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Sir Joseph Rotblat- July Object of the Month

July 1, 201612:33 pmSeptember 25, 2023 12:36 pmLeave a Comment

This month’s object of the month blog is about Sir Joseph Rotblat (born Józef Rotblat on 4 November 1908).  Rotblat was a Polish-born and British-naturalised physicist.  He was the only physicist to leave the Manhattan Project on the grounds of conscience and his work on nuclear fallout was a major contribution to the agreement of the Partial Test Ban Treaty.  A signatory of the Russell–Einstein Manifesto, he was secretary general of the Pugwash Conferences on Science and World Affairs from its founding until 1973.  In conjunction with the Pugwash Conferences, he received the Nobel Peace Prize in 1995 for their efforts towards nuclear disarmament.

We are very lucky at the Peace Museum to have a collection of some of Rotblat’s personal possessions including his graduation gowns from the University of Bradford and the University of Warsaw, type writer, scientific equipment and spectacles.   The collection has long been on prominent display in the museum galleries and is a favourite with visitors.  However, we do regularly rearrange what we have out on display to accommodate the 7000 + items we have in our collection.  To make way for our current temporary exhibition: ‘A force for peace? The history of European co-operation,’ some of the items from the Rotblat collection have now been placed in storage.  However, these items are still available for visitors to see upon request and you can still find some of the collection on display in our Reponses to Conflict room. The collection will be back on display soon!

Photography for The Peace Museum, October/November 2016.

About Joseph Rotblat

Born to a Jewish family in Warsaw Poland on 4 November 1908 as one of seven childrenRotblat was still living in Poland at the age of 6 in 1915 when Germany was invaded.  After the First World War, and without any formal education, Rotblat won a place in the physics department of the Free University of Poland, gaining an MA in 1932; quite an achievement.  He held the position of Research fellow in the Radiation Laboratory of the Scientific Society of Warsaw and became assistant Director of the Atomic Physics Institute of the Free University of Poland in 1937.  By 1938 he was a Doctor of Physics.

Before the outbreak of WWII he had conducted experiments which showed that in the fission process, neutrons were emitted.  In early 1939 he envisioned that a larger number of fissions could occur and if this happened within a sufficiently short time, then considerable amounts of energy could be released.  He went on to calculate that this process could occur in less than a microsecond, and as a consequence would result in an explosion.

The Outbreak of WWII

In 1939, he came to England to study at the University of Liverpool under James Chadwick, winner of the Noble Peace Prize for discovering the neutron.    He went alone because he could not afford to support his wife there.  But, before long, Chadwick gave Rotblat a fellowship (the Oliver Lodge Fellowship), doubling his income, and in that summer of 1939 Rotblat returned home, intending to bring his wife Tola back with him.  However, when the time came to leave, she was ill and remained behind, expecting to follow within days; but the outbreak of war brought calamity.  Tola was trapped, and all of Joseph’s desperate efforts in the ensuing months to bring her out through Belgium, Denmark or Italy came to nothing, as each country in turn was closed off by the war.  She later perished in the Holocaust at Majdanek concentration camp, and Rotblat never saw her again.  This affected him deeply for the rest of his life and he never remarried.

 The Manhattan Project

While still in Poland, Rotblat had realised that his work could be used to produce a bomb. He first thought that he should “put the whole thing out of [his] mind”, but with the rise of Nazi Germany he continued because he thought the only way to prevent Nazi Germany from using a nuclear bomb was if Britain had one to act as a deterrent.  After the start of the war, he started working explicitly with James Chadwick on bomb work.

Early in 1944 Rotblat went with Chadwick’s group to work on the Manhattan Project to build the first atomic bombs. The usual condition for people to work on the Manhattan Project was that they had to become U.S. citizens or British subjects. Rotblat declined and the condition was waived. He continued to have strong reservations about the use of science to develop such a devastating weapon and was shocked in March 1944, at a private dinner at the Chadwick’s, to hear Leslie Groves say “Of course, the real purpose in making the bomb was to subdue the Soviets”. By the end of 1944 it was also apparent that Germany had abandoned the development of its own bomb and Rotblat asked to leave the project. Chadwick was then shown a security dossier in which Rotblat was accused of being a Soviet spy.

However, Rotblat was able to show that much of the information within the dossier had been fabricated.  Despite this, Rotblat was not permitted to re-enter the United States until 1964.  Rotblat was the only physicist to leave the Manhattan Project on the grounds of conscience, though others later refused to work on atomic bombs after the defeat of Japan.

The subsequent bombing of Hiroshima and Nagasaki intensified his ethical concerns over the involvement of scientists in developing weapons of mass destruction, and drove Rotblat to become deeply involved in the anti-war movement.  He was one of the 11 illustrious signatories to the Russell Einstein Manifesto of 1955 which urged peace in a world overshadowed by the nuclear threat.


Rotblat returned to Britain to become senior lecturer and acting director of research in nuclear physics at the University of Liverpool.  He was joined by his mother, sister, and one of his brothers.  He felt betrayed by the use of atomic weapons against Japan and campaigned for a three year moratorium on all atomic research.  Rotblat was determined that his research should have only peaceful ends, and so became interested in the medical and biological uses of radiation.  In 1949, he became professor of physics at St Bartholomew’s Hospital, London, shortly before receiving his PhD from Liverpool in 1950.

At St Bartholomew’s Rotblat worked on the effects of radiation on living organisms.  This led him to an interest in nuclear fallout, especially strontium-90 and the safe limits of ionising radiation.  In 1955, he demonstrated that the contamination caused by the fallout after the Bikini Atoll nuclear test by the United States would have been far greater than stated officially.  Until then the official line had been that the growth in strength of atomic weapons was not accompanied by an equivalent growth in radioactivity released.  Japanese scientists who had collected data from a fishing vessel, the Lucky Dragon, which had inadvertently been exposed to fallout, disagreed with this.  Rotblat was able to deduce that the bomb had three stages and showed that the fission phase at the end of the explosion increased the amount of radioactivity a thousandfold.  Rotblat’s paper was taken up by the media and contributed to the public debate that resulted in the ending of atmospheric tests by the Partial Nuclear Test Ban Treaty.

Rotblat believed that scientists should always be concerned with the ethical consequences of their work.  He became one of the most prominent critics of the nuclear arms race, was the youngest signatory of the Russell-Einstein Manifesto in 1955, and chaired the press conference that launched it.  After the positive coverage of the manifesto, Cyrus Eaton offered to fund the influential Pugwash Conference.

7 July 1957

Convened at the onset of the Cold War, a group of scientists held their first peace conference in the village of Pugwash, Nova Scotia, Canada.  The mission of the Pugwash Conference was to “…bring scientific insight and reason to bear on threats to human security arising from science and technology in general, and above all from the catastrophic threat posed by humanity by nuclear and other weapons of mass destruction”..

The Pugwash Conferences on Science and World Affairs is an international organization that brings together scholars and public figures to work toward reducing the danger of armed conflict and to seek solutions to global security threats. It was founded in 1957 by Joseph Rotblat and Bertrand Russell in Pugwash, Nova Scotia, Canada, following the release of the Russell–Einstein Manifesto in 1955.

Fifty years after the bombing of Nagasaki and Hiroshima, and forty years after the signing of the Russell–Einstein Manifesto, the Pugwash Conferences and Joseph Rotblat were awarded the Nobel Peace Prize jointly “for their efforts to diminish the part played by nuclear arms in international politics and, in the longer run, to eliminate such arms”.  The Norwegian Nobel committee hoped that awarding the prize to Rotblat and Pugwash would, “encourage world leaders to intensify their efforts to rid the world of nuclear weapons”.  In his acceptance speech, Rotblat quoted a key phrase from the Manifesto: “Remember your humanity”.

On 8 July 1996 – The International court of justice declared that, in almost all circumstances use of nuclear weapons is illegal.

Written By Sarah Bartey

Written by Ezra Kingston

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