1.1. The Hector Medal.

James Hector (16 March 1834 - 6 November 1907) was a Scottish geologist, naturalist and surgeon who accompanied the Palliser Expedition to Canada, and was appointed geologist to the Provincial Government of Otago, New Zealand. He arrived in Dunedin in April 1862 and for the next two years he examined the Province and its developing goldfields (up until the beginning of 1864, when he returned to Dunedin). He became Director of the Colonial Museum and Geological Survey, and Manager of the New Zealand Institute, and was recognised as the adviser to the Government on scientific matters of all kinds. On his death regional committees were at once set up with the object of collecting funds to perpetuate by some fitting memorial the great services rendered by him to science and to the Colony. The Hector Medal is in bronze and is accompanied by a prize. It was first awarded in 1912.

1.2. The 1982 Hector Medal.

The 1982 Hector Medal was awarded to Roy Patrick Kerr:-

... for his work on the solution to the Einstein field equations of general relativity which opened up research to black holes in space.

2.1. The Hughes Medal.

The Hughes Medal is awarded for outstanding contributions in the field of energy. The award was named after the scientist David E Hughes FRS and was first awarded in 1902. Hughes was a Welsh-American scientist and musician who invented the first working radio communication system and the first microphone. The medal is of silver gilt, is awarded annually and is accompanied by a gift.

2.2. The 1984 Hughes Medal.

The Hughes Medal was presented to Roy Kerr by the Royal Society of London on 30 November 1984. The presentation was made by the President of the Royal Society, Sir Andrew Huxley. The citation reads:-

The Hughes Medal is awarded to Professor R P Kerr in recognition of his distinguished work on relativity, especially for his discovery of the so-called Kerr black hole. In the early 1960s Professor Kerr discovered a specific solution to Einstein's field equations which describes a structure now termed a Kerr black hole. Not only was the solution especially complex, lacking symmetry of previous solutions, but it became apparent that any stationary black hole can be described by Kerr's solution. His work is therefore of particular importance to general relativistic astrophysics, and all subsequent detailed work on black holes has depended fundamentally on it. Professor Kerr has made other significant contributions to general relativity theory, but the discovery of the Kerr black hole was so remarkable as to compare with the discovery in physics of a new elementary particle.

3.1. The Rutherford Medal.

The Rutherford Medal is named for Sir Ernest Rutherford (1871-1937), the New Zealand physicist who is known as "the father of nuclear physics." In 1908, he was awarded the Nobel Prize in Chemistry "for his investigations into the disintegration of the elements, and the chemistry of radioactive substances." It is awarded by the Royal Society of New Zealand. The Rutherford Medal recognises preeminent research, scholarship or innovation by a person, or team, in any field of engineering, humanities, mathematics, sciences, social science, or technology. The Rutherford Medal was previously known as the New Zealand Science and Technology Gold Medal and was renamed in 2000. The first award was made in 1991 to Vaughan Jones:-

... for his international reputation in topology.

3.2. The 1993 Rutherford Medal.

The 1993 Rutherford Medal was awarded to Roy Kerr, mathematician:-

... for his outstanding discoveries in the extra-terrestrial world of black holes and for his contribution to relativity through the Kerr metric

4.1. The 2006 Marcel Grossmann Award.

Roy Kerr was awarded a 2006 Marcel Grossmann Award at the 11th Marcel Grossman Meeting in St Petersburg:-

... for his fundamental contribution to Einstein's theory of general relativity: "The gravitational field of a spinning mass as an example of algebraically special metrics."

Each recipient is presented with a silver casting of the TEST sculpture by the artist A Pierelli. The original casting was presented to His Holiness Pope John Paul II on the first occasion of the Marcel Grossmann Awards.

5.1. The Albert Einstein Medal.

The Albert Einstein Medal is an award presented by the Albert Einstein Society in Bern. First given in 1979, the award is presented to people for "scientific findings, works, or publications related to Albert Einstein" each year. The first award was made to Stephen Hawking in 1979.

5.2. Einstein Medal for NZ professor.

University of Canterbury professor Roy Kerr has become the first New Zealander to be awarded the Einstein Medal. The award is presented annually to individuals for outstanding service, discoveries or publications related to Albert Einstein. Physicist Stephen Hawking was the first recipient in 1979. Since then, many distinguished scientists, and six Nobel Prize winners, have been awarded the medal. Kerr will be honoured by the Albert Einstein Society in Switzerland for his 1963 discovery of a solution to Einstein's gravitational field equations. The Kerr solution, as it has become known, provided an exact description of the space outside a black hole, helping to understand how galaxies are formed, and becoming crucially important to the world of science. Kerr, who was delighted by the honour, said his discovery was "certainly the most important thing that I've done and it's probably the most useful thing that's come out of general relativity in 50 years". The award adds to a long list of accolades, including being made a Companion of the New Zealand Order of Merit in 2011 for services to astrophysics. Kerr was a professor of mathematics at the University of Canterbury for 22 years before retiring in 1993. He is currently emeritus professor at the department of physics and astronomy. He has been nominated for a Nobel Prize several times but has never won. Kerr will travel to Switzerland to be awarded the medal at a ceremony at the University of Bern in May next year.

