Natural Science Forum / Physics / Research / October 2005

Has anyone ever read this book?  The Evolution of Physics by Albert
Einstein.  I was thinking about trying to get a really nice copy for my
library, like this one on eBay if it is a good read.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6573594864

Hello, spr!
Here are some questions that may stimulate debate here.
1: Does light follow a geodesic or an eikonal? I worked out a simple
case from point A in empty space to point B in a refracting medium, at

What is an example, preferably a reasonably simple one, of a mechanical
system which can be solved using Hamiltonian Mechanics but which does
not yield a solution in Newtonian Mechanics?
Cheers

Also available as http://math.ucr.edu/home/baez/week222.html
October 17, 2005
This Week's Finds in Mathematical Physics - Week 222
John Baez

I need to find some references on "cluster growth" algorithms.
The simplest example would be the simple cubic lattice:
Zeroth shell 1 atom at 0,0,0
First shell 6 atoms at permutations (+/-1,0,0) (first neighbours)

Also available as http://math.ucr.edu/home/baez/week220.html
August 31, 2005
This Week's Finds in Mathematical Physics - Week 220
John Baez

Suppose that I want to study the trajectory of a test particle
that is acted upon by a massive spherical object, say a star.
Suppose the test particle comes in from infinity at an initial
impact parameter b and is deflected by the gravitational

What properties of the big bang singularity can be inferred from the
Penrose-Hawking theorem?
What properties of the big bang singularity can be inferred from modern
physics as a whole?

Hello again:
I just posted some further materials at
http://home.nycap.rr.com/jry/FermionMass.htm, regarding my very strong
suspicion that baryons are third rank antisymmetric tensors, including the

Grassmann numbers correspond to objects with squares equal to zero
(similarly, imaginary numbers correspond to objects with squares less
than zero).  Assuming they form a (distributive) algebra, it follows
that all elements must anticommute:

Hi every one
In classical thermodynamics the four state variables are P, V, T and
composition. These are quite obvious for a system of Gases. However
what are the state variables for any non-gas system. For example, in

According to some physicists (for instance John Baez
and Peter Woit), both string theory and loop quantum
gravity have not made much progress recently.
How active are other approaches like noncommutative

If the expansion of the universe is going to stop and be stopped by
dark energy,dark energy must change in some way because it is
currently postulated to be accelerating the universe.If there is a
change in dark energy i.e if dark energy consists of individual

Is there a legitimate way to define a quantum state as some kind of
superposition of classical states?

Does the Zero Point Energy of Quantum Field Theories depend on the
curvature of spacetime? I suspect so. For we have much greater particle
creation when the early universe was tightly curled than we have today.
And we have Hawking radiation near event horizons of black hole, where