If you went on a trip that seemed twenty years long to you while on board a spacecraft going just slightly less than the speed of light, when you returned to Earth, you might meet your __________ assuming they did no space traveling of their own.

Question

Quizplus · Accepted Answer

According to the theory of relativity, time dilation occurs for objects moving at relativistic speeds. This means that time appears to pass slower for an object in motion relative to an observer at rest. Therefore, if you traveled on a spacecraft at nearly the speed of light for twenty years, time would pass slower for you, while time would continue to pass at a normal rate for people on Earth. As a result, when you returned to Earth after twenty years, you would have aged much less than people on Earth who did not travel with you. Assuming you were around 30 years old when you left, you would be about 50 years old when you got back, but everyone you left behind on Earth would be 20 years older. So, you would meet your great-grandchildren.

If You Went on a Trip That Seemed Twenty Years