Chapter 10 The Unification of Physics Summary and Analysis

Physicists are good at solving small problems regarding the nature of the universe, but nobody has come up with a single theory that explains everything or predicts reliably in all cases. This is why so many theories have been developed and why they sometimes contradict each other in astonishing ways. From one viewpoint, the universe must have had a beginning and will likely have an end. From another, the universe may have always existed and always will. Black holes may be completely black or there might be radiation from the event horizon. On top of this all, quantum mechanics introduces the uncertainty principle. We may never be able to predict everything reliably as a consequence.

Hawking brings out three possibilities: Someday physicists will discover a complete unified theory; no complete unified theory is...