Answer to Question #190097 in Quantum Mechanics for lizzy

Question

Suppose rocket traveler Mary has a clock made on Earth. Every year on her birthday she sends a light signal to brother John on Earth. At what rate does John receive the signals during Mary’s outward journey

Answer 1

The rate is $\frac{1}{\sqrt{1-\frac{v^2}{c^2}}},$ where $v$ is the Mary's speed.