Editing Intergalactic travel (section)

===Time dilation===
While it takes light approximately 2.54 million years to traverse the gulf of space between Earth and, for instance, the [[Andromeda Galaxy]], it would take a much shorter amount of time from the point of view of a traveler at close to the speed of light due to the effects of [[time dilation]]; the time experienced by the traveler depending both on velocity (anything less than the speed of light) and distance traveled ([[length contraction]]). Intergalactic travel for humans is therefore possible, in theory, from the point of view of the traveler.<ref>{{cite news| author=Gilster, Paul| date=25 June 2014| url=http://www.centauri-dreams.org/?p=30929| title=Sagan's Andromeda Crossing| website= centauri-dreams.org | access-date=16 September 2014}}</ref> For example, a rocket that accelerated at [[Standard gravity|standard acceleration due to gravity]] toward the Andromeda Galaxy and started to decelerate halfway through the trip would arrive in about 28 years, from the frame of reference of the observer.<ref>{{cite web|url=http://math.ucr.edu/home/baez/physics/Relativity/SR/Rocket/rocket.html|title=The Relativistic Rocket|website=math.ucr.edu|access-date=4 April 2018}}</ref>