4.0

I have to admit to not following all of the physics in this book. I'm not sure if this is due to intellectual deficiencies, laziness, or a combination of both. But as the book builds on concepts throughout, the concepts I hadn't paid enough attention to in the beginning became even more confusing.

Having said that, this book had me marvelling at the minds who can not only piece all of this together, but also think of ingenious ways of testing out their theories. Mind boggling stuff!