best package for a physical simulation?

[Robert Kern]

sittner at lkb.ens.fr wrote:
> Hello everyone,
> i would like to use python to perform some simulation involving collisions
> of colloidal particles.
> which is the best package/engine to do that in python?

What kind of numerical methods does such simulation require?

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco