Tag Archives: Exhibitions

Alan Turing granted Royal pardon

A posthumous pardon has been granted to the great mathematician, logician, cryptanalyst, and philosopher, reports Roger Highfield, Director of External Affairs

Alan Turing, the wartime codebreaker who laid the mathematical foundations of the modern computer, has been granted a posthumous pardon by the Queen for his criminal conviction for homosexuality.

A Royal pardon is usually only granted where a person has been found innocent of an offence and a request has been made by a family member. This unusual move brings to a close a tragic chapter that began in February 1952 when Turing was arrested for having a sexual relationship with a man, then tried and convicted of “gross indecency”.

Portrait of Alan Turing. Image credits: NPL / Science Museum

Portrait of Alan Turing. Image credits: NPL / Science Museum

To avoid prison, Turing accepted treatment with the female sex hormone oestrogen: ‘chemical castration’ that was intended to neutralise his libido.

Details of the circumstances leading to his death on 7 June 1954, at home in Wilmslow, Cheshire, can never be known. But Turing had himself spoken of suicide and this was the conclusion of the coroner, following an inquest.

In 2009 Gordon Brown, the then Prime Minister, issued a public apology for his treatment. A letter published a year ago in the Daily Telegraph, written by Lord Grade of Yarmouth and signed by two other Science Museum Trustees, Lord Faulkner of Worcester and Dr Douglas Gurr, called on the Prime Minister to posthumously pardon Turing.

Turing has now been granted a pardon under the Royal Prerogative of Mercy after a campaign supported by tens of thousands of people. An e-petition calling for a pardon received more than 37,000 signatures.

Chris Grayling, the Justice Secretary, said: “A pardon from the Queen is a fitting tribute to an exceptional man.”

The pardon states: “Now know ye that we, in consideration of circumstances humbly represented to us, are graciously pleased to grant our grace and mercy unto the said Alan Mathison Turing and grant him our free pardon posthumously in respect of the said convictions.”

But the reaction to the news has been mixed. Turing biographer Dr Andrew Hodges, of Wadham College, Oxford, told the Guardian newspaper : “Alan Turing suffered appalling treatment 60 years ago and there has been a very well intended and deeply felt campaign to remedy it in some way. Unfortunately, I cannot feel that such a ‘pardon’ embodies any good legal principle. If anything, it suggests that a sufficiently valuable individual should be above the law which applies to everyone else.

“It’s far more important that in the 30 years since I brought the story to public attention, LGBT rights movements have succeeded with a complete change in the law – for all. So, for me, this symbolic action adds nothing.

“A more substantial action would be the release of files on Turing’s secret work for GCHQ in the cold war. Loss of security clearance, state distrust and surveillance may have been crucial factors in the two years leading up to his death in 1954.”

The Science Museum’s award-winning Turing exhibition,which closed a few months ago, showed that a signature moment of Turing’s life came on February 13, 1930, with the death of his classmate and first love, Christopher Morcom, from tuberculosis.

Science Museum conservator Bryony Finn inspects the Pilot ACE computer - at a preview of the Codebreaker: Alan Turing’s Life and Legacy exhibition at the Science Museum. Image credits: Science Museum

Science Museum conservator Bryony Finn inspects the Pilot ACE computer – at a preview of the Codebreaker: Alan Turing’s Life and Legacy exhibition at the Science Museum. Image credits: Science Museum

As he struggled to make sense of his loss, Turing began a lifelong quest to understand the nature of the human mind and whether Christopher’s was part of his dead body or somehow lived on.

Earlier this year Turing’s Universal Machine, the theoretical basis for all modern computing, won a public vote, organised by the Science Museum, GREAT campaign and other leading bodies in science and engineering to nominate the greatest British innovation of the last century.

Click and zoink – it’s your birthday!

Ahead of November’s opening of the Collider exhibition, Content Developer Rupert Cole takes a look at the story behind the Geiger counter

“The excitement is growing so much I think the Geiger counter of Olympo-mania is going to go zoink on the scale!”

Thus spoke Boris Johnson in his London Olympics opening speech a little over a year ago. The author of several popular histories including Johnson’s Life of London, is it conceivable Mayor Boris knew the Olympic summer coincided with the 104th birthday of the Geiger counter…?

On this day, 105 years ago, Hans Geiger and Ernest Rutherford published their paper on a revolutionary new method of detecting particles.

Geiger and Rutherford at Manchester, 1912. Credit: Science Museum / SSPL

Geiger and Rutherford at Manchester, 1912. Credit: Science Museum / SSPL

The first generation of Geiger counters did not produce the characteristic click we know and love today. Instead, an electrometer needle would suddenly jump, indicating an alpha particle had been detected.

They worked by picking up electric signals given off by electrons, which had been stripped from gas molecules by passing alpha particles. The beauty of them was that they provided another way to measure radiation, verifying the laborious and blinding method of counting light scintillations.

Once the technology improved, Geiger-Muller counters (as the later ones were called) became extremely nifty particle detectors, essential hardware for any cosmic-ray physicist. They are now used for many different purposes, from airport security to checking the levels of radioactivity in certain museum objects.

One of Geiger’s own counters made in 1932. Credit: Science Museum / SSPL

One of Geiger’s own counters made in 1932. Credit: Science Museum / SSPL

For a long time the device was just a tool used by researchers of radioactivity, an innovation that made Geiger’s task of counting by eye emissions of alpha particles from radium a little easier.

This is not to deny Geiger’s eyes were very effective counters of tiny flecks of light – produced by individual alpha particles as they hit a fluorescent screen. As Rutherford said at the time:

“Geiger is a demon at the work of counting scintillations and could count for a whole night without disturbing his equanimity. I damned vigorously and retired after two minutes”.

Arriving in Manchester in 1907, the German-born Geiger clearly was responsible for the nitty gritty side of the research. Ernest Marsden, a twenty-year old undergraduate, joined the pair the following year. The young student may not at first have realised that he was contributing to one of the most remarkable discoveries of the century.

In a darkened lab, Geiger and Marsden would take turns to count the sparkles of alpha particles as they hit a screen, having been fired straight through a sheet of gold leaf.

As the particles were much smaller than the gold atoms, it must have seemed slightly barmy when Rutherford suggested to move the counting screen behind the radium source and look for scintillations there.

The near-blind researchers hit gold, so to speak, and found the odd alpha particle had bounced back. Rutherford declared it the most incredible event of his life, “as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you.”

The team discovered the atoms had a nucleus – a miniscule core that caused the occasional alpha particle to rebound. Rutherford would soon come up with an entirely new picture of atoms, which depicted electrons orbiting around this central nucleus.

Model of hydrogen atom, according to the theory of Ernest Rutherford and Niels Bohr. Credit: Science Museum.

Model of hydrogen atom, according to the theory of Ernest Rutherford and Niels Bohr. Credit: Science Museum.

Geiger recalled the glory moment: “One day (in 1911) Rutherford, obviously in the best of spirits, came into my room and told me that he now knew what the atom looked like”.

You will have the chance to see up close Rutherford and Bohr’s atomic model, and discover the objects that helped shape modern physics in Collider, a new exhibition opening this November.