Reading progress update: I've read 20 out of 1215 pages.

Gravitation (Physics Series) - Kip Thorne;Kip S. Thorne;Charles W. Misner;John Archibald Wheeler;John Wheeler

I couldn't help glancing into this before heading to the office this morning. 20p later I reluctantly dragged myself away. It's already provided a neat insight into co-ordinate systems.

 

Topology joke my brother used to tell:

Q: How can you escape any prison cell, only using mathematics?

A: Simple! Perform a co-ordinate transform such that the outside of the cell becomes the inside and vice versa - you are now free!