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The astronomer Hubble laid the foundations of the Big Bang Theory of the universe in 1929 when he found that distant galaxies were receding from the earth. The theory holds that the origin of our universe was some 14 billion years ago in a cataclysmic explosion of radiant energy of unknown cause, which formed into atomic particles of hydrogen and helium. From these elements, gravity formed billions of stars gathered into galaxies, and then billions of galaxies. The theory is supported by existence of a cosmic remnant radiation, and the way heavier elements are created. A so far unknown “dark matter” must account for observed effects of gravity, and an unknown “dark energy” must account for the accelerating expansion of the universe.