In particular, the energy of a photon equals Planck's constant times the frequency of the radiation. Mathematically, this is given by the equation E = hf. Planck's constant is the fundamental constant of quantum theory that determines the scale of the small-scale world.lanck's constant = 6.63 * 10^-34 joule-second (J-s). The total energy in an electromagnetic wave is the sum of the energies of each photon in the wave. The energy of a photon is so small that we usually measure it in electronvolts (eV). One eV is the potential energy of each electron in a 1-volt battery.
A social revolution inevitably encounters an obstacle in the form of the political power of the ruling class. Hence, the first act of a social revolution is political revolution, the attainment of state power by the revolutionary class.
Kautsky and his Russian co-religionists who wanted to see the Russian Revolution keep the bourgeois character of its first phase, are an exact counterpart of those German and English liberals of the preceding century who distinguished between the two well-known periods of the Great French Revolution: the good revolution of the first Girondin phase and the bad one after the Jacobin uprising.