Our Universe's Big Bang example essay topic

Since the dawn of intelligent man, humanity has speculated about the origins of the universe. There is evidence, which indicates that the universe started around 15 billion years ago. This is probably the greatest discovery imaginable; however, the universe still seems to be a very controversial subject. Most scientists agree that there was a beginning but there is a lot of speculation of how it (the universe) actually started. The much-celebrated Greek philosopher, Aristotle, denied the fact that there ever was a beginning.

He and his associates believed in the eternal existence of the universe, they also tried to prove that the universe was static, and was unchanging in time. However, there is evidence, which suggests that the universe is changing with time. o Geologists have discovered meteorites on the earth that have existed for many thousands of millions of years, way before the earth came into existence. o A second principle, which concretizes the beginning of the universe, is the second law of thermodynamics. As I quote the cosmologist Sir Arthur Eddington, said", Don't worry if your theory doesn't agree with the observations, because they are probably wrong. ' But if your theory does not agree with the 2nd law of thermodynamics then it is in serious trouble".

The second law states that disorder (which is measured by entropy) always increases with time. Therefore, the idea that the universe existed forever is contradictory, because the second law implies that there was a beginning. Explained: If the universe has an infinite number of stars then the night sky should be uniformly bright as the surface of the sun. This essentially is Olbers' paradox There are many possible explanations for Olbers' paradox. Here are just a few: o There's too much dust to see the distant stars. o The universe is expanding, so distant starts are red-shifted into obscurity. o The universe is young. Distant light hasn't even reached us yet.

The first explanation does not make sense. The dust in a black body will heat up; this essentially acts like a radiation shield, exponentially damping the distant starlight. In addition, one cannot put enough dust into the universe to get rid of all the starlight, without obscuring your own sun. The last two possibilities are correct. There are numerical arguments that effect the finite age of the universe.

Currently, we live inside an "observable universe", objects more than the age of 15 billion are too far away too ever reach us. The question put forward by Newton was:' If the universe is full of static then, why did the stars suddenly turn on? This is where we turn to the Cosmological principal. It states that the universe is homogeneous (the same everywhere) and isotropic. (The same in all directions) It is an extension of the Copernican principle, which states that we are not in a special place at the centre of the solar system, but just one of nine planets.

In relation we can, according to Newton find a gravitational force between to objects of masses M 1 and M 2: FG = GM 1 M 2/d 2 This equation indicates that each star in the universe is attracted to each other star. The problem with this equation is the Gravitational constant. In cosmological terms, how could the stars remain at a constant distance, wouldn't they end up falling? It is possible for the stars / galaxies to be attracted to each other but it is impractical to assume that the stars / galaxies are getting closer to each other. The correct procedure is to assume that there is a finite region of stars, which are distributed uniformly by more stars that are outside the finite region. Adding more stars outside will not stop the collapse.

If the galaxies are not moving relative to one another then, the attraction between the stars will make the galaxies fall towards each other. Therefore, the universe is not static, but expanding. The galaxies are moving steadily apart from each other At the beginning of time, all the matter in the universe would have been on top of itself. The density would have been infinite. It would have been what is called, a singularity.

At a singularity, all the laws of physics would have been broken down. This means that the state of the universe, after the beginning of time, would not depend on anything that may have happened before. Even the amount of matter in the universe, can be different to what it was before the beginning, this is because the Law of conservation of matter, will break down at the big bang. The law of conservations states: Energy can be neither be created nor destroyed but simply changed from one form to another. There is no such law as the Law of conservation of matter. Mass is converted to energy in a nuclear reaction by E = MC 2 where mass = M, energy = E and C 2 = speed of light squared (about 10^16) I will now analyze al the possible theories behind the origin of the universe: Steady State Theory Returning back to the origin of the universe, events before the Big Bang had no observational consequences, one may as well cut them out of a theory, and say that time began with the Big Bang or what ever may have started the universe.

