Rittenhouse Lecture: An imperfect view of the Universe

Alan Heavens (Imperial College London)
- | David Rittenhouse Laboratory, A4
Alan Heavens

Our most expensive telescopes make exquisite images of the distant Universe, but however good the telescope, the images are flawed.  The light has been on a long journey, navigating through the rich array of galaxies, galaxy clusters and filaments - structures that make up the cosmic web.  Einstein’s General Theory of Relativity tells us that this matter bends the light as it moves, typically distorting the images by a percent or so, and in extreme cases distorting the shapes out of all recognition.  But far from being a nuisance, those imperfections are a rich source of information about what the light has encountered along its path, providing us with valuable knowledge about the Dark Matter and the mysterious Dark Energy that make up the Universe, and the nature of gravity itself.