Felix Pirani

Felix Arnold Edward Pirani (2 February 1928 – 31 December 2015) was a British theoretical physicist, and professor at King's College London, specialising in gravitational physics and general relativity.

During the last half of the 20th century Pirani was politically active, studied disarmament and advocated the responsible use of science.

In 1957, Pirani independently discovered what was later called the Petrov classification (also Petrov–Pirani–Penrose classification) and separately discovered by Petrov in 1954. Pirani's work with Bondi and Robinson resulted in correspondence between Pirani and Albert Einstein, some of whose partially expressed views on the subject had been challenged by the paper.

In 1972, Pirani, Jürgen Ehlers and Alfred Schild showed that the space-time geometry of general relativity can be constructed from simple measuring processes with light beams and free-falling particles.

Popular books In 1960, Pirani revised the general audience book "The ABC of Relativity", originally written by Bertrand Russell in 1925. He continued revisions up to 2002. In the 1990s he began writing books aimed at the general audience, e.g. Introducing the Universe, translated into French as L'Astronomie sans aspirine (Astronomy without aspirin).

Political views Pirani was politically active in the 1970s and 1980s, had a left leaning stance, and opposed the unchecked use of science for military purposes. Along with DNA pioneer Maurice Wilkins, who was also at King's, Pirani was involved in the British Society for Social Responsibility in Science.

In 197, Pirani told the New Scientist that during an academic visit to the University of North Carolina issues about slavery and the American Civil War "hit him in the face" and upon his return to England he joined the Scientists of the Left and the Campaign for Nuclear Disarmament and became a political activist. Pirani's efforts were based on his view that the public belief that "science will solve the world's problems" is a delusion because funding for research comes from the top levels of the social hierarchy, which controls the direction of scientific progress for its own purposes.