Notices
Results 1 to 31 of 31

Thread: Faster than the speed of light

  1. #1 Faster than the speed of light 
    New Member
    Join Date
    Jul 2010
    Posts
    2
    Hi all, im not a scienc student, im dont have a career in science, im just a film student who enjoys reading about physice. I've just been thinking about travelling faster than the speed of light when i was reading an article on time travel by stephen hawking.
    Im just wondering if what im thinking would be correct. I might be wrong about somethings or everything im saying here. when we look at the sun, it takes the light from it ten mins [maybe not correct time] to reach earth and our eyes so what we are seeing is what the sun was like ten mins ago, due to the time for its light to reach earth? when i look at someone across the room im seeing them because of the light reflected, so im technically seeing what they did a billionth billionth trillionth [just exaggerating the time] of a second earlier? am i correct so far? now if one where to go twice the speed of light [impossible but this is just hypothetical], what would happen, what would we see? say im flying through space with a friend beside me, we are travelling twice the speed of light, all the light we are reflecting is being left behind us unable to catch up, would i look over at my friend and see nothing but darkness because the lights unable to reach me?

    Im thinking about breaking breaking the speed of light in terms of how the sound barrier is broken, when a jet travels faster than sound, we here the sound after the jet flys by, would it be the same principal with light?
    i hope this all makes sense, i understand it in my head but and not good at wording it. i might be completely wrong on all acounts. this is just a random thought bubbling about my head.


    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Bachelors Degree Shaderwolf's Avatar
    Join Date
    Dec 2005
    Location
    OPSEC, baby. Sorry.
    Posts
    425
    To travel faster than the speed of light is impossible for more reasons than I think you realize.

    The speed of light is the maximum speed that anything can travel. There's this whole thing about Einstein and relativity... Basically though, no matter how fast you travel.... To you, light will still travel at light speed. You cannot catch up to it.

    Also, racing towards light speed, your mass would increase, while at the same time, time would be slowing down. Because of this increase of mass, it would take more and more energy to push you forwards. At light speed, your mass would become infinite. And so would be the energy that would be required to move it. This is one reason why any kind of matter cannot travel even at light speed. Only energy.

    So in as simple terms as possible... ( I do not mean to shoot down the creativity to your idea) there is no light speed barrier. Light speed is the limit. The fastest speed that is physically and scientifically achievable. For anything else, you would just be using your imagination. And as a film student, I can reasonably presume that your imagination (or artistic vision) could create a cooler faster than light reality than I ever could.

    The truth (And I only gave you the smallest little bit) is much more awesome and crazy than any of us could ever imagine.


    Reply With Quote  
     

  4. #3 Re: Faster than the speed of light 
    Moderator Moderator Janus's Avatar
    Join Date
    Jun 2007
    Posts
    2,156
    Quote Originally Posted by tenniskettle
    Hi all, im not a scienc student, im dont have a career in science, im just a film student who enjoys reading about physice. I've just been thinking about travelling faster than the speed of light when i was reading an article on time travel by stephen hawking.
    Im just wondering if what im thinking would be correct. I might be wrong about somethings or everything im saying here. when we look at the sun, it takes the light from it ten mins [maybe not correct time] to reach earth and our eyes so what we are seeing is what the sun was like ten mins ago, due to the time for its light to reach earth? when i look at someone across the room im seeing them because of the light reflected, so im technically seeing what they did a billionth billionth trillionth [just exaggerating the time] of a second earlier? am i correct so far? now if one where to go twice the speed of light [impossible but this is just hypothetical], what would happen, what would we see? say im flying through space with a friend beside me, we are travelling twice the speed of light, all the light we are reflecting is being left behind us unable to catch up, would i look over at my friend and see nothing but darkness because the lights unable to reach me?

    Im thinking about breaking breaking the speed of light in terms of how the sound barrier is broken, when a jet travels faster than sound, we here the sound after the jet flys by, would it be the same principal with light?
    i hope this all makes sense, i understand it in my head but and not good at wording it. i might be completely wrong on all acounts. this is just a random thought bubbling about my head.

