Warning: These books are kind of all over the place as far as technical prerequisites go, but they all satisify being heavier than pop-sci and lighter than a te

Warning: These books are kind of all over the place as far as technical prerequisites go, but they all satisify being heavier than pop-sci and lighter than a textbook. :) ------- Aleksandrov et al - Mathematics: Its content, Methods, ad Meaning. Overview of undergrad curriculum by a number of prominent russian mathematicians. Levi - The mathematical Mechanic. Uses various physical intuitions and scenarios to solve mathematical problems. Pask - Magnificent Principia. Tour of newtons principia that includes both newtons geometric language and modern vector calculus version. Stillwell - Elements of Mathematics. Discusses some important classical problems in the history of mathematics taken from 8 subjects: arithmetic, computation, algebra, geometry, calculus, combinatorics, probability, logic. Wow! Yandell - The Honors Class: Hilbert's problems and their solvers. Lots of mini biographies with some information describing each of Hilbert's famous problems. Lawvere & Schanuel- Conceptual Mathematics. Some basic notions of category theory, geared towards teaching you Lawvere's clarification and generalization of the incompleteness theorems. Cormen - Algorithms Unlocked. Pop Science version of some of the textbook. Nahin - Inside interesting Integrals. Lots of fun integrations! Nahin - He also wrote some books about euler and imaginary numbers which ive partially read, they seemed good. Pierce - An introduction to information theory; symbols signals and noise. sounds and looks like a dover textbook but is a non-fake pop science book. --------------- Boyer - The History of Calculus and its Conceptual Development. A bit old, and spends too much time on formalism in the 18th and 19th century, there might be something better out now. Weyl - Philosophy of Mathematics and Natural Science. Reichenbach - The philosophy of Space and time. Klein - Elementary mathematics from the advanced viewpoint. these were written at the beginning of the 20th century so are slightly outdated, but kline was extremely forward-looking in his point of view. Courant & Robbins - What is Mathemaics. Another classic. Hilbert & Cohn-Vossen - Geometry and the Imagination. The gold standard of popular mathematics writing. A beautiful book.