Religious, Moral and Philosophical Studies s1

Religious, Moral and Philosophical Studies. Christianity: Belief and Science (Higher)

3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory. In Section 1. we learned that science does not deal in absolute truths but supplies provisional models which have to be continually altered and improved to accommodate new information. In this unit we will consider how the general working model that scientists have used to understand the universe has developed over the last 2500 years. This general working model is known as a paradigm.

ARISTOTLE'S PARADIGM. Aristotle was a Greek philosopher who lived about 2,500 years ago. Like most early views of the universe, his was an earth-centred one. He believed that the sun, planets and stars were made of an eternal substance called quintessence. These moved round the earth on invisible crystal spheres, each sphere contained within it the next sphere. Each sphere caused the next sphere to move and so on. The furthest out sphere which caused all the rest to move was called the PRIME MOVER. Aristotle Aristotle's paradigm did well in explaining much of the behaviour of the sun and stars but it failed to explain the wandering behaviour of the planets. Viewed from the earth the planets do not appear to move in a regular way at all but wander about. Planet means "wanderer". Here was a piece of data that the Aristotelian paradigm didn't accommodate.

THE PTOLEMIC UNIVERSE. 500 years later another Greek - Ptolemy offered an explanation of the erratic behaviour of the planets. Like Aristotle, his universe was earth-centred. Ptolemy concluded that the planets moved in epicycles - circles within circles. The picture below shows his theory. This explanation was accepted by astronomers for 1,500 years.

Ptolemy

J.Keenan Section 3 Page 1 Religious, Moral and Philosophical Studies. Christianity: Belief and Science (Higher)

3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory.

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Ptolemy's view of the The picture above shows how universe. Ptolemy improved upon Aristotle's view of the THE UNIVERSE OF COPERNICUS. universe by offering an explanation of the erratic

It was that revolutionary approach of Nicolaus behaviour of the planets. Copernicus (1473-1543) that led to our present understanding of the universe. In order to get at the truth scientists often have to go against what common sense and intuition dictate - Common sense tells us that the sun orbits the earth - We see it rising in the East, passing overhead at midday then setting in the West. Copernicus felt that mathematical discrepancies in the explanation of the Universe of his time could be remedied by going against common sense and imagining a sun centred universe. By . suggesting that the earth spins on its axis, he explained Copernicus day and night and by 3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory.

J.Keenan Section 3 Page 2 Religious, Moral and Philosophical Studies. Christianity: Belief and Science (Higher) suggesting that the earth orbits the sun along with the other planets, he gave an alternative explanation to the problem of the wandering planets. The Copernican view of the solar system is pretty much as we understand it to-day but only six planets were known about then. Like Aristotle's solar system the planets were still held to move on invisible crystal spheres. Sun

GALILEO GALILEI (1564-1642) In 1604, using the newly invented telescope, Galileo set out to prove the theories of Copernicus. The telescope did not reveal the perfect crystal spheres of Aristotle. It did however show that the planet Jupiter had its own moons. This The Solar System of Copernicus. seemed to confirm the solar system of Copernicus. Galileo used the telescope to empirically verify Copernicus' theory. Galileo became a champion of the sun centred universe but met with widespread opposition resulting in his imprisonment. His view of the universe presented a challenge to many deeply held religious beliefs. He was charged by the church in Rome of contradicting the Bible by saying that the earth moves. JOHANNES KEPLER (1571 - 1630) There were still problems with the behaviour of the planets in the Copernican model. Using the data of the Danish astronomer, Tycho Brahe, Kepler came to realise that the planets move, not in circles, but in elliptical orbits. ISAAC NEWTON (1642 - 1727) Every school-pupil has heard the story of how Newton "invented" gravity by observing an apple fall to the ground. Of course gravity had been around for quite some time before Newton! What Newton did do was to realise that the force which draws the apple to the Earth is the same force which keeps the planets in their orbit. Kepler had come to 3. Isaac Newton 3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory. realise that the planets moved in very strict elliptical orbits around the sun. Newton now

