*Watch Online/In person*: When Albert Einstein tweaked his newly invented equations of General Relativity in 1917, he had one goal in mind: to find a solution that described a closed, static, eternal universe. He therefore minted a new universal constant to make it work. After Hubble’s discovery of the expansion of the universe in 1929, Einstein reportedly declared it his “greatest blunder”. Was it? In 1998 observations of exploding stars brought Einstein’s "blunder" back into consideration.