David Blenkinsop wrote:
> "Eliezer S. Yudkowsky" wrote:
> > I happen to believe that time travel is explicitly permitted by General
> > Relativity, which forbids a single correct direction of time just as
> > Special Relativity forbids an "ether" or single correct reference frame.
> Notice that even if this radical idea should happen to work out for
> real, it doesn't remove the need for causality as such. For instance,
> the whole point of getting multiple timelines involved in this is to
> open up the "closed" time loops, so that the causal effects extend
> forward into another history, instead of actually going around in
Wrong, wrong, wrong. (Speaking about the Scientific-American multiple-timelines idea, not necessarily to you personally.) If going into the future doesn't send me into a different timeline, neither will going into the past. There is no "temporal ether", no single direction of time, and the rules have to be the same in both directions. Causality *is* circular.
Using the term "causality" to refer to what I would call "monodirectional causality" doesn't mean that the laws of physics agree with you. Nor does a deliberately narrow definition of "causality" mean that all order and causality get tossed out the window if the definition turns out to be wrong.
Grandfather paradoxes. Deal.
-- email@example.com Eliezer S. Yudkowsky http://pobox.com/~sentience/tmol-faq/meaningoflife.html Running on BeOS Typing in Dvorak Programming with Patterns Voting for Libertarians Heading for Singularity There Is A Better Way