This article is about the possibility of life on other planets. What is the place of earth in the cosmos? What about the Copernican Principle? How should we view the search for Extraterrestrial Intelligence? This article looks at life on our planet and intelligent life on other planets.

Source: Clarion, 2007. 7 pages.

“In Wisdom You Made them All...”

Does the human race have a special place and task in the cosmic scheme of things? The answer to that question has changed drastically over the past century or so. When our civilization could still be called Christian, it was normal to speak of mankind as the “crown of creation” and of its habitat, the earth, as a privileged part of the cosmos. True, Christians knew they were flawed, fallen beings. They also knew that the earth was puny, little more than a dot, by cosmic standards. But they did not for these reasons hold the earth or humanity in contempt. Both served a high purpose. Man had been given the earth as his dwelling place in order to have dominion over his fellow-creatures and so to serve God.

Today that conviction is largely gone. Faith in God has been declared a delusion and with that faith the belief in the significance of both the human species and its habitat has also been lost. Rather than being exceptional, the earth is now a typical planet among many similar ones and the human race is a chance appearance, no better than any of the other species and by no means essential to the earth’s well-being. According to some we are, in fact, the destructive element on earth, the enemy of the other species, the dangerous parasite whose demise would greatly benefit the planet. This is the opinion of some “deep ecologists,” extremist animal rights groups, and other radical branches of the environmentalist movement.

The Copernican Principle🔗

Where did these ideas come from? Are they just subjective impressions, a product of our pessimistic postmodern worldview? According to a majority of today’s scientists, they are not. The current opinion regarding the earth’s and mankind’s insignificance, they say, is based on solid scientific evidence. Whereas people used to believe that the earth was at the centre of the cosmos, we now know that it is located in a corner of the Milky Way, which is but one of many billions of galaxies. This physical “dislocation” implies, we are told, a drastic reduction in our status and provides scientific proof against the biblical message of mankind’s (and the earth’s) unique position, origin, and purpose.

These beliefs receive their justification from the so-called Copernican Principle, which is held to be a scientific concept. Because of the important role it plays in the areas we are dealing with, a note on its origin and function is in order. The principle is named after Nicolaus Copernicus, a Polish cleric, mathematician, and astronomer, who began the process of the earth’s removal from the cosmic centre by proposing (in 1543) the replacement of the ancient earth-centred model by a sun-centred one. The earth-centred model (the so-called Ptolemaic World System) had been inherited from the Greeks and still served the Middle-Ages (about 500-1500). It consisted of a central stationary earth with the “heavenly bodies” – sun, moon, and planets – revolving around it. The Christian Middle-Ages liked this model, which was in a number of ways in accordance with their general worldview. The earth’s location at the centre symbolized man’s special status as the creature made in God’s image, while the fact that it was also at the lowest point in the system symbolized his fallenness. The Middle-Ages further liked the hierarchical nature of the cosmos and the fact that the heavens surrounded the earth. This made manifest God’s unceasing supervision and providence and protection. Medieval people could feel at home in the universe. Space did not terrify them, nor did it convey a sense of cosmic loneliness, as it so often does today. There was no empty space.

The old model had not only a religious but also a scientific function and served, among other things, to predict eclipses. As a scientific model it had its weaknesses, however. A major setback was the difficulty it posed in explaining the apparently erratic orbits of the planets. Copernicus found that the problem could be removed if the model was changed from an earth-centred to a sun-centred one. That solution was not immediately accepted. The idea of a central sun and a moving earth went against common sense and, according to many, also against the Bible. Had not Joshua ordered the sun and not the earth to stand still? Various scientists, however, continued Copernicus’ work and by the late 1600s the sun-centred model had become the accepted one.

The Process of Our “Dethronement”🔗

Although the new model removed the earth from its central place, it did not immediately affect the belief in the earth’s and men’s special status. Most early scientists, including Copernicus himself, were Christians. They saw their work not as an attack upon Scripture but as a means to glorify the Creator by showing the magnitude and order of the universe. They also continued to see humanity as God’s special creation, made in his image. Even when in the eighteenth century (the so-called Enlightenment or Age of Reason) this biblical faith declined, the belief in the superior status of the human race continued, thanks to the predominantly humanistic worldview of that period.

