Created in 1915, Einstein's General Theory of Relativity is one of the crown jewels of human thought and quickly became the standard model for understanding gravity. Within the last few years, however, data has begun to accumulate that the theory cannot account for. As an example the speed of the rotation of galaxies is much greater than the theory predicts. To try and fit these latest findings into the present theory scientists have postulated the existence of dark matter. The hunt for dark matter has become the cause celeb of physics and yet to date no one has been able to find it. Within the pages of this book Dr. Moffat argues that the reason that dark matter hasn't been found is that it doesn't exist and that instead it is the theory that is wrong. If he is right in his modified gravity ideas then many things we now take for granted just aren't so. Maybe the speed of light can vary under certain circumstances, maybe there are no black holes, and maybe dark matter and dark energy really do not exist.

He did his best to keep it simple but remember that this is a physicist's idea of simple. Still all in all he did a pretty creditable job. For science history buffs his recap of the history of gravitation theory is worth a look all by itself. In defending his theory he takes you through all the latest findings, experiments, and theories. If you are interested in physics but know little about it this book is a nice place to start. Weather his modified gravity theory has any merit I am not qualified to say. But in raising the question he reminds us that nothing in science is sacrosanct and that the quest for knowledge never ends