Looking down on the double slit experiment from outside you can ask questions like âwhat is the probability that the photon will go through each slot?â. You have no âgivensâ to affect your probabilities so you say â50/â50â, and youâre right. The photon goes through both, but since thereâs only one photon (conserved number of photons), it does it in a particular (some what obvious) way: it combines the states âleft/ânot rightâ and ânot left/ârightâ.
Now say youâre presented with two doors. You also canât be in the state âright and leftâ. Now when you go through one door, because youâre interacting with yourself, you have givens that affect the probabilities. Ask yourself, âWhat is the probability that I went through the left door, given that I just went through the right door?â Zero, baby!
The version of you that when through the left door will be able to make a very similar calculation.
The explainer doesnât seem to imply the choice is equivalent to a quantum split unless Iâm missing something? Iâve had Jeffâs reservation every time Iâve heard this argument. It seems like it would just be a huge coincidence for our decisions to actually correspond to splits. Subjective senses of uncertainty may not equal actual lack of determinism at the atomic level.
My impression (also not a physicist) is that thereâs no obvious connection between a wave function collapsing somewhere in the universe and your neurons churning through a decision about which door youâd rather walk through. Under Many Worlds, every quantum-possible universe exists, but that doesnât mean that your experience of decision-making is equal-and-opposite distributed across those worlds. If you like the look of the right door better than the left door, then probably most of your selves will go through that door.
(If youâre interested in a fictional exploration of these issues, Ted Chiangâs Anxiety is the Dizziness of Freedom is excellent.)
fwiw, my concern isnât premised on âall futures /â choices being equally likely.â
I think the concern is closer to something like âsome set of futures are going to happen (thereâs some distribution of Everett branches that exists and canât be altered from the inside), so thereâs not really room to change the course of things from a zoomed-out, point-of-view-of-the-universe perspective.â
Is that actually something the many-worlds view implies? It seems like youâre conflating âmade a choiceâ with âquantum splitâ?
(I donât know any of the relevant physics.)
I think so? (Iâm also lacking the relevant physics.)
From the explainer I linked to:
The explainer doesnât seem to imply the choice is equivalent to a quantum split unless Iâm missing something? Iâve had Jeffâs reservation every time Iâve heard this argument. It seems like it would just be a huge coincidence for our decisions to actually correspond to splits. Subjective senses of uncertainty may not equal actual lack of determinism at the atomic level.
My impression (also not a physicist) is that thereâs no obvious connection between a wave function collapsing somewhere in the universe and your neurons churning through a decision about which door youâd rather walk through. Under Many Worlds, every quantum-possible universe exists, but that doesnât mean that your experience of decision-making is equal-and-opposite distributed across those worlds. If you like the look of the right door better than the left door, then probably most of your selves will go through that door.
(If youâre interested in a fictional exploration of these issues, Ted Chiangâs Anxiety is the Dizziness of Freedom is excellent.)
fwiw, my concern isnât premised on âall futures /â choices being equally likely.â
I think the concern is closer to something like âsome set of futures are going to happen (thereâs some distribution of Everett branches that exists and canât be altered from the inside), so thereâs not really room to change the course of things from a zoomed-out, point-of-view-of-the-universe perspective.â
Iâll give the Chiang story a look, thanks!