Events before the Big Bang cannot be defined, because there is no evidence, which can support the pre-events. The laws of science and the idea of singularity, predict that the universe did have a beginning; they also seem to predict that they could not determine how the universe would have begun. Initially, there where a number of ways to get round the conclusion, that there was a singularity of infinite density in the past. There was a comment, which suggested that if one, where to make modifications to the law of gravity, i.e. allow gravity to become repulsive. The idea was that, as the galaxies moved apart, new galaxies were formed in between, from matter that was supposed to be continually created.

This was the Steady State theory. The advantage of the steady state theory was that it allowed one to make definite predictions, which in-turn could be tested by observational data, and possibly could be falsified / altered to fit data Explanation: The fainter the sources are the further away the galaxy would be. One would therefore, expect them (the galaxies) to be more numerous than bright sources, which would be near us. However, a graph of the number of radio sources, against there strength, went up much more sharply at low source strengths, than the Steady State theory predicted. Attempts where made to try and explain this number count graph, by claiming that some of the faint radio sources were within our own galaxy and so did not tell us anything about cosmology. This argument didn't really stand up to further observations.

The final blow to the steady state theory came in 1965 with the discovery of microwave background radiation. Microwave radiation is the same in all directions. The spectrum of radiation in thermal equilibrium at a temperature of 2 points 7 degrees above the Absolute Zero of temperature. The Steady State theory cannot explain this form of radiation. Microwave radiation is a result of the big bang. There came a point where electrons and nuclei were formed.

They were immersed in intense electromagnetic radiation (light, X-rays, gamma rays, etc. ). As time progressed and the expansion of the universe continued, the system became cooler). Eventually a point was reached where the universe was cool enough for atoms to form and from this moment on most of the radiation just streamed forth unimpeded. This happened when the universe was a mere 300,000 years old. The above diagram shows microwave radiation just after the beginning of time.

The Geometric Theory The universal geometric theory states that the universe, early on was essentially just a large lump of matter and, or possibly, antimatter. It appears that in its condensed shape, an impact or for reasons still unknown, the matter / antimatter became very unstable. Figure (1) Eventually, the particles decided that it was about time that the universe expanded, therefore, it began to push and shove in all directions until finally, it (the universe) started to expand in a square like pattern. This can be seen in figure one. Backed up scientifically: I cannot really say that this theory is wrong because it seems to agree with the second law of thermodynamics. But it doesn't really make sense, why on earth would the particles just decide to move, let us remember that energy can not be created / destroyed, therefore, a pondering question is where did the particles get there energy from.

However, it is true that particles can change shape if they are close to a heat energy source. The more energy they absorb the faster they vibrate. Initially, what comes to mind is that what could have been powerful enough to emit so much heat energy and what could this entity possibly be? This entity would have to be more powerful than a million stars put together. On average a start emits about... Apparently, Einstein knew all along that the universe began with a tendency towards cubical geometry; Einstein backed his thought up in his renowned theory of relativity.

The theory E = MC^2, states in plain English that the energy of X is directly proportional to the mass of X, when multiplied by the square of the constant velocity of light. The theory seems to convey that the proto-universe was not only experimenting with different shapes, but was also expanding in its square-like nature; some of the square-like objects in space began to collide with each other. This in-turn created either a rectangular object or a larger square with much more density. The actual principle makes sense, but after analyzing the theory, I am not still entirely convinced. The theory itself doesn't seem to make any sense. For example, if the planets where originally square shaped then, why are they known to be egged shaped.

I am assuming using our sample as the solar system, that all planets are egged shaped. Alternatively, you could simply use the example of the ripple affect. When a stone is thrown in, a pond circular ripple occurs, getting larger as they move away from the origin of impact. The point is that if something collided with the matter / antimatter then it would be more plausible to assume that the particles would move away from the origin of impact in a circular fashion.

