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 world's first antislavery society was founded in 1775 by Quakers in Philadelphia, the year the Revolution began. By 1788, at least thirteen of these clubs were known to exist in the American colonies.