Summary

Einstein "fiddled" his theory to stop the Universe from expanding by giving empty space energy.

Later Hubble showed that the Universe is expanding.

In the modern era data from distant exploding stars and measurements of the "echo of the big bang" confirm the expansion...
But they also indicate that a vacuum really does contain energy!

Einstein was right after all - but for the wrong reasons!

http://find.uchicago.edu/~pryke/compton