Is travel into the future possible even though light has not reflected off that moment to show existence of the moment? If we create a time travel device in the future, is it true that in a sense it already exists, if we are able to travel into the past with it? Can we create a telescope of sorts that seeks out light reflected off our planet and then capture single waves in a film format to actually look into the past? The Hubble looks across the galaxy and snaps a shot of a potential Earth like planet. The light from this planet takes 1 million years to reach Earth. Therefore the image to an earth eye is what that planet looked like 1 million years ago. Do telescopes see a zoomed image of this 1 million year old reflection, or a real time view?
2007-06-02 14:38:10 · 6 answers · asked by s g 2 in Science & Mathematics ➔ Physics
Since it's impossible to go the speed of light, we have no way of knowing what will happen if we can do the impossible.
As for a time machine. It's possible that any such machine will have 2 components. One to take forward at near the speed of light so it experiences time dilation, and leave the other here on earth. Then you can step from one to the other.
But not back before the machine was built.
2007-06-02 14:42:28 · answer #1 · answered by Anonymous · 0⤊ 0⤋
It is just an image of the object as it looked one million years ago. Everything you see is as it was, you can never see anything the way it is. A fraction of time passes for the light reflected by anything to reach your eye, it does not matter if the object is millions of miles or mere inches away, you will see the object as it was at the time light left it's surface on the way to your eye. Even if you could travel faster than the speed of light with a telescope and turn around to view yourself leaving the earth the images would only be images, you would not actually be seeing into the past.
2007-06-06 10:17:22 · answer #2 · answered by johnandeileen2000 7 · 0⤊ 0⤋
Travel into the future is simple in principle, but requires vast energy. You "simply" travel away from earth at very near the speed of light c, and return. If you go fast enough, minutes could pass for you, while centuries have passed on earth. If that is not a future time machine, what is?
As for the past, you need to go faster than c. Exceeding c is thought impossible since it is assumed that there are no particles with negative or imaginary mass. If those assumptions are not true (and they are just assumptions), and c is exceeded, then a round trip from and back to earth would return you to a previous time according to the Lorentz transformation.
Barring this, one could only observe the earth 1 million years ago if there were a really big mirror hanging in space a half million light years away. It has been speculated, however, that the universe is actually smaller than the apparent distance of the furthest galaxies, that these are actually repeated images of nearby ones (perhaps even our own) that have circumnavigated the universe's (noneuclidian) space. We could then see what our galaxy looked like billions of years ago (if we could identify its earlier appearance).
2007-06-02 15:11:04 · answer #3 · answered by Dr. R 7 · 0⤊ 0⤋
I'll answer in backwards order.
The telescope sees the million year old reflection just as your eye does.
Yes, technically we can build a telescope that can see the past, sort of, it can see a few nano-seconds in the past, the time it takes the light to get from the surface to the lens of the telescope, but no if you want something that can see like before it was built or something like that.
No, if you travel to the past, no matter what you do in the past, the future you left is not the one that you would go back to, that blade of grass died in this new world and the time machine only exists in the new alternative reality that you created.
Well, the first question is not a very well worded question, there are parts of our universe that light has not reached, nor will it ever, as the universe is and always has been expanding faster than the speed of light. But a sort of time travel into sort of the future is possible and accepted fact, that is that if you get in a space ship that goes say 0.1 times the speed of light and travel for 10 years and land on Earth, your 'brother' (or person that you left on earth) will have aged about 20 years (roughly). Is that time travel to you?
Also in reference to your title, we will NEVER travel the speed of light, it is impossible because as you go faster the more mass you have, at the speed of light your mass would be infinite and also the energy needed to get you up to that speed would also be infinite, the best we might be able to do is about the 0.1 speed of light I refered to in the last answer, would only take about 1 billion atomic bomb's energy to get a piece of dust up to that speed (sounds do able, right?).
2007-06-02 14:59:41 · answer #4 · answered by cj k 4 · 0⤊ 0⤋
In the truest sense of what we term reality, neither the past nor the future exist in such a way as to allow us to "travel" ahead or behind our time line. We move into the future and we leave the past behind us, existing only in our memories - which, according to Lewis Carrol in Through the Looking Glass - this makes our memories defective simply because I can remember yesterday, but I can't remember tomorrow.
I guess that means all we have is "now" - so make the best of it.
2007-06-02 15:46:41 · answer #5 · answered by LeAnne 7 · 0⤊ 0⤋
Even light takes some time to go from point A to point B so can't possible be a means of time travel.
2007-06-02 14:53:45 · answer #6 · answered by Michael da Man 6 · 0⤊ 0⤋