That's not exactly what I was talking about; I was speaking of the fact that energy, at its most fundamental, is nonlinear.

Planck discovered that physical action could not take on any indiscriminate value. Instead, the action must be some multiple of a very small quantity (later to be named the "quantum of action" and now called Planck's constant). This inherent granularity is counterintuitive in the everyday world, where it is possible to "make things a little bit hotter" or "move things a little bit faster". This is because the quanta of action are very, very small in comparison to everyday macroscopic human experience.

Thus, on the macroscopic scale, quantum mechanics and classical physics converge—the classical limit. Nevertheless, it is impossible, as Planck found out, to explain some phenomena without accepting the fact that action is quantized. In many cases, such as for monochromatic light or for atoms, this quantum of action also implies that only certain energy levels are allowed, and values in-between are forbidden.

In other words (and with massive oversimplification), discontinuous.