The story I’m most sympathetic for acausal trade[1] to look something like this:
Several factions on Earth tried pretty hard to hash out their differences for what to do with space probes but end up deciding that they can’t.
Rather that put compromise solutions on the probes, and rather than go to war, they decided to “agree to disagree” and split fractions of space according to the values of different factions.[2] The key agents on the different probes are tasked to satisfy their respective factions’ values.
Once the probes arrive, they “unfold” and after an initial buildup, a key intermediate stage is turning a lot of stellar mass and energy into computrionium, so they can do more calculations than Sol’s supercomputers were ever able to. The calculations are initially done for entirely instrumental reasons (to figure out the best approach to maximize/satisfy the values loaded into the relevant agents)
One aspect of interest to these probes are what the other agents are doing. They figure this out via simulation.
Meanwhile, perhaps these agents learn highly useful empirical information about the respective regions of the other probes, from light transmissions in galaxies within your past but not future (due to space expansion) lightcone.
4+5 lead many agents to mutually conclude that their preferences will be better satisfied if they swapped places.
At this point, the agents acausally “trade” (in the sense of doing what another faction wants) iff their simulations suggest (with sufficiently high probability) that the other agents will do what they want conditional upon trading.
In such an overly specific, somewhat convoluted setup, I think refusing to consider acausal trade will be obviously foolish.
Maybe you think this setup unreasonably stacks the deck towards acausal trade. I agree! I think it’s plausible enough that simulation limits means trading across multiverses isn’t viable. But I wanted to present the example above as a kind of possibility/existence argument, before drilling down to debate probabilities (as in Fabien’s examples).
The story I’m most sympathetic for acausal trade[1] to look something like this:
Several factions on Earth tried pretty hard to hash out their differences for what to do with space probes but end up deciding that they can’t.
Rather that put compromise solutions on the probes, and rather than go to war, they decided to “agree to disagree” and split fractions of space according to the values of different factions.[2] The key agents on the different probes are tasked to satisfy their respective factions’ values.
Once the probes arrive, they “unfold” and after an initial buildup, a key intermediate stage is turning a lot of stellar mass and energy into computrionium, so they can do more calculations than Sol’s supercomputers were ever able to. The calculations are initially done for entirely instrumental reasons (to figure out the best approach to maximize/satisfy the values loaded into the relevant agents)
One aspect of interest to these probes are what the other agents are doing. They figure this out via simulation.
Meanwhile, perhaps these agents learn highly useful empirical information about the respective regions of the other probes, from light transmissions in galaxies within your past but not future (due to space expansion) lightcone.
4+5 lead many agents to mutually conclude that their preferences will be better satisfied if they swapped places.
At this point, the agents acausally “trade” (in the sense of doing what another faction wants) iff their simulations suggest (with sufficiently high probability) that the other agents will do what they want conditional upon trading.
In such an overly specific, somewhat convoluted setup, I think refusing to consider acausal trade will be obviously foolish.
Maybe you think this setup unreasonably stacks the deck towards acausal trade. I agree! I think it’s plausible enough that simulation limits means trading across multiverses isn’t viable. But I wanted to present the example above as a kind of possibility/existence argument, before drilling down to debate probabilities (as in Fabien’s examples).
In the sense that I’d most obviously think it’s stupid to not at least consider acausal trade
In practice, of course there are many different within-faction compromises.