Text 28606, 66 rader
Skriven 2007-05-05 15:03:38 av John Hull (1:123/789.0)
     Kommentar till en text av VERN HUMPHREY (1:123/140)
Ärende: Muslems
===============
VERN HUMPHREY -> JOHN HULL wrote:
 VH>>> John, imagine we're going to the newly-discovered planet some
 VH> 10 light
 VH>>> years away. At an acceleration rate of 1G, how long would it
 VH> take us to
 VH>>> get there?

 JH>> I haven't a clue.  Velocity is cumulative in zero G under constant
 JH>> acceleration, so you have to know how big the engine is, and what
 VH> its thrust
 JH>> to figure velocity.  In any case, you would have to flip ends about
 VH> halfway
 JH>> begin decelerating at the same rate to maintain constant gravity.
 VH> Starting
 JH>> from lunar orbit would also lower the inertial impulse you had to
 VH> overcome a
 JH>> the start.

 VH> It's easy to figure out, John.  The Earth's gravitational rate of
 VH> acceleration is 32.2 ft/sec/sec.  The speed of light is 186,000 miles
 VH> per second.  If you accelerate at 32.2 ft/sec/sec, how long will it take
 VH> you to reach a speed of 186,000 miles per second?

 VH> Then applying the forumla D = 1/2 G t^2 how far would you have come?

 VH> Remember, having reached the speed of light, you must now DECELERATE to
 VH> make landfall on your planet -- which will take just as long as it took
 VH> you to reach light speed.

That's oversimplified from what I found on a couple of websites.  For example,
your acceleration rate is for gravity in atmosphere, and you can never actually
reach the speed of light in normal space (according to Einstein), etc.  But I
still understood the intent of your question, which was to imply that we can
never reach another inhabited star because the distances are too far to make it
humanly possible.  As I said, I don't think that to be the case, and neither do
a lot of people way smarter than me.


 JH>> There's a formula you can use to figure such things, but I don't
 VH> have it.
 JH>> Suffice to say it would take awhile.  But, from the way you asked
 VH> the questi
 JH>> it is obvious you assume that it will never be done because of the
 VH> time fact
 JH>> You have no way of knowing that, or of knowing whether or not we
 VH> will ever
 JH>> able to achieve FTL travel. There is a rather large group of
 VH> theoretical
 JH>> physicists who think it is possible to "fold space" in order to go
 VH> from A to
 JH>> nearly instantaneously by utilizing curved space.

 VH> My son-in-law, who is an Aerospace engineer with NASA tells me he
 VH> doesn't believe we will ever reach the speed of light.
Remember that most learned scientists once thought the earth was flat, and that
the earth revolved around the sun. Considering where we were in physics just
100 years ago, I would not presume to assume that we know everything there is
to know about quantum physics, or the behavior of light.

-- 
John
..
My Blog: Mad Gorilla's Jungle:      http://madgorilla.terapad.com/

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