How do we know the Universe is expanding? (2017x8)
Yayınlanma tarihi: Nis 26, 2017
Cosmological redshift was our first clue the universe was expanding. A century ago, Edwin Hubble discovered galaxies outside our own supercluster are all moving away from us. But how do we get from redshift to an expanding universe? That's the tricky part and most people get it wrong.