    Here's the problem with questions like "what would we see if we traveled faster than the speed of light". Since the rules that govern the universe as we understand them do not allow for such a possibility, to imagine such an event forces us to abandon those rules. But that leaves us no guide by which to answer the question. We have no idea as to what rules to replace them with, and we can't give an answer.
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


    Edit/Delete Message
    Reply With Quote  
     

  5. #4 Re: Faster than the speed of light 
    New Member
    Join Date
    Jul 2010
    Posts
    2
    Quote Originally Posted by Janus


    Here's the problem with questions like "what would we see if we traveled faster than the speed of light". Since the rules that govern the universe as we understand them do not allow for such a possibility, to imagine such an event forces us to abandon those rules. But that leaves us no guide by which to answer the question. We have no idea as to what rules to replace them with, and we can't give an answer.
    hmm thats a fair point. guess ill never know what will happen, still i like to wonder.

    thanks for the answers everyone. Guess ill just get back to creating Perpetual motion machine out of a shoe, headphones and an old magnum p.i vhs tape and destroying the first law of thermodynamics
    Reply With Quote  
     

  6. #5  
    New Member
    Join Date
    May 2010
    Posts
    4
    Quote Originally Posted by Shaderwolf
    To travel faster than the speed of light is impossible for more reasons than I think you realize.

    The speed of light is the maximum speed that anything can travel. There's this whole thing about Einstein and relativity... Basically though, no matter how fast you travel.... To you, light will still travel at light speed. You cannot catch up to it.

    Also, racing towards light speed, your mass would increase, while at the same time, time would be slowing down. Because of this increase of mass, it would take more and more energy to push you forwards. At light speed, your mass would become infinite. And so would be the energy that would be required to move it. This is one reason why any kind of matter cannot travel even at light speed. Only energy.

    So in as simple terms as possible... ( I do not mean to shoot down the creativity to your idea) there is no light speed barrier. Light speed is the limit. The fastest speed that is physically and scientifically achievable. For anything else, you would just be using your imagination. And as a film student, I can reasonably presume that your imagination (or artistic vision) could create a cooler faster than light reality than I ever could.

    The truth (And I only gave you the smallest little bit) is much more awesome and crazy than any of us could ever imagine.
    ok um i thought Tachyons could go faster than light but could not breach the Light Speed "Barrier" because as they gain speed instead of gaining mass it loses mass and as it loses mass its speed increases right? so yea explain to me please?
    Reply With Quote  
     

  7. #6  
    New Member
    Join Date
    Jul 2010
    Posts
    2
    The universe is expanding. We will never see the edge of the universe as we know it. Why? Because it's moving away from us faster than the speed of light?
    Reply With Quote  
     

  8. #7  
    Moderator Moderator Dishmaster's Avatar
    Join Date
    Apr 2008
    Location
    Heidelberg, Germany
    Posts
    1,624
    Quote Originally Posted by griffinx15
    ok um i thought Tachyons could go faster than light but could not breach the Light Speed "Barrier" because as they gain speed instead of gaining mass it loses mass and as it loses mass its speed increases right? so yea explain to me please?
    Tachyons are as hypothetical as pink dragons. They only exist in science fiction.
    Quote Originally Posted by Gozzer101
    The universe is expanding. We will never see the edge of the universe as we know it. Why? Because it's moving away from us faster than the speed of light?
    From our perspective, yes. Except there is no edge of the universe, as far as we know. If there is an edge, there must be a centre. However, this contradicts everything we know. The edge of the visible universe is defined by an infinite redshift. But someone being just now at that visible horizon looking back to us would see the same thing.
    Reply With Quote  
     

  9. #8  
    New Member
    Join Date
    Jul 2010
    Posts
    1
    The only thing I can add that has not already been mentioned is the fact that you cannot compare the effects of the sound barrier being broken with any hypothetical effects of a "light barrier".

    Sound is simply a pressure disturbance in the air, hence it can only exist in an atmosphere. Light is completely different in that it needs no medium in which to travel making any comparisons irrelivant.