As I quote the lecturer then says"I learnt that apparently the Egyptian civilisation found the pyramids just lying about" This puts every thing into context, there is clear evidence that shows that the pyramids where hand made. Therefore, I really do disagree with this theory. Small Bang Theory For many years, we have assumed that the big bang was big, but while doing research, I came across a very tantalizing thought by Arthur C Clarke. As I quote, he says: "Its at least an interesting thought that the vacuum inside an ordinary light bulb contains enough energy to destroy a galaxy... and perhaps, with a little extra effort, the cosmos". This may suggest that the big bang may have been a small bang. The point being made is that if such a small amount of energy is needed to destroy a galaxy.

Then it is plausible to assume that only a small quantity of energy is needed to create a galaxy, or possibly the cosmos itself. Scientific evidence: To create a vacuum, matter is removed by pumping air out of the vacuum chamber. As air is removed, fewer air molecules are present that can push on the vacuum chamber walls, so the pressure within the vacuum chamber is reduced. In scientific laboratories, vacuum chambers must be very strong, because when the pressure is very low within the vacuum chamber, the atmospheric pressure outside can crush the apparatus. This in principle applies to the galaxy, where the light bulb consists of the vacuum and the surroundings consist of the galaxy.

This was an interesting thought; however, it seems that this theory disobeys the second law of thermodynamics. The second law of thermodynamics describes basic principles familiar in every day life. It is partially a universal law of decay; the ultimate cause of why everything ultimately falls apart and disintegrates over time. In relation to the small bang theory, there is an overall downward trend throughout the universe. Ultimately, when all the energy of the cosmos has degraded, all the molecules will move randomly, and the entire universe will be cold and will be without order. The basic law reveals that in the long run, complex, ordered arrangements actually tend to become simpler and more disorderly with time...

Therefore, I disagree with this theory. Big Bang Theory Though the Big Bang suggests a colossal explosion, it wasn't really an 'explosion' in the sense that we understand it. Space itself exploded. At the instant of the Big Bang, the universe was infinitely dense and unimaginably hot. Cosmologists believe that all forms of matter and energy, as well as space and time itself, were formed at this instant. Since 'before' is a temporal concept, one cannot ask what came before the Big Bang and therefore 'caused' it, at least not within the context of any known physics.

(At least one cosmological theory, however, predicts that our universe's Big Bang is part of a chain reaction in which the demise of one universe spawns the birth of many, parallel, and universes. According to this scenario, our universe may simply be part of a huge, infinitely growing fractal.) Science tells us nothing about the way space, time and matter behaved in our universe's earliest instant, from the time of the Big Bang to 10^-43 seconds later. Space was certainly expanding -- violently -- and from this expansion of space was formed a highly energetic soup of particles and antiparticles. The energy was so great during the so-called Grand Unification Epoch -- a fine-sounding name for the period from 10^-43 to 10^-35 seconds after the Big Bang -- that all matter and energy was essentially interchangeable and in equilibrium. What's more, electromagnetism and the two nuclear forces were as one (gravity, the fourth and weakest force, had separated from the other three at the beginning of the Grand Unification Epoch). As the universe expanded, it cooled down.

At 10^-35 seconds, the temperature was a mere 10^27 degrees K (water boils at 373.16 K or 3.7316^2! ). At this critical temperature, the universe underwent a phase transition, something like the process that happens when liquid water freezes into ice. The strong nuclear force -- which acts at very short distances and holds protons and neutrons together -- split off from the other forces. Physicists call this process 'symmetry breaking,' and it released an enormous amount of energy. Then, in an extraordinary instant that theorists have dubbed 'inflation,' the universe expanded exponentially.

During this time, the universe grew by a factor of 10^50 in 10^-33 seconds. This scenario, much as it strains credulity, neatly explains several different observations made during the last 20 years -- the large-scale smoothness and apparent flatness of the universe among them -- that had weakened the original Big Bang theory of cosmology based on a much more leisurely period of expansion. Things slowed a bit after the inflationary epoch. A number of observations, well supported by theory, suggest that our universe continued to expand, a bit more slowly, and that it is expanding still. As space expanded, it continued to cool down. Matter -- at first photons, quarks, neutrinos, and electrons, and then protons and neutrons -- condensed out, all less than one second after the Big Bang.

