Soon afterwards, astronomer Edwin Hubble discovered the universe was actually expanding, consistent with Einstein's original general relativity theory.
Einstein then removed his cosmological constant describing his failure to predict an expanding universe in theory before it was proven by observation, as his biggest blunder.
In 1998, astronomers studying distant exploding stars called a Type 1A supernovae discovered that not only was the universe expanding, but that the rate of expansion was accelerating due to some type of unknown force or dark energy. Einstein's cosmological constant was back.
"The acceleration was a shocking discovery, because it showed we have a lot more to learn about physics," Blake says.
To verify the supernovae findings, Blake and colleagues spent four years using a powerful spectrograph at the Australian Astronomical Observatory to collect data on more than 240,000 galaxies going back over seven billion years to when the cosmos was less than half its current age.
"It showed the growth of structure in the universe, the development of galaxy clusters and super clusters has slowed down," Blake says. "This implies the most distant parts of the universe which are further back in space-time, have ordinary matter and hence gravity is dominating. But today this antigravity dark energy has taken hold."