Chaos Posted June 17, 2005 Report Share Posted June 17, 2005 it's been a while since i've read "the elegant universe" by brian greene, but i know this is discussed in it. it is said that at the speed of light, there is no time. yet how do we at the same time say some star is x light years away? if it takes light years to get somewhere, how can there also be no time at the speed of light? :shrug: Quote Link to comment Share on other sites More sharing options...
tolworthy Posted June 17, 2005 Report Share Posted June 17, 2005 it is said that at the speed of light, there is no time. yet how do we at the same time say some star is x light years away? if it takes light years to get somewhere, how can there also be no time at the speed of light? :rant: There is distance, but no time. We call it light years because we have time. (or at least we think we do). I imagine that a being-of-pure-energy would call it something else. :shrug: niviene 1 Quote Link to comment Share on other sites More sharing options...
Chaos Posted June 17, 2005 Author Report Share Posted June 17, 2005 i also have 2 interesting questions: what would it be like to exist at roughly 99.99999999999999% the speed of light? i ask because with this motion, there is almost no time for you. what would it be like to exist at roughly .0000000000000000001% the speed of light? i ask because with this motion you're almost moving all through time and not space. Quote Link to comment Share on other sites More sharing options...
Qfwfq Posted June 17, 2005 Report Share Posted June 17, 2005 it is said that at the speed of light, there is no time.This is a simple expression for something more complicated. The same points of space-time have different coordinates for different observers or, more precisely, according to different frames of reference. The Lorentz transformations tell how the coordinates of one relate to those of another. For a relative velocity of c the transformations are singular and this is what causes the difficulty, it doesn't make much sense to match up our coordinates with those of the photon. Quote Link to comment Share on other sites More sharing options...
Little Bang Posted June 17, 2005 Report Share Posted June 17, 2005 With regards to time only, a traveler at near C, with respect to the rest of the universe, it would appear that everything is running infinitely fast. To an outside observer the traveler's time would appear to stop. Remember everything is relative to the observer's frame of reference. Quote Link to comment Share on other sites More sharing options...
UncleAl Posted June 18, 2005 Report Share Posted June 18, 2005 Lightspeed is not an inertial frame of reference. Your question is without meaning. The question of how inertial frames of reference moving at different velocities view each others' clocks has been addressed, Annalen der Physik 4 XVII pp. 891-921 (1905) http://fourmilab.to/etexts/einstein/specrel/specrel.pdf<http://www.geocities.com/physics_world/sr/ae_1905_error.htm><http://www.physics.gatech.edu/people/faculty/finkelstein/relativity.pdf> Longitudinal and transverse mass Quote Link to comment Share on other sites More sharing options...
maddog Posted June 18, 2005 Report Share Posted June 18, 2005 Chaos, This was a comment I made earlier. Yes, I believe the issue of (time=0) for light isdiscussed in "Elegant Universe" by Brian Greene. I think Qfwfq said it best by talkingabout from whose point of reference. Time not existing for light is ONLY from light'spoint of view (reference frame). Uncle Al's comment about inertial reference framesthough correct would Only be pertinent for particles with mass (rest mass). Sinceyou mentioned Brian Greene's excellent book, let give an high salutation for his newone, "Fabric of the Cosmos" !!! I just getting to the section on String Theory. He hasreally branched off from the first book. It is a Great sequel (update on theory &observation). Now back to No time for photons... Photons always travel at C (local reference frame).It is only from our point of view observing with a photon (by its interaction with someother particle (typically with mass) that we observe a speed less than (by travelingthrough a medium other than a vacuum). Were a particle with mass to travel witha speed close to light, we would view it time exceedingly slowed. However theparticle would view that our time was what had slowed by this proportion. This is allby special relativity (SR) of Einstein. Were it to be the other end of exceedingly slowspeed (very near 0), then the sense of time would be imperceptively change fromobserver to observer (depending of frames of reference). Were GR brought in herethen acceleration would become equivalent to a gravitic field of equal intensity forthe appropriate observers point of reference. Hope this clarifies... maddog Quote Link to comment Share on other sites More sharing options...
EWright Posted July 16, 2005 Report Share Posted July 16, 2005 Chaos, This was a comment I made earlier. Yes, I believe the issue of (time=0) for light isdiscussed in "Elegant Universe" by Brian Greene. I think Qfwfq said it best by talkingabout from whose point of reference. Time not existing for light is ONLY from light'spoint of view (reference frame). Uncle Al's comment about inertial reference framesthough correct would Only be pertinent for particles with mass (rest mass). Sinceyou mentioned Brian Greene's excellent book, let give an high salutation for his newone, "Fabric of the Cosmos" !!! I just getting to the section on String Theory. He hasreally branched off from the first book. It is a Great sequel (update on theory &observation). Now back to No time for photons... Photons always travel at C (local reference frame).It is only from our point of view observing with a photon (by its interaction with someother particle (typically with mass) that we observe a speed less than (by travelingthrough a medium other than a vacuum). Were a particle with mass to travel witha speed close to light, we would view it time exceedingly slowed. However theparticle would view that our time was what had slowed by this proportion. This is allby special relativity (SR) of Einstein. Were it to be the other end of exceedingly slowspeed (very near 0), then the sense of time would be imperceptively change fromobserver to observer (depending of frames of reference). Were GR brought in herethen acceleration would become equivalent to a gravitic field of equal intensity forthe appropriate observers point of reference. Hope this clarifies... maddog I believe you are mistaken on one point. From the accelerated particle's 'view' it would appear that our time sped up. We would view its time as having it's time as slowed. That is, according to SR. Quote Link to comment Share on other sites More sharing options...