The situation began to change in the nineteenth century, when among several thinkers the deism of the Enlightenment was replaced by atheism. It is true that the Copernican Principle of mediocrity was not promoted as a scientific tool until the twentieth century, but the preceding age set the stage. Friedrich Nietzsche (1844-1900), the century’s foremost “death-of-God” philosopher, wrote:

Has not man’s determination to belittle himself developed apace precisely since Copernicus? Alas, his belief that he was unique and irreplaceable in the hierarchy of beings had been shattered for good; he had become an animal, quite literal and without reservations; he who, according to his earlier belief, had been almost God ... Ever since Copernicus man has been rolling down an incline, faster and faster, away from the centre...

Nietzsche was partly right in blaming the new astronomy for the loss of human self-esteem, but only partly. In the days of Copernicus and his followers opinions were divided. Many rejoiced that the earth had been moved from its lowly place at the bottom and become a “star,” a glorious heavenly body. Others, however, focused on the possible negative implications of the new model and their number may well have increased over the centuries. But man’s “belittling of himself” has been a result not only of the astronomical discoveries. A more important role has been played by scientific theories that claimed to prove the “death of God” and thereby denied man’s special place in the universe. This was acknowledged by Nietzsche’s younger contemporary Sigmund Freud (1856-1939), who mentioned Charles Darwin’s contribution to the marginalization of man. It was Darwin, after all, who had shown that the human species had descended from the animals. Nor was that the end of the process of demotion. It was continued, Freud said, by his own work. His theory of the unconscious showed that the human ego, which had been so highly exalted by both Christians and humanists, was no more than the plaything of irrational desires and instincts. Instead of being made “a little less than God” (Psalm 8), man had become product and part of a non-rational nature.

Our Position in Space and Time🔗

Although Copernicus and his followers had no intention of lowering the status of man and his habitat, developments in astronomy did underline the message of the earth’s relative insignificance. As early as 1609, the scientist Galileo had searched the heavens with the newly invented telescope and discovered that the Milky Way galaxy consisted of an unimaginably large number of stars. This showed that the cosmos was far greater than previously imagined; that it might even be infinite in size. Its inconceivable vastness was confirmed in the twentieth century. In the 1920s the American astronomer Edwin Hubble, using the most advanced telescope then available, discovered that the Milky Way was not unique (as had been thought until that time) but was only one of several galaxies in an expanding universe. Astronomers now estimate that there are at least a hundred billion galaxies, each of them containing billions of stars. The estimated number of stars in all the galaxies of the universe, scientists tell us, “vastly exceeds the number of grains of sand on all the beaches of the world.”

In such a universe, planet Earth is no more than a speck, and so indeed is the sun (which has been demoted to an “average” star, one among many, whose apparent brilliance is a result of the fact that it is much nearer to the earth than any other star). As the seventeenth-century poet John Donne already complained, in the new model “The Sun is lost and th’earth, and no man’s wit can well direct him where to look for it...” Cosmic distances are so great that they have to be measured in light-years – the distance that light can travel within one year, which is close to ten trillion kilometres. The extent of the Milky Way is estimated to be more than 100,000 of such light-years. This means that in order to go from one end to the other, one would need to travel at the speed of light – which is close to 300,000 kilometres per second – for a period of 100,000 years. (I am assuming here, for simplicity’s sake, that we could measure time by an earthbound clock, although in fact time would greatly change for someone travelling at this speed). By way of comparison: the light of the sun, which is located at a distance of almost 150,000,000 kilometres from the earth, reaches us in about eight minutes. And even the extent of the Milky Way is next to nothing by cosmic standards. In the 1990s astronomers using the Hubble Space Telescope discovered galaxies that they calculated to be up to twelve billion light-years removed in space and time.

If these mindboggling cosmic distances served to diminish the status of the earth and its inhabitants in the eyes of many, so did new theories of cosmic time. The twentieth century witnessed the birth and triumph of the so-called Big Bang theory of the universe’s origin and development. According to this theory the universe was not a few thousand, but billions of years old, and the age of the earth also was much greater than had previously been believed. Even so, the earth was a late-comer. Astronomers date the age of the cosmos at about 14 billion years, that of our galaxy at 10 billion, and that of the earth at 4.5 to 5 billion. The span of humanity’s existence was much shorter yet. According to evolutionary scientists the age of the human species is one (or a few) hundred thousand years.

