Re: Absolute Insanity

Le 07/05/2024 à 20:03, hitlong@yahoo.com (gharnagel) a écrit :

Karl Gauss wrote, “I am coming more and more to the conviction that the
necessity of our geometry cannot be demonstrated...geometry should be ranked,
not with arithmetic, which is purely aprioristic, but with mechanics.”
 I'm a bit uncomfortable with that, and so I'm uncomfortable with trying to
reduce EVERYTHING to geometry.  At least, Gauss put mechanics on an equal
footing.  I would say that his "mechanics" is dynamics.  GR seems to subsume
dynamics into geometry.
 Another thing about the video bothers me.  The experience of the traveler is
described in detail, but no mention is made of what happens to the distant
observer, namely, all us guys.  Consider the GPS.  Time flows more slowly for
us sitting on the earth relative to a point far away from us.  Unlike SR
where each twin sees the other's time slowed down, an observer in a gravity
well sees the time of one who is far away flowing faster while the one far
away sees us in the well flowing slower.  This, in a sense, is an absolute
difference, not relative like the SR case.
 So a guy falling into a black hole sees time in the universe he's leaving
going faster and faster until at the event horizon, all time in the universe
has passed. So even if he could come back, there would be nothing to come
back to.

We come back a little to Langevin's traveler,
or other problems of special relativity
that I have been asking for some forty years.
That is to say that communications would be impossible and that we could never get around the problem of causality.
Thus, an observer could instantly visit one hundred thousand stars, without this posing any problems in terms of time (negligible proper time).
But when he came back to tell us everything he saw in the future of the universe, the earth would already have this same information, since it itself would have aged a hundred thousand years.
Space travel is therefore definitively solved with Dr. Hachel's equations. We will be able to reach any star or galaxy instantly or almost, why not. But in Earth's frame of reference it will still take thousands or billions of years?
The rest is science fiction.
Take good care of your planet, guys. It's not tomorrow that you will be able to see those who leave for the stars return. Leaving will be very easy if we have the technology. But it will always be a departure without return.
Or in a future so distant that our planet will probably no longer exist.
Take care of your planet, guys.
R.H.