Melanin is a complex molecule able to form polymers with varying structures depending on their location in the body. Its active heart, however, is a series of rings of carbon atoms bound together by a sea of mobile electrons. When a high-energy photon from the Sun hits one of the electrons, it doesn’t break the molecule apart. Instead, the energy is dissipated in around a picosecond, which is very fast indeed. In a million millionths of a second, the potentially threatening photon has been adsorbed and all its energy has been converted to heat. The melanin molecule survives intact to fight
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