The mystery of the Hubble tension has deepened with the startling finding that the Coma Cluster of galaxies is 38 million light-years closer than it should be.
In recent years, trouble has been brewing in attempts to measure the universe's expansion, which is governed by the Hubble–Lemaître law. This tells us that the velocity at which a galaxy is being carried away from us by the expansion of space is equal to its distance multiplied by the expansion rate, quantified as the Hubble constant. The farther away a galaxy is from us, the faster it is moving away from us.
