ESO Headquarters, Garching, Germany, 22–26 June 2020
The recently reported discord among Hubble constant determinations – based on the Universe as it is today versus as it was shortly after the Big Bang – is puzzling cosmologists and astrophysicists alike. With the discord's significance rising thanks to improved measurements, the community is getting increasingly excited about the potential for modifications to cosmology. However, questions remain whether systematic uncertainties and biases are sufficiently understood and under control.