The Hubble constant describes how fast the universe is expanding, but our measurements won’t line up, which may mean our standard model of the universe is wrong
The expansion of the universe is accelerating, but we don’t know how quickly. With new observations, this issue has only got more severe, and now some astronomers are saying that it is officially a real problem – not one caused by uncertainties in the measurements.
There are two main ways we measure the Hubble constant, which describes the expansion of the universe. The first is to examine the cosmic microwave background – a relic of the …
Article amended on 24 January 2022
We clarified that 5 sigma refers to the difference between the two ways of measuring the Hubble constant.