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.
The year 2010 marked the centennial (El Centenario) of the Mexican Revolution, an uprising that took place roughly between 1910 and 1920, recognized as the first major political, social, and cultural revolution of the 20th century.