Planck’s constant is the smallest possible unit of energy. Energy, like space and time, is a key concept of physics that was initially thought to be continuous. It was defined in the nineteenth century as the ability to move matter around, which was called work, so burning coal in a steam engine produced work by converting coal energy to the kinetic energy of the moving train. This idea, that energy allows work that transfers energy, explained how engines operate, but there was a problem.
The problem was that light waves didn’t follow the rules. The furnaces of the time gave off light at many frequencies, so as they got hotter, all the frequencies should increase, but they didn’t. Hot furnaces didn’t give off lethal doses of x-rays that killed their workers. Physics then called that fact the ultraviolet catastrophe because for them, it was a disaster that their laws didn’t apply.
The law in question was that a physical wave’s energy increased as its frequency squared, so twice the frequency gave four times the energy. It followed that heating a furnace should increase all its light frequencies, including the dangerous ones. Why it didn’t was a puzzle, until Planck proposed that atoms emit light energy in multiples of a basic amount, later called Planck’s constant, by the equation:
Light Energy = Plank’s constant x Frequency
That the energy of light varied directly with frequency predicted the observed result, but no-one knew why. In theory, waves are continuous, so adding energy to high frequency light should just increase it, but heating a furnace didn’t increase all frequencies equally. Einstein then showed that light comes in little packets, called photons, based on the photo-electric effect. Heating a furnace doesn’t produce as many high frequency photons because they are less likely to happen, so the ultraviolet catastrophe didn’t happen.
It followed that energy isn’t continuous but comes in basic units represented by Planck’s constant, the smallest unit of energy. But why light comes in little indivisible units called photons remains a mystery of physics to this day.
A processing approach answers this question. Processing waves aren’t continuous because there is always a core process that can’t be divided further. Planck’s constant then represents what will now be called a Planck process, which is the basic unit of quantum network operation. Light then comes in little packets because each photon is one Planck process. Photons are the indivisible units of light because the processing behind them has an indivisible unit, so Planck’s constant is the smallest energy transfer because one Planck process is the smallest network transfer.
What then is energy in processing terms? Let it be the processing transfer rate. If every photon is the same process distributed, shorter wavelength light transfers processing faster, as each point has more to pass on. In contrast, a long wavelength divides the same process over more points, so each point has less to pass on. It follows that the energy of a photon depends directly on its wavelength, and hence its frequency, just as Planck described. By this logic, the equation that Planck assumed can be derived from processing principles (Note 1).
To recap, one photon is one Planck process divided over its network wave length, which can’t increase or decrease by less than a point. Adding a point distributes the process more, so the transfer rate we call energy is less, and reducing a point makes the transfer rate we call energy increase.
But if every photon is the same process divided more or less, why does high frequency light have more energy? If each photon makes the same dot on a screen, why doesn’t it have the same energy? It does, but high frequency light delivers more photons per second, so it has more energy. Increasing a photon’s frequency doesn’t increase its total energy, just the rate at which it arrives. X-rays deliver more photons per second than radio-waves, not more energy per photon. Hence the energy of light varies linearly with frequency as per Planck’s equation, not its square, because photons aren’t physical waves.
Note 1. Let one photon be a Planck process divided over the points of its wavelength, and the constant h represent that process as a quantum network transfer. Let energy E be the processing transfer rate at a point and W be the number of points in the photon wavelength. Every photon is then one Planck process divided between W points, so the processing transfer rate at a point E = h/W. If f is the number of network cycles each point takes to run a Planck process that it can complete in one cycle, then f = 1/W. The equation E = h.f then follows, where E, h, and f are defined in quantum units. Converting these units to per second terms then gives E = h.f, which is Planck’s equation. Plank’s constant then represents the transfer of one Planck process.