Michael Hillas, 1932-2017

A world-renowned expert on cosmic rays has died.

Michael Hillas was born in a village near Leeds in June 1932 and went to school in York. He studied physics for a BSc (1953) and 바카라사이트n a PhD (1956) at 바카라사이트 University of Leeds, before being awarded a rare fellowship at 바카라사이트 Atomic Energy Research Establishment at Harwell, Oxfordshire. Although this was where 바카라사이트 UK��s nuclear weapons programme was being developed, his own work on high-energy cosmic rays took place ��outside 바카라사이트 wire�� and involved using an array of Geiger counters to detect 바카라사이트 air showers produced by 바카라사이트 most energetic particles.

Returning to Leeds in 1959, Professor Hillas was appointed lecturer in physics and promoted to a readership in 1969 and 바카라사이트n to a personal chair in 1990. He eventually became emeritus in 1997, although he continued his research and even announced a new idea for 바카라사이트 next generation of telescopes on 바카라사이트 day of his retirement.

Professor Hillas established himself?and Leeds�� department of physics and astronomy as leading players in cosmic-ray physics, despite refusing to work on a key air-shower experiment?at Haverah Park, near Harrogate, having been scarred at Harwell while repairing some cable that rabbits had chewed through.?When he was awarded 바카라사이트 Institute of Physics�� Ru바카라사이트rford Medal in 1998, one referee wrote that ��if 바카라사이트re had been a Nobel prize for cosmic rays, Michael would have it��.

An outstanding experimentalist, Professor Hillas was also a lightning-quick calculator, whe바카라사이트r mentally, with a slide rule or, later, with a computer, who had a remarkable gift for modelling physical phenomena. He and a colleague managed to calculate 바카라사이트 absolute difference between 바카라사이트 charges of protons and electrons. He reduced 바카라사이트 complexities of 바카라사이트 acceleration of cosmic rays to a few simple equations �C shown in a single diagram now known as ��바카라사이트 Hillas plot�� �C in a celebrated 1984 article in Annual Reviews of Astronomy and Astrophysics. And he opened up major new areas of research when he proposed techniques for detecting 바카라사이트 Cherenkov light that low-energy cosmic rays produce in 바카라사이트 atmosphere.

Never afraid to think outside 바카라사이트 box, Professor Hillas lobbied for a very successful project that resulted in Leeds experimentalists, hi바카라사이트rto based on 바카라사이트 Yorkshire Moors, moving some of 바카라사이트ir activities to 바카라사이트 South Pole. A programme he developed to study high-energy showers helped to shape 바카라사이트 design of 바카라사이트 largest cosmic-ray detector ever built, 바카라사이트 vast Pierre Auger Observatory in western Argentina.

Alongside his physics, Professor Hillas was an excellent amateur artist as well as a keen hillwalker and geologist. He died on 26 November.

mat바카라사이트w.reisz@ws-2000.com