Here's a bunch of fun stuff, mostly written
by me. It's mainly about math and physics,
but there's also some about astronomy, biology, and other things.
I've tried to classify it like this:
physics FAQ - Answers to frequently asked
physics questions, compiled by many authors. Please don't send me
comments about this! It's run by Don Koks; I am merely one of many
hosts.
photon - excerpts
from the infamous "Photons, Schmotons" thread,
in which Michael Weiss and I went through a lot of quantum theory,
leading up to some basic quantum electrodynamics.
renormalization -
renormalization in quantum field theory and statistical
mechanics made easy.
spin_stat - a sketch of the proof of the
spin-statistics theorem.
area - some
puzzling possible progress on determining the quantum of area.
background - what is a background-free
theory of physics, and why are they important?
black hole - a picture of a
quantum black hole as we imagine it in the spin network approach
to quantum gravity.
edge -
What I've changed my mind about: should I be thinking about quantum gravity?
connect - a short story by
Greg Egan about future of loop quantum gravity. It's called
"Only Connect" and it appeared in the journal Nature on February
10, 2000.
foam - information
about spin foams, compiled by Dan Christensen. If you know some
math and want to learn about spin foam models of quantum gravity,
check out the archive of his conversation with me about this stuff.
hamiltonian - my paper
"The Hamiltonian constraint for quantum gravity in the
loop representation", which is an introduction to Thiemann's work on
that subject. This is not for the faint-hearted; a
less demanding
versioncan be found in Jorge Pullin's
newsletter, Matters of Gravity.
penrose - Roger Penrose's papers on
spin networks, "Angular momentum: an approach to combinatorial
space-time" and "On the nature of quantum geometry",
in electronic form.
planck - my
paper "Higher-dimensional algebra
and Planck scale physics", a not too technical introduction to current
ideas on quantum gravity.
quantum - my paper
"Quantum quandaries: a category-theoretic perspective",
which is a followup to the previous paper.
QG - notes from the Quantum Gravity
Seminar here at U. C. Riverside. A vast amount of stuff.
the
art of math - an article by Sophie Hebden about my work on
categorification and physics.
boosts - according to Emmy Noether,
symmetries give conservation laws - but what does symmetry under
Lorentz transformations give? You won't find the answer in most
books!
braids - some rambling lectures on knot
polynomials, braids, anyons, noncommutative geometry, and lots of other
neat things.
butterfly - the butterfly, the gyroid
and the neutrino: how beautiful mathematics and physics can be found on
the wing of an iridescent butterfly.
categories - a sketch of category
theory and how it relates to quantization.
harmonic - discreteness and the role
of compact groups and double covers in the quantum mechanics of spin
and the harmonic oscillator.
inverse cube - the inverse cube
force law in classical and quantum mechanics.
information -
an introduction to information geometry and related topics.
kostant - lecture notes and a
video of Bertram Kostant's lecture
entitled "On some mathematics in Garrett Lisi's E8
theory of everything".
golden - tales of fool's gold and
the golden ratio.
groupoidification - an introduction
to "groupoidification", a process that
reveals the bare bones of combinatorics beneath the flesh
of linear algebra.