Twin sisters, Gwen and Jackie, were both 20 years old in the year 2000. Jackie took off on a round trip to Vega, 25 light-years away. She traveled at an average speed very close to the speed of light—say, 0.9999c
Which of the following best describes the situation according to Jackie? A. She stays still, while Earth rushes away from her at 0.9999c and Vega rushes toward her at 0.9999c. Since Vega is 25 light-years away, she says it takes Vega about 25 years to reach her. B. She stays still, while Earth rushes away from her at 0.9999c and Vega rushes toward her at 0.9999c. She sees the distance from Earth to Vega shortened considerably from 25 light-years, and therefore it takes far less than 25 years for Vega to reach her. C. She says that the 25-light-year trip takes only a few months and therefore concludes that she is traveling faster than the speed of light. D. She's taking a trip that takes 25 years from Earth to Vega.