Infinite Wonder of the Divine
by George Coyne
Will the universe ever end? Can we rely on it to continue on and on? The most recent measurements of the velocities of recession of very distant objects in the universe, supernovae, which can serve as standard “light beacons” at distances of about 10 to 12 billion light years from us, indicate that the universe is not only still expanding but that it is accelerating in its expansion and will, unless we discover a braking mechanism, expand forever – an empirically infinite universe.
Several important issues need to be explained here. To measure such large distances we must use probes that are so distant that we cannot experiment upon them. We can only observe them and, in fact, we are limited very much by what we can observe. An astronomer is like the poor old fellow who, while making his way home in the dark and a bit tipsy, loses his watch. While he is searching for it under a lamp post, a gallant policeman comes along and enquires about his activity. He explains that he is looking for his watch. “Well,” says the cop, “did you lose it here?” “Oh no,” says he, “but it’s so dark all around that this is the only place with light enough that I could possibly find it.” As you will see, to measure the age of the universe, astronomers must cleverly, and hopefully more sober than the gentleman searching for his watch, probe where there is light and, even then, since light travels with a finite velocity, we are seeing the universe only as it was, not as it is. “Light beacons” are celestial objects that have the same intrinsic brightness wherever they are in the universe and can, therefore, serve as distance indicators.
Do a simple experiment. Measure the brightness of the lamp sitting on your desk. Now go to the next room, four times farther away from the lamp, and measure its brightness. It will be one-sixteenth as bright (diminished by the inverse square of the distance). Now reverse the experiment. You know the intrinsic brightness of the lamp, as cosmologists do that of supernovae, and you know how bright it appears to you from the next room, as cosmologists do by measuring the apparent brightness of supernovae. You can, therefore, deduce the distance.
So, if we measure the distance and brightness of objects at increasingly larger distances in the universe, we can establish the curve of expansion of the universe and thereby deduce its age. Let me explain. What we are measuring is how fast all objects, outside our sun-centred system, are moving away from one another at various epochs in the history of the universe. At one time, not long after the Big Bang, all of these objects were “together”. So we can extrapolate backwards to the time when they began to separate and, thereby, measure the age of the universe, 13.7 billion years.
This is a simple calculation like the following analogous one. Suppose I run a marathon at a constant rate of 4 miles per hour. You are standing at the 20-mile marker with clock in hand. It is easy for you, knowing my rate and that you are at 20 miles from the beginning, to calculate when I began.
Using this simple calculation, in 1929 Edwin Hubble discovered the observational relationship that bears his name, “the Hubble law”, and made the first calculation of the age of the universe from its expansion. He found for 24 galaxies that their velocities of recession were directly proportional to their distances. He later extended the measurements to more galaxies at larger distances. A modern version of these pioneering observations confirms the “Hubble Law” but with much greater accuracy. In the entire history of observational astronomy this is a remarkable correlation. It holds true for all extra-galactic objects: galaxies of all types, clusters of galaxies of all types, quasars and supernovae. It is so universally true that we intuitively surmise that it is saying something fundamental about the universe itself. And it is. It is telling us that the universe is expanding uniformly. But there is even more to the story.
There are several kinds of supernovae. Astronomers have found that the type about which I am speaking can serve as a “light beacon” despite its very strange and unstable energy source. These supernovae are binary stars in which a white dwarf, a dead star whose mass is very compact so that it has a very large gravity field, sucks matter from its companion giant star. It becomes suddenly millions of times brighter by starting a thermonuclear furnace in its atmosphere from the matter accumulated. This is obviously a very unstable event and lasts for only hundreds of days (the stars involved are about 10 billion years old). None the less, we have found that the maximum brightness that it attains can be an excellent “light beacon” and indicator of distance as I have explained above.
By measuring these distances and the velocity of these supernovae we find that the universe is accelerating in its expansion. This result causes a great deal of head scratching among cosmologists because it defies the law of gravity. Matter in the universe should be constantly drawing the universe in and braking its expansion. What is pushing the universe out, so to speak, against the force of gravity so that it is accelerating? Despite such problems as this, we now know that, since it is accelerating, the universe will expand forever and eventually reach the temperature of absolute zero so that everything in the universe will be dead. There will be no energy. The universe will in this sense be dead but expanding infinitely.
