The Dark Matter problem is now approaching 100 years old. A wide variety of ideas for dark matter have emerged, but then fallen by the wayside, in a complicated picture that reflects the difficulty of using only electromagnetic observations to account for the mass budget of the entire Universe! Amidst this hubbub of scientific activity, a small but determined group of us are pursuing an outlandish dark matter candidate, known as the axion. With a mass around a quadrillionth that of the electron and a physical extent about the size of Mexborough, it's a wave rather than a particle, but it does have mass, and could therefore be the dark matter. And, we're building an experiment at Sheffield to search for them, housed in a fridge at a temperature of a hundredth of a degree centigrade above absolute zero, which is a good reason for a talk at your Society!

About the speaker: Dr Ed Daw

Ed Daw is a professor in Physics at the University of Sheffield.

He's worked on many aspects of 'the Dark universe', including searches for two kinds of dark matter, axions and WIMPs, and the quest for direct detection of gravitational waves with the LIGO instruments, an effort which he joined in 1997.

He leads the University of Sheffield gravitational wave research group, which was a member of the team that announced the first and second direct detection's of gravitational waves from black hole binaries first discoveries were in 2015 (for black holes) and 2017 (for neutron stars)

Professor Ed Daw specializes in ultra-sensitive experiments searching for the signatures of hypothesized and potentially critical signals in the field of particle astrophysics. In particular, searches for WIMPs (weakly interacting massive particles), gravitational waves, and axions.