A Return to the Beginning by Mc Namara PDF

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04 Readings 1 **_Property of STI_*A Return to the Beginning By Daniel J. McNamara, SJWe shall never cease from exploration And the end of all our exploring Will be to arrive where we started And know the place for the first time. - T. S. EliotIt is in the spirit of these lines by Elliot that we want...

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A Return to the Beginning By Daniel J. McNamara, SJ We shall never cease from exploration And the end of all our exploring Will be to arrive where we started And know the place for the first time. - T. S. Eliot It is in the spirit of these lines by Elliot that we want to return to the Beginning, the Origin of all that is, the Start of time and space and all they contain. This study is called Cosmogony from the Greek, from cosmos meaning "order" and gonos meaning "offspring," which in turn, comes from the root meaning "to be born." It is the study of the universe as an ordered system, which the Greeks assumed it to be. The Greeks were struck by the general regularity of the motion of the stars. Even if they observed certain "stars" that were not so regular in their paths (they eventually called them the "sky wanderers" or planets), they still tried to fit these into the universal order that prevailed. This insight into the working of nature-that it obeys natural 'laws'-gave rise, in due course, to science, as we know it, and its presupposition that there exist laws in the workings of the natural world. Returning to the beginning, however, is by no means the full story. In fact, even to return we must start right at the present, at the Now of today. Yes, we do build on the work of those who have gone before us as in any area of scholarship, but we ourselves must also look at the universe. We must discern for ourselves the order or lack of it. Such a study also has a Greek name: Cosmology. From the present cosmos to the origin of the cosmos, that is the story of this paper. If the story begins with the Greeks; that is not to say they did not have forerunners. Their knowledge of the sky came from those careful watchers who preceded them, the Babylonians. But, the Greeks were the first ones who considered what they saw in the light of more basic assumptions - that human beings can know the heavens, chart the stars follow regular motions, that they follow laws that can be comprehended by the human brain. To us, this may seem trivial. But, when we reflect that since time immemorial the stars have looked down on the human scene of life and death, tragedy and rejoicing, birth and dying, with the same impersonal eternal shining, we can begin to realize the significance of what the Greeks did. No longer were we to think of the heavens as controlling our fate. They were impersonal and rightly so. As parts of nature, they obeyed the same laws of nature as human beings. The cosmos was orderly and human reason could reason out this order. It was no longer at the whim of the gods and, thus, a capricious and ultimately scary, uncertain arena into which the human being was thrust at birth. We may not understand, at any one moment, its workings but, in principle, the Universe can be understood .11 Studying the very big When this Greek idea was rediscovered in Christian Europe centuries later, it found a very fertile field in which to be planted and bear fruit. That the human brain could understand the Universe was not a surprise to a culture that celebrated the human Son of God every year2. In fact, much has been written about the religiosity of the founders of modern science, the first scientists. Men such as Isaac Newton and Johannes Kepler were no strangers to religion and, in fact, would find it strange were we to ask how they could be both scientists and religious in their worldview. Their early work was essentially astronomical in nature and it is upon these foundations that modern Cosmology stands. When Newton reasoned that the same force of gravity that he discovered to be operative on Earth - and expressed in mathematical form - was the operative throughout the universe, he gave the clue to the development of the science of the cosmos. Investigate the heavens, assuming it obeys the same physics and chemistry as planet Earth, and much can be discovered about the cosmos. Such a voyage of discovery has proven remarkably successful. 1

One interesting approach to this basic item in the history of science is that of the popular science writer Timothy Ferris (1989). 2 How necessary Christian theology was to the rise of science is a contentious point, but you will find an interesting approach in Stanley L. Jaki's The Savior of Science (1988). 04 Readings 1

