Today is the 10th anniversary of the passing of Carl Sagan. Many people are posting about Carl and the impact he has had on their lives so I thought I'd join in with my own thoughts.
When I was a boy of 12 years I read Sagan's Dragons of Eden: Speculations on the Evolution of Human Intelligence. It was heady stuff for me at the time - cosmology, evolution, the nature of intelligence, DNA, and on and on. I knew a little bit about most of these things but to see it all interwoven and presented in such a clear fashion was a revelation.
One thing that still stands out in my memories of the book was the whole idea of brain/body mass ratio and the relationship to 'intelligence'. The idea of measuring physical characteristics, combining them mathematically in a sensible fashion, and relating them to something so abstract made a deep impression on me at the time. The following graph from the book has been stuck in my head ever since.
I went on to read Broca's Brain: Reflections on the Romance of Science and probably most of his other non-technical writings. He was an extraordinary popularizer of science and he strongly influenced my lifelong interest in science. Thanks Carl.