Science or Ideology?🔗

The description by modern science of the magnitude of the universe undoubtedly contributes to the widespread belief in the insignificance of the earth and mankind. Does it also, however, justify that belief by proving the Copernican Principle of the earth’s and man’s non-exceptional status? In fact, it does not. The principle implies that location and size determine value, which is obviously untrue. Moreover, some scientists are also challenging the principle’s scientific value, pointing out that there are few if any instances where its use has advanced our understanding of the universe.

These dissenters further show that recent scientific discoveries not only fail to endorse but actually provide potent disclaimers of the Copernican Principle. The discoveries support the idea that the earth is unique and uniquely fitted for the sustenance of life. We will turn to the arguments and proofs later. The question that now concerns us is why, in spite of its apparently questionable scientific foundations, the Copernican Principle is so strenuously promoted.

One important reason, it appears, is its ideological function – the fact that it provides “scientific” support for the anti-biblical view of man and his world that characterizes our times. The principle is also, as already suggested, grist for the mill of radical ecologists and animal-rights activists, who blame our ecological problems on the belief that we are superior to other species. That belief, they say, is founded on the biblical teaching of man as the head of creation, which is a major cause of the destruction of the world’s environment under the leadership of western Christianity.

But if hostile to the Bible, the principle is not opposed to all religion. Radical ecologists who subscribe to it have no problem advocating pantheism and a variety of neo-pagan religions. This is telling. Atheists may proclaim that we can live without faith in the supernatural, but our postmodern age shows that for many people this is too difficult. Now that faith in the God of Christianity has been declared a delusion, a replacement must be found, and more often than not the universe and the earth are made into a god (or goddess).

The hope of receiving help and guidance from sources beyond the earth is an important element also in the search for extra-terrestrial intelligence, which, as we will see, has been greatly stimulated by the Copernican Principle.

Is there intelligent life in other parts of the universe? People have for centuries considered the possibility, dreamt about it, and written stories about it. They did not seriously start looking for such life, however, until the astronomical advances of the twentieth century. Since then, the Search for Extra-Terrestial Intelligence (SETI) has become big business. Many scientists are involved in it and some millions of amateurs have joined the quest. This continues in our days, in spite of the fact that today the chance of success does not appear to be nearly as great as was once thought.


The search for intelligent life beyond the earth has, as we noted, received a boost from the Copernican Principle of mediocrity. According to that principle the earth, the solar system, and we ourselves are not exceptional but typical, run-of-the-mill, and the product of an unplanned, evolutionary process. Since the laws of nature are generally held to be the same throughout the cosmos, it follows that developments which have taken place on earth are likely to have taken place also elsewhere. All that is needed for the development of intelligent life like ours, scientists reasoned, is an earth-like planet orbiting a sun-like star and SETI enthusiasts expected that there were millions of these in our galaxy alone. The only problem was to locate such planets and make contact.

The search focused initially on planets in our own solar system, with Mars as the favourite. It was unsuccessful and subsequent space exploration made clear that extra-terrestial intelligence, if it does exist, must be sought elsewhere in the galaxy, or even beyond it. This means that actual visits to inhabited planets are out of the question. The distances are too great for human beings with their limited lifespan. Contact has to be established by means of radio signals. Science journalist Fred Heeren writes that scientists believed that signals sent into space since the middle of the last century, for example by television and FM broadcasts, should have served the purpose. As one expert suggested, programs like Jack Parr and I Love Lucy will have been among the first to spread into space. “Within thirty light-years,” that scientist remarked in the 1990s, “there are some dozens of stars. And if they got the word thirty years ago, they would be sending a reply back to us. And those who are only fifteen light-years away will have sent a message back fifteen years ago, which should just about be reaching us today.”  

Why is there No Message?🔗

Only, it did not happen. The world is still waiting for replies and today scientists are considerably more cautious in their predictions. They admit that the Milky Way may not be quite as full of intelligent life as they had expected. They also remember that civilizations do not last forever. Much like organic life, they tend to flourish, decline, and die; and one has to wonder what may have happened to possible civilizations in our galaxy during the ten billion years of its existence. Would not the overwhelming majority have disappeared? Would any survive? There is also the fact that inhabitable planets in our galaxy may be thousands of light-years away, so that earth-dwellers must wait for millennia before an answer can be expected. And if we go outside the Milky Way, we are talking of planets that are millions and even billions of light years removed in space and time. Even if we received radio signals from them, could we assume that the civilizations still exist today?     

Another problem for SETI enthusiasts is that space civilizations have not made contact with our planet, or even colonized it. If older, more mature and longer-lived civilizations indeed exist, one may assume that their science is well advanced, that their technology has progressed beyond ours, and that their engineers have developed propulsion techniques that come closer to reaching the speed of light. “Figuring on a cruising speed of 10 percent that of light,” Heeren writes, “...astronomers say it would take just five million years for one colonizing group to reach every star system across the Milky Way’s 100,000 light-years.” The question is, of course, whether such propulsion systems are physically possible. Not nearly every expert believes so. And in any event, there are no signs of visits or colonizations by space aliens.

The Religious Factor🔗

In spite of the accumulating evidence that extra-terrestial intelligence may be hard to find, enthusiasm for the enterprise remains great and ever more advanced technology is being used in the search for radio signals. The cause of this perseverance is not just the desire for scientific advances, although that element is present. But there are other motivations. Some hope to find a habitable planet that we can escape to if and when the earth freezes up, or is hit by a meteorite, or if we ourselves blow up our planet or destroy our environment. Colonization in space might be the way to prolong our species’ life. There is also the hope that aliens can teach us a thing or two about the art of living. Some SETI enthusiasts assume that older civilizations will be ahead of us not just in technology but also in practical wisdom. They like to think of extra-terrestials as benevolent and morally superior to us and therefore willing and able to help us deal with the type of thing that can make life on earth so miserable: crime, terrorism, war, as well as illness and poverty.

And then there is the matter of cosmic loneliness. The late Carl Sagan, one of the best-known SETI astronomers, famously described our planet as “a lonely speck in the great enveloping cosmic dark.” It is an echo of the complaint by the seventeenth-century mathematician Blaise Pascal, who in contemplating the new model of the universe exclaimed, “The eternal silence of these infinite spaces frightens me.” Pascal was a Christian, who knew that God exists, even though it was no longer possible to locate his dwelling place. The feeling of being abandoned is much stronger among moderns who have lost that faith. It is sad but not surprising that they seek for father-figures in cosmic space, the only unexplored area left in the universe.

Meanwhile the bankruptcy of Christianity is assumed. Those who are searching for space divinities are sure that the discovery of intelligent aliens will have a devastating effect on the Christian faith. For one thing, they reason, it will manifest the untrustworthiness of the Bible, since Scripture does not speak of intelligent life beyond the earth. It will also show Christian arrogance in believing in a God who has offered a plan of salvation to humanity alone and not to other intelligent species.                        

These types of argument bother some Christians as well. Christian apologist C. S. Lewis dealt with them already half a century ago. He answered the taunt of Christian arrogance by remarking that Christ’s incarnation does not imply particular merit or excellence in humanity. “Christ died for men precisely because men are not worth dying for; to make them worth it.” Lewis did not expect that extra-terrestial life will be found, but neither did he want to set limits to God’s power. Should intelligent life indeed be discovered on other planets, he writes, we should consider the following:

  1. unlike humans, aliens may not have fallen into sin; and

  2. if extra-terrestials, or some of them, have fallen, God may have used different remedies for them.

In this connection Lewis refers to Romans 8:21, where we read that “creation itself will be liberated from its bondage to decay.” This would include intelligent beings beyond the earth, if there are any.

A Fine-Tuned Universe🔗

Confidence in the existence of earthlike planets harbouring intelligent life has declined since Lewis’s time. The problem is not only the disappointing results of the search itself. More ominous is the accumulating scientific evidence (provided by both Christian and non-Christian scientists) against the all-important Copernican Principle. More and more it appears that the earth is exceptional after all and exceptionally fitted for life; that it even seems to have been designed for it. And what goes for the earth goes for the solar system, the galaxy, the universe itself. None of them appears to be the result of an unplanned process. 