5.3. University of Canterbury's Roy Kerr heads to Europe to receive the Einstein Medal.

University of Canterbury Emeritus Professor Roy Kerr heads to Europe next week to become the first New Zealander to receive the Einstein Medal from the Albert Einstein Society in Switzerland. The Einstein Medal will be awarded to Professor Kerr at a ceremony at the University of Bern on 28 May 2013.

Professor Kerr discovered a specific solution to Einstein's field equations which describes a structure now termed a Kerr black hole. He has made other significant contributions to general relativity theory, but the discovery of the Kerr black hole was so remarkable as to compare with the discovery in physics of a new elementary particle. With over 100 million trillion black holes in the observable universe, his achievement has been of crucial importance for science. The Kerr Solution has come to be regarded as the most important exact solution to any equation in physics and has been pivotal in understanding the most violent and energetic phenomena in the Universe.

Professor Kerr's solution has already been recognised by the Royal Society, which awarded him its Hughes Medal in 1984, and by the Royal Society of New Zealand which awarded him its Hector Medal in 1982 and its Rutherford Medal in 1993. The Einstein Medal is awarded annually by the Einstein Society which is based in Bern, Switzerland, where Einstein completed his revolutionary work in the first decade of the 20th century. The Einstein Society works with the University of Bern to preserve Einstein's legacy in Bern and Switzerland through different activities and, in particular, by annually awarding a medal "to deserving individuals for outstanding scientific findings, works, or publications related to Albert Einstein". The medal was first awarded to Stephen Hawking in 1979 and, since then, many distinguished scientists have received the medal including six Nobel laureates.

Professor Kerr says he is honoured to receive the award for his achievements while at the University of Canterbury. "I'm not sure how helpful my award will be for the University of Canterbury but if there are any spinoffs because of it, I will be more than happy. It's a great university," Professor Kerr says. Acting Vice-Chancellor, Professor Ian Town, says the University of Canterbury is immensely proud of Professor Kerr's achievements.

5.4. Medal puts professor in esteemed company.

University of Canterbury professor Roy Kerr has become the first New Zealander to be awarded the Einstein Medal. The award is presented annually to individuals for outstanding service, discoveries or publications related to Albert Einstein. Physicist Stephen Hawking was the first recipient in 1979. Since then, many distinguished scientists, and six Nobel Prize winners, have been awarded the medal.

Kerr will be honoured by the Albert Einstein Society in Switzerland for his 1963 discovery of a solution to Einstein's gravitational field equations. The Kerr solution, as it has become known, provided an exact description of the space outside a black hole, helping to understand how galaxies are formed, and becoming crucially important to the world of science. Kerr, who was delighted by the honour, said his discovery was "certainly the most important thing that I've done and it's probably the most useful thing that's come out of general relativity in 50 years". The award adds to a long list of accolades, including being made a Companion of the New Zealand Order of Merit in 2011 for services to astrophysics.

Kerr was a professor of mathematics at the University of Canterbury for 22 years before retiring in 1993. He is currently emeritus professor at the department of physics and astronomy. He has been nominated for a Nobel Prize several times but has never won. Kerr will travel to Switzerland to be awarded the medal at a ceremony at the University of Bern in May next year.

5.5. Bright sparks and black holes.

Roy Kerr has become the first New Zealander to be awarded the Einstein Medal by the Albert Einstein Society in Switzerland. Professor Kerr has earned the award for his 1963 discovery of a solution to Einstein's gravitational field equations.

Imagine being born Einstein smart, equipped from birth with a brain big enough to win the Nobel prize, but also being born the son of a womanising garage manager in 1930s Depression-era Gore. Your mother forced out of the family home when you were 3 years old. Shuffled off to a farm when Dad went to war. Idling away your formative years in a country school, no mental challenge beyond the thin shelves of the local library. How do you overcome such unlikely beginnings to become New Zealand's most illustrious living scientist? Does genius always out?

I find 78-year-old Roy Kerr in a house tucked just over the back fence of Christchurch International Airport. He explains his wife Margaret breeds pedigree golden retrievers, so they need a yard with no neighbours. Yet it also seems symbolic to discover Kerr right under local noses, almost under the wing of every landing plane, but largely invisible. With a beam, Kerr invites me in. Looking sprightly for his age, he settles in a wicker chair, and relates the story of his complicated life.

It is a tale of could-have-beens and should-have-beens. But also that moment in 1963, when at only 29, he cracked a mathematical conundrum which had been stumping relativity theorists for 50 years and so proved black holes could exist. Kerr continues to get belated recognition for this tremendous breakthrough. In May, he flies to Zurich to pick up the Albert Einstein Medal from the old guy's former university - an honour shared by only the Who's Who of theoretical physics. Yet there are those who still wonder how Kerr has been overlooked for the Nobel despite being nominated several times. He could have ended up on our banknotes like Lord Ernest Rutherford. So is his a tale of the plucky Kiwi outsider? Of genius triumphing against the odds? Or maybe of the lucky fluke - the one-hit wonder? Kerr laughs generously. It is tough cutting a life down to fit a Hollywood plotline. But yes, we can have a go.