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In the beginning, Newton used pencil and paper as his scientific "instruments." Eventually, he built his own telescope, according to his own design. Since then, many and various instruments have been built to study the heavens, simply drawing on data from the stars and other heavenly bodies. As we have never been to a star, all we know comes from our investigation of the data they supply to our senses. The first, of course, is light. But, there are many more. The electromagnetic spectrum can give other information if it can be captured and analyzed. This means going beyond the visible light to the non-visible, such as the infrared and/or ultraviolet ranges of the spectrum. These are not so easily accessible to our senses, and yet, they can supply data about the stars from which they come. Thus, astronomers have always been interested in new ways of capturing these spectrum ranges and have designed various devices to do just that. We refer to these devices as "telescopes," though we, in fact, may not be able to "see" anything since we are "viewing" the spectrum ranges that are not visible to our eyes. It took the development of science and its attendant products until the twentieth century to produce "telescopes" that gathered information beyond the range of visible light. First, there was the radio telescope, to be followed in the latter part of the century by the ultraviolet, X-ray, and gamma-ray telescopes. All of these tell us something more, and often something new, about the heavenly bodies that emit these rays. From such data, the stars are better understood (Chaisson and McMillan 1996) But, what about the Cosmos? New ways of getting data and new wavelengths to use as probes of stellar structure are helpful for specific objects of investigation, but what do these tell us about the big picture, the whole cosmos? Radio astronomy has helped the scientists to find out a great deal more about the heavenly bodies, and it would not be an exaggeration to state that it was this same instrument that unlocked the current understanding of the Big Picture. When Arno Penzias and Robert Wilson tested their early radio receiver, they were surprised to find out that the signal of radio transmission was coming from all directions in the sky. This would mean that the source of the waves was anywhere they looked. How could this be? They soon reported their findings, and it was realized by another group of scientists some one hundred kilometers away, that this could only be true if the sources were evenly distributed in all directions. Further, they realized that the strength of these radio waves was very low, meaning the source was weak. So the theory, called the Standard Cosmological Model (Peebles 1993), was born. To understand this, we must step back a few years to the first two decades of the century. Edwin Hubble was an astronomer who wanted to resolve a conundrum about puffs of cloudy material seen in the telescopes of his day and the decades before. These objects, which appeared puffy and cloudy, were seen through the bigger telescopes that were better able to see fainter and farther objects. Through these telescopes, the stars shone like brilliant diamonds, but these cloudy objects were not point-like, but were diffuse and faint. Only the largest telescopes could make them out. What were they? Due to their appearance, they had, earlier on, gotten the name nebula, Latin for "cloud." But, were they clouds, and if so, what were they made of? Why did they shine, although not very brightly? Hubble set out to discover. After years of watching these objects and recording his investigations on film, using not only the traditional telescope but also specialized instruments, he announced to the world that these objects were not clouds but galaxies, i.e., clusters of stars. They did not exist in our own galaxy, but were sister galaxies to our own, millions of light-years away. Hubble went on to explain that his observations indicated that, not only were there thousands of such galaxies wherever he looked through the telescope but that almost all of them were moving away from the Earth. He stated a mathematical law that summed up his data. The galaxies are moving away from us, in such a way that the farther away it is, the faster it is moving. This became known as Hubble's Law and is a cornerstone of modern Cosmology (Davis 1991). The beginning of space and time By the time Penzias and Wilson discovered that cosmic radiation came into the Earth from all directions and that it was very weak in nature, the implications of Hubble's Law had led astronomers to speculate that the law suggested a time, long ago, when all the galaxies were together in space. To explain such 04 Readings 1

