PDA

View Full Version : general relativity and mass in universe



stitt29
2008-Oct-06, 09:26 PM
How does general relativty predict or calculate the mass of the universe? And (if so) how do scientists know that 90% of mass is dark matter?

Ken G
2008-Oct-08, 03:30 AM
General relativity is a theory that takes as input the mass density of the universe (and any cosmological constant), and outputs the observed redshift as a function of distance. By observing the latter, we infer the correct input.