Question

Explain how scientists know that the universe is expanding

Answer 1

For every million parsecs of distance from the observer, the rate of expansion increases by about 67 kilometers per second. The Hubble parameter is not thought to be constant through time. There are dynamical forces acting on the particles in the universe which affect the expansion rate.

Answer 2

For every million parsecs of distance from the observer, the rate of expansion increases by about 67 kilometers per second. The Hubble parameter is not thought to be constant through time. There are dynamical forces acting on the particles in the universe which affect the expansion rate.