A person in a spaceship flies past the Earth at half the speed of light. A person at rest on Earth says the clock in the spaceship runs slower than the clock at rest on Earth. How much slower? 4. In which frame of reference is the length of an object longest? 5. An experiment testing the prediction of time dilation was done in the early 1960's with an unstable subatomic particle called the muon, a negatively charged particle with a mass greater than that of the electron. How were the muons used in this experiment created? 6. The muon is an unstable particle with a mean life of 2.2 x 10-6 seconds. What is meant by mean life? 7 Experimenters counted the number of muons moving at 0.995c past the top of a mountain 2,000 meters above sea level. If they knew nothing of relativity theory, based solely on the mean life of muons, how should the number of muons that reached the base of the mountain compare to the number passing the top of the mountain?
