Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Looking back in time?

  1. Apr 27, 2008 #1
    If you were to travel away from an object at a speed greater than light, would you begin to see that object go back in time? The way I have come to see it is that as you move away from an object at a speed greater than light, then you are eventually able to reach or pass light that was reflected from the object at an earlier time.
    Any feedback on the subject would be most greatly appreciated as I am always eager to learn new things.
  2. jcsd
  3. Apr 27, 2008 #2
    We are already seeing into the past. If I were to photograph an object 100,000 light years from earth, I'm seeint it as it was 100,000 years ago.

    ANYWAY, I think you would just see its redshift.
  4. Apr 27, 2008 #3


    User Avatar
    Gold Member

    You cannot do this.

    Which is why there's no paradox.
  5. Apr 27, 2008 #4
    oh come on. Use you imagination?:wink:
  6. Apr 27, 2008 #5
    I believe that you may be able to 'look' back in time, because of the reflected light, but the actual object that is going faster than light, would not actually go back in time, as time would still be moving forward around the object, not going backwards. But, if I am right (doubtful), this would raise the question of, 'What happens when you stop moving?' Would you in fact, be at that time that you were viewing, or would land in you own time again? It might be arguable that as you slow down again, time might go forwards and as you slow down you will get closer to the time you started moving.
  7. Apr 27, 2008 #6
    Thank you all for your insight on the subject

    If you were to suddenly stop you'd more than likely die :P. But if you were to stop what I think would happen is that you would start seeing time forward from the moment you stopped. Only if you start traveling towards the object at a speed greater than light would you be able to see into what to you at the time would be the future, but to the object would be the present and past.
  8. Apr 27, 2008 #7


    User Avatar
    Gold Member

    Guys guys guys. This is claptrap. There is only heartbreak and sorrow (and locked threads) down this road.

    You cannot travel faster than c. No object with mass can.

    This is not merely quibbling. This is critical. To "use your imagination" to pretend that you can will generate all manner of silly, spurious paradoxes. "you'd see unicorns and elves"is as valid as any other answer.
    Last edited: Apr 27, 2008
  9. Apr 27, 2008 #8

  10. Apr 27, 2008 #9
    Alright, since no object with 'mass' can go faster than light, lets bring in an object with a mass less than 0. Monatomic metals. These metals, when brought to a monatomic state, can potentially weigh less than zero, if heated/cooled to a certain temperature (unique to the metal), thus, having no detectable mass.
  11. Apr 27, 2008 #10
    You mean the past right?

    But, if you went faster than light away from an object, then looked back, would you see into the future?
  12. Apr 27, 2008 #11


    User Avatar
    Gold Member

    Show me.
  13. Apr 27, 2008 #12
    Well, I don't have enough posts to post URL's...so I will make 2 posts really quick.
  14. Apr 27, 2008 #13
    Tachyons are an excellent example of faster than light particles, and although being merely theoretical (for now), the future can undoubtedly bring things that we do not foresee now.
    If we don't imagine the impossible we can't accomplish the impossible. Imagination is one of our greatest gifts. Also a lot of current scientific material would have seemed "impossible" to many great scientists from hundreds of years back.
  15. Apr 27, 2008 #14


    User Avatar
    Gold Member

    Yes. Absolutely. There's an Imagination Forum down the street.
  16. Apr 27, 2008 #15


    User Avatar
    Staff Emeritus
    Science Advisor

    I'm locking this thread until one of the Physics mentors get a chance to look into it. In the meantime, perhaps we could all take this opportunity to have a read through the PF Guidelines, particularly the part on overly speculative posts.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Looking back in time?
  1. Looking Back in Time (Replies: 7)

  2. Going back in time ? (Replies: 8)

  3. Looking back in time (Replies: 10)