Реферат на тему The Beginning Of Time Essay Research Paper
Работа добавлена на сайт bukvasha.net: 2015-05-31Поможем написать учебную работу
Если у вас возникли сложности с курсовой, контрольной, дипломной, рефератом, отчетом по практике, научно-исследовательской и любой другой работой - мы готовы помочь.
The Beginning Of Time Essay, Research Paper
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 form larger entities. Gravity comes to
mind, but, at this point the largest particle is a helium atom, which due to it’s small size,
has very little of a gravitational pull. The only respectable theory is the “cosmic string
theory” is states that our four dimensional space (three spatial dimensions plus time) is
made up of knots in seven or eight dimensional ’strings’. These strings are really massive
(each meter of string would weigh 1021 kg). This would require that the universe was not
a complete vacuum prior to the Big Bang because space itself would be make up of
cosmic strings. The cosmic strings while being extremely heavy are also very tight, so tight
that if a string were not either a circle (connect to itself in a loop) or of infinite length, it
would pull itself together into nothing. A string can also disconnect and reattach with
other strings that are intersecting it. Now a universe can be pictured with an infinite
number of ‘cosmic strings’ interacting with each other even before the Big Bang. After the
material was dispersed via the Big Bang, particles were attracted to the cosmic strings
(mainly loops, since the mass would be more centralized). These cosmic string loops,
could be the basis for the formation of a galaxy. The small particles would be attracted by
the strong gravitational field of the loops, thus creating a hub for the creation of a galaxy.
After some years all the loops would decay because of their strong emission of
gravitational radiation leaving enough collected matter to form a fully functioning galaxy
behind.
In clouds of dust and gas (mainly hydrogen) at the center of the galaxy, pressure and
temperature build causing an increase in density and gravity. The heavier particles fall to
an orbital cloud of the young star while the lighter elements close in on the core. This
increase in gravity causes a further increase in pressure, until the center of the star has the
conditions ideal for nuclear fusion. This process occurs at the very core of the star and
converts hydrogen into helium at an alarming rate. A star is born.
The outer cloud of the star may also harbor some heavenly bodies usually planets or other
stars. The clouds of dust collect the same way in planet except the temperatures don’t
quite reach the point where nuclear reactions take place.
By means of commonly accepted theories, the origin of the universe from the Big Bang to
the formation of a planet, has been successfully detailed. Thanks to new technology
introduced in the past fifty years and thank to intellectual minds capable of supporting that
technology, more has been learned about our would than ever imagined possible.
Although all the advances assumed feasible have put to use will still are far from knowing
the absolute truth. Surely the early astronomers thought that they were correct in their
theories, but most ended up being dead wrong. We cannot assume that all of our current
theories are correct because although we may know more, we will never know all.
Hawking, S. W. (1988). A Brief History Of Time. New York:
Bantam. Kitchen, C. R. (1990). Journeys To The End Of The Universe.
Bristol: Adam Hilger. Silk, Joseph. (1994). A Short History Of The Universe. New York:
Scientific Americal Library.
Wienberg, Steven. (1977). The First Three Minutes. New York: Basic Books, Inc.