You take a trip to Pluto and back (round trip 11.5 billion km), traveling at a constant speed (except for the turnaround at Pluto) of 44500 km/hr.
a) How long does the trip take, in hours, from the point of view of a friend on earth?
b) About how many years is this?
c) When you return, what will be the difference between the time on your atomic wristwatch and the time on your friend's? (: Assume the distance and speed are highly precise, and carry a lot of significant digits in your calculation!)