Bill Bryson's book not only shows us what we know but more importantly what we don't know. And what we don't know is so much more! The book should be compulsory reading for all those who think that scientific progress is the Alpha and Omega of learning. It shows the shortcomings of the sciences as well as the shortcomings of those who actually do science. I believe that Bryson also gives us a warning. What warning? It is simply this: 'When you advance science, or any part of human knowledge, tread carefully! Nevertheless, I read the book almost in record time. Could hardly put it down.