For eight decades, astronomers have been puzzled by an apparent shortage of visible matter in and between galaxies. A great deal of unseen material, dubbed “dark matter” and of unknown composition, can be inferred by the motions of stars and galaxies. This is similar to the way the presence of the planet Jupiter could be inferred — even if it were invisible — by observing its moons.

Russell Neilson, PhD, will describe the ways physicists are searching for dark matter today: from telescopes in orbit, to the world’s most powerful particle accelerator, to ultra-clean detectors deployed in mines more than a mile under the surface of the earth.

The College of Arts and Sciences' Dean's Seminars are free and open to the Drexel community. Light refreshments will be served.