SCIENCE: No End in Sight

By Robert C. Cowen

Since its publication last year, John Horgan's provocative book, The End of Science--Facing the Limits of Knowledge in the Twilight of the Scientific Age, has caused a stir among scientists and their friends. One wonders why. Like a melancholy air that consoles a rejected lover, its gloomy message may fit the mood of some who feel discouraged by research funding cuts. But it should be obvious to less depressed thinkers that Horgan's thesis--that the age of great discovery is behind us and what remains is to fill in the gaps--cannot be sustained.

Astronauts recently upgraded the Hubble Telescope, which, along with other orbiting observatories, is revolutionizing our cosmic perspective. Japan has orbited a radio telescope satellite with a 26-foot diameter antenna in a joint effort with Australia, Canada, Europe, and the United States that will open a new chapter in radio astronomy. By combining data from the orbiting instrument with data taken simultaneously at ground-based observatories, radio astronomers can use the "magic" of interferometry to simulate an antenna two and a half times the diameter of Earth. Its resolution will be 100 times finer than the Hubble's. Looking from Los Angeles, it could pick out a radio source the size of a rice grain in Tokyo. Such precision should help reveal what's going on in those energetic objects the Hubble is finding at the core of galaxies.

Back on Earth, scientists from several disciplines hope to learn what it will take to sustain the North Atlantic fisheries. The human genome project is moving rapidly. We are inundated with reports of new discoveries. As a science writer, I find it hard to perceive the scientific enterprise as other than vibrant, adventurous and continually fruitful.

Horgan, also a science writer, sees it differently. His distinguished work for Scientific American has given him entré to leading experts. But the mental perspective he has brought to that work and the conclusions he has drawn from his experience seem unrealistically negative. His background as an English major left him disillusioned with literary criticism. He dismisses that discipline as one in which brilliant thinkers write brilliant commentary that never converges on anything--a situation he considers "ironic." He switched his faith to science, which can, he says, "pose questions in a way that [literary] critics, philosophers, historians cannot." Theories are posed, tested experimentally or observationally and accepted or rejected accordingly. Horgan became disillusioned with this system too and now seems to carry over some of his distaste for literary criticism into his conception of science.

Taking a note from Harold Bloom's 1973 essay, The Anxiety of Influence, he explains: "Bloom said, because no poet can hope to approach, let alone surpass, the perfection of such forebears [Shakespeare, Dante, etc.], Modern poets are all essentially tragic figures, latecomers. Modern scientists, too, are latecomers, and their burden is heavier than that of poets. Scientists must endure not merely Shakespeare's 'King Lear', but Newton's laws of motion, Darwin's theory of natural selection and Einstein's theory of general relativity."

These "latecomers," Horgan says, "must settle for refining and applying the brilliant, pioneering discoveries of their predecessors." Those who try to advance beyond those theoretical achievements are pursuing what he calls "ironic science." He explains: "Ironic science resembles literary criticism in that it offers points of view, opinions, which are, at best, interesting and which provoke further comment. But it does not converge on the truth. It cannot achieve empirically verifiable surprises that force scientists to make substantial revisions in their basic descriptions of reality."

Horgan cites superstrings as an example of "naive, ironic" theorizing that can't be verified. Not so. Gordon Kane, a physics professor at the University of Michigan, offers recipes for testing string theory in the February issue of Physics Today, the American Institute of Physics monthly. (String theory would account for fundamental physical phenomena in terms of vibrations of minute ten-dimensional entities. These manifest themselves in our four-dimensional space-time world with six of their dimensions curled up in a way that only a Star Trek mission could discover.) Kane explains how mathematical extrapolation can directly connect string theory to consequences that can be tested experimentally or observationally.

Take the neutrino. These elusive particles interact so weakly with other matter that they zip through our massive planet as though it were not there. The current so-called Standard Model of particle physics predicts that neutrinos should have no mass at all. Yet it does not provide a general reason why this should be so. This is just one area in which the Standard Model is incomplete. As Kane notes, physicists expect that neutrinos should have some mass even though that mass may be quite small. An ultimate, all-embracing theory would have to predict precisely what that mass would be and when it would manifest itself experimentally. Such predictions could then be tested to see which primary theory, including string theory, would give the best fit to the data. Experiments under way in Japan and elsewhere are looking for signs of mass in the neutrino flux coming from the Sun.

