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2007-05-07 10:37:32 · 10 answers · asked by mehrdad s 1 in Science & Mathematics Astronomy & Space

consiering that universe is expanding like a baloon.
if we could travel faster than light we could go back to the same place that the universe was 1000 years ago

2007-05-07 10:46:11 · update #1

10 answers

If we could move faster than light than we would be able to exist ahead of our own image. In a way, that would be time travel.

2007-05-07 10:42:22 · answer #1 · answered by Anonymous · 0 0

It is not certain.

Time spent = time of arrival - time of departure.

Time spent = distance traveled / speed

Let us say your speed is 2 c (twice the speed of light) and the 'proper' distance is 2 light years. The proper distance is measured when you are at rest relative to the segment to be traveled.

From your point of view, time will always flow normally. However, you will preceive the destination as coming towards you at 2 c (you will not see it coming at that speed, but let's not worry about that for now).

According to length compression, you will perceive the distance as 2 l-y * SQRT( 1 - 4) = 2*SQRT(-3)

From the Lorentz formula L = Lo * SQRT (1 - v^2/c^2) Lo being the proper length and L being the perceived length.

Now, if you can make sense of a length of SQRT(-3), well good for you. I admit that I have a hard time (and I've studied analysis in the complex numbers)

If you accept to adopt the complex number i to be such that i^2 = -1, then we could solve your problem by saying that you are travelling a distance of 3.46*i light-years at a speed of 2 c, which is NOT the same as travelling -3.46 light-years at a speed of 2 c (which would mean going back in time 1.733 years).

The trip will take you 1.733*i years (whatever i means in the context of time).

Does that means going back? Does that mean going "sideways" in time (whatever that means? We don't know.

What we do know is that most cosmologies agree that the causality rules cannot be broken (you cannot have the effect precede the cause), whatever the relative speed of travel might be.

My conclusion is that you would not travel backwards. However, something strange would certainly happen, timewise; I just don't know what.

2007-05-07 18:02:24 · answer #2 · answered by Raymond 7 · 0 0

It does not matter how fast we travel. By traveling faster than light in a straight line we could only pass relative time, not actual or real time. Relative time is an illusion created by what we see. Example: A star is 20 light years away and we see it explode and go nova. The actual even occurred 20 years ago but we are just seeing it now.

We can already travel faster than sound but that does not empower us to travel through time. There is nothing magical about the speed of light, it is just another speed.

2007-05-07 17:49:14 · answer #3 · answered by Glytch 2 · 1 0

No need to travel faster than light just equal to or slightly less. If you left the earth and your twin brother behind and traveled at the speed of light, when you returned you would be younger than your brother. Hence you would have traveled forward in time. Unfortunately you cannot do the reverse and travel back in time. Another big problem is that for you and your space ship to accelerate and travel at the speed of light would require more energy than there is in the universe.

2007-05-07 17:49:18 · answer #4 · answered by DaveSFV 7 · 0 0

How about you try it for yourself, use this formula:

This formula is known as the Time Dilation formula derived by Albert Einstein to explain the relation between speed relative to the speed of light and the time experience as compared to the time observed. You'll find this to be a quite interesting formula in how accurate it is. At lower speeds, the change is negligible, but when you approach the speed of light, the amount of time you experience becomes LESS, and at the speed of light... Well, I'll leave that to you:

T(experienced) = T(Observed or Actual)/(sqrt(1 - v^2/c^2))

And there you go, or a more condensed version:

t_e = t_o/(sqrt(1 - v^2/c^2)

Have fun.

2007-05-07 17:54:54 · answer #5 · answered by Eolian 4 · 0 0

Not possible , because "time" is something man created soley for his convenience . Beyond that , there`s no such thing as the passage of "time" . Everything has occurred and will occur in the same "time" period .

But , let`s assume for the sake of your question that "time" is a reality , and you were somehow able to travel back and forth through time . You wouldn`t be able to travel very far !

What would happen if you set the "time machine" you just spent a year building to take you back 5000 years ? You`d go back as far as the exact time your "time machine" became operational , then POOF ! ......... it no longer exists !

If you set it to take you 5000 years into the future , it`ll take you as far as the exact time you died , then POOF ! ........... YOU no longer exist !

2007-05-07 20:57:43 · answer #6 · answered by Anonymous · 0 1

Possibly. More likely we can find a way to travel between the folds in the universe.

2007-05-07 17:41:12 · answer #7 · answered by Clown Knows 7 · 0 0

Indoubetably

2007-05-07 17:44:30 · answer #8 · answered by GF 3 · 0 0

Yes.

2007-05-07 17:43:33 · answer #9 · answered by Paul R 2 · 0 0

I don't know but I'm to tired to try it tonight. Lets try it tomorrow and see where we get.

2007-05-07 18:04:38 · answer #10 · answered by Scott 6 · 0 0

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