[Visualpython-users] Enhanced gas program

In the Contributed section of vpython.org is an enhanced version of
gas.py by Giulio Venezian. Here are notes from the program:

## Based on gas.py, which is distributed in the VPython example programs.
##   modified so initial distribution has no overlapping atoms
##   modified for isotropic distribution (but all atoms start with the
same energy)
##   modified to display additional histograms
## This is an attempt to handle collisions in the order they occur;
## in previous versions, they were handled by position in the loop,
not in order of occurrence
## which makes the system irreversible (aside from rounoff errors).

Bruce Sherwood