Activphysics Relativity

Purpose

       The purpose of this activity is to understand the theory of special relativity such as time dilation and length contraction using a simulation.

Experiment

    Time dilation

    1.      The distance traveled by the light pulse on the moving light clock is longer than the distance traveled by the light pulse on the stationary light clock.

    2.      The time interval for the light pulse to travel to the top mirror and back is longer on the moving light clock compared to the stationary light clock. 

    3.       In the moving frame of reference, the time interval for the light to travel to the top mirror and back is the same as the stationary clock.

   4.       As the velocity of the light clock decreases, the time interval difference decreases, because the value of gamma decreases also decreases. According to t' = t*γ ,  the time interval difference decreases.

   5.    t' =  t*γ = 1.2 * 6.67 µs = 8.00µs

6.    γ = t'/t = 7.45 / 6.67 = 1.12

      Length contraction

      1. The round trip depends on the velocity of the light clock. 

    2.     The round-trip time interval for the light pulse as measured on the earth  is longer than the the time interval measured on the light clock.

    3.  Because d = v*t. When the time intervals decreases, the speed of light has to stay constant, therefore for this equation to be consistent, the distance would decrease.

     4. L' = L/γ = 1000 / 1.3 m =769m

Conclusion
       The online tutorial helps understand the idea of special relativity.