SearchOnMath

Shannon's entropy, \(H(X) = -\sum_{x \in \mathbf{X}} p(x) \log p(x)\), measures how informative the mass function \(p\) is about the occurrence of the possible values of variable \(X\).

Newton's mutual attraction force for masses \(m_1\), \(m_2\) is \(F=G\frac{m_1 m_2}{d^2}\), where \(d\) is the distance between them and \(G\) is the gravitational constant.

The heat equation, \(\frac{\partial \varnothing}{\partial t} = D \nabla^2 \varnothing\), uses the Laplacian of \(\varnothing\) to express diffusion through a medium.