The *Celebrating Mathematicians* concept was born out of the department's work in Equality and Good Practice. The department aims to highlight prominent Mathematicians, both locally and around the world. Our A Celebration of Mathematicians page highlights other academics featured.

Sir Roger Penrose (born 8 August 1931, Colchester, England) is an English mathematician, mathematical physicist, and philosopher of science. His work in the 1960s was one of the main influences behind the renaissance in general relativity and cosmology that led to our current big-bang picture of the universe and which led to our understanding of what is a black hole.

Penrose spent his early childhood during World War II in Canada where his father worked in a hospital in London, Ontario. In 1945, after the war ended, the family returned to England and Penrose’s father was appointed as Professor of Human Genetics at University College London. Penrose attended University College School followed by University College and graduated with a first class degree in Mathematics. Penrose continued his education at Cambridge University and obtained a PhD in algebraic geometry in 1957, but by this time he had already become interested in physics.

Following his PhD, Penrose held temporary posts at a number of universities in both England and the United States. From 1964 to 1973 he served as reader and eventually professor of applied mathematics at Birkbeck College, London. From 1973 he held the Rouse Ball Chair of Mathematics at the University of Oxford.

In 1965, Penrose proved a mathematical theorem that showed essentially that once a star has collapsed sufficiently, then nothing can stop it from forming a black hole. Together with Stephen Hawking, Penrose showed that if Albert Einstein’s general theory of relativity is correct, then there would be a singularity - likely a place of infinite density and space time curvature - where time has a beginning.

Penrose is also known for his 1974 discovery of the Penrose tiling, a pair of rhombus-shaped tiles that can be used to tile a flat surface ad infinitum without the pattern ever repeating itself. These tiles are often used by architects and display a mixture of regularity and disorder that is also of great mathematical interest and also seen in nature eg in quasicrystals.

Penrose continues to publish groundbreaking research with new ideas on topics ranging from cosmology to the way that consciousness arises from brain processes. His work, old and new, continues to influence and inspire the work of mathematical physicists around the world, including several members of the Mathematics Department here in York, where we were honoured to confer on him an honorary doctorate in 2006. He has been awarded many other honorary degrees and prizes, including the Wolf Prize for Physics shared with Stephen Hawking in 1988. He was knighted for his services to Science in 1994. Penrose was awarded the half share of the Nobel Prize for Physics in 2020 "for the discovery that black hole formation is a robust prediction of the general theory of relativity". (The other half was shared between the astronomers Andrea Ghez and Reinhard Genzel who observed evidence for the existence of a supermassive galaxy at the centre of our galaxy.)

References: Wikipedia, Math History, Prospect Magazine, Nobel Prize. , University of Oxford, Hawking.org The University of York