Two twin sisters,Gwen and Jackie,are both 20 years old in the year 2020.Jackie takes off on a round-trip to Vega,25 light-years away.She travels at an average speed very close to the speed of light-say,0.9999c.According to Gwen back on Earth,about how long does it take Jackie to reach Vega?

Question

Quizplus · Accepted Answer

According to the theory of relativity, time dilation occurs at high speeds. As Jackie is traveling at a speed very close to the speed of light, time dilation will occur, and from Gwen's perspective on Earth, Jackie's journey will take approximately 25 years.

Two Twin Sisters,Gwen and Jackie,are Both 20 Years Old in the Year