Lewis Wolpert: 'The Archimedes story is almost universally misunderstood'

When I was invited to join a debate at the Royal Institution in London on who was the first scientist, I readily accepted.

When I was invited to join a debate at the Royal Institution in London on who was the first scientist, I readily accepted. I wanted to promote my hero, whom I regard not only as the first scientist, but probably the greatest scientist ever. He was the first physicist and applied mathematician, and he had no one's shoulders to stand on to help with the science.

Yes, there had been Aristotle with his logic, and Euclid with his wonderful geometry, but they had not provided reliable explanations about how things work, which is the essence of science. It is only natural that Archimedes was a Greek, as all science as we know it comes from the Greeks, and no other culture conceived of this special way of thinking.

The story of Archimedes leaping naked from his bath crying "Eureka!" is well known, but almost universally misunderstood. What had he discovered? Archimedes needed to know if the new gold wreath made for his king was pure gold, or whether silver had also been used. Lying in his bath he suddenly realised that he could measure the volume of the crown by immersing it in a bath of water and seeing how much the water level rose. Then, knowing its weight, he could compare it with gold and silver.

He had discovered density, the weight per unit volume that characterises gold and silver and all other pure compounds. All he had now to do was to get pieces of gold and silver of the same weight as the crown, and then compare their volume with that of the crown by immersing them in water. He could then tell how much gold there was in the crown.

His next discovery relates to levers and balances. Taking a simple balance, a rod supported at its midpoint, he made clear that if two similar weights were placed on either side at equal distances from the midpoint it would balance and would be in equilibrium; but "equal weights at unequal distances are not in equilibrium, but incline towards the weight which is at the greater distance".

Then the key theorem which states that unequal weights will be in equilibrium when their distances from the midpoint are reciprocally proportional to their weights. So a 2kg weight will balance a 100kg if it is 50 units from the midpoint, and the larger weight just two units away. From this he claimed that given somewhere to stand, he could, with a lever, move the Earth.

The proof of his postulate is the first example of mathematics being applied to a physical problem. First he invented the concept of the centre of gravity. For example, the 100kg weight can be divided in two and each part placed one unit away from the original site, but its centre of gravity, through which the force downwards acts, remains the same. So he could now divide the 100kg weight into 100 units and spread them out equally on either side so that there are 51 on one side and 49 on the other, where the 2kg weight is.

On this latter side the 2kg weight is also divided into two units, so there are similar weights, 51kg, at equal distances on either side of the midpoint - equilibrium! He applied these ideas to the mechanics of fluids, and so to why some bodies floated. He showed that a body immersed in a fluid loses weight equal to the weight of the fluid it displaces. So a body floats if the fluid it displaces is more than its own weight.

He would have been contemptuous about this little problem, which many still get wrong. You are in a small boat floating in a swimming pool. There is a stone in the boat, which you throw into the water, and it sinks. Does the level of the water in the pool go up, down, or remain the same? It goes down, because the stone in the water displaces less water when in the water than when it was in the boat.

Archimedes had a major influence on Galileo, who called him divine. The other scientists proposed in the debate were Roger Bacon, an amazing 13th-century scholar, and Clerk Maxwell, who invented electromagnetic theory in the 19th century. In the end, the audience was as persuaded by the achievements of Archimedes as I am.

Professor Wolpert is professor of biology as applied to medicine at University College London

Start your day with The Independent, sign up for daily news emails
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Tradewind Recruitment: PMLD Teacher

Negotiable: Tradewind Recruitment: PMLD Teacher A specialist primary school i...

Recruitment Genius: Online Media Sales Trainee

£15000 - £30000 per annum: Recruitment Genius: Now our rapidly expanding and A...

Recruitment Genius: Public House Manager / Management Couples

£15000 - £20000 per annum: Recruitment Genius: Are you passionate about great ...

Recruitment Genius: Production Planner

£20000 - £30000 per annum: Recruitment Genius: This fast growing reinforcing s...

Day In a Page

As in 1942, Germany must show restraint over Greece

As in 1942, Germany must show restraint over Greece

Mussolini tried to warn his ally of the danger of bringing the country to its knees. So should we, says Patrick Cockburn
Britain's widening poverty gap should be causing outrage at the start of the election campaign

The short stroll that should be our walk of shame

Courting the global elite has failed to benefit Britain, as the vast disparity in wealth on display in the capital shows
Homeless Veterans appeal: The rise of the working poor: when having a job cannot prevent poverty

Homeless Veterans appeal

The rise of the working poor: when having a job cannot prevent poverty
Prince Charles the saviour of the nation? A new book highlights concerns about how political he will be when he eventually becomes king

Prince Charles the saviour of the nation?

A new book highlights concerns about how political he will be when he eventually becomes king
How books can defeat Isis: Patrick Cockburn was able to update his agenda-setting 'The Rise of Islamic State' while under attack in Baghdad

How books can defeat Isis

Patrick Cockburn was able to update his agenda-setting 'The Rise of Islamic State' while under attack in Baghdad
Judith Hackitt: The myths of elf 'n' safety

Judith Hackitt: The myths of elf 'n' safety

She may be in charge of minimising our risks of injury, but the chair of the Health and Safety Executive still wants children to be able to hurt themselves
The open loathing between Barack Obama and Benjamin Netanyahu just got worse

The open loathing between Obama and Netanyahu just got worse

The Israeli PM's relationship with the Obama has always been chilly, but going over the President's head on Iran will do him no favours, says Rupert Cornwell
French chefs get 'le huff' as nation slips down global cuisine rankings

French chefs get 'le huff' as nation slips down global cuisine rankings

Fury at British best restaurants survey sees French magazine produce a rival list
Star choreographer Matthew Bourne gives young carers a chance to perform at Sadler's Wells

Young carers to make dance debut

What happened when superstar choreographer Matthew Bourne encouraged 27 teenage carers to think about themselves for once?
Design Council's 70th anniversary: Four of the most intriguing prototypes from Ones to Watch

Design Council's 70th anniversary

Four of the most intriguing prototypes from Ones to Watch
Dame Harriet Walter: The actress on learning what it is to age, plastic surgery, and her unease at being honoured by the establishment

Dame Harriet Walter interview

The actress on learning what it is to age, plastic surgery, and her unease at being honoured by the establishment
Art should not be a slave to the ideas driving it

Art should not be a slave to the ideas driving it

Critics of Tom Stoppard's new play seem to agree that cerebral can never trump character, says DJ Taylor
Bill Granger recipes: Our chef's winter salads will make you feel energised through February

Bill Granger's winter salads

Salads aren't just a bit on the side, says our chef - their crunch, colour and natural goodness are perfect for a midwinter pick-me-up
England vs Wales: Cool head George Ford ready to put out dragon fire

George Ford: Cool head ready to put out dragon fire

No 10’s calmness under pressure will be key for England in Cardiff
Michael Calvin: Time for Old Firm to put aside bigotry and forge new links

Michael Calvin's Last Word

Time for Old Firm to put aside bigotry and forge new links