Crisis in Cosmology: Resolving the “Hubble Tension” with the James Webb Space Telescope*

Recent observations of the local expansion rate of the universe (i.e., the Hubble Constant) disagree strongly with the scale of the universe predicted by the accepted model of the universe, and we don’t know why. The solution to this “Hubble tension” (which, at more than 5-sigma, could be better characterized as a crisis) may require exotic new physics or could be the result of multiple confounding systematic errors in the distance measurements. The key to determining where the problem lies is removing as many sources of systematic uncertainty as possible from the distance measurements. New data from the James Webb Space Telescope obtained this year are giving us a fresh new look at elliptical galaxies in the nearby universe (out to 65 million light years) where we can now see individual stars with JWST. That allows us to connect reliable stellar distance measurements techniques calibrated geometrically with the techniques that extend out to hundreds of millions of light years, where hopefully we will find the answer to this mystery…or perhaps make it worse!