It was not until one billion years later, when the universe was one-fifth the size it is today, that the matter would form the first stars and galaxies. The diagram below explains how the current universe was created from the Big Bang. One can clearly see that as the universe develops the time intervals of development keep on getting larger and larger. The diagram only shows technical observations made by today's scientists.

Therefore, what is the fate of the Big Bang Theory? The Fate of the Universe... According to the big bang, there are two possibilities of what might happen to the universe. The universe might expand forever or will re-contract How much matter is there in the universe? Moreover, to that we can say: we don't know. If we count all the matter that shines, (stars etc) we get a number very low compared to the critical value.

Nevertheless, could it be that the majority of matter is shining? Could it not be that there is a lot of dust out there? The latest results suggest that the universe will expand forever, but at present, its ultimate fate is unknown. Personal Opinion... Out of the four theories that been observed. The big bang theory seems to be the most reasonable explanation for how "time" it self started!

The ripple effect was discussed in the geometric theory; it shows how the ripples increase in size as they move further away from the origin. As the ripples move further away from the source they also slow down, this is because energy is lost to the surroundings. One could take this concept and apply it to the beginning of time itself. As the expanding ripple, there is evidence that suggests that the universe is expanding. This is where Hubble's law comes into practice.

Hubble noticed that galaxies were shifting towards the red end of the spectrum, interestingly, he also noticed that the fainter the galaxy the larger the red shift. This distance-red shift relationship eventually became known as Hubble's law this is illustrated below: The diagram shows that the further the galaxy is the greater the red shift is. Therefore, the galaxies are moving away from us. Red shift Explained The property of red shift is measured in the spectral output from stars, galaxies, quasars, etc. The red shift is the measure of the difference in the spectrographic appearance of certain atomic-level transitions.

For example, if one where to take the light produced at a standard pressure and temperature by a neon sign. Then if one where to split and measure the frequencies by a spectrograph; the frequencies would appear to be identical, with the same relative intensities. To prove this I have copied a spectrograph of a hydrogen atom. Figure 2 shows a spectrograph of light coming from a Quasar. Spectrograph of Light from a Quasar: Figure 2 The spectrograph shows the red shifted lines of hydrogen. Notice how every so often there are energy jumps.

These energy- jumps occur with frequencies that have specific characteristics Coming back to the redshift, I came across three possibilities that explain how the redshift from a distant galaxy occurs These were: Tired Light: When light travels through empty space, it is possible to assume that there will be obstacles coming in front of the light rays. Explained: As the light rays travel from a distant entity (galaxy) they pass through empty space, they could interact with something which would cause a loss of energy in their passage towards the earth. When something interacts with the light, the likely hood is that there will be a scattering affect. The same effect of when a mirror is smashed and light is pointed towards it, the reflections show how the light has been scattered. It seems unlike that this is the cause of redshift. Gravitational (slow down) RedhiftAccording to General Relativity, the wavelength of light (or any other form of electromagnetic radiation) passing through a gravitational field will be shifted towards redder regions of the spectrum.

To understand this gravitational red shift, one can think of a baseball hit high into the air, slowing as it climbs. Einstein's theory says that as a photon fights its way out of a gravitational field, it loses energy and its colour reddens (like that of a rocket leaving the earths atmosphere). Gravitational red shifts have been observed in diverse settings. The problem with this theory is that the loss of energy is way to small to account for the measurements of redshift. The Doppler Effect The simplest way to describe the doppler effect is with the drop in the pitch of a train whistle. As a train passes your position and from moving towards you to moving away from you.