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great velocities for the galaxies farthest away, and therefore, those that were formed the earliest, they used a term coined by Sir Fred Hoyle, a British astronomer. They spoke of an initial moment when all the galaxies, or at least the matter and/or energy they are made from, were together at one point in space and at the one initial point in time. They referred to this as the "Big Bang." This would explain what Penzias and Wilson were receiving in their radio telescope. They were seeing the remains of this initial Big Bang. They were picking up the energy left over, as it were, from that initial event and the energy had been filling space-time as it has been expanding in the billions of years since the Big Bang. Here, we need to consider this special term "space-time" to further understand this model of the Big Bang and its effects on our world today. The term "space-time" refers to the mathematical formulation of the Theory of General Relativity of Albert Einstein3. In that theory, Einstein models space as a kind of mathematical fabric, which is twisted and bent in accord with the amount of matter or energy that it contains. Actually, this fabric is not made up of space coordinates only, but also that of time. It is, therefore, a four-dimensional "space," which we call a manifold. This four-dimensional manifold tells the matter within it how to move, and the matter tells the manifold how to twist. The problem, of course, is that our imagination cannot picture these four dimensions, and so we have to fall back on the mathematical formulation to really grasp the theory. For our purposes, however, we can use the idea of a space-time manifold as the fabric, so to speak, of the cosmos. It is this, which starts to expand with the Big Bang. As it expands it carries the galaxies and, indeed, all material reality with it. It is this expansion of the manifold that Hubble saw in his telescope. It is as if the galaxies are painted on the surface of a balloon and we see the galaxies move apart from us because we are seeing the effects of the expansion of the underlying manifold. Remember that the manifold has time as one of its dimensions. Therefore, as time increases so does space, its partner dimension. Hubble's Law is describing this ongoing expansion. As the manifold expands, as the Universe expands, so does the space of the galaxies expand, dragging the galaxies away from each other4. Once we accept this concept of space-time as a kind of fabric that has been expanding since time t equals zero, then we are in a position to explore further. From what has been said, we can ask about the shape of this space- time manifold, since we have learned that this shape depends on the amount of matter/energy contained within it. From the shape, we can determine the amount of matter, or we could turn the physics around. We can determine the shape if we knew the amount of matter. Interest in this question has led the cosmologists to try to determine the amount of matter in the Universe. Their equations, following the General Theory of Relativity, establish that only three possible shapes for the space-time manifold are possible. Either the amount of energy-matter is sufficient to bend the manifold back on itself, as it were, and we have a spherical Universe; or it is too little, and we have a saddle-shaped Universe. The third option lies in between. There is just enough energy-matter to, as it were, match the expansion rate of the manifold given by the initial Big Bang, and so the Universe is flat, geometrically speaking. Which of these is true awaited further study by cosmologists into the 1990s. In the meantime, a theory was emerging which was directly related. Cosmologists wanted to know why the cosmos, at its furthest, at the very limits of seeing by our telescopes, appears to be homogeneous. Wherever we look at the order of hundreds of millions of light-years, we see galaxies upon galaxies, evenly spread out in space. In whatever direction we look in the sky the sameness meets our eyes. Why should the Universe be so even at this level of inspection, given that it all started in the boiling cauldron of the energy of the Big Bang? The theory that will resolve this problem and also postulate that the cosmos should be flat is called the Inflation Theory. Its main proponent is Allan Guth of the Massachusetts Institute of Technology in Cambridge, Massachusetts (Lemley 2002). He 3

A simple approach is difficult since the theory is so mathematical in nature that Einstein himself looked for help. Try either Ferris (1989) or Davis (1991). 4 The classic example or image for this expanding Universe was given by Sir Arthur Eddington, a British astronomer. He used the idea of the skin of an expanding balloon. One has to be careful here, however, to remember that it is the skin of the balloon that represents space-time, not the air inside the balloon or the balloon itself. 04 Readings 1

