Jesse F. Hughes wrote: > Herman Jurjus <email@example.com> writes: > >> Apparently there's something wrong with backward supertasks (and not >> with ordinary, 'forward' supertasks). But why should that be? > > Well, I'm not at all sure that there's no problem with forward > supertasks. Surely, it is not difficult to come up with a > problematic case. > > For instance, take our favorite example: at each time t - 1/n, place > balls 10(n-1) to 10n - 1 in a vase and then remove ball n. At the end > the vase is empty. > > Now alter the situation slightly. At each step, again place 10 balls > into the vase and then remove one ball, but remove the ball > *randomly*. At the end, the vase may contain any number of balls. > This strikes me as suitably counterintuitive to say that the forward > supertask has something wrong with it. Or, perhaps, with my > intuitions.
More conclusive (at least for me): you switch a light bulb on and off; after infinitely many steps, is the light on or off? (Or: you put one and the same ball in the vase, out of the vase, in the vase, out of the vase, etc. What's in the vase/where's the ball after infinitely many steps?) If you can't trust supertask-reasoning in this case, why should you trust it in other, seemingly less problematic cases?
For the sake of clarity: I'm not endorsing or advocating the backward-supertask paradox as extremely important. Just wanted to share it here, because I had never heard of it, and thought perhaps others also hadn't.