It's F = T ∇ Sτ.
- F is the force, a directed force (therefore it is bold),
- T is a system temperature,
- Sτ is the entropy field of all states, reachable in the time horizon τ (tau).
- ∇ is the nabla operator. This is the gradient operator that "points" into the direction of the state with the most freedom of action.
If you are not a physicist this might sound like nonsense. Before I try to explain the equation in more detail, let's look at a another physical equation of force.
In a fascinating and informative talk, physicist and computer scientist Alex Wissner-Gross explains what in the world that means.