asprung Posted November 29, 2007 Share Posted November 29, 2007 Questions concerning Relativity 1- As the present moves on becoming the past does anything remain of it other than memory. 2- Is the future anything other than anticipations? 3- A space traveler, moving relative to earth at speed approaching the speed of light, would have his time pass slower than that on earth. Would not that put the space traveler in the earth past, and the earth in his future? How could they ever meet? Would not the traveler return to earth in its past? 4- The theory of relativity is premised on the speed of light being a constant. A factor in the speed of light is time – miles per second-. If the duration of a second is slower for the space traveler how can the speed of light be constant? Link to comment Share on other sites More sharing options...
Klaynos Posted November 29, 2007 Share Posted November 29, 2007 1) What could remain? If you walk forward do you leave yourself behind? 2) The future is just a point where time has increased... 3) Neither from the view point of the space traveller the earth's time would be travelling slower. It's relative, if they meet then one of them has accelerated and this can no longer be thought of as special relativity, but general, which I am not good enough at to talk about really. 3) That is a postulate of special relativity, it can be true because the speed of light always comes out to be c in any frame, velocities do not add linearly... Link to comment Share on other sites More sharing options...
asprung Posted November 29, 2007 Author Share Posted November 29, 2007 1&2- I take it from your answer that you would agree that only the present " now" exsits. 3-How does relativity deal with the concept of past present and future Link to comment Share on other sites More sharing options...
Klaynos Posted November 30, 2007 Share Posted November 30, 2007 now only exists in the same way here only exists, it's a consciousness thing... Link to comment Share on other sites More sharing options...
iNow Posted November 30, 2007 Share Posted November 30, 2007 1&2- I take it from your answer that you would agree that only the present " now" exsits. I know I do. 3-How does relativity deal with the concept of past present and future Does it at all? Right now is the only absolute frame of reference, but it's changed completely by the time you describe it. Link to comment Share on other sites More sharing options...
asprung Posted November 30, 2007 Author Share Posted November 30, 2007 What I am trying to understand,what if anything, exits on either side of now. Link to comment Share on other sites More sharing options...
iNow Posted November 30, 2007 Share Posted November 30, 2007 That's a very philosophical question. Most readings I have done all landed on the conclusion that right now is all there is. There is no past, there is no future, since both are contained in the present. Again... not sure how this relates directly to relativity, as it sounds more philisophical in nature. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted December 1, 2007 Share Posted December 1, 2007 What I am trying to understand,what if anything, exits on either side of now. I think that, in as much as it can be seen, both the past and the future "exist". If the world were perfectly deterministic, you could "see" both the past and the present, and could consider time much like any spatial dimension and say that stuff both in the past and in the future exists, and describe it etc. In a non-deterministic world (as predicted by quantum mechanics), information about the past is irrevocably lost, and new information gets created. So in a non-deterministic world, I would say that the past is fading rapidly, and the future is materializing. I feel as if I just said a bunch of mostly nonsense. Link to comment Share on other sites More sharing options...
asprung Posted December 2, 2007 Author Share Posted December 2, 2007 My question relates to relativity as relativty predicts a slowing of time which could bodies in each others past and future. Link to comment Share on other sites More sharing options...
Klaynos Posted December 2, 2007 Share Posted December 2, 2007 My question relates to relativity as relativty predicts a slowing of time which could bodies in each others past and future. But it's always now in the frame of reference about which you're talking, relativity says nothing of the future... or past... and it's connections with the now, other than causality.... Link to comment Share on other sites More sharing options...
iNow Posted December 2, 2007 Share Posted December 2, 2007 asprung... your understanding is very close, but has some very slight parts that are not correct. Let's see if this can be clarified. Can you ask a more specific (think "smaller") question? I know it would help me to hear the responses you receive, and I think it would help you a bit also. Again, relativity does have implications for the different passage of time for different observers, but the concepts of "past" and "future" don't really enter into it... AFAIK. Link to comment Share on other sites More sharing options...
asprung Posted December 2, 2007 Author Share Posted December 2, 2007 The trouble I see with relativity is that it does not adress the questions of past present and future. The actual slowing of time would place the body for which the time went slower in the past of the body for which time did not slow. This would open a can of worms as to what actualy exsist in the past and future. Link to comment Share on other sites More sharing options...
