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 an idea called "simultaneity". Simultaneity is an important part of Albert Einstein's theory of relativity. Imagine two people who are moving very, very fast relative to each other. Now imagine they see two flashes of lightning. The two people might disagree about when the lightning flashes happened. One person might say they happened at the same time. The other person might say that they happened at different times. According to Einstein, both people could be right!

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

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information.