    As for the effects of what you would (hypothetically) see, my guess is that your answer may lie in what happens to light when it goes past the event horizon of a black hole since everything is moving "into" the black hole at speeds which exceed the speed of light.
    Reply With Quote  
     

  10. #9  
    Forum Ph.D. Leszek Luchowski's Avatar
    Join Date
    Jun 2008
    Location
    Gliwice, Poland
    Posts
    807
    The original question is not as hopelessly unanswerable as Janus argues.

    The speed c which cannot be exceeded is the speed of light in a vacuum.

    To answer the OP's question, we can imagine a (large part of the) universe filled with, say, water, and an observer travelling at a monstrous but still sub-c speed in some super-duper submarine, faster than light does in this medium.

    Both propelling a submarine to such speed and making it survive the hydrodynamic drag is unfeasible by any technology I can remotely think of, and I have no idea where to find a galactic-sized drop of water, but at least this thought experiment does not violate fundamental laws of physics the way faster-than-c travel does. And we can therefore make an educated guess, indeed a prediction, of what the observer would see.
    Leszek. Pronounced [LEH-sheck]. The wondering Slav.
    History teaches us that we don't learn from history.
    Reply With Quote  
     

  11. #10  
    New Member
    Join Date
    Jul 2010
    Posts
    1
    I was confused by this topic as well today while watching something on the History channel.

    If nothing can travel faster than the speed of light (at least nothing that contains mass), why did they state that during the Big Bang matter and objects flew out from the center of the Universe at speeds *faster* than the speed of light?
    Reply With Quote  
     

  12. #11  
    Forum Radioactive Isotope MagiMaster's Avatar
    Join Date
    Jul 2006
    Posts
    3,440
    Space can expand faster than c, and can drag matter along with it, but that's much more complicated and isn't the same as matter travelling faster than c.
    Reply With Quote  
     

  13. #12  
    Forum Bachelors Degree PetTastic's Avatar
    Join Date
    Jul 2010
    Location
    London UK
    Posts
    421
    Quote Originally Posted by MagiMaster
    Space can expand faster than c, and can drag matter along with it, but that's much more complicated and isn't the same as matter travelling faster than c.
    Never liked this part of the inflation idea.
    What happens to photons emitted while space is expanding faster than light?

    But at least it gives hope for warp drive :wink:
    Reply With Quote  
     

  14. #13  
    Forum Radioactive Isotope MagiMaster's Avatar
    Join Date
    Jul 2006
    Posts
    3,440
    There are places the photon would never reach. There is a visible horizon in the universe and if inflation is going fast enough, that horizon will shrink. See "The Big Rip".
    Reply With Quote  
     

  15. #14  
    New Member
    Join Date
    Aug 2010
    Posts
    2
    Since we're on the subject of travelling faster than light, I have a question I'd like to ask. I've read that the closer you get to the speed of light the slower time will be and at light speed time will stop (might be wrong on that last bit). Does that mean that if somehow you did manage to break the speed of light you would go backwards in time?

    Also I've read recently that anti-electrons are regular electrons travelling backwards through time. Does that also mean that if you can break the light barrier and travel backwards through time you would become anti matter?
    Reply With Quote  
     

  16. #15 well 
    Suspended
    Join Date
    Aug 2009
    Location
    Israel
    Posts
    272
    Quote Originally Posted by Shem
    Since we're on the subject of travelling faster than light, I have a question I'd like to ask. I've read that the closer you get to the speed of light the slower time will be and at light speed time will stop (might be wrong on that last bit). Does that mean that if somehow you did manage to break the speed of light you would go backwards in time?

    Also I've read recently that anti-electrons are regular electrons travelling backwards through time. Does that also mean that if you can break the light barrier and travel backwards through time you would become anti matter?
    to go backward is faster then forward , and anti matter , well yes i gues .
    Reply With Quote  
     

  17. #16  
    Forum Radioactive Isotope MagiMaster's Avatar
    Join Date
    Jul 2006
    Posts
    3,440
    Quote Originally Posted by Shem
    Since we're on the subject of travelling faster than light, I have a question I'd like to ask. I've read that the closer you get to the speed of light the slower time will be and at light speed time will stop (might be wrong on that last bit). Does that mean that if somehow you did manage to break the speed of light you would go backwards in time?

