To my great-grandchildren
Would you like to travel to Andromeda? Then you can look around in that other galaxy and investigate what it is like there.
Your great-grandparents had spaceships that traveled so slowly that they could not cover the enormous distance in one lifetime. You have much faster ships, but are they fast enough?
We’ll give you a tip: Thanks to the 1916 Theory of Relativity, you don’t have to go as fast as you think. Because at very high speeds your travel distance to Andromeda becomes much shorter!
