I just noticed that today (or pehaps yesterday, depending on how you
figure it) is the 6th birthday of the everything-list, which was begun
by Wei Dai in January 1998. The list has remained remarkably active
and civil over that time, compared to other lists I've been on.
The initial message stated, "You are invited to join a mailing list for
discussion of the idea that all possible universes exist." This has spun
off into a wide variety of related areas: logic, mathematics, physics,
infinite sets, theory of computation, Godel's and Turing's theorems,
algorithmic information theory, the philosophy of consciousness, decision
theory, and much more.
Although this list did not originate the idea, we have seen it grow from
a little-known curiosity to a model that might be characterized as almost
mainstream, including a widely read article by Max Tegmark in Scientific
American on multiverse theory. For all the attention, though, it is hard
to see much progress being made in terms of possible predictions that
might allow, even in principle, testing the plausibility of the theory.
I'd like to thank Wei and all the other contributors over the years for
creating and maintaining a high quality and lively discussion group.