A Ladder with No Top Rung: Cepheids vs. Supernovae
The cosmological community has been living in a state of quiet civil war for several years. Two camps measure the expansion rate of the Universe and get different answers. Planck, peering at the cosmic microwave background, says 67.4 km/s/Mpc. SH0ES, climbing the distance ladder from Cepheids to supernovae, insists on 73.2.