History of the Universe Investigation The Big Bang theory is a theory that states that the universe originated as a single mass, which subsequently exploded. The entire universe was once all in a hot and dense ball, but about 20 million years ago, it exploded. This explosion hurled material all over the place and all mater and space was created at that point in time. The gas that was hurled out cooled and became our stellar system. A red shift is a shift towards longer wavelengths of celestial objects. An example of this is the “Doppler shift.” Doppler shift is what makes a car sound lower-pitched as it moves further away. As it turns out, a special version of this everyday life effect applies to light as well. If an astronomical object is moving away from the Earth, its light will be shifted to longer (red) wavelengths. This is significant because this theory indicates the speed of recession of galaxies and the distances between galaxies.How do stars form?Small regions within an instellar cloud about a fraction of a light year across begin to collapse under their own gravity. As the collapse continues, the center of this core region becomes denser and denser climbing from only 100 atoms per cubic centimeter to millions of atoms per cubic centimeter and higher. As it collapses, whatever very slight rotation it originally had gets amplified so that it spins faster and faster. Although the gas falling along the axis of the collapsing cloud feels nothing more than the gravitational force of the central core, along the equator of the object, centrifugal forces due to its spinning become so strong that they strengthen the collapse along this direction. The cloud collapses into a flattened disk with a central bulge containing most of the mass, and it is in this central objects that the star will be formed.Life Cycle of a StarA star is born in a high-density nebula and condenses into gas and dust and contracts under its own gravi...