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believes that the Universe expanded extremely quickly near its beginning and then settled down thereafter. This would create a homogenous universe and one whose geometry is flat. Such predictions could be tested and so the cosmologists set out to do just that. To do this testing, they again turned to new technology, new ways of viewing the Universe. Seeing the universe in a new light The new technologies they turned to were not new in themselves but new in their application to astronomy. X-rays had been known for almost a century when they were harnessed to tell us about the Universe. Unlike the X-rays of the medical profession, these X-ray telescopes did not send out Xrays but rather collected the X-rays coming from the stars. To do so, X-ray telescopes had to be placed above the Earth's atmosphere, which would otherwise have absorbed the X-rays. Thus, this new Xray astronomy was only possible when satellite technology had developed far enough to allow such large telescopes to be placed in space. Since X-rays are more powerful than visible light, the X-rays detected by these telescopes were coming sources from more energetic than ordinary stars, or they were coming from ordinary stars, which were very far away. Or both. In the course of resolving this question, the bigger cosmological question as to the flatness of space-time would be answered5. The answers came in the late 1990s. Answers, yes, but with each answer came more questions-the typical "way of proceeding” of science. The Hubble Space Telescope and the X-ray Space telescope were used. They were joined by a less stately device-also a telescope-but looking far more like a huge gas balloon. This was the Boomerang Infrared device, made to take a much closer look at the Big Bang radiation, officially called Cosmic Background Radiation (CBR). This radiation is very weak, yet it contains what the universe was like when the radiation was first able to break free of its source in the Big Bang. This happened some 300,000-400,000 years after the Big Bang itself. Thus, the CBR can tell us the structure of the cosmos at that time, if we can decipher its very cryptic message. The Boomerang device, along with others, was able to do this, and what they saw matches the prediction of the Inflation Theory. The Universe is flat and homogeneous. That very early inflation is the reason why it is so. But, the Hubble telescope and its sister, the X-ray telescope, were not to be left behind. They, too, looked out into the cosmos and back in time. As they probed, they not only confirmed what was now becoming the Standard Theory of Cosmology but they also significantly added to it. They discovered that the very early galaxies were telling us something about our own galaxy that had never been guessed at before. Not only was our cosmos flat, but also it was accelerating. The energy of the Big Bang was dissipating as time went on, as we would expect, yet, the rate at which these early galaxies were moving indicated that our present rate of expansion is actually faster than it should be. Something was speeding up the cosmos. There exists some kind of" dark energy" accelerating the galaxies so that even as the initial energy of the Big Bang is dissipated in time, the galaxies were not slowing down but actually speeding up. We say "dark energy," simply because we do not know what it is. The term "dark" is an old one in Cosmology, but for another reason. All we know about the stars comes from their light, their radiation. They emit radiation of all kinds and by investigating these different kinds of radiation we have been able to piece together the Standard Theory. Only if something emits radiation, which we can detect, can we know anything about it. We have never been to a star. We learn from what they send to us. So it is that the concept of" dark matter" has entered into astronomy. We know from seeing the motion of different stars around each other, or different galaxies around each other that there is something we cannot see, but is present in the Universe. We know of it, not because we can see it, not because it sends out radiation we detect, but rather because we can see the effects of its mass upon its neighboring masses. Its effects can detect gravity and it is this gravitational pull that keeps one galaxy, for example, in orbit about another. But, the matter we see glowing in the central galaxy is not enough 5

Many authors discuss how the Inflation Theory answers many questions, but one that is quite engaging is by Barrow and Tipler (1988).

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to account for this pull of gravity on the other galaxy. Hence, there is some kind of" dark matter" supplying the extra gravitational pull. Thus, the concept of" dark" was not unknown to astronomers. In fact, the necessity for such "dark matter" had been known for decades. But, the late 1990s gave us a new darkness-"dark energy." The Wilkinson Microwave Anisotropy Probe (WMAP) of NASA, launched in June 2001, determined that the "dark matter" and "dark energy" make up 23.3% and 72.1% of the universe, respectively. It further determined the age of the universe to 13.73 billion years (NASA 2010). The attempts to see the Universe in a new light have opened doors to more of the unknown. It seems that it will take humankind a lot more "to arrive where we started and know the [cosmos] for the first time." References: Abbott, E. 1992. Flatland: A Romance of Many Dimensions. Mineola, New York: Dover Books. Baar, E. 2001. Astronomers 'See' Dark Matter. Wired News, December 5. Retrieved February 28, 2003 from http://www.wired.com/news/technology/O,1282,48861,00. html. Barrow, J. & Frank Tipler. 1998. The Anthropic Cosmological Principle. Oxford: Oxford University Press. Carroll, Sean, William H. Press, and Edwin L. Turner. 1992. "The Cosmological Constant." Annual Reviews Astronomy and Astrophysics 30. Accessed February 28, 2003. http:// nedwww.ipac.caltech.edu/levelS/ Carroll/frames.html. Close, Frank. 2000. Lucifer's Legacy: The Meaning of Asymmetry. Oxford: Oxford University Press. Cowen, Ro...