The rocky childhood start turns out to be not much of a clue. Kerr agrees it was rough having a dad with too many girlfriends. "It was very hard on my mother," he says. "In those days, if you separated, the woman just had to go off with no support." And his father was a difficult person. One haunting memory is of him returning from World War II and being unable to exchange a single word with Kerr for several days. "A lot of people didn't last very long around him."

Kerr was moved to Christchurch when a step-family followed his father out from England. He slept under the leaking roof of the factory where after school he helped out with his father's new business venture - cutting up old inner tubes to make rubber band seals for jam jars. "I was 12 and we were putting the bands into packets. I kept figuring out ways to do this faster until I was counting out 25 rubber bands and folding everything up in six seconds. No-one else could get anywhere near that speed." But Kerr says his childhood gave him a reason to aim for something better in life. Starting his education was the real problem.

A lucky break was getting into private St Andrew's College because his father had served under the former headmaster. However, Kerr says the school was at a low ebb. "Most of its real teachers had died during the war." The chemistry teacher was a failed lawyer, the maths teacher a chaplain who could not even add up Kerr's exam marks properly.

"He was giving back the papers this one time and goes '... and Roy Kerr's not got 100 per cent, he's only got 83 per cent'. So the class goes 'Yaay!' But I look through and it's full marks, full marks -- 'Hey sir, you've only added up five of my answers'." Despite dishing his final scholarship chances -- Kerr turned up in the afternoon for one of his morning mathematics papers -- his exceptional ability had been recognised and at 16 he was admitted into the third year of a maths and physics degree at the University of Canterbury.

Kerr says the standard of teaching was not a lot better than at school. As a dusty outpost of empire, Canterbury University College, as it was known then, was still teaching a 19th-century syllabus. Relativity and quantum mechanics were but distant revolutions. "It was all very interesting, but there was nothing from the 20th century like group theory." Kerr was a prodigy, ripping through his courses with ease. "In my first mid-year exam, I probably got 30 or 40 per cent more marks than the No 2 guy -- who was a third-year student, a very nice chap, who went on to become New Zealand's best applied mathematician." After two years of a four-year masters degree, Kerr had absorbed all the university could teach. He should have gone to Cambridge University on a waiting scholarship, but due to some administrative interference, he was held back and left twiddling his thumbs. Kerr boxed in the university team, played billiards, whiled away some time doing random papers on ethics. Athletic and sociable, Kerr was no awkward maths geek. Yet once more he was idling in the shallows. And it had an unfortunate consequence when he arrived in Cambridge in 1954.

In his eagerness to finally get going, Kerr skipped the further undergraduate training that might have eased his passage into the tight-knit world of academic research and plunged almost immediately into a maths doctorate under a random series of thesis supervisors. His first happened to be the world's top algebraist, Philip Hall. "So Cambridge must have thought I had some ability, I guess." But Kerr had barely studied the subject. "I didn't know any modern algebra and now I'm planning to do a PhD on it," he chuckles, laughing at what must have been a ludicrous self-confidence on his part. Kerr says he had grown too accustomed to educating himself by skimming the right books. His relationship with Hall came to an abrupt end when it was suggested Kerr should bone up on discrete algebraic groups and Hall found him instead reading about continuous groups. It was an almost schoolboy level mixup. "I confused the two and he got mad, so I thought, well, I better go do physics."

Next Kerr got another luminary as his supervisor - the future Nobelist Abdus Salam. But Salam was a particle physicist and Kerr had even less grounding in that, so again the relationship did not last long. By the time Cambridge dug up a third PhD supervisor, the authorities were clearly losing patience. "This guy must have been 27th down the line. I asked around and nobody else at the university had even heard of him." Kerr only met him once to say hello. Continuing his haphazard journey from Gore, Kerr drifted off on his own to help a friend, agreeing to do the mathematical grunt work on a theory in yet another area he had barely heard of, let alone studied.

Kerr was really too bright for his own good. He had risen fast because people always allowed him to jump ahead. But this also meant he remained outside the established academic networks. He did not have a mentor guiding him, a teacher steering him on to a path to match his talents. Kerr also appears to fall between two ways of thinking - that of the mathematician and the physicist. Mathematicians could not care less about the real world, says Kerr. They live in their private realm of discovered patterns. Yet he found maths interesting only where it appeared to be saying something deep about reality. On the other hand, Kerr felt physicists were too ready to play it fast and loose with their mathematics. It was enough for them to sketch out an idea with some equations that looked as though they might do the job.

Kerr says physics has a different notion of quality control because the maths can always be fixed up later. What matters is producing predictions plausible enough to be experimentally tested. However, Kerr had a gift for spotting the mathematical flaws of a theoretical argument at a glance. His eye would light upon an equation and he could say, well this is never going to work out. There is no getting here from there. It is an ability that has plagued him. "You know, you're supposed to go from step one to step two to step three, but I just would jump from one to five to eight in my thinking." Writing up his own ideas was always a chore because he could see the end from the start and so could barely be bothered filling in the gaps for others. Kerr confesses it was also a trait that proved as irritating as hell for his colleagues as he came across as the party-pooper. "I always seemed to be in this negative position of telling people that their mathematics was lousy and so their theory can't be true." In this way, Kerr seems almost un-Kiwi. Although he is an easy-going character most of the time, quick to laugh at life's absurdities, he concurs he has a narrow, almost old-fashioned, belief about the right way to do science. Whereas, in his view, it is mostly everyone else in fundamental physics who is happy with a "she'll be right" approach to theory building. Eventually, for a short while after leaving Cambridge in 1959, Kerr did find his niche.

