# Relativity - Simultaneity

##### This movie explains the concept of "simultaneity", which is part of Einstein's theory of relativity.Image courtesy of Trent Schindler, National Science Foundation.

This movie explains the concept of "simultaneity". Simultaneity is an important part of Albert Einstein's theory of relativity. If two observers are moving very fast relative to each other, they may disagree as to whether two events happen at the same time. According to Einstein, both observers could be right, even though they disagree!

(Note: If you cannot see the movie you may need to download the latest QuickTime player.)

Last modified May 29, 2008 by Randy Russell.

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