The doppler effect is associated with the wave nature of sound. Light can also be described as a wave, and relative motion of the source of light waves, lead to a corresponding doppler effect for light. In this case it is not the pitch but the colour (wavelength) that is shifted by motion. The frequency of light received from the star increases slightly, shifting slightly toward the blue end of the spectrum. This is known as the blue shift, this has been observed in a number of nearby galaxies. The Doppler effect equation: Red and blue shifts have been observed, therefore, it is safe to assume that the Doppler effect causes red / blue shift.

Just to recap the redshift shows that the universe may be expanding, therefore remembering the ripple effect, the beginning of time may have started with a central bang. Astronomers use Doppler shifts to calculate precisely how fast stars and other astronomical objects move toward or away from Earth. For example the spectral lines emitted by hydrogen gas in distant galaxies are often observed to be considerably red shifted. The spectral line emission, normally found at a wavelength of 21 centimetres on Earth, might be observed at 21.1 centimetres instead. This 0.1 centimetres red shift would indicate that the gas is moving away from Earth at over 1,400 kilometres per second (over 880 miles per second).

Summary: The universe has not existed forever. The universe, and time itself did have a beginning in the big bang, about 15-20 billion years ago. Physics has managed to break down the singularity of time. The way the universe began can probably be determined by the law of physics, that's only if the universe the no bound ry condition.

The no bound ry condition states "In imaginary time direction, space time is fin ate in extent, but does not have a bound ry or an edge". The no bound ry also predicts that the universe will eventually collapse again. However, this seems to be unfeasible, because firstly it says "Collapse again", this indicates that the universe has already collapsed, secondly, that time it self will end up reversing itself. The contracting phase, will not have the opposite arrow of tim, to the expanding phase. So we will keep on getting older, we will not return to our youth, because time should not go backwards.

Science can solve the problem of how the universe began, but it cannot answer "Why the universe seizes to exist?" Only god himself can answer that! Glossary: Cosmic censorship hypothesis States that the singularities produced by gravitational collapse must be hidden behind an event horizon. Doppler effect Relationship between wavelength and speed where shifting of wavelength occurs when the movement of an object is away or towards an observer. General relativity Albert Einstein's theory that proposes that gravity is a curvature of four-dimensional space-time caused by the presence of matter. Gravitational slow down The wavelength of light (or any other form of electromagnetic radiation) passing through a gravitational field will be shifted towards redder regions of the spectrum.

Conservation Law Energy can be neither be created nor destroyed but simply changed from one form to another. quantum mechanics Conservation of energy theory developed from Planck's quantum principle and Heisenberg's uncertainty principle. Red shift Reddening of light as it moves away from us, due to the Doppler effect. singularity The centre of a black hole at which matter is crushed to an infinite density, the pull of gravity is infinitely strong, and the space-time curvature becomes infinitely large.

Bibliography

In this article I used extracts and idea's which came from Steven Hawkings lecture: "The origin of the universe " Extracts can be found from the following website: web obtained the Law of conservation from the following website: web controversial Geometric theory was obtained from: web the site is currently down, till further notice. I based the small bang on a made by Arthur C Clarke the quote was obtained from: Reannex, Darryl, "The Death of Forever" ISBN: 0 285 63239 Idea's of the Big Bang Theory were obtained from: o web Steven Hawking's Lecture web web web web web HAWKING, Stephan, A Brief History Of time, Bantam Press 1988 Ideas of the steady State theory were obtained from: o Steven Hawkings lecture o web web state.
html o web HAWKING, Stephan, A Brief History Of time, Bantam Press 1988 o ABRAMS, Benard and MOORE, Patrick.
Astronomy: Extending science, Stanely Thornes 1989 Ideas of the red shift theory was obtained from the following resources: o web web ABRAMS, Benard and MOORE, Patrick.
Astronomy: Extending science, Stanely Thornes 1989 TV Documentaries Although I was not doing an article on black holes, I decided to watch the following documentary, merely because it was related to the cosmos.