Sun tanning However, it operates not by inducing direct DNA damage, but by producing reactive oxygen species which damage DNA indirectly. UVA (see above) induces a cosmetic tan but little extra melanin protection against sun damage, sun burn, or cancer. Ultraviolet B (UVB) radiation is in the wavelength range 280 to 320 nm. Much of this band is blocked by the Earth's ozone layer, but some penetrates. UVB: A person's natural skin color affects their reaction to exposure to the sun. An individual's natural skin color can vary from a dark brown to a nearly colorless pigmentation, which may appear white .
The empire on which the sun never sets ring, the phrase is sometimes used critically with the implication of American imperialism, as in the title of Joseph Gerson's book, "The Sun Never Sets: Confronting the Network of Foreign U.S. Military Bases". The empire on which the sun never sets The phrase "the empire on which the sun never sets" has been used with variations to describe certain global empires that were so extensive that there was always at least one part of their territory that was in daylight. It was originally coined for the Spanish Empire, mainly in the 16th and 17th centuries. In more recent times, it