Perhaps the most famous modern example of confirmation bias is in measurements of the Hubble constant [466], where over many years de Vaucouleurs persistently found H ≈ 100 km s−1 Mpc −1 0 while Sandage persistently found H ≈ 50 km s− 1 Mpc −1 0. Then, as now, there was a conflation of data with theory: the lower value of H 0 was more widely accepted because it was required for cosmology to be consistent with the ages of the oldest stars.