A Canterbury University astrophysicist has become the first New Zealander to be awarded the Einstein Medal.

Emeritus Professor Roy Kerr will be awarded the medal by the Albert Einstein Society in Switzerland for his 1963 discovery of a solution to Einstein's gravitational field equations relating to black holes.

Known as the Kerr Solution, it provides an exact description of the space outside a rotating black hole.

It has come to be regarded as the most important exact solution to any equation in physics, and has been pivotal in understanding the more than 100 million trillion black holes in the observable universe.


The Kerr Solution has already been recognised by Britain's Royal Society, which awarded Prof Kerr the Hughes Medal in 1984, and the Royal Society of New Zealand, which awarded him the Hector Medal in 1982 and the Rutherford Medal in 1993.

Canterbury University physics professor David Wiltshire said rotating black holes, as described by Prof Kerr, were key to understanding the universe.

"Our own galaxy contains a black hole of over four million solar masses, as deduced from the motion of nearby stars.

"In other galaxies measurements of X-rays emitted by matter falling into central black holes show that they are often rotating at close to the maximum rate allowed by the Kerr solution.

"Increasingly, we are discovering that the interaction between central black holes and nearby matter is essential to understanding the origin and evolution of galaxies. Roy's solution is key to all of this."

The annual Einstein Medal is awarded by the Einstein Society in Bern, Switzerland, where Einstein completed his revolutionary work in the first decade of the 20th century.

It was first awarded to world-famous physicist Stephen Hawking in 1979 and many distinguished scientists have received the medal since then, including six Nobel Prize laureates.

The medal will be awarded to Prof Kerr at a ceremony at the University of Bern next May.