OFF: SETI, ETs

[J Strobridge]

Jerry Guizar writes:

> In <960710104123_431176746 at emout08.mail.aol.com>, on 07/10/96 at 10:41 AM,
>    Andy Gilham <AndyGilham at AOL.COM> said:
>
> >Steve Hawking did come up with something recently that suggested that
> >backward time travel may be possible in certain limited circumstances,
> >but I think it was of the order of nanoseconds in the vicinity of a naked
> >singularity, or some such.
>

I think the reasoning goes that the fundamental forces in particle
physics are symmetrical in time (they are unchanged if time is reversed)
so time travel is possible in theory but it would need an Aweful lot of
energy!   However there also seems to be an argument about whether a
quantum theory of gravity (if one could be produced) would violate this
and produce a time asymmetry - which would mess things up a bit.   But
if such a thing existed this might explain the difference between the
uniformity of the beginning of the universe and the mess it'll be in at
the end.

Read on....


jill

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J.D.Strobridge at ed.ac.uk                         eset08 at tattoo.ed.ac.uk
                                                ELIJSA at srv0.arts.ed.ac.uk

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