NASA: Einstein's Cosmic Speed Limit

In its first year of operations, NASA's Fermi Gamma-ray Space Telescope has mapped the entire sky with unprecedented resolution and sensitivity in gamma-rays, the highest-energy form of light. On May 10, 2009 a pair of gamma-ray photons reached Fermi only 900 milliseconds apart after traveling for 7 billion years. Fermis measurement gives us rare experimental evidence that space-time is smooth as Einstein predicted, and has shut the door on several approaches to gravity where space-time is foamy enough to interfere strongly with light.

This version of the film is missing a shot. If you want to see the full version in all its glory, go to its listing in our film archive: http://svs.gsfc.nasa.gov/goto?10510

To find out more visit: http://www.nasa.gov/mission_pages/GLAST/news/first_year.html

Category:

Science & Technology

Tags:

• laboratory equipment
• news
• science
• gamma-rays
• gravity
• Einstein
• space
• time
• light