*A. "How can velocities always be smaller than c as required by special relativity - if there are two rockets moving away from each other with velocities of .5c each relative to the earth, won't they have a relative velocity of c to each other?"*

In relativity, there is a formula for addition of relative velocities that limits the relative speeds to less than c:

- v

_{relative}=(v1+v2)/(1+v1*v2/c

^{2})

As can also be seen, in the classical limit of very small velocities, v1*v2/c^{2} is approximately zero, so the relative velocity goes to the classical, intuitive (Galilean) value.

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