Vulcan (hypothetical planet) Vulcan (hypothetical planet) Vulcan is a small hypothetical planet that was proposed to exist in an orbit between Mercury and the Sun. Attempting to explain peculiarities of Mercury's orbit, the 19th-century French mathematician Urbain Le Verrier hypothesized that they were the result of another planet, which he named "Vulcan". A number of reputable investigators became involved in the search for Vulcan, and despite occasional claimed observations, no such planet was ever confirmed. Peculiarities in Mercury's orbit have now been explained by Albert Einstein's theory of general relativity. Searches of data gathered by NASA's two "STEREO" spacecraft have failed to find
The empire on which the sun never sets Sam". In 1906, William Jennings Bryan wrote, "If we can not boast that the sun never sets on American territory, we can find satisfaction in the fact that the sun never sets on American philanthropy"; after which, "The New York Times" received letters attempting to disprove his presupposition. A 1991 history book discussion of U.S. expansion states, "Today ... the sun never sets on American territory, properties owned by the U.S. government and its citizens, American armed forces abroad, or countries that conduct their affairs within limits largely defined by American power." Although most of these sentiments have a patriotic