This is a pretty book and a good idea, but it doesn't amount to much. Each theory is presented in around 300 words of text with afterthoughts in sidebars. It seeks to cover physics, cosmology, the Earth, biology, the mind, etc. The text is written by relevant scientists: John Gribbin, Sue Blackmore, Mark Ridley, etc. The content is generally okay, but it can't give more than the most superficial glimpse of what each field is concerned with.
I had quibbles with the text; here's a couple of examples:
* Gribbin, describing panspermia, asserts: "It seems certain that some [prebiotic chemicals]... fell on to the young Earth and kick-started life." Certain? Since when?
* Jim Al-Khalili says that the Uncertainty Principle allows one property (speed or position) to be "measured to infinite accuracy", when in fact the UP imposes a finite limit on the accuracy obtainable.
* We are informed that in the film "A Beautiful Mind" the "mathematical content... was greatly simplified." This is a bit rich in a science book that only dares include one equation in the entire text, and that's E=mc^2!
However, my biggest beef with this book was the illustrations, which occupy the facing page beside each theory. Here was an opportunity to enrich the text with informative diagrams providing clear and practical insight into each subject: perhaps the Hertzsprung–Russell diagram, or RNA transcription at work. Instead, each illustration is little more than a decorative collage of clip-art, with inane captions: "if you believe in quantum theory" (as if 'belief' were an appropriate concept in this context). The one accompanying the article on Selfish Genes is incoherent rubbish. Beside Global Warming is not a graph but a travesty of a graph, by an illustrator who has evidently not grasped that the units on a linear axis must be evenly spaced!
Whilst its overviews are broadly okay, there is little to be learnt here if you're moderately familiar with science, and little that will stick in your mind if you aren't. There are other books that seek to provide an overview (Bryson's, for instance), and I should think most would do a better job than this one. It's barely coffee-table science.