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TIME TRAVEL

Started by Mister_Comics,

176 posts in this topic

14 of spades

14 of spades

Posted
Posted
I've thought this was interesting: when we see a star die, which is 2000 light years away, we're actually seeing something that happened 2000 years ago.

 

So could we see back in time, if we could travel faster than light? If we could travel 2000 light years away, and have a telescope powerful enough to see earth, we could see Jesus walking on the earth, right?

 

No, because we'd still be moving forward in time, same as you. If you were moving at the speed of light away from the earth and you went 2000 light years away, we'd all toast each other and divvy up your collection.

 

No, that's why I said faster than the speed of light, which October said is impossible. (However, I assumed my entire premise was impossible, but an understandable idea to view events that occurred in the past.) You would need to travel 2000 light years in like a year. Maybe have your molecules teleported. Now the trick is developing a telescope that can see 2000 light years away.

 

would you? the whol epremise is to travel far enough away to catch up to the light rays from Earth 2000 years ago. And, in this scenario, that where we traveled to - - - so you wouldnt need a super powered telescope, unless that power was in order to collect the faint light into a picture. And it would be very faint, Not only would th eoriginal reflected light be fragmented and diminished by its journey...but of all the light reflected off Jesus in all directions, you will be only able to see the tiniest percent of an angle in one minute direction. Actually. youd have to CHOOSE WHERE to go, not JUST 2000 light years away, because th elight only would be visible in about 40% of the sky. All the other reflections would have bounced off Jesus into the Earth itself.

 

 

aman, i mentioned in a post above,

 

it's an interesting thought experiment - but it's obviously not going to happen. the flaws in the reasoning that u "could" see jesus are too numerous to even mention.

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Aman619

Aman619

Posted
Posted
what about someone already at a position 2000 light years away looking at earth with a big magnifying glass? they don't have to overtake anything.

 

rob's point isn't trying to discuss theoretical physics. his point is that at a position 2000 light years away - hypothetically, u "should" be able to see jesus walking, if u had a strong-enough magnifying glass.

 

Right but hed be an astronomer, not a time traveler

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Stifler-migration

Stifler-migration

Posted
Posted
yes, unbelievably this has been proven. they've mounted atomic clocks on airplanes and have flown them around. the clocks moved at different speed than land clocks.

Yep, it's been proven. Kind of weird when you think about it. The closer you can get to the speed of light, the slower time will progress for you when compared to someone who isn't moving.

 

If space travel were to become fast enough, it's not unfeasible that an astronaut could leave on a one year mission and return to find that 10 years had passed on earth. You could find some safe, long-term investments and cash in pretty quickly that way. stooges.gif

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14 of spades

14 of spades

Posted
Posted

i think it's reasonable to suggest that we won't have any astronauts returning to earth with any significant time disparities in the near future.

 

if u put the math to it, u need to be travelling at some 0.4c-0.6c (i.e. 40-60% the speed of light) in order to start having significant elapses in time (i.e. several seconds on the minute).

 

c (the speed of light) is 3.0 x 10 (power of 8) m/s. 50% of the speed of light is thus 1.5 x 10 (power of 8) m/s. we ain't gonna see a rocket engine propel a spacecraft at that speed in the near future....

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Aman619

Aman619

Posted
Posted
i think it's reasonable to suggest that we won't have any astronauts returning to earth with any significant time disparities in the near future.

 

if u put the math to it, u need to be travelling at some 0.4c-0.6c (i.e. 40-60% the speed of light) in order to start having significant elapses in time (i.e. several seconds on the minute).

 

c (the speed of light) is 3.0 x 10 (power of 8) m/s. 50% of the speed of light is thus 1.5 x 10 (power of 8) m/s. we ain't gonna see a rocket engine propel a spacecraft at that speed in the near future....

 

but arent some of the design for solar sailing ships able to reach those speeds? Especilaly by whipping thru planetary gravitational fields?

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october

october

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Posted
They already have atleast 3 theoretic designs. One involves small nuclear blasts to propell the craft, but will never happen under current laws that would not allow for such propulsion.

 

I read about one that used some huge scoop to capture hydrogen in space to burn as fuel using nuclear fission.

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october

october

Posted
Posted
i think it's reasonable to suggest that we won't have any astronauts returning to earth with any significant time disparities in the near future.

 

if u put the math to it, u need to be travelling at some 0.4c-0.6c (i.e. 40-60% the speed of light) in order to start having significant elapses in time (i.e. several seconds on the minute).

 

c (the speed of light) is 3.0 x 10 (power of 8) m/s. 50% of the speed of light is thus 1.5 x 10 (power of 8) m/s. we ain't gonna see a rocket engine propel a spacecraft at that speed in the near future....

 

but arent some of the design for solar sailing ships able to reach those speeds? Especilaly by whipping thru planetary gravitational fields?

 

50% of the speed of light? 27_laughing.gif I seriously doubt it. That would mean those ships would be travelling at about 300,000,000 MPH. 893whatthe.gif

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Scheradon

Scheradon

Posted
Posted
They already have atleast 3 theoretic designs. One involves small nuclear blasts to propell the craft, but will never happen under current laws that would not allow for such propulsion.

 

I read about one that used some huge scoop to capture hydrogen in space to burn as fuel using nuclear fission.

 

Yep, that was another one. They've had these specials on Discovery Channel if anyone has seen them. I'm forgetting what the third was right now.

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october

october

Posted
Posted
They already have atleast 3 theoretic designs. One involves small nuclear blasts to propell the craft, but will never happen under current laws that would not allow for such propulsion.

 

I read about one that used some huge scoop to capture hydrogen in space to burn as fuel using nuclear fission.

 

Yep, that was another one. They've had these specials on Discovery Channel if anyone has seen them. I'm forgetting what the third was right now.

 

If you guys are really interested in this sort of thing, check out these books. I liked all of them.

 

http://www.amazon.com/gp/product/0385477...5Fencoding=UTF8

 

http://www.amazon.com/gp/product/0684818...ce&n=283155

 

http://www.amazon.com/gp/product/0385292...ce&n=283155

 

http://www.amazon.com/gp/product/0385484...ce&n=283155

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october

october

Posted
Posted
who let the geeks out? Woof Woof Woof Woof

 

My brain hurts thinking about this...

 

This is great stuff. It's weirder than any science fiction, trippier than any drug, and scarier than any horror movie. For reals. insane.gif

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14 of spades

14 of spades

Posted
Posted

but arent some of the design for solar sailing ships able to reach those speeds? Especilaly by whipping thru planetary gravitational fields?

 

for land based-stuff (really slow due to drag etc.)

 

fastest plane in the world (guiness recognized)

http://www.nasa.gov/missions/research/x43-main.html

 

It's Official. X-43A Raises the Bar to Mach 9.6

Guinness World Records recognized NASA's X-43A scramjet with a new world speed record for a jet-powered aircraft - Mach 9.6, or nearly 7,000 mph. The X-43A set the new mark and broke its own world record on its third and final flight on Nov. 16, 2004.

 

Speed of asteroid, Temple 1

http://www.nasa.gov/centers/jpl/pdf/117810main_deep-impact-encounter.pdf

37 100 kilometers per hour. even if we can get a spacecraft travelling faster than an asteroid... i dunno. i think i can stop here

 

 

light is at

300 000 000 METERS/SECOND.

 

the above are all measured in much smaller absolute numbers PER HOUR...

 

it's not even close - we're talking about 0.0000001% the speed of light.

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