It is a mistake to project the sins of literary criticism onto scientific theorizing. Scientists know their speculations are often vaporware. Yet they often also inspire useful experiments and observations. They can spur on research, as in the case where Sir Fred Hoyle's countervailing theory of continuous creation challenged Big Bang proponents to find definitive evidence for their theory of our universe's birth. Black holes looked mighty speculative some six decades ago when Robert Oppenheimer showed that general relativity predicts that objects only a little more massive than our Sun could collapse to the point where not even light could escape their strong gravity.

For a long time it was hard to see how astronomers could verify the existence of these invisible wonders. Yet as new technologies extended astronomers' vision to include radio, infrared, and X-ray emissions, they realized that, while they couldn't see black holes themselves, they could detect emissions theorists predict should be coming from matter caught in a black hole's grip. Finally, the extraordinary reach of the Hubble Space Telescope permits astrophysicists to conclude that black holes really do exist.

Isaac Newton said that, if he had seen farther than his scientific predecessors, it was because he stood on the shoulders of giants. It seems ludicrous to think of him as standing on the backs of his successors. The legacy of Newton, Darwin and Einstein doesn't burden scientists today. It inspires and supports them. To borrow Newton's famous simile, few, if any, living scientists would deny that they, too, are like children "playing on the seashore, and diverting [themselves] in now and then finding a smoother pebble or a prettier shell than ordinary, while the great ocean of truth lay all undiscovered before [them]."

There's far more to the scientific quest than the search for basic principles, fundamentally important though they may be. Surely, the overarching goal is to understand that "great ocean of truth"--how the universe has evolved under the basic laws and our place in it. Basic principles and laws derived from them inform that understanding. Scientists have to study the universe itself to learn how those principles have expressed themselves in its structure, functioning, and history. You can't deduce the existence of a sparrow from quantum mechanics.

Certainly we don't have to reinvent Newton's laws. But those laws were the beginning, not the end, of classical mechanics and all the wealth of knowledge it has generated. We don't have to rediscover the electron. What's done is done. But wait a minute. What exactly did British physicist Sir J. J. Thomson discover in 1897? We know that what seems to be a fundamental entity called the electron manifests itself as a point source of electric charge. We have classical laws that specify its behavior over a wide range of phenomena. We have quantum laws that specify its behavior even more widely. We know where it fits in the zoology of elementary particles. Yet no one knows what it is intrinsically, the way we know what a baseball is. We may never know that. Nevertheless, there seem to be aspects to this old discovery that have yet to be discovered.

One step forward in that exploration came across my desk as I was writing this commentary. According to quantum theory, an electron is accompanied by a swarm of so-called virtual particles. They buzz around it like bees around a jam pot, continually popping in and out of existence. This concept, which has been around for six decades, predicts that the virtual particle swarm should cloak an electron in a way that reduces its electric charge and electromagnetic force as measured outside the cloak.

Now David S. Koltick and colleagues at Purdue University have penetrated that virtual particle screen. They were part of an international team working with Japan's TRISTAN particle accelerator at the National Laboratory for High Energy Physics in Tsukuba. In Science News February 8, Koltick explains: "As we probe the cloud, getting closer and closer to the core charge, we see less of the shielding effect and more of the core. This means that the electromagnetic force from the electron as a whole is not constant but rather gets stronger as we go through the cloud and get closer to the core." Koltick adds, "we have to go much deeper to learn more about the 'bare' electron." That sounds a lot more fundamental than just filling in the gaps left by Thomson's original discovery.

Horgan considers Darwin and Wallace's proof of evolution through natural selection as the key biological discovery from which all else flows. He sees nothing left for biologists to do but fill in the gaps. There's more to life science than that. The Darwin-Wallace concept is a process, not a fundamental law. Unlike physical laws that govern the motion of a particle, it doesn't predict where a living system undergoing evolution will end.

Paleontologists see nothing inevitable in the evolution of humanity from the primordial slime. However, given the development of earthly life, evolution through natural selection is an overarching concept that enables biologists to make sense of the fossil record. Without it, we wouldn't understand how the living world of which we are a part came to be. Yet that great insight does little to help us understand how our world is evolving under the pressures of unplanned, unnatural selection imposed by human activity.