The 60s were the golden age of relativity theory, when scientists began to extract a whole range of important cosmological consequences from Einstein's famous equations. The mathematics started to produce physically meaningful results. Kerr got into relativity theory sideways through helping out his Cambridge colleague, John Moffatt. Moffatt's theory did not pan out -- no surprise to Kerr. He soon saw it had more undefined variables than the equations could keep track of.

"We wrote a paper up, but it was never going to work," Kerr says with a dismissive shake of the head. But the collaboration did give him experience in handling the maths of the complicated motions of bodies moving in curved space time. So Kerr ended up doing his thesis on the gravitational interactions of planets and stars -- the kind of results that astrophysicists could use, he says with satisfaction -- then moved on to a succession of post-doctorate research positions in New York, Ohio and Texas.

Relativity was still a small world at this point with perhaps a half dozen serious university groups. And with the US Air Force vying with the US Navy for the prestige of funding the research, the Americans had come into some extra money. So at last Kerr found himself in the thick of things, in hand-to-hand combat with a gang of other bright young minds. The kid from Gore had finally reached the centre of the action. Kerr continued to plug away at his many body physics, his thesis material, pursuing a grand project to boil down Einstein's 10 field equations to something simpler. If he could find a way to drop any unnecessary assumptions, then something valuable was sure to pop out of a more condensed theory. Kerr says even Einstein had felt this was an impossible task.

There had been one such early success when in 1915, the German Karl Schwarzschild -- while serving on the Russian front -- had produced a result suggesting that a big enough mass must collapse under its own gravitational field to form a singularity -- a black hole with gravity so strong even light could not escape its grip. But Schwarzschild's argument was rather simple and most people treated his black holes as physically unlikely -- just science fiction speculation. For the next 50 years no-one else could squeeze anything much better out of Einstein's equations.

In the US, several others were working on the same problem. Kerr says in 1963 a rival Syracuse University team produced a paper which he saw contained some fatal mathematical blunders. Realising this gave him his opportunity, Kerr "went mad" for several weeks and managed to produce his own still horrible, but rather more tractable framework of equations. The mental gymnastics involved are arcane. But it came down to visualising how different mathematical objects were actually the same thing if switched about in the right fashion -- in this case, a symmetric spinor and conformal tensor, if you are interested, says Kerr.

He continued to strip down the equations until eventually he was left with two terms, two parameters, that Kerr could recognise as likely to stand for a mathematical description of a flat space containing a spinning object. Excited, he grabbed his boss, University of Texas physics professor Alfred Schild, and they sat together to make the final calculation. Schild was in an armchair, puffing away on a pipe, watching while Kerr scrabbled out the last steps. Then came the moment when Kerr could look up and exclaim: "It's rotating!"

OK, that is getting a bit too Hollywood, he admits. It took some time to understand he had stumbled on the only possible precise mathematical description of a spinning black hole, and not just any old spinning object. But he had achieved the result that will for ever more be known in physics textbooks as the discovery of the Kerr metric.

It was big. Huge even. A basic finding from which much else was to flow. But for Kerr, there was an element of bad timing about it. Earlier that same year, without realising it, astronomers had discovered actual black holes in deep space. Their radio telescopes had picked up some unnaturally bright stars or quasars (quasi-stellar objects) in distant galaxies. Astrophysicists were agog. And by a twist of fate, Kerr's own professor, Schild, was helping organise an international conference in Dallas to discuss them. It seemed the perfect opportunity for Kerr to present his findings. But it was too soon for the connection between the two to be grasped.

The astronomical community was not even considering black holes as a possible quasar mechanism at that stage and so they brushed over his paper. When Kerr got up to speak, many slipped out. Others chatted in the rows or catnapped. Kerr has since been thoroughly vindicated. Quasars are black holes glowing hot with all the surrounding matter they drag in. Black holes are believed to litter the universe. Indeed, our own galaxy has a supermassive one, Sagittarius A*, whirling at its heart, the size of four million suns.

If quasars had been discovered just a few years later, long enough after Kerr's calculations to look like the confirmation of a bold scientific prediction, then as a junior scientist, only loosely attached to any recognised research group, he might have been treated rather differently. Instead, he says, he felt like meat being tossed to the lions. As soon as others studying relativity saw what he had achieved, they began trying to snatch the glory for themselves.With no-one to protect his back, he seemed fair game.

"They all wanted a piece of the pie. There was one famous 40-page paper to prove that the angular momentum was what I said it was. Yet I had already done it in a four-line proof." Schild did become a benefactor, getting Kerr a full-time post as a professor of mathematics at the University of Texas. Looking back, Kerr feels he was poised on the verge of greater things as his next natural step would have been foundational work on gravity waves -- a field of relativity that is only now coming into its own. However, Kerr became disillusioned by the politics and the way other physicists were taking his Kerr metric and spinning it into flights of fantasy way ahead of any definite mathematics. With so few genuine results to go round, he says, most theorists have to take some flawed idea and promote it.