iNow Posted December 2, 2007 Share Posted December 2, 2007 The trouble I see with relativity is that it does not adress the questions of past present and future. The actual slowing of time would place the body for which the time went slower in the past of the body for which time did not slow. This would open a can of worms as to what actualy exsist in the past and future. See... actually, it does. Your past is relative. Your future is relative. My past is relative. My future is relative. These are, in that sense, entirely addressed by relativity. Everything is relative to one's frame of reference. If you and I are standing 10 feet apart, but look at the same mailbox, that mailbox will show itself to each of us a bit differently. You will see different shapes and shadows from a different angle than I will. It's basically the same with time. Link to comment Share on other sites More sharing options...
asprung Posted December 3, 2007 Author Share Posted December 3, 2007 The space traverlers want to meet and shake hands, what is tnre date when they do this? The space traverlers want to meet and shake hands, what is tne date when they do this? Link to comment Share on other sites More sharing options...
swansont Posted December 3, 2007 Share Posted December 3, 2007 The space traverlers want to meet and shake hands, what is tnre date when they do this? They won't agree on what the date and/or time is, as they will disagree on the measurement. Link to comment Share on other sites More sharing options...
asprung Posted December 14, 2007 Author Share Posted December 14, 2007 How could time pass slower for the space twin without his falling in his brothers past ? Link to comment Share on other sites More sharing options...
iNow Posted December 14, 2007 Share Posted December 14, 2007 How could time pass slower for the space twin without his falling in his brothers past ? Interesting question. The brother who stays on earth would age more "quickly" than the brother on the spaceship, but if they ever met again they would be in each other's present. So... instead of being in the non-travelling brothers past, they are in the present and one is just "more aged" than the other. Like I said above... there really is no such thing as "past." It's entirely abstract. The two brothers, regardless of their age, exist in the present. When they are apart, their present is their own. When they meet up again, they share that present. AFAIK... Link to comment Share on other sites More sharing options...
swansont Posted December 14, 2007 Share Posted December 14, 2007 How could time pass slower for the space twin without his falling in his brothers past ? Because time isn't absolute, and comparisons of different reference frames must account for this. Link to comment Share on other sites More sharing options...
asprung Posted January 2, 2008 Author Share Posted January 2, 2008 I cannot understand how a space travelers present – now – can fall behind that of earths so that he ages slower than his twin on earth, and earth itself with, his watch running slower than a similar watch on earth, yet come back to earth, jump somehow and where, into the earths present with his watch speeding up? It seems to me in my ignorance that the present¬-(now)-would be the same throughout the universe evolving into the future at the same pace i.e. the universe would age uniformly. If time would appear to flow slower for any body or particle this would be due to a slowing of the measuring instrument but the advancement of the present would stay in step with earths. Thus an atomic clock or particles decay could be slowed by there speed while their march toward the future would not. I also cannot understand how the speed of light could be constant if time, an element thereof were not ? (Miles per minute). Link to comment Share on other sites More sharing options...
swansont Posted January 2, 2008 Share Posted January 2, 2008 "The present" is a tautological concept. It is always "now." Relativity deals with time intervals, and the interval between two events will depend on your reference frame. Link to comment Share on other sites More sharing options...
asprung Posted January 2, 2008 Author Share Posted January 2, 2008 The space twins "now" would be in the year 2000 while the earth twins "now" would be in the year 3000. What do they do when they meet ? Agree what year they should be in ? If they are in the year 3000 the space would have to have a time jump to get there. Link to comment Share on other sites More sharing options...
swansont Posted January 2, 2008 Share Posted January 2, 2008 The space twins "now" would be in the year 2000 while the earth twins "now" would be in the year 3000. What do they do when they meet ? Agree what year they should be in ? If they are in the year 3000 the space would have to have a time jump to get there. You're still treating time as an absolute. It's not. We have two threads going on about this. I'm locking this one. http://www.scienceforums.net/forum/showthread.php?t=29963 Link to comment Share on other sites More sharing options...
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