Hyperspace (52 page)

Billions of years into the future, humanity consists of a trillion, trillion, trillion immortal bodies, each cared for by automatons. Humanity’s collective mind, which is free to roam anywhere in the universe at will, eventually fuses into a single mind, which in turn fuses with the AC itself. It no longer makes sense to ask what the AC is made of, or where in hyperspace it really is. “The universe is dying,” thinks Man, collectively. One by one, as the stars and galaxies cease to generate energy, temperatures throughout the universe approach absolute zero. Man desperately asks if the cold and darkness slowly engulfing the galaxies mean its eventual death. From hyperspace, the AC answers:
INSUFFICIENT DATA FOR A MEANINGFUL ANSWER
.

When Man asks the AC to collect the necessary data, it responds:
I WILL DO SO. I HAVE BEEN DOING SO FOR A HUNDRED BILLION YEARS. MY PREDECESSORS HAVE BEEN ASKED THIS QUESTION MANY TIMES. ALL THE DATA I HAVE REMAINS INSUFFICIENT
.

A timeless interval passes, and the universe has finally reached its ultimate death. From hyperspace, the AC spends an eternity collecting data and contemplating the final question. At last, the AC discovers the solution, even though there is no longer anyone to give the answer. The AC carefully formulates a program, and then begins the process of reversing Chaos. It collects cold, interstellar gas, brings together the dead stars, until a gigantic ball is created.

Then, when its labors are done, from hyperspace the AC thunders:
LET THERE BE LIGHT!

And there was light—

And on the seventh day, He rested.

The known is finite, the unknown infinite; intellectually we stand on an islet in the midst of an illimitable ocean of inexplicability. Our business in every generation is to reclaim a little more land.

Thomas H. Huxley

PERHAPS the most profound discovery of the past century in physics has been the realization that nature, at its most fundamental level, is simpler than anyone thought. Although the mathematical complexity of the ten-dimensional theory has soared to dizzying heights, opening up new areas of mathematics in the process, the basic concepts driving unification forward, such as higher-dimensional space and strings, are basically simple and geometric.

Although it is too early to tell, future historians of science, when looking back at the tumultuous twentieth century, may view one of the great conceptual revolutions to be the introduction of higher-dimensional space-time theories, such as superstring and Kaluza-Klein-type theories. As Copernicus simplified the solar system with his series of concentric circles and dethroned the central role of the earth in the heavens, the ten-dimensional theory promises to vastly simplify the laws of nature and dethrone the familiar world of three dimensions. As we have seen, the crucial realization is that a three-dimensional description of the world, such as the Standard Model, is “too small” to unite all the fundamental forces of nature into one comprehensive theory. Jamming
the four fundamental forces into a three-dimensional theory creates an ugly, contrived, and ultimately incorrect description of nature.

Thus the main current dominating theoretical physics in the past decade has been the realization that the fundamental laws of physics appear simpler in higher dimensions, and that all physical laws appear to be unified in ten dimensions. These theories allow us to reduce an enormous amount of information into a concise, elegant fashion that unites the two greatest theories of the twentieth century: quantum theory and general relativity. Perhaps it is time to explore some of the many implications that the ten-dimensional theory has for the future of physics and science, the debate between reductionism and holism in nature, and the aesthetic relation among physics, mathematics, religion, and philosophy.

When caught up in the excitement and turmoil accompanying the birth of any great theory, there is a tendency to forget that ultimately all theories must be tested against the bedrock of experiment. No matter how elegant or beautiful a theory may appear, it is doomed if it disagrees with reality.

Goethe once wrote, “Gray is the dogma, but green is the tree of life.” History has repeatedly borne out the correctness of his pungent observation. There are many examples of old, incorrect theories that stubbornly persisted for years, sustained only by the prestige of foolish but well-connected scientists. At times, it even became politically risky to oppose the power of ossified, senior scientists. Many of these theories have been killed off only when some decisive experiment exposed their incorrectness.

For example, because of Hermann von Helmholtz’s fame and considerable influence in nineteenth-century Germany, his theory of electromagnetism was much more popular among scientists than Maxwell’s relatively obscure theory. But no matter how well known Helmholtz was, ultimately experiment confirmed the theory of Maxwell and relegated Helmholtz’s theory to obscurity. Similarly, when Einstein proposed his theory of relativity, many politically powerful scientists in Nazi Germany, like Nobel laureate Philip Lenard, hounded him until he was driven out of Berlin in 1933. Thus the yeoman’s work in any science, and especially physics, is done by the experimentalist, who must keep the theoreticians honest.

Victor Weisskopf, a theoretical physicist at MIT, once summarized the relationship between theoretical and experimental science when he observed that there are three kinds of physicists: the machine builders (who build the atom smashers that make the experiment possible), the experimentalists (who plan and execute the experiment), and the theoreticians (who devise the theory to explain the experiment). He then compared these three classes to Columbus’s voyage to America. He observed that

the machine builders correspond to the captains and ship builders who really developed the techniques at that time. The experimentalists were those fellows on the ships that sailed to the other side of the world and then jumped upon the new islands and just wrote down what they saw. The theoretical physicists are those fellows who stayed back in Madrid and told Columbus that he was going to land in India.
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If, however, the laws of physics become united in ten dimensions only at energies far beyond anything available with our present technology, then the future of experimental physics is in jeopardy. In the past, every new generation of atom smashers has brought forth a new generation of theories. This period may be coming to a close.

Although everyone expected new surprises if the SSC became operational by about the year 2000, some were betting that it would simply reconfirm the correctness of our present-day Standard Model. Most likely, the decisive experiments that will prove or disprove the correctness of the ten-dimensional theory cannot be performed anytime in the near future. We may be entering a long dry spell where research in ten-dimensional theories will become an exercise in pure mathematics. All theories derive their power and strength from experiment, which is like fertile soil that can nourish and sustain a field of flowering plants once they take root. If the soil becomes barren and dry, then the plants will wither along with it.

David Gross, one of the originators of the heterotic string theory, has compared the development of physics to the relationship between two mountain climbers:

It used to be that as we were climbing the mountain of nature, the experimentalists would lead the way. We lazy theorists would lag behind. Every once in a while they would kick down an experimental stone which would bounce off our heads. Eventually we would get the idea and we would follow the path that was broken by the experimentalists…. But now we theorists might have to take the lead. This is a much more lonely enterprise.
In the past we always knew where the experimentalists were and thus what we should aim for. Now we have no idea how large the mountain is, nor where the summit is.

Although experimentalists have traditionally taken the lead in breaking open new territory, the next era in physics may be an exceptionally difficult one, forcing theoreticians to assume the lead, as Gross notes.

The SSC probably would have found new particles. The Higgs particles may have been discovered, or “super” partners of the quarks may have shown up, or maybe a sublayer beneath the quarks may have been revealed. However, the basic forces binding these particles will, if the theory holds up, be the same. We may have seen more complex Yang-Mills fields and gluons coming forth from the SSC, but these fields may represent only larger and larger symmetry groups, representing fragments of the even larger E(8) × E(8) symmetry coming from string theory.

In some sense, the origin of this uneasy relation between theory and experiment is due to the fact that this theory represents, as Witten has noted, “21st century physics that fell accidentally into the 20th century.”
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Because the natural dialectic between theory and experiment was disrupted by the fortuitous accidental discovery of the theory in 1968, perhaps we must wait until the twenty-first century, when we expect the arrival of new technologies that will hopefully open up a new generation of atom smashers, cosmic-ray counters, and deep space probes. Perhaps this is the price we must pay for having a forbidden “sneak preview” into the physics of the next century. Perhaps by then, through indirect means, we may experimentally see the glimmer of the tenth dimension in our laboratories.

Any great theory has equally great repercussions on technology and the foundations of philosophy. The birth of general relativity opened up new areas of research in astronomy and practically created the science of cosmology. The philosophical implications of the Big Bang have sent reverberations throughout the philosophical and theological communities. A few years ago, this even led to leading cosmologists having a special audience with the pope at the Vatican to discuss the implications of the Big Bang theory on the Bible and Genesis.

Similarly, quantum theory gave birth to the science of subatomic particles and helped fuel the current revolution in electronics. The transistor
—the linchpin of modern technological society—is a purely quantum-mechanical device. Equally profound was the impact that the Heisenberg Uncertainty Principle has had on the debate over free will and determinism, affecting religious dogma on the role of sin and redemption for the church. Both the Catholic Church and the Presbyterian Church, with a large ideological stake in the outcome of this controversy over predestination, have been affected by this debate over quantum mechanics. Although the implications of the ten-dimensional theory are still unclear, we ultimately expect that the revolution now germinating in the world of physics will have a similar far-reaching impact once the theory becomes accessible to the average person.

In general, however, most physicists feel uncomfortable talking about philosophy. They are supreme pragmatists. They stumble across physical laws not by design or ideology, but largely through trial and error and shrewd guesses. The younger physicists, who do the lion’s share of research, are too busy discovering new theories to waste time philosophizing. Younger physicists, in fact, look askance at older physicists if they spend too much time sitting on distinguished policy committees or pontificating on the philosophy of science.

Most physicists feel that, outside of vague notions of “truth” and “beauty,” philosophy has no business intruding on their private domain. In general, they argue, reality has always proved to be much more sophisticated and subtle than any preconceived philosophy. They remind us of some well-known figures in science who, in their waning years, took up embarrassingly eccentric philosophical ideas that led down blind alleys.

When confronted with sticky philosophical questions, such as the role of “consciousness” in performing a quantum measurement, most physicists shrug their shoulders. As long as they can calculate the outcome of an experiment, they really don’t care about its philosophical implications. In fact, Richard Feynman almost made a career trying to expose the pompous pretenses of certain philosophers. The greater their puffed-up rhetoric and erudite vocabulary, he thought, the weaker the scientific foundation of their arguments. (When debating the relative merits of physics and philosophy, I am sometimes reminded of the note written by an anonymous university president who analyzed the differences between them. He wrote, “Why is it that you physicists always require so much expensive equipment? Now the Department of Mathematics requires nothing but money for paper, pencils, and waste paper baskets and the Department of Philosophy is still better. It doesn’t even ask for waste paper baskets.”
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)

Nevertheless, although the average physicist is not bothered by philosophical
questions, the greatest of them were. Einstein, Heisenberg, and Bohr spent long hours in heated discussions, wrestling late into the night with the meaning of measurement, the problems of consciousness, and the meaning of probability in their work. Thus it is legitimate to ask how higher-dimensional theories reflect on this philosophical conflict, especially regarding the debate between “reductionism” and “holism.”

Heinz Pagels once said, “We are passionate about our experience of reality, and most of us project our hopes and fears onto the universe.”
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Thus it is inevitable that philosophical, even personal questions will intrude into the discussion on higher-dimensional theories. Inevitably, the revival of higher dimensions in physics will rekindle the debate between “reductionism” and “holism” that has flared, on and off, for the past decade.

Webster’s Collegiate Dictionary
defines
reductionism
as a “procedure or theory that reduces complex data or phenomena to simple terms.” This has been one of the guiding philosophies of subatomic physics—to reduce atoms and nuclei to their basic components. The phenomenal experimental success, for example, of the Standard Model in explaining the properties of hundreds of subatomic particles shows that there is merit in looking for the basic building blocks of matter.