Gravitation, by Misner, Thorne, Wheeler (http://a.co/dczH4eS http://a.co/dczH4eS) Fully understanding the math in this book requires a solid background in line

Gravitation, by Misner, Thorne, Wheeler (http://a.co/dczH4eS http://a.co/dczH4eS) Fully understanding the math in this book requires a solid background in linear algebra, calculus, differential equations. But I find it an incredibly interesting book even without understanding all the math: the engaging writing style and numerous illustrations capture the intuitions behind differential geometry and relativity, but without sacrificing the rigorous mathematical formulations underlying it.