He thus ended up on the outer again, unable to join anyone else's group because their mathematical shortcomings seemed too obvious. "I could see their approaches would be doomed to failure" - but also then not tied to any group that might want to promote his reputation. "By 1966 or 1967 I just got depressed. There's no other way of looking at it," says Kerr. He began to do other things. He got passionate about bridge and golf. "With bridge, all I had to do was win. I didn't have to explain to people why they were silly to do this, and that they should be doing that." He won national titles and invented new bidding systems. Kerr says golf was the same. He positively purrs as he recalls once standing on a tee and hitting six perfect 2 irons in a row just because he could.

In 1971 Kerr returned to Christchurch on sabbatical and in 1983 took over Canterbury University's mathematics department. By this time his scientific contribution was becoming increasingly well recognised and when he wasn't representing New Zealand in bridge tournaments, he was travelling to Brazil or Italy as an honoured conference guest.

In 1993 Kerr retired early, with the idea of sailing the world in a yacht. That ambition lasted a single storm and demasting off the West Coast.

As professor emeritus, he has remained on the scientific circuit as a spectator and commentator. At 78, Kerr believes he has still got it. He says there is this little idea he has about negative particles that would have repulsive gravity. If he can refine the mathematical detail, he might just alarm his hosts with a presentation when he collects his Einstein Medal in May.

Does a Nobel remain a possibility? Kerr shrugs. It is a little late in the day. And these things are like Oscars. It helps who you know. But certainly the value of what he did is becoming more apparent every year. And, in relativity theory, no other person has made an equivalent advance since his 1963 paper. "I may not have done anything as significant again - but then the point is that neither has anyone else."

Standing at the door to say goodbye, Kerr looks the tanned and fit pensioner. The unremarkable face you might have bumped into around Christchurch any day recently. But the far from ordinary brain. Quite definitely the cleverest kid to have ever come out of Gore.

6.1. The Crafoord Prize.

Anna-Greta and Holger Crafoord's Fund was established in 1980 by a donation to the Royal Swedish Academy of Sciences from Anna-Greta and Holger Crafoord. The Crafoord Prize was awarded for the first time in 1982. The purpose of the Fund is to promote basic scientific research worldwide in the following disciplines:

Mathematics and Astronomy
Geosciences
Biosciences (with emphasis on ecology)
Polyarthritis (e.g. rheumatoid arthritis)

Support to research takes the form of an international prize awarded annually to outstanding scientists, and of research grants to individuals or institutions in Sweden. Both awards and grants are made according to the following order:

Year 1: Astronomy and Mathematics
Year 2: Geosciences
Year 3: Biosciences
(repeat)

Starting in 2012, there are two separate prizes in mathematics and astronomy awarded at the same time.

The laureates are announced in mid-January each year, and the prize is presented in April/May on the "Crafoord Days".

6.2. The Crafoord Prizes in Mathematics and Astronomy 2016.

The Royal Swedish Academy of Sciences has decided to award the Crafoord Prize in Mathematics 2016 to Yakov Eliashberg, Stanford University, Stanford, California, USA, "for the development of contact and symplectic topology and groundbreaking discoveries of rigidity and flexibility phenomena" and the Crafoord Prize in Astronomy 2016 to Roy Kerr, University of Canterbury, Christchurch, New Zealand, and Roger Blandford, Stanford University, CA, USA, "for fundamental work concerning rotating black holes and their astrophysical consequences".

6.3. The Crafoord Prize in Astronomy 2016.

Roy Kerr and Roger Blandford received equal shares of the 6 million Swedish krona Crafoord Prize in Astronomy. The prize award ceremony was held at the Royal Swedish Academy of Sciences on 26 May 2015, in the presence of H M the King of Sweden. The Prize Lecture was delivered on Tuesday 24 May at Lund University, Lund. The Prize symposium tool place on Wednesday 25 May in Stockholm. The Prize ceremony took place on Thursday 26 May in the Beijer hall, the Royal Swedish Academy of Sciences, Stockholm.

6.4. Black Hole Expert Roy Kerr Honoured in Nice.

One of the world's most brilliant mathematicians, New Zealander Roy Kerr, 81, has been awarded the Crafoord Prize for his work on black holes. With an award of US$700,000 the prize is one of the world's biggest scientific accolades.

The Crafoord Prize recognises and promotes research in the scientific disciplines that are not eligible under the Nobel Prize. It is awarded by the Royal Swedish Academy of Sciences to outstanding individuals in the fields of astronomy and mathematics, biosciences, geosciences or polyarthritis research. The prize is presented by the King and Queen of Sweden each May.

Since its creation in 1982, only six astronomers and astrophysicists have been awarded the Crafoord Prize, with Kerr the seventh.

Mayor of Nice Christian Estrosi has applauded Kerr for his work with the International Center for Relativistic Astrophysics Network based in Nice.

"I want to congratulate Professor Roy Kerr, the New Zealand mathematician and physicist, for obtaining the prestigious Crafoord Prize which has rewarded his work on black holes and astrophysical consequences," Mayor Estrosi said.

Kerr was born in Kurow. He is best known for discovering the Kerr vacuum, an exact solution to the Einstein field equation of general relativity.

In 2013, Kerr was honoured by the Albert Einstein Society in Switzerland winning the Albert Einstein Medal. He is the first New Zealander to receive the prestigious award.

