Archive for the ‘Paul Davies’ Category

Watching the history of the universe unfold

January 16, 2008

When astronomers peer at the heavens through telescopes, they see distant objects not as they are now, but as they were when the light reaching the telescopes embarked on its journey across space.  In this respect, a telescope is also a “timescope.”  For example, if a nearby star exploded yesterday, we would be blissfully unaware of this cataclysm for years, until the pulse of light announcing the star’s demise arrived on Earth.  Looking further afield, we see stars in the neighboring Andromeda galaxy as they looked about 2.5 million years ago.  More distant galaxies appear correspondingly older.  The Hubble Space Telescope routinely records images of galaxies as they appeared long before Earth even existed.  The oldest galaxies can actually be seen still in the process of formation, more that 12 billion years ago.  So by penetrating farther and farther into space, astronomers can watch the history of the universe unfolding in reverse.

Cosmic Jackpot by Paul Davies

The “big bang” was not an exploding ball of matter

January 13, 2008

Popular accounts of the big bang often describe it as the detonation of a compact ball of matter poised in a preexisting void, with the galaxies compared to fragments flying away from the center of the explosion.

Easy though this image may be to grasp, it is seriously misleading and the source of much confusion: people are inevitably prompted to ask, “Where is the center of the universe?”

If the big bang really had been an exploding ball of matter, then some galaxies would lie deep in the midst of the melee, surrounded on all sides, while others would be located near the edge of the assemblage.  Suppose this were so, and picture the view from a far-flung galaxy.  In one direction would lie the center of the universe; in the opposite direction there would be empty space.  The sky would appear dramatically different depending on which way an observer looked.

That is certainly not what we see from Earth: the universe looks very much the same in all directions.  As far as our telescopes can penetrate, which is about 13 billion light-years, encompassing roughly 100 billion galaxies, matter is distributed uniformly (strictly, it is clusters of galaxies that are distributed uniformly).  There is no evidence for any bunching up around some sort of center or, conversely, for any thinning out toward an edge.

How, then, should we describe the big bang and the expanding universe, given these observational facts?  Cosmologists have struggled to find ways to describe the expanding universe in simple language.  Here’s one attempt:

The big bang happened everywhere, not at one point in space.

A simple analogy that may help is to imagine a very long string of elastic with beads attached at regular intervals.  As the elastic is stretched, the beads move apart.  Every bead extends its separation from its neighbors, so the view from any given bead will be of other beads moving away.  All beads are equal: there is no center bead.

Cosmic Jackpot by Paul Davies

First and second attempts to explain the universe: (1) religion, (2) science

January 10, 2008

Religion was the first systematic attempt to explain the universe comprehensively.  It presented the world as a product of mind or minds, of supernatural agents who could order or disorder nature at will.

Science was the second great attempt to explain the world.  This time explanations were cast in terms of impersonal forces and natural, physical processes, rather than the activities of purposive supernatural agents.

When scientific explanations conflicted with religious explanations, religion invariably lost the battle.  Mostly, theologians retreated to concentrate on social and ethical matters such as spiritual enlightenment, content to leave interpreting the physical universe to the scientists.

Cosmic Jackpot by Paul Davies

Reading the great book of nature

January 9, 2008

The fact that the physical world conforms to mathematical laws led Galileo to make a famous remark.  “The great book of nature,” he wrote, “can be read only by those who know the language in which it was written.  And this language is mathematics.”  The same point was made more bluntly three centuries later by the English astronomer James Jeans: The universe appears to have been designed by a pure mathematician.”

Cosmic Jackpot by Paul Davies

Human beings have been made privy to the deepest workings of the universe

January 8, 2008

You would never guess by looking at the physical world that beneath the surface hubbub of natural phenomenon lies an abstract order, an order that can’t be seen or heard or felt, but deduced.  Even the wisest mind couldn’t tell merely from daily experience that the diverse physical systems making up the cosmos are linked, deep down, by a network of coded mathematical relationships.   Yet science has uncovered the existence of this concealed mathematical domain.  We human beings have been made privy to the deepest workings of the universe.  Other animals observe the same natural phenomena as we do, but alone among the creatures on this planet, Homo sapiens can also explain them. 

How has this come about?  Somehow the universe has engineered, not just its own awareness, but also its own comprehension.  Mindless, blundering atoms have conspired to make not just life, not just mind, but understanding.  The evolving cosmos has spawned beings who are able not merely to watch the show, but to unravel the plot.  What is it that enables something as small and delicate and adapted to terrestrial life as the human brain to engage with the totality of the cosmos and the silent mathematical tune to which it dances?  For all we know, this is the first and only time anywhere in the universe that minds have glimpsed the cosmic code.

Cosmic Jackpot by Paul Davies

Searching for that deeper meaning to life? The key to the universe has been found!

January 1, 2008

Throughout history, prominent thinkers have been convinced that the everyday world observed through our senses represents only the surface manifestation of a deeper hidden reality, where the answers to the great questions of existence should be sought.

So compelling has been this belief that entire societies have been shaped by it.  Truth seekers have practiced complex rituals and rites, used drugs and meditation to enter trancelike states, and consulted shamans, mystics and priests in an attempt to lift the veil on a shadowy world that lies beneath the one we perceive.

Attempts to gain useful information about the world through magic, mysticism, and secret mathematical codes mostly led nowhere.  But about 350 years ago, the greatest magician who ever lived finally stumbled on the key to the universe — a cosmic code that would open the floodgates of knowledge.  This was Isaac Newton — mystic, theologian, and alchemist — and in spite of his mystical leanings, he did more than anyone to change the age of magic into the age of science.

The word science is derived from the Latin scientia, simply meaning “knowledge.”  Originally it was just one of many arcane methods used to probe beyond the limitations of our senses in the hope of accessing unseen reality. The particular brand of “magic” employed by the early scientists involved hitherto unfamiliar and specialized procedures, such as manipulating mathematical symbols on pieces of paper and coaxing matter to behave in strange ways.  Today we take such practices for granted and call them scientific theory and experiment.

We really are in possession of the key to the universe.  The ancients were right: beneath the surface complexity of nature lies a hidden subtext, written in a subtle mathematical code.  This cosmic code contains the secret rules on which the universe runs.  Newton, Galileo, and other early scientists treated their investigations as a religious quest.  They thought that by exposing the patterns woven into the processes of nature they truly were glimpsing the mind of God.

Cosmic Jackpot by Paul Davies