During all the years of formal training as a scientist, I found myself trying to reconcile my passion for music with physics. I started to not only see how the act of doing physics research could benefit from musical analogies but how our physical world actually had a musical character. Aside from the few mentors, such as Chris Isham and Robert Brandenberger, who had encouraged me to blend the two, I felt pressure to keep these two worlds separate. Physics to some is about absolute truths encoded in rigid mathematics, and music is a language of emotion. Perhaps this tension would not have been a big deal had I known that in the early days of science, music and astronomy were inseparable. To the modern musician and scientist, this may seem preposterous, but to early people, who lacked the scientific tools we now have, music became an analogy for the ordering and structure of the cosmos.

Weaving music and physics into one avenue of thought has showed me how to use notions in music as points of access to various fields in modern physics and cosmology. Analogies have helped make the physics more accessible and stimulating.

It is wonderful to think of following the footsteps of our ancestors -- the great ancient thinkers who sought to understand physics through sound, and sound through physics. Pythagoras played with hammers and strings to try to understand where the pleasures of music came from, while Kepler used his intuition that the universe was musical to make major advances in the fields of astronomy, physics, and mathematics.

This book is not only about the analogy between music and cosmology but also about the importance of musical and improvisational thinking in doing physics. Theoretical physicists exemplify John Coltrane's approach to music. We use an arsenal of conceptual and mathematical tools that we practice through examples that were worked out by past masters, like Einstein and Feynman. Likewise, jazz musicians like Coltrane master their tradition throughout countless hours of practice. But for both the theoretical physicist and the jazz improviser, it is not enough to simply master the material of the past; discoveries must be made.