Einstein's theory was not valid, as recognized by himself and by the scientific world. In terms of using his theory of relativity to explain the universe, it was valid, however on a broader spectrum that included other astronomical discoveries, Einstein's "static theory" was not valid. In 1917, Albert Einstein added a cosmological constant to his equations of general relativity to counteract the effects of gravity on ordinary matter, which would otherwise cause a static, finite universe to collapse or expand forever. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay This model of the universe became known as Einstein's world or Einstein's static universe, implying that Albert had the idea that the universe was static or not -expansionistic, after his theory of relativity was applied to the universe. This motivation to demonstrate that the universe was static vanished after astrophysicist Georges Lemaître's proposal that the universe appears not to be static, but expanding. Edwin Hubble had researched the data of observations made by the astronomer Vesto Slipher. This confirmed a relationship between redshift and distance. This forms the basis for the modern expansion model introduced by Lemaître and Hubble, which is still used today. According to George Gamow this led Einstein to declare that his cosmological model contradicted the more popular theory of Hubble and Lemaitre. Einstein's universe was soon recognized as unstable and was soon abandoned as a viable model for the universe. Why was the theory abandoned? Einstein's universe was unstable in the sense that any slight change in the value of the cosmological constant, the density of matter, or the curvature will result in a universe that expands and accelerates forever or collapses again into a big crunch. For a model of a static, infinite universe to be viable, it must explain three things: It must explain intergalactic redshift (stretching of the wavelength of light, so light is seen as "shifted" towards the red part of the spectrum) . it must account for cosmic microwave background radiation (as explained earlier in the report) and must have a mechanism for recreating matter (particularly hydrogen atoms) from radiation or other sources. In the absence of such a mechanism, the universe would consist of dead objects such as black holes and black dwarfs.