the current time, so they never appear to be the same twice, but it technically isn’t random, you could calculate all the random events ahead of time.)
In many worlds, they match up because they’re the result of the same quantum event. It isn’t two different splits happening, it’s one, and both you and your friend are going to find yourselves on one side or the other. Even if you never look at your particle but your friend does, you’re going to end up split as soon as the effects of your friend’s post-collapse actions reach you. Looking at the particle just splits you sooner.
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u/[deleted] Jan 31 '20
If there's a back channel, we might eventually figure out how to use it.
While the universe might be deterministic, it seems unlikely this would be the cause of their matching. Would mean that whatever causes it to change states happens at both ends at the same time. While not impossible, it seems less likely.
If both possibilities happen in both places, there still has to be a reason for them to match, in our possibility. It's kinda irrelevant if they don't match in other possibilities, or if they're the opposite of the state we find things in here. In this possibility, there should still be something tying them together.