If the train left the station at rapid speeds approaching the speed of light, the clock’s hands would still move, but the train would be moving so quickly that light could not catch up with it. The faster the train accelerated, the slower the hands would move, ultimately freezing once the train reached the speed of light. Time would effectively freeze. And if the train could go faster than the speed of light—an impossibility, but for argument’s sake, assumed—then time might roll backward. There it was. The new rule was so simple and natural. Newton’s laws about the physical universe only
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