Fredu Posted July 16, 2005 Report Share Posted July 16, 2005 Time does not exist.How can there be no time? Quote Link to comment Share on other sites More sharing options...
EWright Posted July 16, 2005 Report Share Posted July 16, 2005 Time does not exist.How can there be no time? Your statement and then quetion do not compute. I assume both were questions? Special Relativity says there would be no passage of time at the speed of light, and thus for a photon. But be warned, SR is mistaken about a great many things. Quote Link to comment Share on other sites More sharing options...
Erasmus00 Posted July 16, 2005 Report Share Posted July 16, 2005 But be warned, SR is mistaken about a great many things. You are either here to discuss your ideas, or you are not. You follow your posts, almost without exception, with "SR is wrong." Sometimes you even include "and I'm right." If you aren't willing to discuss your ideas, these statements don't lead anywhere, so why keep making them? -Will Quote Link to comment Share on other sites More sharing options...
niviene Posted July 16, 2005 Report Share Posted July 16, 2005 I'd also like to know... what mistakes? Please tell me what you think are the flaws, I'm curious to know. Quote Link to comment Share on other sites More sharing options...
EWright Posted July 16, 2005 Report Share Posted July 16, 2005 I'd also like to know... what mistakes? Please tell me what you think are the flaws, I'm curious to know. See my posts in the Physics and Mathmatics section. To go into detail I would have to explain too much of my own theory, and I'm not yet ready to do that. Quote Link to comment Share on other sites More sharing options...
lindagarrette Posted July 18, 2005 Report Share Posted July 18, 2005 Time does not exist.How can there be no time? Here's how I understand it. Time is merely a means of measuring the interval between events. It measured nothing before there was a universe. Velocity is a means of measuring how quickly an object in motion travels from one point to another. In equations using velocity, events occur at longer or shorter intervals of time depending on the observer's perspective -- SR. Quote Link to comment Share on other sites More sharing options...
lindagarrette Posted July 18, 2005 Report Share Posted July 18, 2005 Special Relativity says there would be no passage of time at the speed of light, and thus for a photon. SR applies to the space/time observable universe. No passage of time would mean that only one event occurs. Anything in motion creates a series of events which are measured by time. A photon cannot travel from one point to another simultaneously. Quote Link to comment Share on other sites More sharing options...
EWright Posted July 18, 2005 Report Share Posted July 18, 2005 SR applies to the space/time observable universe. No passage of time would mean that only one event occurs. Anything in motion creates a series of events which are measured by time. A photon cannot travel from one point to another simultaneously. So you disagree with SR? Quote Link to comment Share on other sites More sharing options...
xersan Posted July 23, 2005 Report Share Posted July 23, 2005 Special relativity is wrong. I have mathematical evidences and key knowledges. All of the logic traps had been solved. One of them: Numerical analysis with Lorentz equation : Position A : The source and the light are the direction of (+ x) (For this position ; v = 0.60 c , t = 5 s , c = 300 000 km/s) => x’ = 750 000 km t’ = 2.5 sec (Tempo of time becomes slower: Time dilation) Position B : The light is at the direction of (+ x) ; The source goes at the direction of (- x) (For this position: v = - 0.60 c ; t = 5 sec ; c = 300 000 km/sec) x’ = 3 000 000 km ; t’ = 10 sec (Tempo runs faster: time contraction) Position C: The source goes at the direction of (+ x), light is at the direction of (- x) (For this position: v = 0.60 c ; t = 5 sec ; c = - 300 000 km/sec x’ = - 3 000 000 km ; t’ = 10 sec ( Tempo of time runs faster: Time contraction) The velocity of light for allpositions: C = 750 000/2.5 = 3 000 000 / 10 = | - 3 000 000| / 10 = 300 000 km/sec The velocity of light for each position is obtained the fixed value of < c> (= 300 000 km/sec). But the tempos of time run faster for the position (:hihi: and © . If the tempo of time could have been slower for also the position B and C, the scientific integrity of SR would be assured. But this condition could not be realized. Faster and slower tempos never becomes simultaneously on the same experiment . If Einstein was alive, he would take back his theory (SR)certainly because of the results of analyzing with opposite directional light. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.