Only a small part of the matter in the universe is visible, a large part of the matter is dark - more in this Talk
Only a small part of the universe is directly visible, the major part of matter is dark. Dark matter can only be detected indirectly via its gravitational interactions with luminous matter. Dark matter could consist of massive, still unknown particles, which originated in an early universe. UZH physicist Laura Baudis tries to detect these particles with the help of sensitive detectors which use liquid xenon.