The original link looks like a scratchpad/notes page to me.<p>For insight into John Baez's ideas around this time, try the slides from this colloquium: <a href="http://math.ucr.edu/home/baez/quantum_spacetime/" rel="nofollow">http://math.ucr.edu/home/baez/quantum_spacetime/</a><p>(<a href="http://math.ucr.edu/home/baez/quantum_spacetime/qs.pdf" rel="nofollow">http://math.ucr.edu/home/baez/quantum_spacetime/qs.pdf</a>)<p>Urs Schreiber currently is at the forefront of where this line of mathematics ties in with fundamental physics. Here is a series he has started recently:<p><a href="https://www.physicsforums.com/insights/20-years-ago-today-m-theory-conjecture/" rel="nofollow">https://www.physicsforums.com/insights/20-years-ago-today-m-...</a><p>Baez's higher dimensional algebra program formed a large part of the heritage to these ideas.