Up to the Present, and Beyond

Abstract

In 2009 the European Space Agency finally launched the Planck satellite, an ambitious observatory to study the cosmic microwave background in even more detail than had been done by WMAP, including some polarisation measurements. Meanwhile, over the last decade, ground based telescopes at the South Pole and high in the dry Atacama desert of northern Chile have been looking for signs of the ‘B-mode polarisation’ in the CMB, which it is argued is a direct test of inflation theory. We have moved into an era of ‘precision cosmology’, where fine details of our theories are being tested, but we are possibly approaching the limit of what we can learn about the Universe from studying the CMB. For future cosmological studies we are developing alternative methods including gravitational wave detectors which will probe the beginnings of time in a different way. Neutrino astronomy is coming of age, and we are increasingly diverting our efforts into understanding the nature of dark matter and dark energy. Some theorists postulate that our Universe is only one of many, that we live in a ‘multiverse’. Will we ever be able to know this, and if we can is there a way to learn anything about the properties of other members of the multiverse? Will we ever be able to say anything about the very moment of the beginning of the Universe, or will this always lie beyond our grasp?