J.Keenan Section 3 Page 3 Religious, Moral and Philosophical Studies. Christianity: Belief and Science (Higher) combined this observation with the findings of Galileo to produce his theory of UNIVERSAL GRAVITATION. Newton's model allowed for predictions to be made. Given currently available data, it was possible to calculate the future position of the planets, which could be checked by observation. The solar system was seen as a giant clock in which everything was predetermined. Newton also started the process of searching for an underlying principle which would unify a number of different phenomena. This is a questwhich has been taken up by most of the giants of science and carries on today. FARADAY for example, discovered that magnetism and electricity were really different aspects of the same reality. As you will see below EINSTEIN more recently did the same for space and time.

ALBERT EINSTEIN (1879-1955) AND RELATIVITY THEORY. At the beginning of this century physics was in a crisis. Somehow the laws of electromagnetism and Newton's laws of motion didn't fit together. The laws of electromagnetism had been established by MAXWELL. Since Newton was held in such high esteem it was generally assumed that Maxwell's equations must somehow be wrong. Einstein showed that it was Newton's equations that needed modifying since space and time were somehow locked together. Think about this: You are on a train travelling at 100 kilometres per hour. You decide to get up and go to the restaurant which is at the front of the train. You walk along Albert Einstein the carriage at a speed of 3 kilometres per hour. Outside the train, at the side of the track, someone watches you through the window. From their perspective you are travelling at a speed of 103 kilometres per hour but from your own perspective you are only travelling at 3 kilometres per hour. We can see that speed is relative to the motion of the observer. Einstein applied the same thinking to time and space and came up with some strange conclusions which once again contradict common sense:-All the experiments which have ever been made on the speed of light have confirmed that light travels at 300,000 kilometres per second in a vacuum. Einstein wondered about this and asked himself the question, "Would the speed of a beam of light change if its source were moving in a similar manner?" He found that it did not and that the speed of light was an absolute constant. Since speed = distance divided by time, the consequences of this seemed absurd. It meant that if the speed of 3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory. light was fixed, then time itself can't be a fixed constant, as common sense had previously assumed - that it must be capable of being stretched or shrunk It meant

J.Keenan Section 3 Page 4 Religious, Moral and Philosophical Studies. Christianity: Belief and Science (Higher) that space and time were somehow interconnected and that time was not an absolute but relative. Paul Davies says, “Einstein demonstrated that time is in fact, elastic and can be stretched and shrunk by motion. Each observer carries around his own personal scale of time, and it does not generally agree with anybody else’s. In our own frame, time never appears distorted, but relative to another observer who is moving differently, our time can be wrenched out of step with their time. This weird dislocation of time scales opens the way to a type of time travel. In a sense, we are all travellers in time, heading towards the future, but the elasticity of time enables some people to get there faster than others. Rapid motion enables you to put the brake on your own time scale, and let the world rush by as it were. By this strategy it is possible to reach a distant moment more quickly than by sitting still. In principle one could reach the year 2000 in a few hours. However to achieve an appreciable time warp, speeds of many thousands of miles per second are necessary. At currently available rocket speeds only precision atomic clocks can reveal the minute dilations. The key to these effects is the speed of light. As it is approached, so the time warp escalates. The theory forbids anyone to break the light barrier, which would have the effect of turning time inside out. ---time distortions of this sort are a favourite sci-fi gimmick, but there is nothing fictional about them. They really do occur. One bizarre phenomenon is the so called twins effect. One twin blasts off to a nearby star, nudging the light barrier. The stay-at-home twin waits for him to return ten years later. When the rocket gets back, the Earth-bound twin finds his brother had aged only one year to his ten. High speed has enabled him to experience only one year of time, during which ten years have elapsed on Earth” All this is no unsubstantiated theory. Experiments in flying very accurate clocks at high speeds have all verified Einstein’s theory. Speed slows down time and so does gravity. It also means there is no simultaneous present! One observer might see two events as simultaneous. For another they might happen in sequence. The theologian and physicist Ian Barbour in his Aberdeen Gifford lecture said of this, "Because there is no universal present and no common present separating past and future, the division between past and future will vary among observers. Some events which are past for one observer, may well still be future for other observers." Another major implication of Einstein's' discoveries about time is that if the universe 3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory. had a beginning then time must have come into existence with space and matter. Einstein also showed that energy and matter are related through the formula E = MC2.

