Spring 2010

Science and Environment

In the Beginning

Martin Coates

In his act, Welsh comedian, singer and poet Max Boyce tells tales relating to his beloved Wales. These often involve the national rugby squad beating the English team in an epic match. At times he concludes with a statement meant to add gravitas to the account: “I know ’cos I was there.”

In more formal settings, such as a court of law, great value is placed on an eyewitness account. Similarly, news reporters often try to interview someone who actually saw or heard something. Historians, too, seek out first-hand experiences; hence the importance of documents such as the diaries of Samuel Pepys and Anne Frank. But when we go back beyond recorded history, indeed to a time before humankind existed, we run into difficulty: where is the first-hand account to which we can turn?

This is the situation in which scientists find themselves when trying to explain how our universe came into being and how those early conditions resulted in what we can observe and measure today. In his book A Briefer History of Time (2005), British theoretical physicist Stephen Hawking attempts to explain, among other things, the early state of our universe. He and collaborator Leonard Mlodinow, who holds a doctorate in theoretical physics and teaches at Caltech, ask: “What do we really know about the universe, and how do we know it? Where did the universe come from? Where is it going? Did the universe have a beginning, and if so, what happened before then?”

These are questions to which humanity has long sought an answer. And as the authors note, “today we still yearn to know why we are here and where we came from.”

But how can we know the answers to these questions without reference to source material? What Hawking and Mlodinow offer is this: “Today we have powerful tools: mental tools such as mathematics and the scientific method, and technological tools like computers and telescopes. With the help of these tools, scientists have pieced together a lot of knowledge about space.”

Are we therefore on the cusp of finding answers to some of our most pressing questions?

Looking Back in Time

When we look up at distant stars in the night sky, or view a beautiful sunset courtesy of our local star, we are looking back in time; that is, we see these objects as they were in the past. Light travels at a finite speed; given the vastness of the universe, it takes time for light from distant objects to reach us. In the case of the sun, we see it as it was about eight minutes ago, whereas light reaching us from stars in the Andromeda Galaxy was generated around 2.5 million years ago.

Telescopes enable us to peer across the universe and therefore back in time. The Hubble Space Telescope, for example, has produced images from galaxies in the early stages of development, over 12 billion years ago. Other telescopes scan the sky at infrared and microwave wavelengths, longer than those of visible light. The recently launched Planck satellite is due to provide greater detail concerning the cosmic microwave background (CMB) radiation, which is thought to hold vital clues to origins.

Despite the possibility of peering into the past, it can still be difficult to draw firm conclusions about the early universe. Paul J. Steinhardt is the Albert Einstein Professor in Science at Princeton University and director of Princeton’s Center for Theoretical Science. He has worked with Neil Turok, the former chair of Mathematical Physics at Cambridge and now director of the Perimeter Institute for Theoretical Physics in Waterloo, Ontario. In their book, Endless Universe: Beyond the Big Bang (2007), they describe cosmology as “the study of the origin and evolution of the universe.” Because scientists cannot perform direct experiments on the universe or travel back in time, the coauthors call for a high level of caution: “The best they can do is gather indirect information about the history of the universe through painstaking observations of distant objects that emitted their light a long time ago and try to piece together a logical account.”

Many scientists have worked on parts of the puzzle that is our universe. Using all the tools at their disposal but lacking a written eyewitness account, and with built-in limits to experimentation, they have sought to produce and test theories that can expand our understanding.

One could go back centuries detailing their small steps, setbacks and dramatic breakthroughs. The point at which we have arrived today should not be seen as a linear progression, however. Various models of how the universe formed have dominated for periods of time, only to lose favor and then resurface later. Often a piece of scientific evidence or theorizing seems to point in one direction but is overturned by a later discovery. Historically this field of research has given rise to heated debate within the scientific community; indeed, this is so even today.

Of the many cosmological models that have attempted to explain the origins of the universe, Steinhardt and Turok say the vast majority fall into one of three categories: created universe, unchanging universe and episodic universe. Let us briefly consider each to see whether it can explain the seemingly inexplicable.

Big Bang or Not?

Picking up the story in the relatively recent past, we find that a version of the unchanging universe model held sway by the late 19th century. This was because of the growing uniformitarian movement, whose ethos was to explain the history of the universe by gradual and uniform change. Dating rock samples had made it clear that Earth was a lot older than previously thought, and thus the universe incredibly old, possibly infinitely so. In his book Big Bang (2004), Simon Singh, the BAFTA award–winning documentary maker who earned a doctorate in particle physics at Cambridge, writes that “an eternal universe seemed to strike a chord with the scientific community. . . . If the universe had existed for eternity, then there is no need to explain how it was created, when it was created, why it was created or Who created it.” However, Singh also notes that belief in this model was largely a leap of faith, that there was no scientific justification to go from an ancient Earth to an eternal universe.

Later, even Albert Einstein fell foul of the perceived wisdom of his day. When he applied his general theory of relativity and gravity formula, the result indicated an unstable universe that should collapse. Einstein therefore introduced the “cosmological constant” as a mathematical fix for the general theory of relativity—something he later regretted and rescinded. Singh puts it this way: “It was a fudge that Einstein used to get the result that was expected, namely a stable and eternal universe.”

