[kwhitefoot]

> This computer does not physically manipulated electricity.

Sophistry.

The whole purpose of a computer is to manipulate electricity, it is what electronic computers do.

Perhaps it really is kosher (I have no idea, I'm not Jewish and I'm not well informed about what kosher really means) but whatever it is or is not, it is quite certainly not true that 'This computer does not physically manipulated electricity.'

Perhaps the author actually meant something else, if so I'm curious as to what that might be.

Presumably the inclusion of the superfluous word physically means something to the author. To me (B. Sc. Physics) there is no need to include the word because all manipulation of electricity is physical, there is no other kind.

[compsciphd]

one can start a fire before the sabbath and benefit from its heat. One can't stoke the fire (to make it hotter) or extinguish it. On the flips side (as an example only) if I was sitting around a camp fire that I lit before the sabbath with a non jew, and he wanted to extinguish it or stoke it for his own benefit (I might benefit as well, but he's supposed to be doing it for his own benefit) that would be permitted.

apply to a computer: one can let it keep on doing what it is doing, but he owner wouldn't manipulate it.