The discoveries began in the twentieth century and the evidence against the Copernican Principle is by now overwhelming. There is first of all the exceptional “fine-tuning” of the universe: the fact that the laws of nature appear to be designed for the purpose of accommodating life. Should the laws and other features be altered even to the smallest degree, a life-sustaining universe would be impossible. Giving only a few examples out of many, physicist Karl Giberson writes:

Make gravity one percent stronger or weaker and the sun won’t shine properly; change the electrical force just a bit and organic molecules won’t form; make the universe expand just a little faster and there won’t be any solar systems. And so on. All of the various features of this universe appear to have been optimized life.” He adds, “All this would occasion no surprise if it turned out that the laws of nature somehow have to have their current form, if there were some reason why gravity has its particular strength, electrons their mass, the photon its energy, and so on. But, as nearly as anyone can tell – and they seem to be able to tell quite nearly – there is no reason why the various features of our universe are the way they are, and not some other, equally plausible, way.

And a Rare Planet🔗

A similar type of fine-tuning can be observed locally, that is, on the level of the earth and its solar system. There is, for example, the nearness of the moon, as well as its exceptional size and gravity. It is large and heavy enough to stabilize the earth’s rotation and prevent its axis from tilting too far into the direction of the sun or giant planet Jupiter. The earth’s axis is tilted at 23.5 degrees, which gives us our seasons, assuring a relatively limited range in temperatures. The moon also helps raising ocean tides and currents, which again play a role in regulating climate. In these and in various other respects the moon’s life-supporting function is exceptional compared to other planet-moon systems that have been observed.

The earth’s situation appears optimal for the existence of life also because the planet enjoys protection from asteroids, comets, and other “near earth objects” from space. There are large numbers of such objects threatening us and depending on their size their impact could be devastating. Although the danger remains, other planets, including Jupiter, Saturn, and Mars, form a protective shield around the earth, safeguarding our planet from ongoing bombardments. They serve as “cosmic vacuum sweepers,” drawing killer rockets to themselves and so diverting them from planet earth. Fred Heeren quotes a scientist as saying that without a giant neighbour like Jupiter, for example, “comets would strike Earth between 100 and 10,000 times more frequently than they do, meaning ‘that we wouldn’t be here.’”                                           

There are various other data supporting the “rare-earth hypothesis.” For example, the earth is located at the proper distance from the sun. If it were further away, its temperature would be closer to that of Mars with its perpetual deepfreeze; if it were closer, it might suffer the scorching heat of Venus. In either case, complex life would be impossible. Other necessities of life which the earth provides (unlike other planets in our system) are liquid water, an oxygen-rich atmosphere, and a protective magnetic field. Our sun, in turn, is at the right distance from the overcrowded centre of the galaxy, where cosmic radiation is too high for life to exist. The sun also has the proper mass, making it possible for its planets to orbit at a safe distance – neither too close to their star nor too far away from it. Although more massive than many other stars, the sun is not so massive that it would produce excessive amounts of radiation and thereby make life impossible. It is also a very steady source of energy. If energy output was not constant – if there were great increases or decreases – the consequences could again be deadly for the existence of complex life. In brief the earth’s sun is far from being an “average star.”

Astronomy and the Bible🔗

Astronomers refer to these coincidences” (from anthropos, Greek for “human being”), since they suggest the “human-friendliness” of the earth, the solar system, the galaxy, and the cosmos itself. Going directly against the Copernican Principle, the discoveries have caused considerable embarrassment among many scientists. Some try to disprove them, but others agree that the evidence is too strong to be ignored. In his A Brief History of Time Stephen Hawkins admits, “It would be very difficult to explain why the universe should have begun in just this way, except as the act of a God who intended to create beings like us.” And Nobel prize-winning scientist Arno Penzias writes, “The best data we have are exactly what I would have predicted, had I nothing to go on but the five exceptional? After? all Books of Moses, the Psalms, the Bible as a whole.”                                             

Christian scientist Francis S. Collins, who quotes these men, suggests that Penzias may have been thinking of Psalm 8: “When I consider your heavens, the work of your fingers, the moon and the stars, which you have set in place, what is man that you are mindful of him?” It is true, as Collins also reminds us, that we should not overestimate the religious significance of the recent findings. Scientific theories are subject to change, and in any case, no scientific evidence can ever provide us with proof of the existence of the God of the Bible. Nevertheless, in an age where these theories are so frequently used against the Christian religion, it is good to be reminded of the need to distinguish between science proper and its ideological uses. The case of the rise and Copernican Principle is as good an example as any.

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