Trevor Dann meets two more of our city’s great thinkers. American-born Jim Secord heads up Cambridge University’s Department of History & Philosophy of Science where he specialises in nineteenth century scientists. He’s also the leader of the Darwin Project which is publishing all of Charles Darwin’s letters online.

Back in the 21st century, David Tong is Cambridge’s answer to Brian Cox. He’s a professor of theoretical physics and spends his time wondering about quarks and black holes and trying to show where Newton and Einstein got things wrong.