y. These cosmologies, or explanations for the existence of creation, generally share four basic ideas. First, there is an intelligence or creator behind creation. Second, the universe came into being at a specific point in time and that what existed before the universe came into being is irrelevant as there was no existence or time before it. A major exception to this model of a universe created at a single moment in time comes from Hindu cosmology which states that the universe exists in cycles, of roughly 4.5 billion years, or one day in the life of the Brahma, the creator, endlessly being born, dying, and being reborn. The third component of most ancient cosmologies was that the Earth stood at the center of creation. p> And the final element was that, once the universe was created, it remained essentially static - nothing added, nothing taken away, all matter and energy in perpetual balance. That, too, was the model advanced by English scientist Isaac Newton in the late seventeenth and early eighteenth centuries, whose understanding of the laws of the universe dominated physics for more than 200 years. But even in Newton's own time, the idea of ​​a perpetually balanced creation was questioned by some thinkers, who pointed out that the universe would come apart if just one object should slip out of balance. And while Newton's laws attempted to explain how the universe operated, they did not offer much insight into its origins.
Immanuel Kant, a German philosopher of the late eighteenth century, was the first major Western thinker to tackle the question that the Big Bang theory would eventually answer-had the universe always existed or did it come into existence at a specific point in time? Kant concluded that since both arguments were equally valid on the face of things and that it was impossible to determine which was fundamentally true, the question of the universe's origins, or lack thereof, was beyond human comprehension. Even as nineteenth century astronomers began to push back the envelope of what was known about the universe's scale, they did not have the means or, given their religious faith, the inclination to grapple with Kant's question.
Early Hypotheses
Early twentieth century physicists and astronomers, of course, would prove Kant wrong. In 1912, an American astronomer named Vesto Slipher noted a Doppler shift in the wavelengths of light coming from spiral nebulae, an antiquated term for galaxies, dating from before the existence of other galaxies was confirmed. (It was American astronomer Edwin Hubble who first concluded in the mid-1920s that the nebulae were, in fact, galaxies similar to our own Milky Way.) The Doppler shift, named after Christian Doppler, the early nineteenth century Austrian mathematician who discovered it, says that waves alter in relation to the movement of the observer or the object causing the wave. While Slipher noted that almost...