    Also I've read recently that anti-electrons are regular electrons travelling backwards through time. Does that also mean that if you can break the light barrier and travel backwards through time you would become anti matter?
    For your first question, you're asking "what would happen if what we know is wrong?" and the answer is "we wouldn't know."

    For your second question, no. It was an interesting idea, but has been disproven.
    Reply With Quote  
     

  18. #17  
    New Member
    Join Date
    Aug 2010
    Posts
    2
    Quote Originally Posted by MagiMaster

    For your first question, you're asking "what would happen if what we know is wrong?" and the answer is "we wouldn't know."

    For your second question, no. It was an interesting idea, but has been disproven.

    Thank you.
    Reply With Quote  
     

  19. #18  
    Forum Bachelors Degree
    Join Date
    May 2010
    Posts
    419
    Anti-electrons or positrons can be treated mathematically as regular electrons travelling backwards in time. I believe it was Paul A. M. Diracwho first formulated this model of anti-matter, but that's all it is . An analogue of reality which can make some useful predictions but not actual reality.
    Reply With Quote  
     

  20. #19  
    Time Lord
    Join Date
    Mar 2007
    Posts
    8,035
    The thing about C is that it's all perception. Even if you went faster than C from the perspective of one observer, another observer might perceive you to be going only 1/2 C, or barely moving at all. In any event, you never measure yourself to go faster than C. You just think the distances got shorter.




    Quote Originally Posted by Shaderwolf
    To travel faster than the speed of light is impossible for more reasons than I think you realize.

    The speed of light is the maximum speed that anything can travel. There's this whole thing about Einstein and relativity... Basically though, no matter how fast you travel.... To you, light will still travel at light speed. You cannot catch up to it.
    Of course, unless Dark Matter is someday found to exist, at least we know that General Relativity will have to receive a revision at some point in the future.

    If you want to write good science fiction, I think the best way is to take the current laws of physics as they are understood today, and try to make an educated guess (one that doesn't contradict any existing experimental data, if possible) about how you think those laws are going to be changed by the next generation of scientists.

    I mean, instead of trying to guess how engineers will manipulate the known laws, try to guess what they'll do when they have a more complete set of rules to work with. That, of course, exposes you to being proved wrong later on, but your predictions will be interesting while they last anyway, right?
    Reply With Quote  
     

  21. #20 Re: Faster than the speed of light 
    Forum Bachelors Degree Shaderwolf's Avatar
    Join Date
    Dec 2005
    Location
    OPSEC, baby. Sorry.
    Posts
    425
    Quote Originally Posted by Janus
    Here's the problem with questions like "what would we see if we traveled faster than the speed of light". Since the rules that govern the universe as we understand them do not allow for such a possibility, to imagine such an event forces us to abandon those rules. But that leaves us no guide by which to answer the question. We have no idea as to what rules to replace them with, and we can't give an answer.
    I am going to quote you in my signature. This is true for so many things. Even in subjects such as philosiphy.
    Reply With Quote  
     

  22. #21  
    Forum Freshman
    Join Date
    Sep 2010
    Posts
    6
    It is not physically possible to travel "Faster Than Light."

    However, that's only if we're talking about moving at the same SPEED as Light.
    It's been suggested that wormholes may be able to connect Point A to Point B, though this would likely apply to all of the dimensions (11, I believe) and we'd really have no way of figuring out what's on the other side. There's also the issue of technology levels - I am uncertain whether we're capable of coming up with the energy required to "Expand" a wormhole, and I doubt we'd be able to get there for any less than a million years.
    Reply With Quote  
     

  23. #22  
    Forum Bachelors Degree
    Join Date
    May 2010
    Posts
    419
    I just re-read this thread and realised that the original question is very valid. Most of us came down all over the original question but failed to realise that the speed of light IN A VACUUM is the absolute. Particles have been observed to travel faster than light in various media. When this happens, the particle is observed to leave behind it, a wake of blue radiation, much like the pressure discontinuity behind a supersonic plane that gives rise to a sonic boom. This blue radiation is called Cerenkov radiation after the Russian scientist who first observed it.

