Theory of Intelligent Design, the best explanation of Origins

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Theory of Intelligent Design, the best explanation of Origins » Astronomy & Cosmology and God » The Goldilocks Enigma - Paul Davies

The Goldilocks Enigma - Paul Davies

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1 The Goldilocks Enigma - Paul Davies on Tue May 16, 2017 11:43 am


The Goldilocks Enigma - Paul Davies

The Universe Is Bio-Friendly :
For life to emerge, and then to evolve into conscious beings like ourselves, certain conditions have to be satisfied. Among the many prerequisites for life—at least, for life as we know it—is a good supply of the various chemical elements needed to make biomass. Carbon is the key life-giving element, but oxygen, hydrogen, nitrogen, sulfur, and phosphorus are crucial too. Liquid water is another essential ingredient. Life also requires an energy source and a stable environment, which in our case are provided by the sun.   It has to be orderly enough to allow the untrammeled formation of galaxies and stars. There have to be the right sorts of forces acting between particles of matter to make stable atoms, complex molecules, planets, and stars. If almost any of the basic features of the universe, from the properties of atoms to the distribution of the galaxies, were different, life would very probably be impossible.

Now, it happens that to meet these various requirements, certain stringent conditions must be satisfied in the underlying laws of physics that regulate the universe, so stringent in fact that a bio-friendly universe
looks like a fix—or a “put-up job,” to use the pithy description of the late British cosmologist Fred Hoyle.

It appeared to Hoyle as if a superintellect had been “monkeying” with the laws of physics. He was right in his impression. On the face of it, the universe does look as if it has been designed by an intelligent creator expressly for the purpose of spawning sentient beings. 

Like the porridge in the tale of Goldilocks and the three bears, the universe seems to be “just right” for life, in many intriguing ways. No scientific explanation for the universe can be deemed complete unless it accounts for this appearance of judicious design.

Until recently, “the Goldilocks factor” was almost completely ignored by scientists. Now, that is changing fast. Science is, at last, coming to grips with the enigma of why, at last, verse is so uncannily fit for life. The explanation entails understanding how the universe began and evolved into its present form and knowing what matter is made of and how it is shaped and structured by the different forces of nature. Above all, it requires us to probe the very nature of physical laws.

The existence of laws of nature is the starting point of science itself. But right at the outset we encounter an obvious and profound enigma: Where do the laws of nature come from? As I have remarked, Galileo, Newton, and their contemporaries regarded the laws as thoughts in the mind of God, and their elegant mathematical form as a manifestation of God’s rational plan for the universe. Few scientists today would describe the laws of nature using such quaint language. Yet the questions remain of what these laws are and why they have the form that they do. If they aren’t the product of divine providence, how can they be explained?

English astronomer James Jeans:
“The universe appears to have been designed by a pure mathematician.”

Only in the past few decades have astronomers been able to pencil in the numbers that calibrate the vast scale of things. Our sun is one among hundreds of billions of stars that make up the Milky Way galaxy, and the Milky Way is in turn just one among hundreds of billions of galaxies scattered through space to the limits of our instruments. The gaps between stars are so large that astronomers measure them in light-years—the distance light travels in one year. One light-year works out to be about 6 trillion miles, or 10 trillion kilometers. To put this into perspective, the moon is just over a light-second away, and the sun a little more than 8 light minutes. The Milky Way, which is a typical spiral galaxy, measures about 100,000 light-years across. The Andromeda galaxy, a near neighbor of the Milky Way, lies at a distance of about 2.5 million light years. The farthest galaxies imaged by the Hubble Space Telescope are over 10 billion light-years away. In human terms, the universe is almost unimaginably vast.

Is the Universe Pointless?
Even atheistic scientists will wax lyrical about the scale, the majesty, the harmony, the elegance, the sheer ingenuity of the universe of which they form so small and fragile a part. As the great cosmic drama unfolds before us, it begins to look as though there is a “script”—a scheme of things—that its evolution is following. We are then bound to ask, Who or what wrote the script? Or did the script somehow, miraculously, write itself? Is the great cosmic text laid down once and for all, or is the universe, or the invisible author, making it up as it goes along? Is this the only drama being staged, or is our universe just one of many shows in town?

The fact that the universe conforms to an orderly scheme, and is not an arbitrary muddle of events, prompts one to wonder—God or no God—whether there is some sort of meaning or purpose behind it all.

