Colossal Quasar Clump Too Huge To Exist, In Theory

Astronomers have discovered a clump of 73 quasars that spans four billion light years at its widest point--that's like 40,000 Milky Way galaxies lined end-to-end. The only problem? Theory says the quasar cluster is too big to exist. Astronomer Gerard Williger and reporter Ron Cowen discuss this cosmological oddity, and other news about the cosmos.