Outer Limits of Reason (53 page)

Let me clarify. In the last section I emphasized the idea that humans learned mathematics from the regularity of the physical universe. This explained why there really is no mystery that mathematics can describe the physical universe. In this section I am asking a deeper question: Why does the physical universe have any regularities at all? Why should we be able to learn mathematics and logic from the physical universe?

To answer these questions, researchers have formulated a set of ideas that go under the collective name of the
anthropic principle
. This says that the fact that sentient beings exist can be used to tell us something about our universe. It tells us that the universe must contain enough structure for intelligent human beings to exist. If this structure were absent, we would not be here to ask the questions.

The
weak anthropic principle
says that the observed universe must be of a form that would permit the existence of intelligent human observers. In other words, not all universes are possible. In a sense, the fact that we can make observations and we are somewhat intelligent tells us that the universe we live in has to have the complexity and the time necessary for humans to be born. Our intelligence is a type of sieve that tells us what type of universe we are going to find. A psychologist taking averages of IQs at a university will find that IQs are higher than those of the average population since university students generally have higher IQs. Similarly, when we survey the universe we should expect to find a universe that has beings capable of asking these questions—since we are asking these questions. Most researchers agree with the weak anthropic principle since it says something that is obviously true.

Some physicists have gone on in this line of reasoning and formulated a more powerful idea that is controversial: the
strong anthropic principle
. Rather than just saying that the universe is a certain way because we see it, they say that the universe
must be this way
because the universe must contain intelligent life. Via some mysterious force, the universe must create intelligent life. It should be noted that the vast majority of physicists do not accept the strong anthropic principle. They do not see any reason to believe that this universe must have brought about intelligent life. While the weak anthropic principle is hard to argue with, the strong anthropic principle is usually considered beyond the pale of science.

The anthropic principle says something very interesting about our position in the universe. Since the Enlightenment, science has deprived human beings of their special status in this universe. Copernicus showed us that we are no longer at the physical center of the universe. Rather, the Earth is simply an average planet circling some insignificant star. Darwin took away the status of humans as the most important creatures in the animal world. For him, a human being was simply one of many creatures that sprang from random mutations. And finally, it was Freud
⁴⁵
who took away reason's status as a uniquely human ability and showed that it is simply a handmaiden to the mysterious animalistic subconscious. By incorporating all these findings, science has come to accept something termed the
principle of mediocrity
or the
Copernican principle
that says that what we observe in the universe is not special in any sense. We are a typical species on an ordinary planet spinning around a commonplace sun in a usual galaxy. There is nothing special about us.

That is, until now. In a sense, the anthropic principle has returned humans to the center of the universe. The Copernican principle has proved to be wrong. The very fact that intelligent human beings exist places restrictions on the type of universe we live in. The universe is the way it is because
we
have certain distinguishing features: we are alive and we think. Since there is human reason in the universe, the universe has the form that it has. One can study the universe by looking at intelligent life and seeing what laws the universe had to follow in order for such intelligence to emerge. The very fact that humans can observe and understand the universe shows that humans with their reason are at the center of the universe. We might not be in the physical center of the universe, but our rationality makes us the center.
⁴⁶
(If we are not the only ones in the universe, then the intelligence of other beings is also at the center of the universe.)

The weak anthropic principle is a bit unsatisfying. Yes, it explains why we have to see the universe a certain way, but it does not explain
why
the universe is the way it is. It could have been another way and we would not be able to see or report it. The philosopher John Leslie compares this to a man surviving a firing squad. There were ten soldiers firing guns at the man, and he reported surviving the event. In analogy to the anthropic principle, the man would answer that had he not survived the firing squad, he could not report surviving it. Because he survived, he can tell us about it. While what he is saying is certainly true, it is not what we want to hear. We want to know
why
he survived. Were the soldiers bad at shooting? Did someone change the bullets for blanks? Was it just a strange accident? So, too, with the universe, we want to know
why
the universe is set up so that intelligent beings are capable of reporting about it.

 

Over the years researchers have proposed several possible explanations for the anthropic principle.

A Deity

Deists have no problem explaining why the universe is the way it is: a deity created the universe out of nothing and set it up to have life—more importantly, intelligent life. The universe and its laws were created exactly as they are because an omniscient, omnipotent deity wanted to see the human drama unfold. The deity knew the exact requirements for the human species to arise and established an appropriate world. As it says in the book of Psalms (19:2), “The heavens declare the glory of God; And the firmament shows His handiwork.” In fact, this explanation has been used for millennia as a proof of the existence of a deity. It has been called the
argument from design
or the
teleological argument
.
⁴⁷
All three of the questions about the structure in the universe are easily answered by the existence of a deity.

While this explanation is satisfactory for deists, those who do not believe in a deity will find this solution unsatisfying. Such a deity raises all kinds of other, more mysterious, questions about the nature of a deity. For such nonbelievers, there is a need for a more physical, scientific, and testable explanation.

The Universe Is a Fluke

We are simply incredibly lucky to find the universe the way it is. The universe and its laws were formed for no particular reason whatsoever. It was not formed for humans or intelligent beings. As David Hume wrote, “The life of man is of no greater importance to the universe than that of an oyster.” If such intelligent beings exist, that is not of any importance. To people who accept this idea, we live in an absurd universe and need to accept this fact. If forced to think about it, such people would have to agree with the weak anthropic principle that if the universe was any other way we would not be able to exist. But they will not look into the implications of this. This stance is extremely antiphilosophical. The universe is the way it is and there is no reason for it. This response does not give any answers to the three questions we had about the structure in the universe. While this might be satisfying for people who do not think about the origins of the universe or of reason,
⁴⁸
the rest of us, cursed with that strange desire to understand why the universe is the way it is, will continue looking for answers. To us, ignoring or denying a mystery does not make the mystery go away. We will just have to look further.

