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Q & A: special relativity at more than c

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Most recent answer: 10/22/2007
Q:
I have always believe Einsteinís theory that time would stop and then reverse if something was able to equal the speed of light or exceed it. But I was contemplating this and I came up with this example that seems to cancel the reversal of time. If you were standing one light second away from a clock and moved at the speed of light toward the clock, the clock would move one second. If you went 2x the speed of light the clock would move 1/2 second, and so on, but time would never stop, but just slow to a near infinite level. Is this an acurate assessment.
- daniel todd (age 36)
clay city, ky usa
A:
Nope. The laws for translating from the time-space coordinates of one observer and those of another are not the common sense ones you've used here. The real laws, called the Lorentz transforms, are available in any beginning Special Relativity text. It turns out that these translation rules do not exist for any two frames moving at or greater than the speed of light with respect to each other. We have no reason to complete any sentence starting "if you went 2x the speed of light..." because we believe that nature forbids any such condition.

Learning these Special Relativistic rules can be a mind-opening experience, because they seem impossibly strange at first. Gradually it seeps in that they are just a set of rules, like the Galilean transforms of common sense, but just a little different mathematically. Our crudely evolved minds have just locked on to the simplest rules that work well enough for daily life.

Mike W.

(published on 10/22/2007)

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