NOVA Online > Einstein Revealed > Time Traveler

What happens to time when you travel very quickly? Does it speed up, slow down, or stay the same? Tom and Jane have volunteered to help you find out. Send Jane on a round-trip journey to a star and then compare her age with Tom's on Earth.



  1. Click on Jane or Tom to set their starting ages.
  2. Click on the spaceship to set its speed.
  3. Click one of the twinkling stars to choose a destination and start the journey.
  4. When the spaceship lands, compare Tom's age with Jane's age.
What happens if....
  • you change the speed of the spaceship?
  • you send the spaceship at the same speed to two stars--one that is close by, and one that is far away?
  • Can you find ways to set the ages, speed, and destination so that Tom and Jane are almost the same age when Jane returns from her journey?
What's going on here?

Einstein Home | Timeline | Genius | Relativity
Light Stuff | Time Traveler | Teacher's Guide | Links

NOVA Home | WGBH Home | PBS Home
Search | Feedback | Shop
© 1996 WGBH
Einstein Revealed Home Page Links and books Time Traveler Light Stuff Relativity Genius Timeline NOVA NOVA Home To print Shop NOVA Site at a Glance Search NOVA Previous Sites Teachers Schedule Feedback Einstein Revealed Home Page