- #36
PeterDonis
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The andromeda argument as it is usually given does (sort of--but see comments at the end below), but your claim leaves open a slightly different argument that does not break down. If, for example, all events not in the causal future (i.e., past light cone plus spacelike separated "elsewhere") of the Andromedans launching the space fleet are fixed and certain, that includes events in our causal future here on Earth. And similarly for us with regard to events in the causal future of the Andromedans launching the fleet. What's more, there will be events in "elsewhere" of both Earth and Andromeda, which are now, by this new premise, taken to be fixed and certain, whose "elsewhere" region includes the arrival of the Andromedan space fleet on Earth (just pick an event far enough away from both Earth and Andromeda). So this alternative premise does not avoid the block universe conclusion. (Basically, this alternative premise is where the block universe argument I described ends up, once you add relativity of simultaneity to the premise that all events to the past of any surface of simultaneity are fixed and certain. That's why it leads to the same conclusion.)PAllen said:It occurs to me that one could even choose to claim that everything not in my causal future is fixed and determined, and then the whole andromeda argument still breaks down completely.