The Beginning Of Time Essays - Physical Cosmology, Big Bang

The Beginning Of Time The Beginning Of Time There was a period in history when the beginning of the world in which we live in was a expressed through legends and myths, now, through the use of increasingly advanced scientific equipment we can see that the universe is more vast and complex than ever imaginable. The purpose of this paper is to show some of the modern beliefs regarding the beginning of the universe by finding the answer of these questions. What are the commonly excepted theories of the evolution of the universe? What is meant by the Big Bang Theory and how does it work? How our planet and solar system developed from The Big Bang? This paper will use scientific data to base the evolution of our universe around The Big Bang. At the present time there are two theories which are used to explain the creation of the universe. The first theory is the infamous Big Bang Theory, which will be detailed later. The second is the Steady State Theory. A later hypothesis was created to replace the common belief that the universe was completely static. The expansion of the universe was discovered in 1929 when Edwin Hubble discovered that every galaxy in the universe was moving away from each other, this meant that the universe was expanding. Hubble found the movement of the galaxies by using a phenomenon known as the Doppler effect. This effect caused bodies moving away from an observer to have a red-shifted spectrum (the light spectrum of the body had been shifted closer to red) and bodies moving towards an observer to be blue-shifted The expansion was traced backwards through time to discover that all the galaxies were created from the same point. It was later believed that all matter spawn from that center of the universe discovered by Hubble. Matter would collect outside this singularity and form every moon, planet, and star known today. The Steady State Theory was very attractive because it featured a universe with no beginning or end. The theory meant that scientist had to abandon the laws of conservation of mass and energy. It seemed convincing that the laws of physics could breakdown at a certain point but more and more evidence gathered against the Steady State Theory, leading to many modifications to it. Until finally the theory was dropped completely with the discovery of the smooth microwave background radiation (radiation so ancient it had shifted right out of the visible spectrum into microwave radiation). A smooth background to the universe suggested that it was hot and uniform - the ideal conditions for the Big Bang. The Big Bang was almost exactly what it sounds like - a giant explosion. During this explosion all the materials in the universe today (matter, energy and even time) were expelled into a vacuum about 12 billion years ago. The combined mass of the universe was interpolated to a point of zero volume (therefore infinite density). It is impossible to guess what the universe would physically be like because the density of the universe cannot be plugged into any physical equation. The history of the universe can be traced back to a moment 10- 33 seconds after the big bang. At this moment the universe is filled with a sea of various exotic particles along with electrons, photons, and neutrinos (and their respectable anti-particles). At this time there are also a small number of protons and neutrons. The protons and neutrons are participating in sub-atomic reactions. The two most important of these reactions are: Antineutrino + Proton ----* Positron (anti-electron) + Neutron Neutrino + Neutron ----* Electron + Proton In effect the protons are becoming neutrons and vice-versa. The energies are so great that simple atoms being formed fall apart immediately after coming together. As the universe expands, and loses energy the electrons and positrons begin to collide, effectively annihilating one another, leaving only energy in the form of photons and neutrinos. Appropriately fourteen seconds after the Big Bang simple atoms are formed like deuterium and helium. About three minutes after the incidence of creation, the universe has sufficiently cooled to allow formations of helium and other light elements. As it is proven by the cosmic background radiation, the universe was uniformly smooth. A change had to have occurred, otherwise no celestial objects would have formed and as the particles lost energy, they would simply decompose into simpler particles. Something had to have caused the particles to group together and