Re: Interstellar exploration - do we have the technology today?

In article <3bd51$47eab617$4212a5e4$12221@xxxxxxxxxxxx>,
Greg Crinklaw <theskyhoundyoureye@xxxxxxxxx> wrote:
Paul Schlyter wrote:
In article <524288df-7ac4-4561-9b34-de4564300a78@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Quadibloc <jsavard@xxxxxxxxx> wrote:
On Mar 25, 11:45 pm, jerry warner <"warner(ns)"@mchsi.com> wrote:

As a practical matter, as Sam has already pointed out,
physical structures traveling near c would undergo stresses
no usual structures could withstand, including biological
tissues.
Spaceships travelling at a high fraction of the speed of light would
indeed find the interstellar medium was moving fast relative to them,
so particles of dust, and even hydrogen atoms, would carry a lot of
energy.

But all the relativistic effects on the ship itself would be
invisible; it would seem to those on the ship that the outside world
was experiencing Lorentz contraction, time dilation, and increase in
mass. So the structure of the ship wouldn't be squeezed or anything
like that, of course.

John Savard

And aberration of light would be quite pronounced: at a high enough fraction
of the speed if light, the entire universe would appear to contract into
a small area right in front of the ship. THis would of course make navigation
quite difficult....

But of course you don't need to obtain the speed of light to travel
interstellar distances, just a significant fraction of it.

:-) .... as I wrote above: "at a high enough fraction of the speed of light"...

But that
assumes you are actually onboard the spacecraft and you don't expect to
return home to your family...

That too was the fate of many early explorers in the past. Consider for
instance all the immigrants to North America - most of them never returned
to their homelands in Europe. However, they did often bring their families
along. And the eventual first interstellar exploreres could do the same
thing: bring their family with them. After all, if the ship cannot reach a
high enough fraction of the speed of light, then the travel time as perceived
by the people onboard the ship will exceed a human lifetime - and the only
ones who can hope to reach the destination is the offspring of those who once
started the journey.

No, this is not an ordinary business trip where you "return home to your
family" afterwards. It's a dedication for the rest of your life, and
probably for the life of your kids and grandkids, etc, too.


Greg

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To reply take out your eye


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