    So, for a noob, the questioner was thinking outside the box more than we were, and 'what you would see if you are travelling faster than light THROUGH A SUITABLE MEDIUM' is certainly a question that we can explore.
    Reply With Quote  
     

  24. #23  
    New Member
    Join Date
    Oct 2010
    Posts
    1
    Quote Originally Posted by DanielIM
    If nothing can travel faster than the speed of light (at least nothing that contains mass), why did they state that during the Big Bang matter and objects flew out from the center of the Universe at speeds *faster* than the speed of light?
    Since for all intent and purpose people believe space is synonymous with 'nothing', the statement "Nothing can travel faster than light" may be factual after all. Space does 'travel' or more correctly put, expand faster than c
    Reply With Quote  
     

  25. #24  
    Time Lord
    Join Date
    Mar 2007
    Posts
    8,035
    The complicated thing about the big bang expansion having a "Speed" is that it wasn't expanding into anything. It's not like there was empty space outside the universe that our universe was filling, at least not according to the theory. (Note that I don't particularly believe in the Big Bang Theory, but I also don't know of any really great alternatives theories.)
    Reply With Quote  
     

  26. #25  
    Forum Sophomore
    Join Date
    Sep 2010
    Posts
    108
    It wasn't expanding into anything, but by the diameter of the space in any given moment, you can calculate the speed of expansion.
    Reply With Quote  
     

  27. #26  
    Suspended
    Join Date
    Oct 2010
    Posts
    19
    It would have to be Super/Hyper Light... we only think that way because we need light to see.

    See?
    Reply With Quote  
     

  28. #27  
    Forum Freshman
    Join Date
    Oct 2010
    Posts
    7
    From my understanding, the only time any physical object traveled faster than the speed of light was during the big bang.

    But thats subject to interpritation.

    It wasnt an explosion, it was an expansion. so mass wasnt moving THROUGH anything, mass was moving INTO something that didnt exist.

    Kind of abstract.

    Within the "coordnates", if you will, of the universe nothing can (travel through existance) faster than light.
    Reply With Quote  
     

  29. #28  
    . DrRocket's Avatar
    Join Date
    Aug 2008
    Posts
    5,486
    Quote Originally Posted by quantumboy
    From my understanding, the only time any physical object traveled faster than the speed of light was during the big bang.

    But thats subject to interpritation.

    It wasnt an explosion, it was an expansion. so mass wasnt moving THROUGH anything, mass was moving INTO something that didnt exist.

    Kind of abstract.

    Within the "coordnates", if you will, of the universe nothing can (travel through existance) faster than light.
    Not quite right.

    Relativity prevents anything from moving faster than c through space -- a local notion. However relativity does not prevent objects from separating from one another at a speed greater than c due to metric expansion of space itself --a global notion. In fact distant galaxies are receding from us at superluminal speed right now.
    Reply With Quote  
     

  30. #29  
    Forum Freshman
    Join Date
    Oct 2010
    Location
    Johannesburg
    Posts
    7
    Quote Originally Posted by Gozzer101
    The universe is expanding. We will never see the edge of the universe as we know it. Why? Because it's moving away from us faster than the speed of light?
    But Shaderwolf said;
    "This is one reason why any kind of matter cannot travel even at light speed. Only energy."

    I'm confused now.
    Dean
    Reply With Quote  
     

  31. #30  
    . DrRocket's Avatar
    Join Date
    Aug 2008
    Posts
    5,486
    Quote Originally Posted by deanvr
    Quote Originally Posted by Gozzer101
    The universe is expanding. We will never see the edge of the universe as we know it. Why? Because it's moving away from us faster than the speed of light?
    But Shaderwolf said;
    "This is one reason why any kind of matter cannot travel even at light speed. Only energy."

    I'm confused now.
    Dean
    Then read my post above.
    Reply With Quote  
     

  32. #31  
    Forum Freshman
    Join Date
    Oct 2010
    Location
    France
    Posts
    17
    Well, there is only one way to travel faster than the speed of light.

    And that is travelling to an alternate dimension (Sakharov-Petit's anti-material Möebius-shaped dimension for example).

    With the laws of our universe, it's not doable, hence the need for another one.
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •