What you see is not what you get when it comes to mass in the universe. We've known for more than 50 years, for example, that spiral galaxies rotate much faster than one would expect based on the mass in their twinkling stars and the intervening gases. Furthermore, large‐scale observations of the universe imply that the cosmic mass density is so large that radiant mass accounts for no more than a few percent of the total. So, what is the missing mass?
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© 2000 American Institute of Physics.
2000
American Institute of Physics
