I barely knew anything from Kepler, appart from those concepts explained in the Physics class in High School, and didn't realize his true weight in modern science.
This book novelizes Kepler's life, at least his adult years. The author is interested in showing how great achievements came by, made by great genious, who lead lives that are more often than not dire and disaggreeable. It reminded me of "Measuring the World", only I find this novel better, more fulfiling.
Kepler was a genious (like Copernicus and Galileus) was a genious that had to build a new branch of science, had to develop the mathematical tools for that pursuit, and on the same journey had to pull down his own assumptions, theories and prejudice. He had to build on observations that were not his, buth Brahe, and at the same time to struggle for life. As other readers point out, it is difficult to know where the novel starts and where the true history begins, but the author has done a very clever and outstanding job of it.
One can only marvel how this man, who had everything against him (family position, religious prejudice, wars, illness, lack of understanding from his family...) could achieve such an intelectual peak that would tumble astronomy, physics and reshape the whole world. The book accompanies him through this voyage, from one poor house to a palace, from school to obsevatory, from family life to imperial court.
I would have liked the author to linger a bit longer on his adolescent and formative years, to get a deeper insight of the human character, but this does not diminish the novel.
It left me wishing it had lasted longer, and wanting to buy a "hard" Kepler biography.