6.5. Black holes light up the universe.

Black holes are the source of the universe's most powerful radiation, as well as to jets that can stretch many thousands of light years out into space. Roger Blandford's theoretical work deals with the violent processes behind these phenomena. Roy Kerr laid the foundation for this research early on, when he discovered a mathematical description of rotating black holes before anyone had even seen them. This became one of the most important theoretical discoveries in modern cosmology.

They bend space and distort the passage of time. Everything that gets close to a black hole falls in and nothing gets out, not even light. Black holes remain invisible; they have long been a mystery and still hold many secrets. However, some of these have been revealed, so we now know that a massive black hole can spin quickly and make its closest surroundings shine brighter than anything else in the universe.

Black holes are the strangest result of the general theory of relativity. When Albert Einstein finally presented his theory in November 1915, all previous concepts of time and space were turned upside-down. Instead of the familiar Newtonian gravity that makes an apple fall straight to the Earth, Einstein described gravity as a geometric property of space and time connected in a four-dimensional spacetime. According to Einstein's theory, gravity is not a force -- instead it is a consequence of spacetime being bent. This also affects the passage of time -- seen from the outside, time moves more slowly close to a large mass.

All massive space objects bend spacetime; they create a pit into which other, smaller, objects can fall. Gravity is therefore an illusion; the apple falls because it follows the trajectory that is caused by the Earth's mass. The larger the mass, the more spacetime bends. For small masses and short distances this effect is the same, regardless of whether one uses Einstein's general theory of relativity or Newton's laws of motion, which are more than 200 years older.

The equations of the general theory of relativity are famous for being very technically complicated to solve. Despite this, just a few weeks after publication, the German astrophysicist Karl Schwarzschild was able to provide Einstein with a precise solution for the shape of a gravity field surrounding a spherical star that does not rotate. In fact, the solution included a description of what later came to be called a black hole. But even if there had been historic discussions of invisible stars, it took almost 50 years to start seriously studying something as bizarre as black holes. The name itself -- black hole -- first appeared at the end of the 1960s.

Schwarzschild's calculations showed that it was possible to determine a spherical surface, an event horizon, for every heavenly body. Time stops at the event horizon (for the external observer) and a black hole, once formed, remains forever hidden behind its event horizon. Inside it, spacetime is so bent that no light can escape. And, furthest in, hides an abyss with no bottom, a singularity in which density, according to the theory of relativity, approaches infinity, as does the curvature of space-time. In this singularity, time comes to an end. However, the theory of relativity may be wrong; to establish what really happens inside a black hole requires a quantum theory for gravity and, as yet, no such theory exists.

The heavier the hole, the greater the event horizon - the area that delimits the hole from its surroundings. To form a black hole and disappear from our view, the Earth would need to be compressed to a radius of around nine millimetres, and the sun to about three kilometres.

Long before Einstein, scientists were speculating - purely theoretically - that massive stars could be transformed into extremely heavy objects. Now, with the help of the general theory of relativity, among other things, it was possible to calculate how this could happen. Towards the end of the life of a really massive star's life, one of around 10 solar masses or more, when its nuclear fuel is running out and the gas pressure outwards is gradually declining, that star has less energy for resisting its own, inwardly-directed gravity. A gravitational collapse becomes unavoidable. At its moment of death, the star explodes as a supernova and an extremely tightly compressed remnant is left behind - a neutron star or a black hole.

A neutron star can be just a few kilometres across but have a mass greater than the sun's. However, this only applies to neutron stars up to 2-3 solar masses. Large neutron stars cannot withstand gravity, which means it is impossible to resist further collapse - irrevocably leading to the formation of a black hole. At the end of the 1930s, the first calculation of this transformation from a massive star to a black hole was led by physicist Robert Oppenheimer, later the legendary leader of the Manhattan Project, which built the American atomic bomb.

Black holes were still regarded as speculative theoretical monstrosities, because most people believed that in reality nature would carefully shy away from them. This could also have been due to a misunderstanding, as it wasn't easy to order the passage of time in the various frames of reference: if one were to observe a star collapse into a black hole it would take an infinitely long time. This means that a black hole could never be formed, went the reasoning.

The explanation for this paradox is that everything depends on the frame of reference in which the calculations are carried out. From the star's perspective, its collapse would be completed in less than a millisecond if the star were a few times heavier than the sun. In the early 1960s, John Wheeler was one of a few leading researchers in the world who began to be interested in black holes, after long doubting their existence.

A breakthrough came with Roy Kerr's solutions to Einstein's notoriously complicated equations for what spacetime looks like around rotating stars and black holes. Almost fifty years after the general theory of relativity saw the light of day, Roy Kerr succeeded with something that nobody else had been able to do. So when he submitted his short article of $1\large\frac{1}{2}\normalsize$ pages, in July 1963, it was a real breakthrough.

However, not many people realised what a landmark Kerr's achievement was. The previous Schwarzschild solution for stationary black holes was just an ideal image. It was now Kerr who came closest to a real image of what actually happened in black holes, because almost all stars and black holes rotate. For example, our sun rotates once on its axis between 25 and 35 days.

