There were two teams that didn't much like each other.They were trying to measure the rate at which the universe has been expanding at different times in the past and compare it with the rate at which it's expanding now.The way to check comes from Hubble.It finds supernova explosions in remote galaxies and uses the light from the explosion as a yardstick to measure the distance from earth to the galaxy.But Hubble's findings do not fit the accepted model for the expansion of the universe.The galaxies with supernovae are not just moving away.They are moving at an accelerated rate.Hubble's results convinces astronomers that they must think of the universe in an entirely new way.You toss a ball up and it comes back down or slows down.What you don't expect is the ball to speed up and speed up and speed up more and more and more.It doesn't happen.But it does happen.According to Hubble's evidence, the universe is expanding more and more quickly.The only explanation is as simple as it is unlikely.Something is causing the expansion of the universe to accelerate.An unseen force called, "Dark Energy".