(Energy = Mass x The Speed of Light x The Speed of Light) He also affirmed that gravity could be understood as bent space. What we see happening here is that various aspects of the natural world which were once seen as separate and unconnected are brought into relationship. We see a dynamic and interconnected universe. Space and time now become space-time, mass is repackaged energy and gravity and acceleration are the same thing. One of the major tasks of physics today is to complete the work of Einstein and others by finding a theory that finally shows the relationship between all things in a unified Theory of Everything (TOE).

QUANTUM THEORY -THINGS ARE UNPREDICTABLE. Another great paradigm shift has been stimulated by Quantum Physics - the word "quantum" means "parcel". Quantum theory is therefore a description of nature, based on the tiny packets of energy and matter that make up the universe Certain processes in physics such as radioactivity are random and unpredictable. It seems that the behaviour of atoms and subatomic particles is very uncertain. In linear accelerators particles just seem to pop out of nowhere and disappear again into the void in what would appear to be a completely spontaneous matter. This seems to go against the world-view presented by Kepler, Newton and Einstein where it was assumed that all material objects complied strictly with the rules of mechanics- the same rules which keep the planets in their orbits, or direct the bullet to its target. The atom was felt to be like a scaled down model of the solar system and therefore governed by the same predictable rules. However the evidence indicates that the behaviour of subatomic particles can't adequately be described by these laws due to their unpredictable behaviour. Quantum theory gives a much greater place to CHANCE than the Newtonian paradigm although Einstein would not accept this saying “God does not play dice with the universe” HEISENBERG (see Section 1.) put forward his uncertainty principle which showed that it was wrong to ask about an electron’s position and speed at the same time. You can measure one or the other but not both. According to BOHR, the problem arises from assuming that an atom is a “thing”. According to him, the fuzzy and nebulous world of the atom only sharpens into concrete reality when an observation is made. In the absence of an observation, the atom is a ghost. It only materialises when you look for

3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory. it. And you can decide what to look for. Look for its location and you get an atom at a place. Look for its motion and you get an atom with speed. But you can’t measure both

J.Keenan Section 3 Page 6 Religious, Moral and Philosophical Studies. Christianity: Belief and Science (Higher) simultaneously. Consciousness and reality, mind and matter seem to interact somehow. The separation between subject and object is not clear cut. Heisenberg said “The common division of the world into subjects and objects, inner worlds and outer worlds, body and soul is no longer adequate.” If you find this all too strange, Einstein would have agreed with you when he famously said, “God does not play dice with the Universe.” but experiments carried out in the 80’s show that Bohr was right and Einstein wrong -uncertainty seems to be built into the micro-world. The experimental evidence supports particles jumping out of nowhere, events without causes, reality triggered only when you observe it.

YOUNG'S SPLIT SCREEN EXPERIMENT. Some other strange implications seem to emerge from quantum physics. You may be aware that light behaves both as a wave and as particle. Young set out to investigate this ambiguous behaviour of light in the experiment shown below.

Light is shone through two slits in screen B onto screen C. This causes bands of bright light separated by dark bands to appear on C. This is an interference pattern caused by the light waves either adding up or cancelling each other out. What would now happen if we turn down the amplitude of the source of light so that the light was emitted a particle (photon) at a time? You would not expect an interference pattern yet this is exactly what Young found. Even when the light is released a particle at a time, the same interference pattern is produced. The implications of this are bizarre:- The photons seem to "know" what each other are doing. If one photon goes one way then the next photon knows it has to go another way.

