Ironically, of course, the very world we live in is discontinuous at a base physical level. Thinking in groups and classifications may just be one of those universal human qualities that comes from the world around us.
That's not exactly what I was talking about; I was speaking of the fact that energy, at its most fundamental, is nonlinear. 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.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.
Quanta of energy have to do with the wavelengths of light emitted from, say, an electron jumping to a lower energy level. That is what is quantized, and it comes from the boundary conditions of the energy levels themselves. I was making a comment about how many people have speculated that quantization extends to space-time itself, that we move through the universe in a quantized way; that is what a discontinuous universe would look like. This new research suggests that there aren't boundary constraints on space-time, apparently.
Ah, I see. "Smooth, not foamy" makes quite a bit more sense in this context, actually. I'm just not sure how much I want to hinge a change in our entire physical worldview on the fact that some particles acted like they were on pavement rather than gravel, as it were. This is extremely interesting, though. Planck's constant has long been thought they be-all end-all, I believe. Perhaps nuts to that."If foaminess exists at all, we think it must be at a scale far smaller than the Planck length, indicating that other physics might be involved," study leader Robert Nemiroff, of Michigan Technological University, said in a statement.