This is literally a life or death matter for species threatened by, or already terminated by, those pressures. In the long run, it could be a capital issue for humanity if we inadvertently trash the naturally evolved biological system. We may have already passed an ecological point of no return. Even if we curb our nature-bashing ways, we cannot return to the days when, by and large, we could let evolution take its natural course. We have to learn to manage the planet's living system in a sustainable manner.

One of the least understood and most crucial components of that system is the microbes--bacteria, fungi, viruses, etc. At last year's American Association for the Advancement of Science (AAAS) meeting in Baltimore, microbiologist Jennie Hunter-Cevera from the Lawrence Berkeley National Laboratory in California explained: "With every plant and animal on this planet, there are microorganisms. If there weren't, the Earth would look very much like Mars.''

Many microbes are troublesome; others are beneficial and essential. They help digest food. They break down toxins and enrich soil and prepare bare rock to support life. Without them, Earth's higher life forms couldn't exist.

Yet microbes are disappearing at an alarming rate while we scarcely notice their passing. If this continues, one day we will notice their absence to our chagrin. Like a suddenly lost friend we had taken for granted, we would lament that we scarcely knew them. More to the point of this commentary, biologists can't understand Earth's ecology without knowing how it works at the microbial level. As to fundamental discoveries, speakers at that AAAS session pointed out that research in recent years has identified 20 new major biological kingdoms among the microbes.

Alessio Fasano, a research pediatrician at the University of Maryland School of Medicine in Baltimore, says microbes are the most ancient form of intelligent life--"intelligent" in a literal sense. As he explained to a group of science writers at the Council for the Advancement of Science Writing meeting last November, "It's a mistake to underestimate these guys." Bacteria, for example, store information in their genetic systems. They are quick learners. Witness their ability to develop immunity to antibiotics and to pass that immunity on to others. Fasano explained that, if we expand our notion of language, it's fair to say that at least some bacteria "speak" several languages. These are the chemical and structural languages understood by living cells. As they have co-evolved with higher life forms, bacteria have learned to "talk" to the body cells of those life forms and manipulate them to bacteria's advantage. They are like master spies who have the access codes and passwords to a target nation's key facilities and who speak the language of the target country like a native.

Fasano noted that certain bacteria--especially pathogens--have a sophisticated knowledge of the human body at the cellular level that far surpasses that of the most advanced physiologist. Therefore, he said, he has changed his perspective to try to look at the body from the bacterium's point of view. He is gaining deep insight into the interplay of pathogen and body cells. This is cutting-edge research. It is so cutting-edge, in fact, that Fasano brought a lawyer along when he spoke to us. He didn't want to give away those aspects of his discoveries that the university plans to patent.

Knowledge at these basic levels is as fundamental for ecology as is the dance of the particles for physics. Gaining it is no latecomers' clean-up job. For life scientists, the legacy of Darwin and Wallace is an awesome challenge to go and do likewise--to develop new overarching insights that can guide wise stewardship of our planet.

In spite of his downbeat thesis, Horgan does offer a hopeful prophecy: "Any proof that life exists--or even once existed--beyond our little planet would constitute a huge surprise. Science, and all human thought, would be reborn." What impact this much-anticipated discovery may have on human thought remains to be seen.

But science needs no intellectual Geritol. As the few examples I have drawn from my experience as a science writer illustrate, science is healthy and fruitful. It has become a cliché but still valid to say that more scientists are alive today than the total of all scientists who have lived in the past. Few of them feel they are "facing the limits of knowledge in the twilight of the scientific age." Who knows when the next Einstein or Darwin will emerge with a totally unexpected revelation.

This has been a spectacular century for science. It has produced a wealth of beneficial knowledge. It also leaves us with challenging problems that require the cooperative efforts of all scientifically capable nations to solve. We are still paddling about the edge of an ocean of undiscovered truth. The twenty-first century may see us move a little farther off-shore.

Robert C. Cowen ('71) has covered science for The Christian Science Monitor since 1950. He is a past president of the National Association of Science Writers.

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