> Minor nitpick: Someone who is smart enough to crack quantum mechanics, and build a "manual" computer when alone, should be smart enough to figure out a way to find a source of energy so the computation happens automatically.
Not to take this xkcd too seriously but: if he were truly there for infinity (that is, the duration of his existence is infinite), then he wouldn't be in any hurry. Another way to put it is that, in the steady-state sense of things, no means of computation is "noticeably" faster to him than any other (only relatively faster).
Consider that any time difference between events (e.g. the termination of the same calculation performed by different mechanisms) would be infinitesimal compared to the duration of his infinite existence. Also, interestingly, since he is there for eternity then his existence does not really have a start time or end time, as far as he's concerned.
If he wanted to have some real fun with infinity, he might kick off a couple of interacting harmonics in the sand, maybe watch them interact, as anything else - finite - cannot last.
Not to take this xkcd too seriously but: if he were truly there for infinity (that is, the duration of his existence is infinite), then he wouldn't be in any hurry. Another way to put it is that, in the steady-state sense of things, no means of computation is "noticeably" faster to him than any other (only relatively faster).
Consider that any time difference between events (e.g. the termination of the same calculation performed by different mechanisms) would be infinitesimal compared to the duration of his infinite existence. Also, interestingly, since he is there for eternity then his existence does not really have a start time or end time, as far as he's concerned.
If he wanted to have some real fun with infinity, he might kick off a couple of interacting harmonics in the sand, maybe watch them interact, as anything else - finite - cannot last.