Key 10

Up a level : Space-Time diagrams / Minkowski diagrams
  1. Set the velocity to 0.5c.
    1. Move the green point to the coordinates (6, 3).  What will the primed coordinates be?
      About (0, 5.2).  We are on the primed time axis, so the object is still at the origin if the object is seen as stationary.  The time is slightly less due to time dilation.
    2. Now move the point to (3, 6). What will the primed coordinates be?
      We get about (5.2, 0). So this will be at time 0 according to the primed system. So the point will be in the future, according to the unprimed system, but now according to the primed system.
  2. You see the Andromeda galaxy on the horizon. Now you start to walk towards it at 5.0 m/s. How much would that change the “now” at Andromeda? The Andromeda galaxy is 2537000 ly away.
    2537000 ly =2537000·9.46·1015=2.40·1022 m.
    \displaystyle t=\frac{{vx}}{{{{c}^{2}}}}=\frac{{5\cdot 2.4\cdot {{{10}}^{{22}}}}}{{{{c}^{2}}}}=1.433·106 s = 15.4 days.
Up a level : Space-Time diagrams / Minkowski diagramsLast modified: Jun 17, 2025 @ 20:26