Modern Cosmology
Cosmology, or modern astronomy, has deep roots in the Big Bang theory, which seeks to explain the beginning of the universe, the structure of the objects within it, and the laws that govern it. The Big Bang and string theory are two highly respected theories in science for the universe.
In the history of astronomy, very little discoveries have been more important than the introduction of the new heliocentric cosmology. It was common belief up until the 1500s that the Earth was the center of the universe-- with everything else orbiting around it. With the 1500s, however; a new idea came to light. Nicholas Copernicus suggested in his book “On the Revolution of the Heavenly Spheres,” that the Sun was the center of the solar system. Later, into the early 1600s, Johannes Kepler was an advocate Copernicus’ heliocentric universe. Kepler is responsible for discovering that planets revolve around the Sun in elliptical orbits—which is the first of his three laws of planetary motion. His second law, according to "Johannes Kepler: The Laws of Planetary Motion" (n.d.), is “the line joining the planet to the sun sweeps out equal areas in equal times as the planet travels around the ellipse,” (para. 14). "Johannes Kepler: The Laws of Planetary Motion" (n.d.), also states that the third of Kepler’s laws is “the ratio of the squares of the revolutionary periods for two planets is equal to the ratio of the cubes of their semi-major axes,” (para. 15). Kepler also proposed that the Sun provided a force responsible for keeping the planets in orbit. Later, Isaac Newton’s law of gravity would also support this third law.
After Copernicus, Kepler, and Newton’s discoveries, the introduction of the Big Bang theory came to be. According to this theory, the universe began with its energy in an incredibly dense point. This point eventually exploded with immense force,