SLAC Public Lecture Series
The Tug of War that Shapes the Universe
Below is a recording of this lecture which is available on SLAC's YouTube channel.
As the universe expanded from the Big Bang, regions where the density of matter was higher than average grew into galaxies and clusters of galaxies. The overall form of the universe and the evolution of galaxies within it have been shaped by a delicate balance of two competing forces – the inward gravitational pull of matter, dominated by dark matter, and the outward stretching of space, controlled by a mysterious force called dark energy. In this lecture, I will describe how we can gain an understanding of these hidden elements by measuring the properties of galaxies and the web of structure they form. The Dark Energy Survey (DES) has done this for one-eighth of the sky, observing and measuring more than 100 million galaxies. I will illustrate how we use DES images of this huge number of galaxies to trace the growth of structure and measure the expansion of the universe under the influence of its dark components.