[net.space] SPACE Digest V2 #270

knutsen@SRI-UNIX@sri-unix (08/13/82)

From: Andrew Knutsen <knutsen@SRI-UNIX>
	I received about 20 requests, so the list "Physics@SRI-Unix"
now exists. Hopefully this will redirect some of the not-entirely-
relevant material. Requests to Physics-request@SRI-Unix.
	The problem with replies to usenet sites is somewhat of a
mystery to me too, since it works for me (except in pathological cases
caused by a bug which resulted in very long routes).  It is possible
that some originating mailsystems dont handle the address strings
correctly, or that the gateway at UCB (which I dont know much about) is
doing something odd.  In any case if you send me your undeliverable
mail, Ill see if I can figure it out.

	Regarding FTL travel, it seems to me that the subject is very
closely tied with time travel.  Time dilation at relativistic speeds
results in the people aboard the ship seeming to travel FTL; its just
that when they get back to their original reference-frame everybody
they knew is dead and buried.  If they could go back in time,
everything would be fine, right?
	This makes the causality problems a bit clearer once youve
accepted time dilation, which has been pretty well proven
experimentally using decay rates of slow and fast particles.  Hubble's
red-shift can also be interpreted as a time-dilation effect I think.