Relativistic Aging

If I leave Earth when I am 54 and my daughter is 27, how long in Earth years will I have to be gone, if I am traveling at 98% of the speed of light, in order for my daughter and I to be the same age when I return to Earth?
- Brenda Thimke (age 54)
Milwaukee, WI USA

This problem is a bit unrealistic, since it takes years to accelerate up to 0.98c (relative to the frame in which you're initially at rest) at the maximum comfortable acceleration. Still, I'll answer as if that weren't an issue.  If from the daughter's point of view, the trip takes 33.75 years, you'll age only about 6.75 years, so she'll gain 27 years and end up the same age.

Mike W.

(published on 05/16/2013)