Out-of-Tune Universe

Some researchers scoff at the whole idea that this universe is fine-tuned for life in general and for intelligent life in particular. When we look at the cosmos, rather than seeing a place suitable for life, every star system that we point our telescopes at seems devoid of life. How can we say that the universe is waiting for life when there are billions of destructive supernovas, black holes, asteroids, and comets slamming into each other and into planets and stars? Despite years of looking, we have never found another planet that could sustain life. A further indication that the universe is not fine-tuned for intelligent life is that no one has ever visited us from any other place in the cosmos. Even within our solar system, there are no planets that would be able to support any type of intelligent life. If an astronaut stepped out of a spaceship, they would either instantly freeze to death or the sun will burn them in seconds flat.

What about Earth as a place perfectly suited for life? Let us take a closer look at our own beautiful planet. Two-thirds of our little blue planet is covered with water and (other than the supposed intelligence of dolphins), the sea does not seem very conducive to intelligent life. We are usually restricted to the dry surface of the Earth. Yet even in those parts, there are large swaths of land that are too high, too hot, too dry, or too cold to sustain long-term human life. Within environments capable of sustaining humans, there are constant tsunamis, volcanoes, earthquakes, hurricanes, mudslides, poisonous mushrooms, and lawyers, all of which make human life painfully fragile. There is an unending list of diseases, viruses, plagues, and deadly bacteria that have, over time, vanquished large segments of human societies. Perhaps the most destructive of all forces against human life is human nature itself, with its indomitable desire to murder and destroy its own species and environment. The list of reasons why the Earth is not perfectly suited for human life can go on and on.

Rather than seeing our universe as perfectly fine-tuned and propitious for intelligent life, such people see the universe as unsuited to the existence of sentient beings.
⁴⁹
They would say that there is no reason to explain the supposed fact that the world is so ordered—because it is, in fact, not so ordered. This brings to light an even deeper mystery: if the universe is so inappropriate for the development of intelligent life, why did just such life develop anyway?
⁵⁰

Notice that this is only an answer to questions 2 and 3. It does not answer any of the deep questions.

Restrictive Definitions of Life

Others disparage the idea that the universe is fine-tuned for intelligent life by pointing out that our requirements for intelligent life are tailored to our lives, and this is too restrictive. They feel that the constants of nature and the laws of physics are not as restrictive as we think. Other forms of life would have emerged if the laws were different. Maybe life could have been created with other materials besides carbon. Some speculate that silicon life forms are a possibility. Scientists have recently found certain life forms that live in arsenic.
⁵¹
Marine biologists have been shocked to find some life forms living near active underwater volcanoes. Perhaps there are certain types of creatures made entirely of neutrons that live on the surface of a star. Scientists have formulated other ways of making more complicated elements in suns even with different physical constants.
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Some people wonder if a computer virus with its uncanny ability to replicate, maintain homeostasis, and overcome all forms of security is not a type of life form. In fact, computer viruses even show signs of intelligence. To a certain extent, the assumption that the only life forms that can exist are the ones we are familiar with is a sign of a lack of imagination. The questions posed by the anthropic principle are answered by including more exotic types of life forms—the idea being that if we include all these possibilities, then redefined-life could have emerged with any of the other ways the universe was set up. Had the universe been any other way, the other life forms would have been amazed that the universe was their way and not any other way.

This response to the anthropic principle answers questions 2 and 3. There is no mystery why the universe is the way it is because it could be many different ways and (intelligent) life would have emerged. This solution again does not answer question 1 in our list of questions. Whether there is some weird type of life does not take away from the fact that there is a lot of structure in the universe. Why should that be?

Many Universes

One very popular explanation for the amazing fine-tuning of the universe is that our universe is just one of many universes that comprise something called a
multiverse
. Each of these universes has its own sets of laws and constants. In the vast majority of these universes the laws and constants are not propitious for life or intelligent life. Our universe is one of the lucky ones where intelligent life is a possibility.

Before you immediately discard the very idea of the existence of many different worlds, let us look at science's ever-expanding horizons. Throughout ancient and medieval times, people believed that our sun was the only sun in the universe. It is only in modern times that we have realized that our sun is just one of billions in the Milky Way galaxy. It was not too long ago that we learned that our galaxy is one of billions of other galaxies in the universe, each having billions of stars. People who believe in a multiverse are just taking this idea one step further. Maybe there are billions of other universes besides our universe, and we just cannot see them or get any empirical confirmation of their existence.

How does a multiverse help in explaining why our universe has such a life-sustaining structure? Imagine walking into a bingo hall and being the only player there. If your card wins the game, you must believe that this was miraculous. From all the random numbers to call, it happens to be your numbers that are called. This must be divine intervention. Similarly, if you walk into a random hotel room and this is the only room that has your size clothes in it, that would be a miracle. If this is the only universe in existence, then the fact that it is so perfectly made for us is somewhat miraculous. Now consider walking into a crowded bingo hall with many other players. One of them is going to win the game and jump up and scream “I won! It's a miracle!” To the winner, it is, in fact, a miracle. Why should she win and everyone else lose? But to you who are observing all of the players, and know that
someone
must win, it is not a miracle that
someone
wins. Similarly with the hotel rooms. It is not so miraculous if every room has clothes in it. Someone has to find the clothes that fit so well. Similarly with our universe. If there are many universes and some have laws that make intelligent life seem possible, then that is not so strange. We happen to find ourselves in one of those types of universes. Presumably the vast majority of the other universes in a multiverse are devoid of life. All these different universes will have different laws and different constants of nature. Only some of them will be “just right.” It is not miraculous that the intelligent inhabitants of those universes that can support intelligent life jump up and scream, “It's a miracle!” It is expected of them.