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Correct me if I'm wrong

  1. Jun 28, 2012 #1
    Einstein's theory that the faster you go, the slower time flows is not correct. I can give his example. You're standing near a clock. Then, you start speeding up, and what you see, is the faster you go, the slower the clock ticks. When you reach speed nearly that the speed of light, it seems that clock is almost still, because light can't catch up to you. Now imagine you stop. What happens? The light catches you and the time seems to flow faster than normal. If you travel near the speed of light to slow down time, you lose distance. The speed doesn't effect the time flow. Clock is only a tool to measure time.
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  3. Jun 28, 2012 #2


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    You are incorrect because you did not understand the basic physics.

    The concept of time dilation is the observed time in ANOTHER INERTIAL REFERENCE FRAME. The proper time in your own frame does not change! If the clock moves with you with respect to another frame, then you see NO CHANGE in the clock's time! You detect no time dilation! So that is where you are mistaken!

    Furthermore, when you stop with respect to a reference frame, you are decelerating, and another set of rules occur on how your time changes with respect to the "stationary" reference frame.

    Einstein's theory is correct. You are not.

  4. Jun 28, 2012 #3


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    This is also wrong. The fundamental rule of relativity is that light has the same speed in all frames of reference. Light has not trouble catching up to you because it is catching up to you to you with "the speed of light" just as if you were stationary.

    In fact, It makes no sense at all to say you were "stationary" or moving except relative to some given frame of reference- that's why it is called "relativity".

    I would suggest that before you assert that relativity is wrong, you at least learn the basics of relativity.
  5. Jun 28, 2012 #4
    This is practically an exact description of some of the material presented in the Einstein biography on the History Channel. It is totally bogus, and punctuates the PhysicsForums warning about not believing everything you see presented in the popular media. There are other incorrect excerpts in this same video as well, including a well-known physics professor (Michio Kaku) saying that gravity does not pull on an object in free fall, it pushes on it. I don't know what could possibly have motivated him to say this. Part of the reason I studied relativity was so that I could discriminate between what is true and what is bull when I watch TV programs like this.

  6. Jun 28, 2012 #5
    As already mentioned, it's all quite wrong. To elaborate:

    You are referring to comparisons at constant speed, and what is claimed is that the faster you go, the slower your proper time progresses according to the "rest system" relative to which you are moving.
    In order to determine the clock rate of a co-moving clock, you can either use another co-moving clock - which will show nothing different! - or you can use clocks and rulers of the reference system in which you were in rest before. I'll pretend/assume that you did the last, for then we can go to the next:
    "because"?? Light rays that happen to be chasing you, cannot cause your clock to stand almost still! And similarly when you stop. (I also omitted a sentence of which I could make no sense to me at all). Sure a clock is only a tool to measure time, and it sounds as if you confound the Doppler effect with time dilation - but don't worry, that's a common beginners mistake. :smile:
    The Doppler effect is explained here:
  7. Jun 28, 2012 #6
    I didn't mean to say that line can't catch up to you. I meant that if you move for example at c-1km/h, the light takes more time to travel than the situation when you are standing still.
  8. Jun 28, 2012 #7


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    No. That would imply a variable speed of light. The entire point of SR is to integrate a constant speed of light with the principle of relativity.

    You need to start over from scratch and learn what SR says. Everything you think you know about it is wrong.
  9. Jun 28, 2012 #8
    That's irrelevant - see my post #5 in which I tried to explain that. "Special relativistic" effects such as time dilation are in addition to the classical effects to which you refer here.
  10. Jun 29, 2012 #9
    Most important thing my teacher told me about special relativity: the seemingly 'abnormal' effects of relativity are NOT a result of not taking into account the delay of light reaching you.
  11. Jun 30, 2012 #10


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    In the frame of the clock, emitting light. But not in your frame.

    Special relativity modifies space and time in many different ways. If you keep track of all of them, you get consistent physics. If you pick one of them and neglect (or do not know) the others, you get wrong results.
  12. Jun 30, 2012 #11


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    Maybe if you could actually try your experiment, you might think you were right because after traveling at a high speed away from the other clock and then stopping, the other clock would read a much earlier time than your own, as you say, but then what do you think would happen if you came back to the other clock at a high speed? Of course you would see it ticking faster than your clock, but how do you think your two clocks would compare when you finally stop at the other clock?
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