On June 1, Adam Riess, a Nobel laureate and professor of physics and astronomy at Johns Hopkins University, delivered the Reines Lecture at UC Irvine, focusing on the accelerating expansion of the universe. Riess captivated the audience with a historical overview of this phenomenon, which was first realized a century ago. He explained his methodology of measuring the speed at which galaxies are receding using light from supernovae, noting that a redshift indicates that a galaxy is moving away from us. Riess posed the critical question of why the universe is currently accelerating, suggesting that the energy of empty space may not be zero, a concept reminiscent of Einstein's theories. This inquiry has led to the exploration of dark energy and dark matter, which are believed to influence the universe's expansion. Riess emphasized that understanding these forces could bridge the gap between general relativity and quantum theory, potentially revealing deeper insights into the nature of physics. The lecture was introduced by UC Irvine's Hal Stern and included demonstrations from student groups before the event.