III. The Age of the Universe
Galaxies, such as our Milky Way, are not isolated: they generally lie in small groups, or in larger clusters which sometimes contain thousands of member galaxies. (Our Milky Way does not lie in a large cluster, but rather in a small group of over thirty members, known as the "Local Group" - see Figure 175. It is some 10 million light years across. The two most massive members of the Local Group are the Milky Way and the Andromeda Spiral Galaxy.) Light from the relatively nearby Virgo and Fornax clusters of galaxies has taken some 60 million years to reach our eyes; Light from the most distant objects ever observed has taken billions of years to reach our telescopes; our observable Universe is estimated to be approximately 14 billion light years across.
The Universe is very old. After many decades of uncertainty, we now know from the WMAP observations of the cosmic microwave background that the age of the Universe is close to 14 billion years.
We can say that 14 billion years ago, the density was immensely high. This is what cosmolo-gists mean when they refer to the "age of the Universe."
Bernard de Fontenelle knew only a little of what we know today. Yet he felt lost as he pondered the distances between planet and planet, star and star. Today we know the Universe is about fourteen billion years old, and some fourteen billion light years across. Is Mankind simply irrelevant? Are we a chance event in one minute part of an ever expanding cosmos? Is life, as Bertrand Russell once defined it, "an accidental co-location of atoms?"
The fact that we are here, as self-aware carbon based beings, requires the entire Universe to have certain properties. One of these is that it cannot be small.
In the initial formation of the Universe, an extremely delicate balance had to be established between the densities of the "blobs" of matter destined to form galaxies, and the expansion rate of the Universe. If the early Universe expanded too slowly, regions of higher density
The Insignificance ofMan?
(which could have formed galaxies) would have had time to collapse in on themselves. Today there would be no constellations, no stars and no suns to support any life.
On the other hand, if the early Universe expanded too quickly, the same regions of matter of higher density would have continued to expand outwards indefinitely. The star systems could not have been held together by gravity to form galaxies. Again, no stars, no suns.
The balance is critical. In the early Big Bang scenario, a reduction in the rate of expansion by only one millionth, millionth when the temperature was 10 000 million degrees would have caused the Universe to recollapse when its radius was only 1/3 000th of its present value. In the most modern version of the Big Bang (the inflationary Big Bang models) the balance at early times is even more critical: a change of one part in 1055 (a decimal point followed by 54 zeros and a 1) would have meant we would not have had an opportunity to come into existence. Put simply, the early Universe expanded at just the critical rate to produce galaxies ... and hence life.
We live in a finely tuned Universe. By very reason of our existence, the Universe must have special, and not arbitrary, properties.
IV. The Necessity for an Immense Universe
To address the fear of de Fontenelle:
Could our Universe harbour beings made of carbon based star-dust from those majestic Shrouds of the Night - if it were not as large (and as old) as astronomers find it to be?
The key point here is that the observable extent of a Universe expanding from a highly dense Big Bang state is inextricably bound up with its age. A Big Bang Universe one year old would be one light year in observable radius. A Big Bang Universe one million years old would be The Insignificance ofMan?
one million light years in observable extent. Each year our observable horizon increases by 355
one light year, so that the Universe we find ourselves in now must be at least 14 000 million light years in size because it is at least 14 000 million years old. Cosmologists John Barrow and Frank Tipler explain:
The requirement that enough time pass for cosmic expansion to cool off sufficiently after the Big Bang to allow the existence of carbon ensures that the observable Universe must be relatively old and so, because the boundary of the observable Universe expands at the speed of light, very large.
We can therefore say that no one should be surprised that the Universe is so large. We could not exist in one that was any smaller!
A naïve person looking at the cosmos has the impression that the whole thing is extravagantly, even irrelevantly, large. This extravagant size is our primary protection against a variety ofcatastrophes writes Princeton physicist Freeman Dyson.
In our own Milky Way Galaxy, stars that are chemically like the Sun do not appear until the Universe is about four billion years old. Parameters conducive to life required a Universe which was not small. Even at that time the observable Universe was already about 4000 million light years in extent.
Cosmologist Bernard Carr sums up the scene. He writes:
Until recently, the progress of science seemed to involve a continual denigration of Man - we are insignificant as judged by scale and duration and life itself appears to be no more than an accident, a result of random chance processes. However, recent developments in cosmology suggest that the existence of life is very sensitive to the initial conditions of the Universe and to the values of the physical constants. This has led to the Anthropic Principle, the proposal that the Shrouds ofthe Night existence of life imposes a selection effect on where and when we observe the Uni-
356 verse - and even on the nature ofthe Universe itself.
An important point here (as carefully elucidated recently by Canadian historian Dennis Danielson) is that Copernicus himself never viewed his Sun-centered model as denigrating men or women - or of God Himself. To Copernicus, God was the Architect of the Universe. Copernicus wrote:
And behold, in the midst of all resides the sun. For who, in this most beautiful temple, would set this lamp in another or better place, whence to illuminate all things at once? ... Truly indeed does the sun, as if seated upon a royal throne, govern his family of planets as they circle about him.
To Galileo, it was an Earth-centered Universe which would denigrate men and women, the Earth being in Galileo's writing "the sump where the Universe's filth and ephemera collect." The poet, novelist and philosopher Goethe (1749-1832) was therefore wrong when he wrote in 1808 about the "colossal privilege" of an Earth-centered cosmos:
Perhaps no discovery or opinion ever produced a greater effect on the human spirit than did the teaching of Copernicus. No sooner was the earth recognized as being round and self-contained, than it was obliged to relinquish the colossal privilege of being the centre of the Universe
To Galileo, a great stride forward which would elevate the status of humankind was made by Copernicus. Galileo wrote: "As for the earth, we seek ... to ennoble it when we strive to make it like the celestial bodies, and, as it were, place it in heaven ..." (as quoted by Dennis Danielson. Italics, ours).
The writings of Thomas Traherne (ca 1637-1674) are most insightful here. Traherne was a contemporary of Sir Isaac Newton (1642-1727) and lived in the wake of the Copernican Revolution. "Traherne's life spanned less than forty years, a time not only of catastrophic events but also of the beginnings of major shifts in religion, philosophy and science, which shook the foundations of authority and belief. He wrote against a background of growing atheism ... Traherne was profoundly aware of the currents of his age, theological, political, The Insignificance ofMan?
sociological and scientific" comments the Cambridge scholar Jan Ross. 357
Did Traherne view the Earth as a pale, insignificant, blue dot? Absolutely not. In his work entitled The Kingdom of God, Traherne imagines a Celestial Stranger viewing and visiting our planet from outer space. He writes:
Had a Man been allwayes [sic] in one of the Stars ... at vast and prodigious Distances from the Earth, acquainted with nothing but the Azure Skie [sic], and face of Heaven, little could he Dream ofany Treasures hidden in that jAzure vail [sic] afar off, or think the Earth (which perhaps would be Invisible to him, or seem, but a Needle's Point, or Sparkle of Light) in any Measure Capable of such a World of Mysteries as are comprehended in it... He would think himself faln [sic] (fallen) into the Paradise of God, a Phoenix nest, a Bed of Spices, a Kingdom of Glory.
A far cry from a pale, insignificant globe of dirt and of purposelessness. Rather, a Paradise of God. Traherne writes of the inhabitants of this Sparkle of Light, the Earth:
How Blessed are thy Holy People; how Divine, how highly Exalted! Heaven itself is under their feet! A people satisfied with Favour! The fat places of Eterni-tie [sic] are faln [sic] to their Province! The Lines are faln [sic] unto them in pleasant places, yea they hav [sic] a Goodly Heritage!
Thus would a Celestial Stranger be Entertained in the World .
Traherne continues: "How is it (the Earth) Exalted, and Magnified; How is it Honored! ... It (the Earth) is apparently the Darling and the Bride of Heaven! ... Men that trample the Earth under feet, are the Creatures for whom this Marriage (of Earth and Heaven) is made, and theirs is the Benefit of all the union ..." (Explanatory words, in parenthesis, are inserted by the authors.)
We have retained the original spelling and use of capitals by Traherne, from a transcription entitled "The Works of Thomas Traherne" edited by Jan Ross. The lost manuscript by Tra-Shrouds of the Night herne was only discovered in 1997, by Jeremy Maule, Fellow of Trinity College, Cambridge.
358 The Kingdom of God appears in folios 148-370 of the manuscript MS1360, housed in the
Lambeth Palace Library. It lay unknown and unpublished for over three hundred years. We refer the reader to the remarkable historical research of Dennis Danielson for further insights in the myth of the pale blue dot being a fruit of the work of Copernicus. The key point, as elaborated by Danielson, is that Copernicanism never demoted humankind.
Bernard de Fontenelle saw the human world as terrifyingly insignificant. We have turned the argument on its side: without a cosmos spanning 15 billion light years, we could not be reading this chapter.
American astronomer Allan Sandage was asked the question, "If you could design the Universe any way that you wanted to, how would you do it?" In reply, he said:
If I were present at the creation, would I give the Creator better advice ? And you are asking for that better advice. I wouldn't want to destroy all the mystery, as we do in reductionist science. The greatest mystery is why there is something instead of nothing, and the greatest something is this thing we call life. I am entirely baffled by you and me ... Perhaps the Universe is the only way it can be for us to exist. If that's true, to ask to create a different Universe is to ask to enter into genocide. Now that's the anthropic principle, but the more I think about how everything is so finely tuned, the more that principle makes sense.
It is our signature on the picture that gives it value. The whole canvas of our observable Universe is so framed, in terms of both size and age, that it might display our name (Figure 176). We awake from de Fontenelle's terror as though from a bad dream. We may be "the focus" after all.
The Insignificance of Man?
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