Wijaya -
Here's a fact to think about... the speed of a space shuttle in
orbit around the earth is about 17,500 miles/hour or 8000 m/s - this is
about 20 times the speed of sound in air (340 m/s). So how come people
don't get squished every time they go up into space? The reason is
simple. The human body can endure ANY speed! The thing we can't endure
is getting there. It's the acceleration that hurts.
Think about when you're riding in a car. You get pulled forward or
backward when the car speeds up or brakes. But you don't feel much when
you're just cruising at a steady speed.
I did a quick (
REALLY simplified) calculation, figuring that one wanted to travel 10
9
meters (the distance from the sun to Pluto), accelerating with a rate
of exactly 1 gee for the first half of the trip and then slowing down
at the same rate for the second half of the trip, it would take a mere
6 hours to get all the way there! The fastest speed the shuttle would
reach is about 100,000 m/s or 300 times the speed of sound in air!
Of course, there's a lot more to space travel than just speeding up
and slowing down. You have to keep track of gravitational forces, fuel
supply, and a gazzillion other things that make a 6 hour trip to Pluto
impossible (at least for now). To learn about these things, check out
Ask a Space Scientist from
NASA.
If you're talking about trips to other solar systems or galaxies,
things get way more complex than even that. This is because then you're
talking about going close to the speed of light, and then you have to
start figuring for the effects of
Relativity.
-Tamara
(published on 10/22/2007)
