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Time equals ?

  1. May 16, 2013 #1

    Just wondering: is it possible to construct an equation from known validated physics isolating time on one side of the equation sign? I'm asking because the famous E=MCC tells us Energy and Mass are two manifestations of the same fenomenen. And I have often wondered about the nature of time, so maybe an equation where "time equals whatever" can be used as a guidance for confused thoughts :-)

  2. jcsd
  3. May 16, 2013 #2
    Of course. Consider an object that moves with constant acceleration. Then, ##\Delta x = vt+\frac{a}{2}t^2##. Thus, we obtain that ##t=\frac{-v\pm\sqrt{v^2+2a\Delta x}}{a}##.

    Have we obtained a strikingly awesome new understanding of time? ...No.

    Time is often best considered as an independent variable. There really isn't any true way of working with time, since we can't really do any real "experiments" with it. In order to run an experiment, we have to be able to affect the subject of interest. Time does not, as far as I am aware, react to things (id est, in more colloquial terms, you can't poke it with a stick or something to make it do something).
  4. May 16, 2013 #3
    Revisit what c is. your answer is already in that concept, which is part of that equation you mentioned familiarity with, not to mention that curious c squared part of it.
    Last edited: May 16, 2013
  5. May 18, 2013 #4


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    There are many such equations, v= d/t so t= d/v, a= v/t so t= v/a, etc. Surely that's not what you mean?
  6. May 18, 2013 #5
    Thank you all for answers. It's not going to help me, is it. But just to be sure I'll ask - doen't all three answers still contain time on the right side of the "="? As well velocity as acceleration cannot be described without time?

    Thanks, Henrik
  7. May 18, 2013 #6


    Staff: Mentor

    Were you replying to what HallsOfIvy wrote? If so, I have quoted it below.
    The first and second equation are equivalent, as are the third and fourth. The second equation gives t as a function of d and v; the fourth equation gives t as a function of v and a.

    I don't know what you're asking here.
  8. May 19, 2013 #7
    Thanks Mark44. My math is not very good, so maybe I'm just being a fool. But my guess was that t=d/v is the same as t=d/d/t, so there's still time on both sides, as it makes no sence talking about velocity without the time part of that concept. And the same with the t=v/a,

    But anyway - I realize that the point made by Mandelbroth:
    "Have we obtained a strikingly awesome new understanding of time? ...No." is a good description for all the equations you have reminded me of here. :-)

    Again: Thank all.
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