Eventually, it was discovered that every black hole can be described using just two properties - its mass and its rotational speed. Whatever happened when a black hole was formed, the memory of the past is entirely hidden inside it. A black hole can thus appear to be a simple space object, but nothing could be more misleading, as it may be very complicated in its interior.

Kerr demonstrated that the rotation changes the black hole's surroundings. It is not just that the event horizon differs from Schwarzschild's, but two important boundaries are created around the black hole. Seen from the outside, there is first an outer horizon that is not completely spherical; it is flattened at the poles. Inside the outer horizon, an additional event horizon is formed, marking the area of no return. From the outside, the closer one comes to this outer horizon the slower time passes. Everything that passes this horizon is dragged, hopelessly, into the rotation of the black hole; even spacetime is twisted around it.

Outside these two event horizons is the ergosphere, a name that is linked to energy production (from the Greek ergon - work). Indeed, it is in the processes around and inside the ergosphere that the black hole's rotational energy drives the astonishingly strong radiation that can been seen throughout the universe. It is also from there that charged particles are shot out in each direction as two narrow jets, travelling hundreds of thousands of light years out into space.

Ever since the mid-1970s, Roger Blandford has dedicated himself to -- among other things -- the issue of how this energy transformation takes place. Theoretical models are developed as new astronomical observations arrive. Telescopes on Earth and observations from satellites continually supply researchers with increasingly detailed images of what is happening around black holes.

The smaller black holes, which are around ten times heavier than the sun, are often found as part of a binary star, where the partner is an ordinary star. Around 25 such binary star systems are now known. The high-mass X-ray Cygnus X-1 in the Cygnus constellation has become the archetype of such binary systems, as it was the first to be discovered, in 1964. Gas from the black hole's neighbour star spills across it, spins around and forms an accretion disk. The friction in the disc makes the gas spiral in towards the edge of the black hole, but before it disappears entirely, the gas is heated so much that it emits powerful X-ray radiation. The luminous accretion discs are often followed around a black hole by a pair of hot gas flows, jets.

In 1963, a number of powerful but also mysterious sources of radio waves were discovered, such as the blinding 3C 273 in the Virgo constellation. It shines 4,000 billion times more brightly than the sun. This is far too strong to come from an ordinary star so it was named, like other similar objects, a quasistellar radio-source, quasar. In addition, the distance to the quasars was determined to be several billion light years from us, which means that they emitted their rays when the universe was young. The oldest now known quasar started radiating around a billion years after the big bang, almost 14 billion years ago.

Gigantic black holes are the only known energy source that can provide the quasars with adequate energy within the limited volume from which the radiation is emitted. With a mass from a few million to several billion solar masses, black holes are located in the centre of host galaxies that feed them with gas. Even if the galaxies themselves can be incredibly big, quasars often completely outshine them.

How is this enormous radiation energy created? How can a black hole send out two jets in opposite directions? Back in 1977, Roger Blandford and his colleagues were able to put forward a proposal for how this happens in the ergosphere of a rotating black hole. Now the models have been refined and are increasingly realistic.

The magnetic field is decisive here, in combination with fluid dynamics, the study of liquids and gases in motion. The gases that flow in, primarily hydrogen, get so hot from the friction that they glow and become radiant, while the heat also makes the hydrogen atoms decompose into positive atomic nuclei, protons, and negatively charged electrons. Their movements create a magnetic field that spins around the black hole's rotational axis. The lines of the magnetic field are woven into a spiral that conducts the electrically charged gas. The gas shoots out from the black hole in two opposite directions in the form of jets. These mostly consist of charged particles that cross space, thousands of light years away, at almost the speed of light.

The source of all of this power is the rotational energy of the black hole. These processes in the accretion disc are actually incredibly efficient. A rotating black hole can transform up to 40 per cent of the energy contained in material that falls into it, into radiation. This is many times more than is calculated for stationary black holes; these are only able to transform around six per cent of gravitational energy to radiation, while the core processes inside stars, such as the sun, only achieve up to one per cent at the most.

All this work means that supermassive black holes lose energy so that their rotation slows down. Over time, the availability of fuel also dwindles in the quasars' host galaxies. After 10 to 100 million years, when the gases around it are becoming exhausted, the black hole goes out. In the youth of the universe there was much more gas available, which is why quasars then shone most brightly.

But it takes a long time for light to reach us, even if it travels at the greatest possible speed. The quasar light that we capture now was emitted long ago, when there were still abundant materials available in the young days of the universe. It could also be that if the circular movement of a galaxy is disrupted, for example by coming too close to another galaxy, gas and stars are linked to the dark black hole at the centre so that the quasar is reignited, even if it's just for a while.

There is also a large supermassive black hole in the centre of our galaxy, the Milky Way - Sagittarius A*. It is smaller than the known giant quasars, but it is still estimated to weigh around four million solar masses. We are not exceptional, most galaxies have a black hole in their centres. Many of them are like our black hole - they sit there, quietly, only being recognisable when the trajectories of the stars around them are studied. Such studies of the Milky Way's black hole were rewarded with the Crafoord Prize in 2012.

No one nowadays doubts that there are many black holes in the universe. Some of them lead reserved lives in the centres of their galaxies, others are more lively and are found in the most luminous binary stars and the most powerful quasars. Altogether, black holes are estimated to emit as much as one-third of all the radiation in our universe. However, how they really work remains hidden, both literally and in the mind, because our knowledge of superdense materials and the most bent spacetime is still too inadequate.

