Meg Urry : A mile down in an old gold mine , physicists search for `` dark matter '' particles . Urry : Putting the experiment deep underground screens out particles other than dark matter . We know dark matter only by gravitational effect , but it is most of the universe 's mass . According to his theory , gravity bends light much as the lenses in my glasses bend incoming light rays . The detectors are located at a depth where they can see all kinds of things that we can't yet detect with our instruments on Earth.
Meg Urry : A mile down in an old gold mine , physicists search for `` dark matter '' particles . Urry : Putting the experiment deep underground screens out particles other than dark matter . We know dark matter only by gravitational effect , but it is most of the universe 's mass . The detectors are located at a depth where they can see all kinds of things that we can't yet detect with our instruments on Earth.