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Distance travelled by light

  1. Aug 18, 2012 #1

    hubble_bubble

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    Is it true that the distance traveled by light during a particular time period is expressed by d=tc^2 where d is the distance travelled in metres and t is the elapsed time in seconds?
     
    hubble_bubble, Aug 18, 2012
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  3. Aug 18, 2012 #2

    Muphrid

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    Distance = time x speed

    What you wrote is the equivalent of distance = time x speed^2. That doesn't make sense.
     
    Muphrid, Aug 18, 2012
  4. Aug 18, 2012 #3

    hubble_bubble

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    Sorry the time is in Planck time not seconds. My mistake.
     
    hubble_bubble, Aug 18, 2012
  5. Aug 18, 2012 #4

    Muphrid

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    The Planck time is still a time. The equation makes no sense just on dimensional grounds. A time multiplied by a speed squared doesn't give a distance, regardless of units.
     
    Muphrid, Aug 18, 2012
  6. Aug 18, 2012 #5

    hubble_bubble

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    Well it does work. The units all balance.
     
    hubble_bubble, Aug 18, 2012
  7. Aug 18, 2012 #6

    Muphrid

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    By all means, if the units do balance, then I am here to learn. Show me.
     
    Muphrid, Aug 18, 2012
  8. Aug 18, 2012 #7

    hubble_bubble

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    Sorry I messed up.

    It should be dc^3 = tc^2.

    That's where I needed the cubed value.
     
    hubble_bubble, Aug 18, 2012
  9. Aug 18, 2012 #8

    Muphrid

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    speed = distance / time

    Distance x (distance^3)/(time^3) is not equal to (time)x(distance^2)/(time^2), right?
     
    Muphrid, Aug 18, 2012
  10. Aug 18, 2012 #9

    hubble_bubble

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    Sorry scrub that I have mixed up two sets of equations. It is 12.53 AM here.
     
    hubble_bubble, Aug 18, 2012
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