This is a video based on a talk Greg Michaelson and I gave to the British Maths Colloquium on the centenary of Turing. It is part of our continuing effort to defend materialist mathematics and computer science from idealist Platonism. A fuller account is given in our book Computation and its Limits
https://global.oup.com/academic/product/computation-and-its-limits-9780199640324?cc=gb&lang=en&