The Universe Might Weigh Nothing!
How can space be flat overall when the sun and stars distort it locally? Obviously, something in between the stars must make space curve the other way to average out to zero. (Remember that space can curve both positively and negatively.) What is this something? The answer comes from Einstein’s famous equation E = mc2, which tells us that mass is energy, and energy has mass. I shall often refer to “mass-energy” as a single concept in what follows. In estimating the mass of the universe we have to include all forms of energy, not just the mass of matter in the sun, the stars, and other astronomical objects. Also contributing to the total mass-energy are the heat energy of the CMB ( cosmic microwave background), magnetic fields, and cosmic rays. Last, but by no means least, is the gravitational field itself: gravity is a form of energy. But now we notice a curious fact. Imagine trying to pluck the Earth out of its orbit around the sun. You would have to do work—that is, expend energy—to draw it away against the sun’s gravitational pull. So the gravitational energy binding the Earth to the sun is negative (it requires work to sever the bond). If the gravitational field has negative energy, it must also have negative mass and must be subtracted from the positive mass-energy of the sun and planets. Let’s see how the negative gravitational energy comes into the total mass-energy of the universe. Within the solar system, the amount of gravitational mass-energy is puny compared with the enormous mass of the sun. The overall mass of the solar system, even with all the gravitational binding energy included, is still large and positive. But when it comes to the universe as a whole, it’s a different matter. One of the distinctive things about gravity is that it is universal: it acts between all particles of matter in the universe. So to work out the (negative) gravitational energy for the whole universe, you have to tot up all the gravitational energy due to every object tugging on every other object: that’s a lot of tugs in all, even if for each star the vast majority of the others are enormously distant.

A simple estimate of the gravitational energy binding all the galaxies to one another gives an effective mass for the gravitational field (using E = mc2) of about minus 10^50 tons, which is roughly equal (and opposite) to the mass of all the stars and other stuff. The fact that the two very large numbers are of the same order, and of opposite sign, suggests very much that they are doing their best to cancel one another and make the net mass of the universe zero!

Einstein’s general theory of relativity provides a link between the mass of the universe and the geometry of space. Specifically, if the total mass is positive—matter wins out over negative gravitational energy—then space is curved positively, like Einstein’s universe. If the mass is negative —gravitational energy wins out over matter—then space is curved negatively, like the saddle. If it is precisely zero, then space is flat. Cosmologists knew for years that the positive and negative contributions to the mass of the universe roughly cancel out. But WMAP clinched it. To within the 2 percent accuracy of the measurement, the satellite found space to be flat, which translates into the conclusion that the universe contains no net mass at all! And that, as we shall see later, is yet another one of those “coincidences” that is needed for a life-permitting universe.

Why Is the Universe So Smooth?
On the face of it, an explosion is an unlikely way to create a smooth and orchestrated expansion; explosions are normally rather messy affairs. If the big bang had been slightly uneven, so that the expansion rate in one direction outstripped that in another, then over time the universe would have grown more and more lopsided as the faster galaxies receded. We don’t see that. Evidently, the big bang had exactly the same vigor in all directions, and in all regions of space, tuned to very high precision. In itself, this would be enigmatic enough, but it looks downright contrived when we remember the existence of the horizon. Imagine two regions of space on opposite sides of the sky, A and B, each 10 billion light-years from Earth. They look very much the same, containing similar distributions of galaxies with similar red shifts. Located poles apart, these cosmic regions are seen by us today to be separated by about 20 billion light-years from each other. Since the universe is less than 14 billion years old, light cannot have had time since the big bang to have traveled from one region to the other. An inhabitant in region A would not be able to see region B or know of its existence, even though human beings, situated as we are between them, can see both (see Figure 13).

The horizon around A will not yet have extended as far as B. Regions A and B evidently cannot know about each other. This means that they are what is termed causally independent because no object or force can travel faster than light, so no physical influence can have linked these regions. What has happened in region A cannot (in this simple picture) possibly affect what has happened in B, and vice versa. Why, then, do A and B look more or less identical? How has the universe contrived its explosive genesis with such exactitude that there is no distinguishable difference across the sky, even between regions that have never been in causal contact? It’s as if a troupe of blind and deaf ballerinas were to perform a perfectly choreographed dance. To throw the problem into stark relief, at the epoch from which the CMB emanates, the observed universe contained millions of apparently causally independent domains, and yet—as I have stressed—this radiation is astonishingly uniform. How has the entire cosmos cooperated to achieve this? Was it just an incredible fluke, or did some physical process operate in the very early universe to bring about such a very special state of affairs?

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