Abstract

One hundred years ago, Hubble determined that the Milky Way does not constitute the entirety of our Universe. Two years earlier, Friedmann had derived his eponymous equations describing the evolution of homogeneous and isotropic models of the universe. These discoveries elevated cosmology to an observational and quantitative science. In the intervening century, our understanding of the Universe and our cosmic history has been transformed. Careful comparisons between measurements of fluctuations in the cosmic microwave background (CMB) and precise calculations of their expected statistical properties have been pivotal to these developments. In this talk, I will discuss how we can use the CMB to constrain the physics of the early universe and what we have learnt with recent data from space- and ground-based measurements.