If “you” is not just one Everett branch, but a set of sufficiently similar Everett branches, that makes the coinflip even more similar to quantum measurement, in the sense that when “you” flip the coin, the different branches flip it slightly differently, so you get heads in some of them, and tail in others.
If I push the classical uncertainty into the past by, say, shaking a box with the coin inside and sticking it in a storage locker and waiting a year (or seeding a PRNG a year ago and consulting that) then even though the initial event might have branched nicely, right now that cluster of sufficiently-similar Everett branches are facing the same situation in the original question, right? Assuming enough chaotic time has passed that the various branches from the original random event aren’t using that randomness for the same reason.
I understand from things like this that it doesn’t take a lot of (classical) uncertainty or a lot of time for a system to become unpredictable at scale, but for me that pushes the question down to annoying concrete follow-ups like:
My brain and arm muscles have thermal noise, but they must be somewhat resilient to noise, so how long does it take for noise at one scale (e.g. ATP in a given neuron) to be observable at another scale (e.g. which word I say, what thought I have, how my arm muscle moves)?
More generally, how effective are “noise control” mechanisms like reducing degrees of freedom? E.g. while I can imagine there’s enough chaos around a coin flip for quantum noise to affect thermal noise to affect macro outcomes, it’s not as obvious to me that that’s true for a spinner in a board game where the main (only?) relevant macro parameter affected by me is angular momentum of the spinner.
I think the quantum uncertainty can propagate to large scale relatively fast, like on the scale of minutes. If we take an identical copy of you (in an identical copy of the room, isolated from the rest of the universe), and five minutes later you flip a coin, the result will be random, as the quantum uncertainty has propagated through your neurons and muscle fibers.
(Not sure about this. I am not an expert, I just vaguely remember reading this somewhere.)
Usually we do not notice this, because for non-living things, such as rocks, a few atoms moved here or there does not matter on the large scale; on the other hand, living things have feedback and homeostatis, keeping them in some reasonable range. However, things like “flipping a coin” are designed to be sensitive to noise. The same is true for pinball.
If “you” is not just one Everett branch, but a set of sufficiently similar Everett branches, that makes the coinflip even more similar to quantum measurement, in the sense that when “you” flip the coin, the different branches flip it slightly differently, so you get heads in some of them, and tail in others.
Some keywords you may find useful: logical uncertainty, probability is in the mind.
If I push the classical uncertainty into the past by, say, shaking a box with the coin inside and sticking it in a storage locker and waiting a year (or seeding a PRNG a year ago and consulting that) then even though the initial event might have branched nicely, right now that cluster of sufficiently-similar Everett branches are facing the same situation in the original question, right? Assuming enough chaotic time has passed that the various branches from the original random event aren’t using that randomness for the same reason.
I understand from things like this that it doesn’t take a lot of (classical) uncertainty or a lot of time for a system to become unpredictable at scale, but for me that pushes the question down to annoying concrete follow-ups like:
My brain and arm muscles have thermal noise, but they must be somewhat resilient to noise, so how long does it take for noise at one scale (e.g. ATP in a given neuron) to be observable at another scale (e.g. which word I say, what thought I have, how my arm muscle moves)?
More generally, how effective are “noise control” mechanisms like reducing degrees of freedom? E.g. while I can imagine there’s enough chaos around a coin flip for quantum noise to affect thermal noise to affect macro outcomes, it’s not as obvious to me that that’s true for a spinner in a board game where the main (only?) relevant macro parameter affected by me is angular momentum of the spinner.
I think the quantum uncertainty can propagate to large scale relatively fast, like on the scale of minutes. If we take an identical copy of you (in an identical copy of the room, isolated from the rest of the universe), and five minutes later you flip a coin, the result will be random, as the quantum uncertainty has propagated through your neurons and muscle fibers.
(Not sure about this. I am not an expert, I just vaguely remember reading this somewhere.)
Usually we do not notice this, because for non-living things, such as rocks, a few atoms moved here or there does not matter on the large scale; on the other hand, living things have feedback and homeostatis, keeping them in some reasonable range. However, things like “flipping a coin” are designed to be sensitive to noise. The same is true for pinball.