MillerComm Lecture Series

Gravitational Lensing: Looking for Invisible Matter in the Universe

Tuesday, February 11th, 1997
Charles Alcock

Room 141, Loomis Laboratory of Physics

1110 West Green Street, Urbana

Event Description

More than 90 percent of the matter in the universe is invisible, hence the term dark matter. But the question of what exactly dark matter is remains outstanding in the field of astronomy.

How do you search for objects that cannot be seen?

We look for how the invisible object's gravity affects light from distant stars. Dark objects can act as lenses magnifying the starlight, and in this way reveal their presence. Charles Alcock will describe how this magnification comes about and how we may exploit it to search for otherwise invisible objects.

Cosponsored by: Office of the Chancellor, Office of the Provost and Vice Chancellor for Academic Affairs, Office of the Vice Chancellor for Research and the Graduate College, Office of the Vice Chancellor for Student Affairs, The Council of Deans, The Center for Advanced Study, George A. Miller Endowment, George A. Miller Committee, Peggy Harris Memorial Fund, Department of Astronautical and Aeronautical Engineering, Department of Astronomy, Department of Atmospheric Sciences, Department of Electrical and Computer Engineering, Department of Geology, National Center for Supercomputing Applications (NCSA), University Laboratory High School, Astronautical Society at the University of Illinois, Staerkel Planetarium at Parkland College

Charles Alcock

Head, Institute of Geophysical and Planetary Physics, Lawrence Livermore National Laboratory