'Stephen Hawking put abstract science on the map'
Theoretical physicist Stephen Hawking (76) passed away on 14 March at his home in Cambridge, having been a long-term sufferer of the muscular disease ALS. A number of Leiden scientists look back at the life and scientific career of this world-famous physicist. 'He was very approachable and extremely socially minded.'
Vincent Icke, emeritus professor of Theoretical Astronomy
‘Hawking’s research was of an extraordinary calibre and it stands rock fast. Ironically enough, that means his death isn't so interesting for science. On a personal level, however, his loss is a different matter. I first got to know Stephen when he was still able to walk and talk - he was always making jokes. Physics is like a family, we are all brothers and sisters. Stephen's death is a great loss for all of us.
'Stephen put abstract science on the map. He exploited the fact that he was remarkable and used that for the benefit of science. The name Stephen Hawking has become a brand in science, one that is absolutely well deserved.'
Koen Kuijken, professor of Galactic Astronomy
‘Hawking is without doubt an icon, a unique figure who was known far beyond his own field. We have lost someone who could talk with great authority about the importance and the societal impact of fundamental research, someone whom the whole world regarded a kind of "rock legend". As a student at the Department of Applied Mathematics & Theoretical Physics in Cambridge, I met him often, and later at conferences too. He was always very approachable and extremely socially minded.'
Koenraad Schalm, professor of Theoretical Physics
'One of Hawking’s greatest contributions to physics was his breakthrough in correlating the theory of quantum mechanics and Einstein's general theory of relativity. These theories are difficult to combine mathematically, and they mainly play a role in the description of black holes.
'Hawking discovered that black holes not only soak up light and matter, but, according to the laws of quantum mechanics, they also emit radation. What was so typical of Hawking was not only that he made this important discovery, but that he was also able to explain its enormous implications. He showed that this radiation depended only on the energy of the black hole and not on its original matter. This information paradox fuelled the mathematical conflict between Einstein's general theory of relativity and quantum mechanics, given that according to the latter, information can never be lost.
'I and my colleagues at Leiden University are working on this issue. We may not be making the giant steps that Hawking made, but we are nonetheless making progress year by year. Hawking was an icon in our field and he made some pioneering discoveries. His death is very sad. But, as he himself once said, 'Time moves relentlessly onwards.'
Pedro Russo, university lecturer in Maths and Physics
‘Stephen Hawking did more than anybody else to broaden the public understanding of our universe. That makes him one of the most significant science communicators of the past 20 years.
'His first book, A Brief History of Time, sold over 10 million copies in a period of 30 years. In 2002 he also wrote On the Shoulders of Giants: a book of scientific texts written by prominent astronomers and thinkers such as Copernicus, Galileo and Einstein. Hawking has now joined these giants. It is our duty as astronomers and science communicators to continue to stand on his shoulders and to continue to communicate our discoveries to a broad public.'
Ana Achúcarro, professor of Astroparticle Physics and Quantum Field Theory
‘This is a very sad day. Stephen Hawking was a great scientist and a remarkable person. He has become a part of public culture and I don't think he will ever be forgotten.
'I obtained my PhD in Hawking's research group in the '80s. My supervisor was Paul Townsend, but I saw Stephen every day. He was already very sick when I started; it was just after his tracheotomy. Even so, he managed to keep his sense of humour. I am one of the few people to have seen Stephen dancing in his wheelchair, going round in circles, with a huge smile on his face and his eyes alight with the fun of it.'