Simulation

To me, the most remarkable story outlined by John Barrow is Living in Simulation.

The idea is simple. If we follow the modern idea of quantum physics, there are many possible universes. The inevitable consequence is civilisations with far more advanced technology than ourselves should exist, and they have the capability of simulating universes. In other words, they can study the formation of galaxies and watch the evolution of life in vivo. And, within these simulated universes, self-conscious entities (for example, René Descartes) can emerge and consider the meaning of their own life.

The question is, therefore, are we existing in a simulated reality rather than a real one?

Sounds familiar, eh? You did watch Matrix, didn't you? In fact, I have also outlined a similar story previously in this site. (Go read http://ccszeto.blogspot.hk/2010/05/being.html) The annoying bit is, many scientists argue that it is highly likely that we are living in a simulated reality, basically because there should be far more simulated universes than real ones.

How could we tell?

John Barrow outlines a method in the book.

PS. I must say, as an admirer of David Hume, I am not convinced with the answer provided - there are so many "glitches" that we encounter in the nature.

You would know what I mean if you have read this book.