Authors: Michio Kaku,Robert O'Keefe
String theory also demonstrates this pattern, but in a startlingly different fashion. Because of its mathematical complexity, string theory has linked vastly different branches of mathematics (such as Riemann surfaces, Kac-Moody algebras, super Lie algebras, finite groups, modular functions, and algebraic topology) in a way that has surprised the mathematicians. As with other physical theories, it automatically reveals the relationship among many different self-consistent structures. However, the underlying physical principle behind string theory is unknown. Physicists hope that once this principle is revealed, new branches of mathematics will be discovered in the process. In other words, the reason why the string theory cannot be solved is that twenty-first-century mathematics has not yet been discovered.
One consequence of this formulation is that a physical principle that unites many smaller physical theories must automatically unite many seemingly unrelated branches of mathematics. This is precisely what string theory accomplishes. In fact, of all physical theories, string theory unites by far the largest number of branches of mathematics into a single coherent picture. Perhaps one of the by-products of the physicists’ quest for unification will be the unification of mathematics as well.
Of course, the set of logically consistent mathematical structures is
many times larger than the set of physical principles. Therefore, some mathematical structures, such as number theory (which some mathematicians claim to be the purest branch of mathematics), have never been incorporated into any physical theory. Some argue that this situation may always exist: Perhaps the human mind will always be able to conceive of logically consistent structures that cannot be expressed through any physical principle. However, there are indications that string theory may soon incorporate number theory into its structure as well.
Because the hyperspace theory has opened up new, profound links between physics and abstract mathematics, some people have accused scientists of creating a new theology based on mathematics; that is, we have rejected the mythology of religion, only to embrace an even stranger religion based on curved space-time, particle symmetries, and cosmic expansions. While priests may chant incantations in Latin that hardly anyone understands, physicists chant arcane superstring equations that even fewer understand. The “faith” in an all-powerful God is now replaced by “faith” in quantum theory and general relativity. When scientists protest that our mathematical incantations can be checked in the laboratory, the response is that Creation cannot be measured in the laboratory, and hence these abstract theories like the superstring can never be tested.
This debate is not new. Historically, scientists have often been asked to debate the laws of nature with theologians. For example, the great British biologist Thomas Huxley was the foremost defender of Darwin’s theory of natural selection against the church’s criticisms in the late nineteenth century. Similarly, quantum physicists have appeared on radio debates with representatives of the Catholic Church concerning whether the Heisenberg Uncertainty Principle negates free will, a question that may determine whether our souls will enter heaven or hell.
But scientists usually are reluctant to engage in theological debates about God and Creation. One problem, I have found, is that “God” means many things to many people, and the use of loaded words full of unspoken, hidden symbolism only clouds the issue. To clarify this problem somewhat, I have found it useful to distinguish carefully between two types of meanings for the word
God
. It is sometimes helpful to differentiate between the God of Miracles and the God of Order.
When scientists use the word
God
, they usually mean the God of Order. For example, one of the most important revelations in Einstein’s early childhood took place when he read his first books on science. He immediately realized that most of what he had been taught about religion could not possibly be true. Throughout his career, however, he clung to the belief that a mysterious, divine Order existed in the universe. His life’s calling, he would say, was to ferret out his thoughts, to determine whether he had any choice in creating the universe. Einstein repeatedly referred to this God in his writings, fondly calling him “the Old Man.” When stumped with an intractable mathematical problem, he would often say, “God is subtle, but not malicious.” Most scientists, it is safe to say, believe that there is some form of cosmic Order in the universe. However, to the nonscientist, the word
God
almost universally refers to the God of Miracles, and this is the source of miscommunication between scientists and nonscientists. The God of Miracles intervenes in our affairs, performs miracles, destroys wicked cities, smites enemy armies, drowns the Pharaoh’s troops, and avenges the pure and noble.
If scientists and nonscientists fail to communicate with each other over religious questions, it is because they are talking past each other, referring to entirely different Gods. This is because the foundation of science is based on observing reproducible events, but miracles, by definition, are not reproducible. They happen only once in a lifetime, if at all. Therefore, the God of Miracles is, in some sense, beyond what we know as science. This is not to say that miracles cannot happen, only that they are outside what is commonly called
science
.
Biologist Edward O. Wilson of Harvard University has puzzled over this question and asked whether there is any scientific reason why humans cling so fiercely to their religion. Even trained scientists, he found, who are usually perfectly rational about their scientific specialization, lapse into irrational arguments to defend their religion. Furthermore, he observes, religion has been used historically as a cover to wage hideous wars and perform unspeakable atrocities against infidels and heathens. The sheer ferocity of religious or holy wars, in fact, rivals the worst crime that any human has ever committed against any other.
Religion, notes Wilson, is universally found in every human culture ever studied on earth. Anthropologists have found that all primitive tribes have an “origin” myth that explains where they came from. Furthermore, this mythology sharply separates “us” from “them,” provides a cohesive (and often irrational) force that preserves the tribe, and suppresses divisive criticism of the leader.
This is not an aberration, but the norm of human society. Religion,
Wilson theorizes, is so prevalent because it provided a definite evolutionary advantage for those early humans who adopted it. Wilson notes that animals that hunt in packs obey the leader because a pecking order based on strength and dominance has been established. But roughly 1 million years ago, when our apelike ancestors gradually became more intelligent, individuals could rationally begin to question the power of their leader. Intelligence, by its very nature, questions authority by reason, and hence could be a dangerous, dissipative force on the tribe. Unless there was a force to counteract this spreading chaos, intelligent individuals would leave the tribe, the tribe would fall apart, and all individuals would eventually die. Thus, according to Wilson, a selection pressure was placed on intelligent apes to suspend reason and blindly obey the leader and his myths, since doing otherwise would challenge the tribe’s cohesion. Survival favored the intelligent ape who could reason rationally about tools and food gathering, but also favored the one who could suspend that reason when it threatened the tribe’s integrity. A mythology was needed to define and preserve the tribe.