3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory. This leads to the conclusion that the potential photon paths somehow thread through both slits, the path that is not followed influencing the actual path of the photon. Other

J.Keenan Section 3 Page 7 Religious, Moral and Philosophical Studies. Christianity: Belief and Science (Higher) quantum particles are similarly found to behave more like waves than particles. EDWIN HUBBLE (1889-1953) AND THE BIG BANG THEORY. Have you ever noticed, standing at the side of the road, that when a car passes you at speed, the sound of its engine drops in pitch? This is known as the Doppler Effect and it happens because as the car approaches you the sound waves are bunched up, increasing in frequency but as the car moves away, the sound waves are stretched out and this is experienced as a drop in pitch. Because, like sound, light also travels in waves it too is subject to the Doppler effect. If a source of light is travelling away from you then it appears more red because light arriving from the source decreases in Edwin Hubble frequency compared to if it were at rest relative to Earth. Now the genius of Hubble was that he applied this to astronomy and came up with the Big Bang theory. Hubble observed that all the galaxies (groups of stars) were becoming more red which meant they must be moving away from us. Hubble came to realise that everything in the universe was moving away from everything else. Since all the galaxies are moving away from each other the conclusion would be that at one time all the galaxies were compressed into a small space, their current motion being explained by a giant cosmic explosion. His theories were confirmed in the sixties when two scientists working for the Bell Telephone Company discovered the remains of the radiation emitted by the big bang. The Big Bang Explanation of the universe is supported by a great deal of evidence and is almost universally accepted.

This universe of space, matter and time came into existence some 15 - 17.5 billion years ago in an enormous explosion. Before that there was nothing at all. By nothing we mean no time, no space and no matter. (Since there was no time before the Big Bang it is meaningless to ask what was before the Big Bang.)

3.5 minutes after the explosion the basic building blocks of the universe, atomic nuclei were formed- 1 million years later the first atoms were formed (these were the atoms of hydrogen and helium when electrons joined with the nuclei.)

Millions of years later these atoms began to form into vast clouds, slowly spinning. These clouds were the beginning of galaxies. Within these young galaxies, smaller 3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory.

J.Keenan Section 3 Page 8 Religious, Moral and Philosophical Studies. Christianity: Belief and Science (Higher) clouds of gas developed. The effect of gravity made them spin faster and also made them very hot; so hot that nuclear reactions occurred which produced the first stars.

Within stars hydrogen atoms fuse to form helium. Eventually, when a star becomes old, it becomes unstable and other elements start to be fused. For example, 3 helium atoms will form a carbon atom, 4 heliums will form an atom of oxygen and so on. Eventually the star erupts in an explosion, throwing its elements out into space.

About 4.5 billion years ago it is probable that a neighbouring star went supernova. The debris from the resulting explosion was pulled into the orbit of our sun. This matter formed the planets of our solar system.

So the universe is not infinitely old but had a beginning. Up until recently many scientists had held the belief that the universe was infinitely old. The reason why the scientific community accept that the universe had a beginning stems from a body of evidence known as the second law of thermodynamics.

Paul Davies says,

"In its widest sense this law (the second law of thermodynamics) states that every day the universe becomes more disordered. There is a sort of gradual but inexorable descent into chaos. Examples of this law are to be found everywhere; buildings fall down, people grow old, mountains and shorelines are eroded, natural resources are depleted......

At first sight there seem to be many counter-examples of this law. New buildings are erected. New structures grow. Isn’t every new - born baby an example of order arising out of disorder? In these cases you have to be sure you are looking at the total system, not merely the subject of interest. The concentration of order in one region of the universe is always paid for by increasing disorder some-where else. Take the construction of a new building, for example. The materials used inevitably deplete the world’s resources, while the energy expended in the building process is also lost irretrievably. When a full balance sheet is drawn up, disorder always wins...... Physicists have invented a mathematical quantity called entropy to quantify disorder, and many careful experiments verify that total entropy in a system never decreases......

If the universe has a finite stock of disorder, and is changing irreversibly towards disorder two inferences follow. The first is that the universe will eventually die, wallowing, as it were, in its own entropy. This is known among physicists as the heat 3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory.

J.Keenan Section 3 Page 9 Religious, Moral and Philosophical Studies. Christianity: Belief and Science (Higher) death of the universe. The second is that the universe cannot have existed for ever, otherwise it would have reached its equilibrium end state an infinite time ago. Conclusion: the universe did not always exist."

