As a lapsed scientist myself, not a huge amount of this book was new to me, but I can see why it is popular with people who have never had to crack open a science textbook since leaving school, or even with some who have. Bryson's chatty style, which hasn't always worked for me, carries us fairly effortlessly through the fundamentals of physics, geology and evolutionary biology, with a decent amount of reflection on the men and women behind the scientific theories (though without going very far into the sociology of knowledge).
Two things really jumped out at me, both of which I was vaguely aware of but which Bryson really brought to life: 1) the imminent and catastophic eruption of the Yellowstone caldera, which will wipe out a significantly large chunk of the continental United States; and 2) the catastrophic impact of human fishing on the fauna of our oceans. Definitely losing sleep about both of those now.
Top UnSuggestion for this book: The New Reformation Study Bible. Hmmm.