Revert "Mark's Example"

This reverts commit 09e9766c0e72ae153b2749a44b92f4eb0cf5d8b6.
commit
Merge branch 'master' of github.com:mdbenjam/PhysicsSolver
Revert "commit"

This reverts commit 6348def5c5cd550d4d3bbf3e7957bcddf160bb1c.
Merge branch 'master' of github.com:mdbenjam/PhysicsSolver
demo