Members of Trinity have won 34 Nobel Prizes out of the 121 won by members of Cambridge University, the highest number of any college at either Oxford or Cambridge. Members of the college have won five Fields Medals in mathematics (of the seven awarded to members of British universities) and one Abel Prize. Trinity alumni include the father of the scientific method (or empiricism) Francis Bacon, six British prime ministers (the highest of any Cambridge college), seven head of states and leaders of various countries, physicists Isaac Newton, James Clerk Maxwell, Ernest Rutherford and Niels Bohr, mathematicians Srinivasa Ramanujan and Charles Babbage, poets Lord Byron and Lord Tennyson, English jurist Edward Coke, writers Vladimir Nabokov and A. A. Milne, historians Lord Macaulay and G. M. Trevelyan, philosophers Ludwig Wittgenstein and Bertrand Russell (whom it expelled before reaccepting), and Soviet spies Kim Philby, Guy Burgess, and Anthony Blunt.