Alan Turing

At www.dailygalaxy.com/my_weblog/2015/12/quantum-conundrum-some-aspects-of-… … Alan Turing is famous, in books, urban myth and in a film, for cracking the Enigma Code – but among mathematicians and computer scientists he is even more famous for proving that certain mathematical questions are 'undecidable' – they were neither true or false (but beyond the reach of mathematicians). Astronomers think they have reached an 'undecidable' point – but read on (at the link).