To Wilson, religion was a very powerful, life-preserving force for apes gradually becoming more intelligent, and formed a “glue” that held them together. If correct, this theory would explain why so many religions rely on “faith” over common sense, and why the flock is asked to suspend reason. It would also help to explain the inhuman ferocity of religious wars, and why the God of Miracles always seems to favor the victor in a bloody war. The God of Miracles has one powerful advantage over the God of Order. The God of Miracles explains the mythology of our purpose in the universe; on this question, the God of Order is silent.
Although the God of Order cannot give humanity a shared destiny or purpose, what I find personally most astonishing about this discussion is that we humans, who are just beginning our ascent up the technological scale, should be capable of making such audacious claims concerning the origin and fate of the universe.
Technologically, we are just beginning to leave the earth’s gravitational pull; we have only begun to send crude probes to the outer planets. Yet imprisoned on our small planet, with only our minds and a few instruments, we have been able to decipher the laws that govern matter billions of light-years away. With infinitesimally small resources, without even leaving the solar system, we have been able to determine what
happens deep inside the nuclear furnaces of a star or inside the nucleus itself.
According to evolution, we are intelligent apes who have only recently left the trees, living on the third planet from a minor star, in a minor spiral arm of a minor galaxy, in a minor group of galaxies near the Virgo supercluster. If the inflation theory is correct, then our entire visible universe is but an infinitesimal bubble in a much larger cosmos. Even then, given the almost insignificant role that we play in the larger universe, it seems amazing that we should be capable of making the claim to have discovered the theory of everything.
Nobel laureate Isidor I. Rabi was once asked what event in his life first set him on the long journey to discover the secrets of nature. He replied that it was when he checked out some books on the planets from the library. What fascinated him was that the human mind is capable of knowing such cosmic truths. The planets and the stars are so much larger than the earth, so much more distant than anything ever visited by humans, yet the human mind is able to understand them.
Physicist Heinz Pagels recounted his pivotal experience when, as a child, he visited the Hayden Planetarium in New York. He recalled,
The drama and power of the dynamic universe overwhelmed me. I learned that single galaxies contain more stars than all the human beings who have ever lived…. The reality of the immensity and duration of the universe caused a kind of ‘existential shock’ that shook the foundations of my being. Everything that I had experienced or known seemed insignificant placed in that vast ocean of existence.
10
Instead of being overwhelmed by the universe, I think that perhaps one of the deepest experiences a scientist can have, almost approaching a religious awakening, is to realize that we are children of the stars, and that our minds are capable of understanding the universal laws that they obey. The atoms within our bodies were forged on the anvil of nucleosynthesis within an exploding star aeons before the birth of the solar system. Our atoms are older than the mountains. We are literally made of star dust. Now these atoms, in turn, have coalesced into intelligent beings capable of understanding the universal laws governing that event.
What I find fascinating is that the laws of physics that we have found on our tiny, insignificant planet are the same as the laws found everywhere else in the universe, yet these laws were discovered without our ever having left the earth. Without mighty starships or dimensional windows,
we have been able to determine the chemical nature of the stars and decode the nuclear processes that take place deep in their cores.
Finally, if ten-dimensional superstring theory is correct, then a civilization thriving on the farthest star will discover precisely the same truth about our universe. It, too, will wonder about the relation between marble and wood, and come to the conclusion that the traditional three-dimensional world is “too small” to accommodate the known forces in its world.
Our curiosity is part of the natural order. Perhaps we as humans want to understand the universe in the same way that a bird wants to sing. As the great seventeenth-century astronomer Johannes Kepler once said, “We do not ask for what useful purpose the birds do sing, for song is their pleasure since they were created for singing. Similarly, we ought not to ask why the human mind troubles to fathom the secrets of the heavens.” Or, as the biologist Thomas H. Huxley said in 1863, “The question of all questions for humanity, the problem which lies behind all others and is more interesting than any of them is that of the determination of man’s place in Nature and his relation to the Cosmos.”
Cosmologist Stephen Hawking, who has spoken of solving the problem of unification within this century, has written eloquently about the need to explain to the widest possible audience the essential physical picture underlying physics:
[If] we do discover a complete theory, it should in time be understandable in broad principle by everyone, not just a few scientists. Then we shall all, philosophers, scientists, and just ordinary people, be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason—for then we would know the mind of God.
11
On a cosmic scale, we are still awakening to the larger world around us. Yet the power of even our limited intellect is such that we can abstract the deepest secrets of nature.
Does this give meaning or purpose to life?
Some people seek meaning in life through personal gain, through personal relationships, or through personal experiences. However, it seems to me that being blessed with the intellect to divine the ultimate secrets of nature gives meaning enough to life.
1
. The subject is so new that there is yet no universally accepted term used by theoretical physicists when referring to higher-dimensional theories. Technically speaking, when physicists address the theory, they refer to a specific theory, such as Kaluza-Klein theory, supergravity, or superstring, although
hyperspace
is the term popularly used when referring to higher dimensions, and
hyper-
is the correct scientific prefix for higher-dimensional geometric objects. I have adhered to popular custom and used the word
hyperspace
to refer to higher dimensions.