NASA recently discovered the first habitable exoplanet with the Kepler space telescope.
Recently I was on this site: http://www.cthreepo.com/lab/math1/
With the Long Relativistic Journeys calculator on that page, I calculated the amount of time it would take according to the traveler to travel 500 light years with half of the journey at a constant acceleration of
2g and the second half with equal deceleration.
The result was under 7 years.
Does this require going near the speed of light? Or does it only require acceleration? If, say, we were to accelerate the space ship up to a certain speed and then decelerate periodically, could the same result be achieved? Or would no significant time dilation occur?