It takes a ray of light roughly 2.5 million years to travel from our galaxy to the Andromeda galaxy. In a new science fiction film, travelers aboard a spaceship reach the Andromeda galaxy by traveling at high speed. The travelers get about 15 years older during the journey. Which of the following statements is true?
a) This is impossible, although an observer on Earth would see the travelers aging slowly, in fact the observers age more quickly.
b) This is impossible, the travelers would need to live for at least 2.5 million years to reach the Andromeda galaxy.
c) This is a possible scenario. An observer in the Andromeda galaxy would measure the travel time to be over 2.5 million years, but time runs more slowly for the travelers.
d) This is a possible scenario, but only if the travelers go faster than the speed of light.
e) This is impossible, time dilation only applies to observers on Earth.