The universe is not infinitely old nor is it infinite in size. According to Einstein it can be imagined as the surface of a sphere bending back on itself, without edges.

A further major argument against an infinite universe is based on logic for in an infinite universe anything would go. All possibilities would become inevitabilities as the combination of conditions which produced the present situation were endlessly repeated with an infinite number of variations. This would lead to some impossible consequences. Think about it - as well as the normal you here, there would inevitably have to be an infinite number of exact copies and very near copies of you. Somewhere you would be the prime-minister, somewhere else you would be suffering in great pain, somewhere else you would be Cliff Richard as the conditions that made you were repeated over and over again in an infinite multitude of variations.

3. Scientific Accounts of the Origin of the Universe The Development of the Big Bang Theory.

THE THEORY OF EVOLUTION.

Within the scientific community, the theory of evolution has become widely accepted as the best explanation for the origin and development of human life. The theory is particularly associated with Charles Darwin (1809 - 1882) although evolutionary theories can be traced back to ancient Greece. Until the end of the 18th century it was commonly thought that the world was about 6000 years old, that each species had been created separately; and that no one species could develop out of another. Such beliefs, based on a literal interpretation of the biblical accounts of creation, were challenged by developments in geology and biology.

William Smith (1769-1839), a drainage engineer and amateur geologist, collected information about rock strata and the fossils contained in them. He saw that the deeper strata were older than those near the surface. Because the fossils in each stratum showed life forms very different from those of today, he concluded that there had been many successive acts of creation. He took the six days of creation in Genesis to refer to six geological periods.

In Principles of Geology (1830) Charles Lyell argued that geological changes were going on all the time, and that there did not have to be a number of separate acts of creation to explain the different strata and fossils in the rocks. His theory, Uniformitarianism was opposed to the catastrophic theories which argued for a series of acts of creation, each followed by a catastrophe, the latest of which had been the flood of Noah's time.Lyell argued that God created a succession of life forms, by natural means, discoverable by science. Apart from the fact that creation was thought of as a continuing process, there was not a great difference between this theory and William Paley's belief that God had designed the world. The older strata held creatures that were extinct, and the younger ones had animals like those of today, but there were no human fossils. It was therefore concluded that mankind was a very recently created species.

3. Scientific Accounts of the Origin of Life The Theory of Evolution.

In the 18th century a Frenchman called Lamarck developed a theory of evolution. He started from the observation that we inherit characteristics from our parents. For instance, if your parents have brown eyes, then the chances are you will also have brown eyes. Lamarck suggested that an animal might acquire characteristics during its lifetime which it passes on to its offspring. A horse for example might stretch its neck by continually reaching for the leaves at the top of trees. When it mates, perhaps its young are born with slightly longer necks. The offspring continue to stretch for the higher leaves and in turn stretch their necks even further. Their even longer necks are then passed on to the next generation who in turn pass yet even longer necks on to the next generation and so on. After some generations we have a giraffe! This is a different species of animal. Lamarck suggested that other animals have adapted to their environment in a similar way. The drawback with this solution is that there is no evidence that we hand on characteristics which have been gained in our own lifetime. The data doesn't support the hypothesis. The evidence supported gradual change over time but the mechanism whereby this was achieved was still a mystery.

It was Darwin who gave a plausible explanation of how evolution might occur. Charles Darwin was born of a wealthy parents. Originally he had studied medicine at Edinburgh University but gave it up to study religion at Cambridge. While he was there he became interested in the writings of William Paley and biology. Paley argued that the way animals are so well adapted to their environment was evidence that they had been designed by God. Initially Darwin was much impressed by this argument but as a result of a 5-year voyage around the world, Darwin began to see an alternative way of explaining how living things suited their environment. When Darwin was in the Galapagos Islands, he observed 13 different kinds of finch, and noted that each of the islands had its own species of giant tortoise. Darwin started to question Paley's ideas. He could see no point in God creating different species for each island. Until then, in keeping with the teaching of the Bible, it was believed that God had created each species of animal

