From: goldenfieldquaternions@gmail.com   
      
   On Friday, September 29, 2017 at 8:21:02 AM UTC-5, John Heath wrote:   
   > A car is moving at .1 c. The tire on the road at 6:00 o'clock , bottom ,   
   > is moving at 0 c as it is touching the road but at 12:00 o'clock , top ,   
   > the tire is moving at .2 c twice as fast as the car. Does this mean the   
   > car is limited to speed .5 c as at this speed the top of the tire will   
   > be moving at c twice as fast as the car ?   
      
   Tom Roberts has the right idea. The Lorentz transformations of dx   
   and dt are   
      
   dt' = gamma(dt - vdx/c^2)   
      
   dx' = gamma(dx - vdt) --- gamma = 1/sqrt{1 - (v/c)^2}.   
      
   Now for dx/dt = u compute dx'/dt' to get the velocity addition   
   formula. You can see that you can't add up velocities so they are   
   greater than c.   
      
   --- SoupGate-Win32 v1.05   
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