Hello all, I am new to the Forum and have no formal Physics training. I have an interest in the subject mainly due to other pursuits. I am reading Joe Haldeman's The Forever War. I would definitely recommend this book to anyone with an interest in Time Dilation or Humans vs Aliens at war. Here's a snippet from Wikipedia The last part gets to my questions. If I go from earth to planet xyz at x speed that gets me there in a reasonable time, say 6 months, will I probably experience a fair amount of time dilation, lets say 20 years? When I arrive i am told to wait for more of my people to arrive on another ship that left 3 months after I did. I can't really wrap my head around this part, which is funny because I am creating this scenario. Do they arrive in 3 months or in 20 years?