3. Scientific Accounts of the Origin of Life The Theory of Evolution. separately. This idea was known as the fixity of species. Darwin's observations in the Galapagos islands caused him to question this idea. It seemed more likely, as Lyall had argued in the case of geology and Lamarck in the case of biology, that change occurred gradually over a great period of time and that as argued in the case of geology the various species had not been specially created but that they had somehow developed from existing species. Darwin saw in the ideas of Thomas Malthus the means by which this occurred. In 1789 Malthus had published An Essay on the Principle of Population. Malthus argued that contrary to Paley's cosy view of nature, all living things were engaged in a fight for survival in which only the fittest survived. (This was brought about because more individuals than can survive are born. Those animals and plants which are not well adapted to their environment die out.) Darwin now took this idea and applied it to the problem of evolution. Darwin believed that evolution occurs through natural selection. Artificial selection occurs when stock breeders allow certain animals to mate in order to develop specific qualities - A horse breeder, for example, only allows race winners to breed and in this way develops faster running horses. Darwin observed that in each generation of a species there are always some variation. Some are taller than others, others have longer legs or bigger beaks, or thicker fur for example. These variations either give a particular individual an advantage or a disadvantage in the struggle for survival. Let's say a group of rabbits come under threat from an increased fox population. The rabbits with the longest legs will be able to run fastest and escape the foxes. Because they have a better chance of surviving into maturity, they have a better chance of reproducing and passing their long legged characteristic onto the next generation. In time the long legged rabbits would come to predominate over their shorter legged cousins. In this way useful characteristics would be passed onto the next generation. After hundreds of generations one species could develop into another. Darwin had turned Paley's teleological ideas back to front. (teleology – idea that things, events are geared to a purpose.) The giraffes did not have long necks in order to eat the leaves at the top of the trees. Rather giraffes could eat the leaves at the top of the trees because they had long necks.

In the 1950's two scientists, Crick and Watson worked out the structure of DNA. As a result the mechanism whereby characteristics are passed on from one generation to the next came to be fully realised.

3. Scientific Accounts of the Origin of Life The Theory of Evolution.

You are made of and controlled by proteins. Proteins in turn are made of amino acids. Different combinations of amino acids give different proteins. The proteins which make you up have been manufactured in your cells under the controlling influence of stuctures known as chromosomes which in turn consist of genes made of DNA. Basically the DNA tells the amino acids how to form up to make the various proteins. The DNA can be Crick and likened to a computer programme consisting of a set Watson of instructions which is run on the hardware of the cell.

Half the complement of genes you have in your cells comes from your mother and half from your father. You therefore resemble your parents because your genes are instructing your cells to manufacture proteins similar to those of your parents. However, you differ from your parents because each new combination of genes is unique. This is what accounts for the variety within a species necessary for evolution to occur.

Occasionally something can go wrong when the sex cells which transmit the genes from one generation to the next are being formed. This is known as gene mutation. Usually gene mutation leads to offspring which are handicapped in some way and less well adapted to their environment. However, occasionally the process of gene mutation can lead to advantaged offspring, better adapted to their environment than their parents. In the fight for survival such offspring have a better chance of reaching maturity and reproducing. The advantage brought about by gene mutation is thus passed on to succeeding generations. Gene mutation accounts for the more dramatic changes within a species and is a further factor involved in the evolutionary process.

How Did Human Life Develop?

The theory of evolution now gives us an explanation of how human life developed in marked contrast to that based on a literal interpretation of the Bible. Life can be said to have started with the first molecule of DNA. How this came about is not yet understood but many biologists say by the chance collision of atoms. Others find

3. Scientific Accounts of the Origin of Life The Theory of Evolution. problems with this as we shall later see. The development of DNA eventually led to the first single cell animals, rather like the amoeba found in pond water today. Through a process of gene mutation, more complex, multiple cell organisms developed. In time these evolved into fish. From the fish, reptiles developed and in time fully fledged land animals. From these the mammals developed leading to the arrival of the primates (monkey family) and finally us homo sapiens sapiens.

FURTHER : Download and watch the video clips – Big Bang and Darwin and the Theory of evolution.

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