7.1. The Oskar Klein Medal.

The Oskar Klein Memorial Lecture at Stockholm University, dedicated to the memory of the Swedish physicist Oskar Klein (1894-1977), is held annually since 1988 by a prominent physicist, who also receives the Oskar Klein Medal. The lecture is sponsored by the university and the Nobel Committee of the Royal Swedish Academy of Sciences.

7.2. Canterbury Distinguished Professor Roy Kerr Gives Black Hole Lecture Via Zoom.

The Royal Swedish Academy of Sciences awarded the Oskar Klein Medal to the University of Canterbury's renowned Canterbury Distinguished Professor Roy Kerr. He gave the 2020 Oskar Klein Memorial Lecture on Friday morning (NZ time), on campus at the University of Canterbury. In 2019, astronomers captured the first image of a black hole, heralding a revolution in our understanding of the universe's most enigmatic objects, and proving Canterbury Distinguished Professor Kerr's 56-year-old solution correct.

7.3. Kerr gives the 2020 Oskar Klein Lecture.

The 2020 Oskar Klein Memorial Lecture 'Kerr Black Holes have no Singularities' was delivered by Zoom by Roy Kerr.

Abstract: All proofs that Black Holes have real physical singularities make assumptions about the nature of the matter inside and of certain light rays. It is shown that there are such lines inside Kerr that do not satisfy these assumptions. As an example to show that the behaviour inside the event horizon for real matter is very different from the idealisation of empty Kerr we consider two slowly rotating Black Holes collapsing to a single object. There have been many different approaches used to calculate the collapse of two Black Holes to a single one. We show that the best starting point is the Kerr-Schild form for a Black Hole. This explains the unexpected accuracy of a calculation by Jose Rodriguez for the first gravitational wave discovery, GW150914.

7.4. Roy Kerr biography.

Professor Roy Patrick Kerr is an eminent mathematician, known internationally for discovering the Kerr solution, an exact solution to the Einstein field equation of general relativity.

Professor Kerr began his long association with the University of Canterbury in 1951, earning a Bachelor of Science in 1954 and a Master of Science in 1955. He then went to Cambridge to research his PhD, and was awarded his doctorate in 1959.

From England, Dr Kerr moved to the United States, where as a postdoctoral student in Syracuse, New York, he worked with Professor Peter Bergmann, Albert Einstein's collaborator.

In 1963, while working at the University of Austin in Texas, Dr Kerr did something that had eluded scientists for 47 years -- he discovered the solution to Einstein's equations that define the space outside a rotating star or black hole. This was something many in the field doubted could be done.

Professor Kerr's discovery triggered a revolution in the field of astrophysics, and is now known as the 'Kerr geometry' or 'Kerr solution'.

Dr Kerr returned to New Zealand and the University of Canterbury in 1971, where he became a Professor of Mathematics for 22 years until his retirement in 1993, when he was appointed an 'Emeritus Professor'. Professor Kerr developed strong links with the department of physics and astronomy, where his seminal work on the Kerr Vacuum provided the basis of much research and teaching.

Professor Kerr was awarded the British Royal Society's Hughes Medal in 1984 and the Rutherford Medal from the New Zealand Royal Society in 1993. He was made a Companion of the New Zealand Order of Merit in 2011, and was awarded the 2013 Albert Einstein medal by the Albert Einstein Society in Switzerland.

The University of Canterbury awarded the rare honour of the title Canterbury Distinguished Professor to Professor Roy Kerr who also received the prestigious Crafoord Prize in Sweden in 2016. Canterbury Distinguished Professor is the highest academic title that can be awarded by UC and has been conferred only twice before in the University's history. Title recipients are Nobel Prize winners or equivalent, such as the Crafoord Prize, which is worth over $NZ1 million.

7.5. Stephen Hawking on Roy Kerr.

One of the world's foremost theoretical physicists famous for his work on black holes, Stephen Hawking, described Kerr's discovery in his celebrated book, A Brief History of Time. Professor Hawking wrote:-

In 1963, Roy Kerr, a New Zealander, found a set of solutions of the equations of general relativity that described rotating black holes. These 'Kerr' black holes rotate at a constant rate, their size and shape depending only on their mass and rate of rotation. If the rotation is zero, the black hole is perfectly round and the solution is identical to the Schwarzschild solution. If the rotation is non-zero, the black hole bulges outward near its equator (just as the Earth or the Sun bulge due to their rotation), and the faster it rotates, the more it bulges. So ... it was conjectured that any rotating body that collapsed to form a black hole would eventually settle down to a stationary state described by the Kerr solution. In 1970 a colleague and fellow research student of mine at Cambridge, Brandon Carter, took the first step toward proving this conjecture. He showed that, provided a stationary rotating black hole had an axis of symmetry, like a spinning top, its size and shape would depend only on its mass and rate of rotation. Then, in 1971, I proved that any stationary rotating black hole would indeed have such an axis of symmetry. Finally, in 1973, David Robinson at Kings College, London, used Carter's and my results to show that the conjecture had been correct: such a black hole had indeed to be the Kerr solution."