Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Space Time Velocity

  1. Aug 29, 2003 #1
    Is it true that we're traveling through the 4 dimensions of space time at the constant, c? This implies that velocity through the spatial dimensions detracts from our velocity through time and vice versa. For example, if I were traveling at the speed of light, I wouldn't be aging because I wouldn't be traveling through time (V=0).
  2. jcsd
  3. Aug 29, 2003 #2


    User Avatar

    Please define "travel"
  4. Aug 29, 2003 #3


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    In converting time to units of length, for use in formuilas and components, we multiply by the invariant speed, c. So many length units per time unit. As a result of that your squared displacement from one event in spacetime to another becomes

    c2Δt2 - Δx2- Δy2- Δz2.

    If you remain still, your space displacements are all zero, and only your time displacement (aging) is effective. Evidently this is cΔt in length units. This is the origin of the statement that we are moving through time at the speed of light. It is really because we convert time units to length units using c. And we use c because it is the same in all inertial frames of reference.
  5. Aug 29, 2003 #4


    User Avatar

    Yes, but that will only be true from a perspective that is travelling at c relative to you. From your point of view, your time proceeds normally and it is THEY that do not age.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook