Otto Robert Frisch OBE FRS[1] (1 October 1904 – 22 September 1979) was an Austrian-born British physicist who worked on nuclear physics.

[4] He himself was talented at both but also shared his maternal aunt Lise Meitner's love of physics and commenced a period of study at the University of Vienna, graduating in 1926 with some work on the effect of the newly discovered electron on salts.

After some years working in relatively obscure laboratories in Germany, Frisch obtained a position in Hamburg under the Nobel Prize-winning scientist Otto Stern.

[5] The accession of Adolf Hitler to the chancellorship of Germany in 1933 caused Otto Robert Frisch to make the decision to move to London, where he joined the staff at Birkbeck College[6] and worked with the physicist Patrick Maynard Stuart Blackett on cloud chamber technology and artificial radioactivity.

While there she received the news that Otto Hahn and Fritz Strassmann in Berlin had discovered that the collision of a neutron with a uranium nucleus produced the element barium as one of its byproducts.

[14] In mid-1939 Frisch left Denmark for what he anticipated would be a short trip to Birmingham, but the outbreak of World War II precluded his return.

With war on his mind, he and the physicist Rudolf Peierls produced the Frisch–Peierls memorandum at the University of Birmingham, which was the first document to set out a process by which an atomic explosion could be generated.

[16] He did this by stacking several dozen 3 cm bars of enriched uranium hydride at a time and measuring rising neutron activity as the critical mass was approached.

[20] In 1946 he returned to England to take up the post of head of the nuclear physics division of the Atomic Energy Research Establishment at Harwell, though he also spent much of the next thirty years teaching at Cambridge where he was Jacksonian Professor of Natural Philosophy[6] and a fellow of Trinity College.