From: Paul Grant (shade999@optonline.net)
Date: Fri Jul 11 2003 - 22:03:39 MDT
They're basically saying the effects of gravity can't be felt until the
light from the event hits you.
Its like a sonic boom; since light is travelling faster than sound, you
see the light first, before the
pressure waves hit you. So if you lived in a universe where the speed
of gravity (its propogation),
was as slow as the speed of sound, then you might see the event, before
you feel the effects of
the gravitational change...
Think of it this way, ur one light year away from a spontaneous black
hole forming (hypothetically
just say it popped into existence one light year away); you would see
(just assume for the example
that light could escape it at that distance) the black hole suck
everything in, before you would feel
your body suddenly get pulled into it :)
Interesting example though :) Kudos to the poster :) It also suggests a
way of confirming it; the
propogation speed of gravity that is....
omard-out
-----Original Message-----
From: owner-extropians@extropy.org [mailto:owner-extropians@extropy.org]
On Behalf Of ABlainey@aol.com
Sent: Friday, July 11, 2003 8:35 PM
To: extropians@extropy.org
Subject: Re: Sol-like system discovered...SETI new directions?
In a message dated 12/07/2003 01:20:55 GMT Daylight Time,
asa@nada.kth.se writes:
In general it seems that the speed of gravity disturbances is very close
to the speed of light. It might be interesting to imagine a universe
where this was not true. What about a world where gravity was as slow as
the speed of sound?
Can you clarify what you imagine this world would be like. To me I can't
really see that the propogation speed would make any observable
difference as the effective force levels would still be the same in any
region. Due to the fact that gravity doesn't switch on and off and has
already propogated to any region where its effect might be felt.
Also due to the fact that the force of gravity is due to the mass of the
body exerting the force, not the propogation speed.
Does that make any sense at all, or should I go get a cool beer and
start chemically pruning my slower brain cells ?
Alex
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