One scientist and mathematician who challenged Einstein’s cosmological constant, and indeed his view of an unchanging universe, was Alexander Friedmann. He theorized that the universe was able to overcome the gravitational pulls that seemed to predict it should collapse, because it had been subject to an initial and possibly continuing expansion.

Following Friedmann’s death, Belgian priest and cosmologist Georges Lemaître applied logic to the concept of an expanding universe and worked backward in time. Singh relates Lemaître’s reasoning: if the universe is expanding today, then it must have been smaller yesterday and the day before that. Keep going, and you end up at what Lemaître termed “the primeval atom”—a super-dense atom that suddenly expanded, generating all matter in the universe. Although Lemaître thought this primeval atom might always have existed before rupturing, he viewed this explosive event as the effective start of the universe. So the model of an eternal universe was being challenged by one that again seemed to indicate a point in time when it came into being—a moment of creation.

Meanwhile astronomer Vesto Slipher, working at the Lowell Observatory in Arizona, had been making some discoveries of his own. The combination of spectroscopes and giant telescopes, along with sensitive photographic plates, provided the opportunity to examine stars in new ways. It had been known for some time that light waves from a receding source get stretched and shifted toward the red end of the spectrum. In his analysis of the light emitted from a number of galaxies, Slipher discovered that most appeared to be exhibiting this red shift, the implication being that they were moving away from us and, if his calculations were correct, at great speed.

Edwin Hubble and his colleagues later confirmed and explained this effect using the 100-inch Mount Wilson Telescope in California. They discovered a relationship between a galaxy’s velocity and its distance from Earth, and the equation to explain this became known as Hubble’s Law. Observations indicated that far from being a static and unchanging place, the universe was largely populated with galaxies appearing to rush away from us in an orderly pattern of expansion. Thus Hubble provided the first major evidence to back up Friedmann and Lemaître’s model of cosmological creation. Singh remarks: “The significance was nothing less than the realisation that at some point in history all the galaxies in the universe had been compacted into the same small region. This was the first observational evidence to hint at what we now call the Big Bang. It was the first clue that there might have been a moment of creation.”

Not everyone was taken with the notion of an explosive start to the universe or the suggestion of a point of creation. British astronomer Fred Hoyle was one of its most vociferous opponents. Along with colleagues Thomas Gold and Hermann Bondi, he worked on a model that would square the notion of an eternally existing universe with Hubble’s observations of an expanding one. It was Gold who eventually came up with the concept of a universe that underwent continual development and yet on the whole did not change. In this model, which became known as the steady-state model, new matter was thought to be created to fill the gaps left by expansion. Singh states: “Such a universe would apparently be developing and expanding, yet it would be largely unchanging, constant and eternal.” The three colleagues then published papers and worked to advocate their model of the universe against the rival explosive-start theory, also known as the “dynamic evolving model.” It was actually Hoyle who first coined the phrase “big bang,” used derisively during a radio broadcast lecture for the BBC. The name stuck.

Fierce debate over the two rival theories continued for some time, stalling for a while for lack of definitive scientific evidence to back up one or undermine the other. Over time, scientists using new methods and equipment provided observational data that helped to clarify each position.

Beyond the Big Bang

The big-bang model gradually became the consensus view during the later part of the 20th century. Broadly speaking, current understanding sees this event not so much as an explosion in time and space but an explosion of time and space. It is thought by many to be when both began. From an infinitely condensed point, time and space expanded, at the same time going from incredibly hot to comparatively cool. From the sea of protons, neutrons and electrons, gradually atoms and nuclei were formed, largely of hydrogen and helium, which later condensed to form stars and galaxies. Nuclear reactions within stars and later the conditions within dying stars gave rise to heavier elements such as carbon, nitrogen and oxygen, essential for life here on earth. All this is thought to have begun from a single point approximately 13.7 billion years ago. Of course, a question naturally arises: What came before the big bang? 

In the 1960s several new phenomena were discovered. . . . These findings sounded the death-knell for the steady-state cosmology. This paved the way for widespread, although never universal, acceptance of the Big Bang cosmology.” 

Owen Gingerich, “Scientific Cosmology Meets Western Theology: A Historical Perspective,” in Annals of the New York Academy of Sciences (December 2001)

Various modifications and amendments have been made to the big-bang model along the way to include concepts such as inflation, dark matter and dark energy. All of these are nuanced, but inflation is essentially the rapid expansion of the universe in the earliest moments after the big bang. It seeks to explain the cause of the density variations in the early universe and in particular the higher-density regions that led to the seeding of galaxies, as well as explaining why the universe appears to be flat rather than curved. Dark matter, widely theorized but as yet undetected, has been posited as a reason for stars at the extremities of galaxies being held in their orbits, despite the fact that the combined gravitational pull of more-central stars is insufficient to achieve this. Due to its repulsive gravity, the equally elusive dark energy has been suggested as the force that still causes the universe to expand, and at an apparently increasing rate. Considering this, Singh comments: “With a momentarily violent period of inflation, peculiar dark matter and weird dark energy, the new Big Bang universe of the twenty-first century is a strange place indeed.”

