The age of the universe is said to be about 13.75 billion years old. The method used in determining this age would be attempting to find the age of chemical elements, oldest star clusters, as well as white dwarf stars. Scientists also try to find the universes rate of expansion, and behavior of globular clusters, which are spherical collection of stars. In order to find this, scientists can use radioactive decay to determine how old a given mixture of atoms is in rock samples. In order to find the rate of expansion of the universe, The Hubble constant was the basic cosmological model dependent on density and composition of the universe. Some formulas used by The Hubble Constant is that the earth is composed of primary matter and the age of the universe is 2/3(Ho) with Ho being The Hubble constant (1). Another formula is that the earth is said to have very little matter and the age of the universe is 1/ Ho, which is now considered to be more accurate (1).
The age of the earth is approximately 4.54 billion years old, about 9.21 years after the universe was formed. The main theory of how the earth was formed is the Big Bang Theory, or a star explosion. Some also call is a supernova. This happens in the universe when the wreckage from an explosion crashed into a cloud of gas, bringing in the ingredients for our solar system. The formation of our sun came first from the collapse of a solar nebula. After about ten to twenty million years after this collapse, dust then clustered to grains, to lumps, to boulders, to planetesimas. Soon it became chunks of rock big enough to have their own gravitational field. So, some plantesimals became the embryonic form of planets in our solar system today. As more asteroids and other planets collided with planet earth, crust began to cool and water began to form and collect on the surface.
Age of the Earth . (2007, July 9). USGS....