The Broken Cosmic Distance Ladder

Measuring distances to astronomical objects outside our Galaxy is a surprisingly hard challenge: it wasn't until 1923 that Edwin Hubble obtained proof that Andromeda is indeed a galaxy in its own right. Today, astronomers extend distance measurements in the cosmos to the edge of the visible Universe, building up a 'cosmic distance ladder' made of several rungs. This talk will explore a major conundrum of contemporary astronomy: as observations have become more precise, the distance ladder a...