Sunday, March 20, 2005

A theory of everything?

In his later years, Einstein sought a unified theory that would extend general relativity and provide an alternative to quantum theory. There is now talk of a 'theory of everything' (although Einstein himself never used the phrase). Fifty years after his death, how close are we to such a theory?

Read the rest in Nature

Symposium on Roger Penrose's Shadows of the Mind

'In his book Shadows of the Mind, Roger Penrose suggests that deep problems in artificial intelligence, physics, and the philosophy of mind are closely connected. He presents a detailed argument, using Gödel's theorem, for the conclusion that human thought cannot be simulated by any computation. This leads him to the conclusion that physics is noncomputable, and he presents suggestions about how noncomputability may enter into a theory of quantum gravity. Finally, he argues that this may take effect at the level of the mind through quantum collapse processes in microtubules, protein structures found in the skeleton of a neuron.

In this symposium, nine researchers in computer science, philosophy, psychology, mathematics, and molecular biology address Penrose's positions at some length, concentrating on his Gödelian arguments against artificial intelligence and on his proposal that quantum processes in microtubules are essential to the functioning of the mind. The commentaries are followed by a reply by Penrose.'

Symposium on Roger Penrose's Shadows of the Mind

Saturday, March 19, 2005

Roger Penrose's Platonism

Listen to this wonderful lecture by Sir Roger Penrose, author of The Emperor's New Mind and most recently The Road to Reality. Accompanying the talk are his handwritten slides, to help you follow along. Here is the first one: