How far could you travel in a spaceship?

[dreamdancer 0]

a long way...

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HOW far could an astronaut travel in a lifetime? Billions of light years, it turns out. But they ought to be careful when to apply the brakes on the return trip.

Ever since cosmologists discovered that the universe's expansion is accelerating, many have wondered just how much this will constrain what we could see with telescopes in the future. Distant regions of the universe will eventually be expanding so fast that light from any objects there can never reach us.

Likewise, dark energy - the mysterious force behind the acceleration - places a limit on human exploration of the universe, says Juliana Kwan at the University of Sydney in New South Wales, Australia, who has now refined this limit on our travels. Even with rockets that could take us to within a whisker of light speed, expansion would still eventually leave us behind.

The furthest that light emitted from our sun today could reach, as it races in vain to outdo the accelerating expansion, currently lies around 15 billion light years away. According to previous calculations by Jeremy Heyl of the University of British Columbia in Vancouver, a super-advanced rocket could get most of this way in a human lifetime. Accelerating at around 9 metres per second per second - which would feel roughly like a comfortable 1 g - a craft could get 99 per cent of the way to the expansion "horizon". Despite the vast distance, this would take only about 50 years in the astronaut's reference frame, because time would pass slower than on Earth due to relativity.

http://www.newscientist.com/article/mg20327274.200-how-far-could-you-travel-in-a-spaceship.html

stay away from moving propellers - they bite
blue skies from thai sky adventures
good solid response-provoking keyboarding

[airdvr 210]

How did cosmetologists figure that out?

Please don't dent the planet.

Destinations by Roxanne

[SkyBastard 0]

i'm drinking.

someone tell me is any of this makes sense.

are we talking about the YoYo theory?

Dude #320
"Superstitious" is just a polite way of saying "incredibly fucking stupid".
DONK!

[DiverMike 5]

Maybe they discovered that dark matter is made up of moles and freckles?

For the same reason I jump off a perfectly good diving board.

[muff528 3]

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How did cosmetologists figure that out?

Don't tell me you've never heard of relativistic time dilation. In a nutshell -- It's a function of how much Oil of Olay one's relative (his old lady for instance) needs to pack on to lose 15 billion years of age. Well, I suppose she would need a little botox and some eye shadow, too. The math is readily found on wiki.

Whoops! I think there is an error in the equations. Actually, it is the LACK of use of these cosmetological substances that would stop a clock! The minus sign was in the wrong place. Sorry.

[Andy9o8 2]

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How did cosmetologists figure that out?

They followed the old adage: "Make-up your own solution."

[airtwardo 7]

When ya said 'YOU', I took that to mean ME!

I wouldn't travel very far into space at all, unless they replace that freeze dried shit with In & Out burgers!

~ If you choke a Smurf, what color does it turn? ~

[JohnMitchell 16]

I've heard the dark force behind that accelleration matches nicely with the cosmological constant that Einstein used when he was trying for his unified field theory. He later discarded it as a cheat and a crutch, calling it his biggest mistake. Is there any truth to that?

[dreamdancer 0]

yes.

stay away from moving propellers - they bite
blue skies from thai sky adventures
good solid response-provoking keyboarding

[JohnMitchell 16]

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yes.

Wow, Einstein was right, even when he thought he was wrong.

[airtwardo 7]

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yes.

Wow, Einstein was right, even when he thought he was wrong.

Wait, what??

~ If you choke a Smurf, what color does it turn? ~

[theonlyski 8]

Depends how much fuel you have I guess, but with no wind resistance, you could just stay away from any gravity pull and should just keep on going.

According to this picture, you can go pretty damn fast!

"I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly
DPH -7, TDS 578, Muff 5153, SCR 14890
I'm an asshole, and I approve this message

[muff528 3]

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yes.

Wow, Einstein was right, even when he thought he was wrong.

Except - even though he was instrumental in the development of quantum theory he never really accepted Heisenberg's "uncertainty principle" and other quantum weirdness. He believed in the principle of "causality"... basically that events happen as a result of earlier events. Conversations and thought experiments with Niels Bohr sort of convinced him but I don't think he really accepted some of the implications of quantum theory. That was expressed by his comment to the effect of "God doesn't play dice with the universe." Whether or not he was right about that at an even more fundamental level than we are today remains to be seen. We still haven't reconciled gravity with quantum ideas.

[JohnMitchell 16]

Very true. His most productive period was in his twenties and early thirties. The white haired, elderly Einstein we remember was on the downhill side of his career, shuffling up a lot of blind alleys. He said it was better he did it, though, than a younger man.

[quade 4]

Article has an error in a basic assumption although they sort of hint at it in the second half of the article they completely miss a vital point in the first half.

Let's say you want to go whatever enormous distance you want to go at 1g. At the half way mark, you have to turn around and decelerate at 1g as well. You certainly can't get there at .999c and then just stop.

quade -
The World's Most Boring Skydiver

[airtwardo 7]

You certainly can't get there at .999c and then just stop.




You ever ride with Divot??

~ If you choke a Smurf, what color does it turn? ~