On Mon, 13 Oct 1997 "Eliezer S. Yudkowsky" <sentience@pobox.com> Wrote:
>Tipler cylinders, which postulate no additional laws of physics, are
>sufficient to demonstrate that time travel is not prohibitedby the
>known laws of physics.
The trouble with Tipler's cylinders it that they're infinitely long, nobody
knows if one of finite length would work. Also, they'd be spinning so fast,
almost the speed of light, that no known force would be strong enough to keep
them intact, so to build one you would need new laws of physics.
If I wanted to invest in the time machine business I think I'd rather put my
money on one of Kip Thorne's wormholes, although either would be a rather
speculative venture.
John K Clark johnkc@well.com
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