March 5, 2021 SHARE The ordinary atoms that make up the known universe — from our bodies and the air we breathe to the planets and stars — constitute only 5% of all matter and energy in the cosmos. The remaining 95% is made up of a recipe of 25% dark matter and 70% dark energy, both nonluminous components whose nature remains a mystery. Theoretical physicist Katherine Freese, the Jeff and Gail Kodosky Endowed Chair in Physics at the University of Texas at Austin, will explore dark matter in the 2021 McDonnell Distinguished Lecture at Washington University in St. Louis. Freese (Photo: Marica Rosengard) Freese’s online lecture, “The Dark Side of the Universe,” will begin at 7 p.m. Thursday, March 25. The event is free and open to the public; attendees should register in advance to obtain the Zoom link.