# A very basic question -- traveling to a destination several thousand light years away

Where has my thinking gone wrong in the following?

A man begins traveling to a destination several thousand light years away, accelerating to a velocity of near-light speed. Time dilations and space contractions would result in the trip lasting only a few years from his perspective. From the perspective of people at the destination point, the trip would last longer than the time it would take for light to traverse several thousand light years. Hence, many generations of people at the destination would come and go over the course of the trip, which would only be few years for the traveler.

Where is the flaw here? Any help would be greatly appreciated.

ghwellsjr
Gold Member
Where has my thinking gone wrong in the following?

A man begins traveling to a destination several thousand light years away, accelerating to a velocity of near-light speed. Time dilations and space contractions would result in the trip lasting only a few years from his perspective. From the perspective of people at the destination point, the trip would last longer than the time it would take for light to traverse several thousand light years. Hence, many generations of people at the destination would come and go over the course of the trip, which would only be few years for the traveler.

Where is the flaw here? Any help would be greatly appreciated.
The people at the destination won't know that the man is coming their way until just a few years before he arrives. Many generations will pass from the time he leaves until they see him leave. At that time they will see him come towards him very quickly and they will see time on his spaceship progress very rapidly. After they see him leave and after he arrives, they can calculate when he left according to their rest frame and they will establish that he left several thousand years earlier.

Constantine
Ibix
No flaw - that's what I'd expect.

Constantine
Thank you, Ibix. Embarrassingly, a lack confidence prompted my post. I wanted to confirm that my account of what would happen under the specified conditions is consistent with relativity theory. I appreciate your response.

DaveC426913
Gold Member
Concur with Ibix. The scenario accurately describes a relativistic rocket trip.

Constantine
Ibix