To appreciate the current age of the universe and its temporal infinitude we must compare it to the times at which other events, such as the appearance of life, have occurred. To do this I suggest that the actual age of the universe, 13.7 billion years for which we have no sensation, be reduced in our imagination to one Earth year, one rotation of the Earth about the sun. The following calendar results:
1 January: The Big Bang
7 February: The Milky Way is born
14 August: The Earth is born
4 September: First life on the Earth
15 December: The Cambrian explosion
25 December: The dinosaurs appear
30 December: Extinction of the dinosaurs
19.00.00: First human ancestors
23.58.00: First humans
23.59.30: Age of Agriculture
23.59.47: The pyramids
23.59.58: Jesus Christ is born
23.59.59: Galileo is born
We see that the dinosaurs, although having the good fortune to have been born on Christmas Day, only lived for five days; it took 60 per cent of the age of the universe for the first life to appear on the Earth; but once the Earth was formed it took only 21 days or about 6 per cent of the age of the universe for life to appear; but then it took about 3 months for the first humans. However, the last day of the year provides startling news. Jesus Christ was born only two seconds before the end of the year and Galileo one second. We now have some idea of where we humans stand with respect to the age of the universe.
In the course of the ageing of the universe the human person has come to be through the process of physical, chemical and biological evolution. As to the evolutionary process, I offer the following brief considerations.
Why did it take 60 per cent of the age of the universe for life to begin? How did we humans come to be in this evolving universe? It is quite clear that we do not know everything about this process. But it would be scientifically absurd to deny that the human brain is a result of a process of chemical complexification in an evolving universe. After the universe became rich in certain basic chemicals through the birth and death of stars, those chemicals got together in successive steps to make ever more complex molecules. Finally, in some extraordinary chemical process the human brain came to be the most complicated machine that we know.
Did all of this happen by chance or by necessity in this evolving universe? Was it destined to happen? The first thing to be said is that the problem is not formulated correctly. It is not just a question of chance or necessity because, first of all, it is both. Furthermore, there is a third element here that is very important. It is what I call “fertility”. What this means is that the universe is so prolific in offering the opportunity for the success of both chance and necessary processes that such a character of the universe must be included in the discussion. The universe is 13.7 billion years old, it contains about 100 billion galaxies each of which contains 100 billion stars of an immense variety. Thus it is the combination of chance and necessary processes in a fertile universe that best explains the universe as seen by science. When we combine these three elements: chance, necessity and the fertility of the universe, we see clearly that evolution, as many hold, is not simply a random blind process. It has a direction and an intrinsic destiny. By intrinsic, I mean that science need not, and in fact cannot methodologically, invoke a designer as those arguing for intelligent design attempt to do.
How are we to interpret this scientific picture of life’s origins in terms of religious belief? Do we need God to explain this? Very succinctly, my answer is no. In fact, to need God would be a very denial of God. God is not the response to a need. One gets the impression from certain religious believers that they fondly hope for the durability of certain gaps in our scientific knowledge of evolution, so that they can fill them with God. This is the exact opposite of what human intelligence is all about. We should be seeking for the fullness of God in creation. We should not need God; we should accept him when he comes to us.
But the personal God I have described is also God, creator of the universe. It is unfortunate that, especially in America, creationism has come to mean some fundamentalistic, literal, scientific interpretation of Genesis. Judaic-Christian faith is radically creationist, but in a totally different sense. It is rooted in a belief that everything depends upon God, or better, all is a gift from God. The universe is not God and it cannot exist independently of God. Neither pantheism nor naturalism is true. God is working with the universe. The universe has a certain vitality of its own like a child does. It has the ability to respond to words of endearment and encouragement. You discipline a child but you try to preserve and enrich the individual character of the child and its own passion for life. A parent must allow the child to grow into adulthood, to come to make its own choices, to go on its own way in life. Words that give life are richer than mere commands or information. In such wise ways does God deal with the universe – the infinite, ever-expanding universe. That is why, it seems to me, that the Intelligent Design Movement, a largely American phenomenon, diminishes God, makes him a designer rather than a lover.
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George Coyne is director of the Vatican Observatory, based at Castel Gandolfo and Arizona. This is an edited version of a talk given last month at the Vatican. Article reproduced with permission of TheTablet.co.uk
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