There is often much debate about who is the greatest among sportsmen and women, movie stars, leaders or artists. But some scholars have truly made a staggering difference to the world.
Winning a Nobel prize is a rare, extraordinary achievement, but five remarkable people have done it twice. Who are they? What sets them apart? And who is the greatest?
This is an inherently subjective discussion in which time and context matter a great deal. Here are five top contenders.
Marie Curie - physics (1903) and chemistry (1911)
In a photo of the first Solvay conference for physics and chemistry in 1911, one person stands out among the giants of physics in attendance: the only woman. Marie Curie is the most famous of these five scholars and for good reason.
The world today, as well as science in general, is different because of her. She won her first prize for her work on radioactivity (physics), and then her second a mere eight years later for discovering the elements radium and polonium (chemistry). Among laureates she is the first woman, first double winner, and the first (and only) in two different scientific fields.
The first prize as co-winner was shared with her husband and with Henri Becquerel. The Curies are a family of five Nobel winners, and the institute she established produced four more.
Curie's accomplishments are all the more impressive given that she had to fight to obtain a great deal of her opportunities, including gaining a world-class laboratory and becoming a member of the French academy (for which she was never selected).
Fred Sanger - chemistry twice (1958 and 1980)
As a molecular biologist, I confess to a soft spot for Fred Sanger - he is one of my heroes. His two prizes were awarded for creating the processes for sequencing (reading the instruction booklet of) proteins and DNA.
The first, for work on the structure of insulin, he won alone. He shared the second with two other researchers. Sanger's contribution was his method for determining DNA structure, still used today.
There is no overstating the importance of Sanger's breakthroughs. Everything from the Human Genome Project to the very discipline of practical molecular biology stem from his sequencing methods. In contrast to the picture painted of Marie Curie, Sanger was a quiet, unassuming figure. It suggests double Nobel laureates don't all fit the same mould. He should also be far more recognised than he is.
Linus Pauling - chemistry (1954) and peace (1962)
Pauling is the only person to receive two unshared prizes. Only he and Curie have won for two different fields. His discoveries in chemical bonding won him the first, and he helped found molecular biology as a discipline. His work inspired others in race for the DNA structure.
He pioneered quantum chemistry and made the extraordinary prediction of the existence of alpha helices and beta sheets - the secondary structures of proteins. If not for basic errors in predicting the DNA structure, he could have won a third prize but that eventually went to the molecular biologists Francis Crick, James Watson and Maurice Wilkins. His mistakes inadvertently helped the scientist Rosalind Franklin find what was missing. Franklin was the unsung hero of DNA's discovery, excluded from the Nobel prize despite her crucial contribution.
His second prize was not one of the science prizes but the peace prize. It was awarded for his passionate advocacy for nuclear disarmament with his wife, and he placed himself in the public eye against nuclear testing of weapons wherever possible. He was awarded every major chemistry prize during his life.
John Bardeen - physics twice (1956 and 1972)
Much as with Sanger, Bardeen's practical breakthroughs cannot be overstated.
The invention of transistors - a device used to amplify or switch electrical signals and power - and the discovery and communication of superconductivity, where materials conduct electricity with little or no resistance, won him his two physics prizes.
Both were shared three ways, but he was the first to receive two prizes in the same field. He really should be a household name, as his work has touched every area of our lives and impacted multiple disciplines.
Some might imagine double Nobel laureates as highly focused on their own careers, but Bardeen helped contribute to others winning the physics prize through generous collaboration with other scientists.
Karl Barry Sharpless - chemistry twice (2001 and 2022)
A more modern champion, Sharpless is the only one still living. Both his prizes were shared but sit among an extraordinary list of prizes he has been honoured with including the Priestley medal and Wolf medal.
His first was for a process called catalytic asymmetric synthesis. The second was for "click chemistry", where molecular building blocks can be made to snap together quickly and efficiently to form new compounds.
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Not only was he the scientific "king" of click chemistry, but he was also a fine communicator of the science behind the processes named after him.
Sharpless has transformed life around us without our knowing it by making difficult chemistry processes easier. Like others in this shortlist, his passion for the subject and curiosity are boundless. Indeed, in his eighties, he is still at the forefront of research and one of the most respected academics in the world.
So there isn't an archetype for double Nobel prize winners. Everyone will have their own view on the greatest among these five. For me, it is hard to argue against Marie Curie, who had to overcome huge obstacles as a female scientist at the beginning of the 20th century.
The deck was stacked against her in an extraordinary manner and she blazed a trail for other Nobel winners. Sanger should also be considered among the greatest practical scientists in history, because we're still reaping the benefits of his successes through the modern genomics revolution.
Sam McKee, Tutor and researcher in Philosophy of Science, Manchester Metropolitan University
