I'm not qualified to say anything about this stuff, but I get the impression this is just a tradeoff: - Collect bits from many "points" in space, but a single

I'm not qualified to say anything about this stuff, but I get the impression this is just a tradeoff: - Collect bits from many "points" in space, but a single "point" in time - Collect bits from a single "point" in space, but many "points" in time In either case, you are not eliminating the possibility that your "random" bits are subject to external influence, you're just moving it into some different domain.