Some see the current incarnation of the big-bang model as a somewhat makeshift amalgam of concepts. Steinhardt and Turok, in assessing the merits of the inflationary big-bang model, take issue with what they describe as its bizarre basic attributes. For example, “For mysterious and unexplained reasons, the universe emerges from nothing into a super-dense state.”

They have proposed a model that can be classified as episodic or cyclic: the ekpyrotic universe, from the Greek ekpyrosis (literally “out of fire,” referring to the conflagration in which they say one universe ends and a new one is born). Essentially, their model states that the big bang is not the beginning of time and space but rather part of a repeating cycle, where a big bang creates hot matter and radiation, which expand and cool to form galaxies. After increasingly rapid expansion in which matter and radiation spread out, dark energy decay leads to a slowing and eventually stopping of the expansion. This is followed by a gradual contraction of the universe, which in turn leads to a “big crunch.” Some of the dark energy is then suddenly converted into matter and radiation, and the universe begins to expand again. As the authors put it: “The crunch has turned into a bang.”

The explanation for this has its roots in a particular overarching version of string theory, called M-theory, which is complex and highly mathematical. This led to the notion that our three-dimensional universe is separated from another, hidden to us, by a tiny gap—maybe as small as 10-30 centimeters, along a fourth spatial dimension. According to this theory, the collision of these “worlds” (or membranes, or brane worlds) causes repeated big bangs over the course of trillions of years.

Does the ekpyrotic model hold the answer to the mystery that is our universe? In Steinhardt and Turok’s own words, “many string theorists remain skeptical about the ability of the crunch to transform into a bang, and this makes them uneasy about the whole cyclic concept. There is no way to resolve the issue other than performing detailed calculations. . . . Today, many theorists around the world are hotly pursuing the problem.”

In Perspective

Scientists have investigated these various models by holding them up to the known laws of physics, the observable and measurable qualities of the universe, and mathematical scrutiny. Our response to current theories of the beginnings of the universe may well reveal our intuition concerning how accomplished humanity has become. Steinhardt and Turok are among those who feel we are on the brink of a great breakthrough: “The next decade or two is likely to have an historic impact in determining which kind of theory and which specific model best explain the universe in which we live. . . . We are optimistic that, through the collective efforts of experimentalists, observers, and theorists, the crucial breakthroughs will be made that will ultimately decide the debate.”

Could it be that we are truly reaching the pinnacle of human knowledge—that the tools we now have at our disposal are about to reveal the final secrets of the cosmos? Currently the search is on for a grand unified theory, termed by some scientists as “the theory of everything.” This proposed theory hopes to reconcile or even supersede the general theory of relativity and quantum mechanics to provide a full explanation of the universe.

For Hawking and Mlodinow, echoing comments made by Einstein, this may lead to an even more astounding possibility: “If we do discover a complete theory . . . [we will] be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason—for then we would know the mind of God.” This, of course, is the eternal hope of science, though most scientists probably would have expressed it in different terms.

Their method of discovery, the scientific method, involves the construction of theories, which are then held up to scrutiny and tested. Over time these theories are either built upon as new investigative techniques reveal greater clarity, or they are rejected and superseded by a different paradigm.

We can all agree that [the study of cosmology] is highly ambitious. To claim, however, as many supporters of big-bang cosmology do, to have arrived at the correct theory verges, it seems to me, on arrogance.” 

Fred Hoyle, Home Is Where the Wind Blows: Chapters From a Cosmologist’s Life (1994)

An alternative, often dismissed, source of understanding “the mind of God,” which may complement the scientific approach or may challenge it, is the Bible. Although not intended to be read as a scientific explanation of cosmology, this book offers answers to the big questions that many ponder. It also has much to say about origins.

The book that most think of first, of course, is Genesis, which speaks of beginnings in succinct but nonscientific terms. A lesser known piece of understanding comes from the story of Job. As presented to us, Job was clearly an intelligent and accomplished individual. He did have one overriding fault, however: he failed to see God in a proper perspective. In order to give Job that perspective in terms he would understand, God asked some pointed questions: “Where were you when I laid the foundation of the earth? Tell me, if you have understanding. Who determined its measurements—surely you know! Or who stretched the line upon it? On what were its bases sunk, or who laid its cornerstone. . . . Have you commanded the morning since your days began, and caused the dawn to know its place?” (Job 38:4–6, 12).

The conclusion of the matter? Job got the point and began to properly honor God as the supreme, all-wise Creator and Sustainer of everything we see around us.

How about the rest of us? The fascinating and complex insights that science has given us as possible explanations for the origin of our universe are by turns incredible and baffling. As technological advances continue apace and the scientific and mathematical tools at our disposal reveal ever more detail, we will no doubt have new scenarios to ponder in the years ahead. But can science ever succeed in answering our most fundamental questions?

It seems more appropriate to conclude that we will find those answers by seeking first to know the mind of God—not the other way around as Hawking and Mlodinow declared. As part of the quest for answers, therefore, we might wish to consider an alternative approach to the big questions about origins: to ask someone who knows, because He was there.