Public Lecture
Galaxy Clusters: Nature’s Giant Magnifying Glasses
Galaxy Clusters are vast concentrations of many hundreds of galaxies bound together by gravity. Einstein's theory of general relativity predicts that if light traveling towards us passes close to such a massive object, its path will be bent, and it will take longer for the light to reach us. Indeed, galaxy clusters act as giant and spectacular magnifying glasses that not only magnify background galaxies but also create multiple images of them. In this lecture, Professor Kelly talked about what happens when a massive star explodes as a luminous supernova in one of those distant, multiply imaged galaxies. He also described a recent discovery that individual stars in galaxies more than halfway across the universe can become so highly magnified by galaxy clusters that we can see them one-by-one from Earth.
