The Scientist as Rebel (23 page)

But there are other areas of research in which a network of well-equipped and well-coordinated amateurs can do at least as well as the professionals. Amateurs have two great advantages, the ability to survey large areas of sky repeatedly and the ability to sustain
observations over long periods of time. As a result of these advantages, amateurs are frequently first to discover unpredictable events such as storms in the atmospheres of planets and catastrophic explosions of stars. They compete with professionals in discovering transient objects such as comets and asteroids. It often happens that an amateur makes a discovery which a professional follows up with more detailed observation or theoretical analysis, and the results are then published in a professional journal with the amateur and the professional as co-authors.

On Mount Palomar in California there are two famous telescopes, the huge 200-inch and the little 18-inch. The 200-inch was for many years the largest in the world, exploring the far reaches of the universe with unequaled sensitivity. The 18-inch was on the mountain before the 200-inch and made equally important discoveries. It was the brainchild of the German amateur astronomer Bernhardt Schmidt. Schmidt was a professional optician who made a living by grinding lenses and mirrors. He worked as an unpaid guest at the university observatory in Hamburg. In 1929 he invented a new design for a telescope that produced sharply focused photographic images over a wide field of view. He built and installed the first Schmidt telescope at Hamburg. The Schmidt telescope made it possible for the first time to photograph large areas of sky rapidly. Compared with previously existing telescopes, the Schmidt could photograph about a hundred times more area every night.

The 18-inch at Palomar was the second Schmidt telescope to be built and the first to be used in a mountaintop observatory with good astronomical seeing. Fritz Zwicky, a Swiss professional astronomer, understood the potential of Schmidt’s invention and installed the 18-inch on the mountain in 1935. He used it to do the first rapid photographic sky survey, photographing large areas of sky every night and mapping the positions of hundreds of thousands of galaxies. As a result of this survey, Zwicky made two fundamental discoveries. He
found that galaxies have a universal tendency to congregate into clusters. And he found that the visible mass of the galaxies is insufficient to account for the clustering. From the observed positions and velocities of the galaxies, Zwicky calculated that the clusters must contain invisible mass that is about ten times larger than the visible mass. His discovery of the invisible mass, made with the little Schmidt telescope, opened a new chapter in the history of cosmology. Our later explorations of the cosmos have confirmed that Zwicky was right, that the dark unseen mass dominates the dynamics of the universe. Professional and amateur astronomers are using Schmidt telescopes all over the world to continue the revolution that Schmidt and Zwicky started. Schmidt himself did not live to see the triumph of his invention. When Hitler came to power in Germany in 1933, Schmidt was so disgusted that he gave up hope and quietly drank himself to death.

David Levy is an amateur astronomer in the modern style. He observes at his home in Arizona where he has three modest but well-equipped telescopes, two of them of Schmidt design. He has also visited frequently as a guest observer at the Palomar observatory in California, where he collaborates with the professionals. At Palomar he was using Zwicky’s original 18-inch telescope, which was still going strong and making important discoveries after sixty years of intensive use. Levy’s collaborators were Eugene and Carolyn Shoemaker, until Eugene’s untimely death in a car accident. Now he continues the collaboration with Carolyn alone.

The most famous event of the collaboration occurred in 1993 when Eugene was still alive. This was the discovery of the comet Shoemaker-Levy 9, which was seen in the process of tidal disruption after passing too close to the planet Jupiter. The newly discovered comet was at that moment breaking up into eighteen pieces. The pieces moved apart until they looked like a string of pearls, stretched out into a straight line, each with its own tail of gas and dust shining in the light of the distant sun. After a few days of careful observation
and calculation, it became clear that the pieces of the comet were all destined to crash into Jupiter sixteen months later. This was the first time in the history of astronomy that two celestial objects were seen to collide.

At the time when Jupiter was under bombardment in July 1994, I was lucky to be a guest of the amateur astronomer Gilbert Clark in the dome occupied by a 24-inch telescope on Mount Wilson in California. Clark is a retired navy officer who founded and directs a charitable foundation called Telescopes in Education, or TIE for short. The 24-inch telescope is on loan from the Mount Wilson Observatory to TIE and is instrumented so that it can be operated by remote control. While Clark and I were in the dome, the telescope was being operated by children in a classroom in Virginia. We could see the same images that the children were seeing, and we could hear their voices. They were deciding where to point the telescope. They looked intermittently at various deep-sky objects, galaxies, and star clusters, but always came back to Jupiter. There on the screen was Jupiter, not the familiar image of Jupiter with bland horizontal bands in its cloudy atmosphere, but a wounded Jupiter with five big black scars at the places where fragments of the comet had struck. To me the most remarkable feature of the view was that we could see Jupiter spinning. The scars made the rotation of the planet visible. Jupiter spins fast, making one revolution in nine hours, forty degrees of longitude per hour. We could see the scars moving across the face of the planet, disappearing at one edge and appearing at the other. And the children could see them too.

Ferris is saying that amateur astronomy is a growth industry, gaining in scientific importance as new technologies increase the reach of amateur instruments. Another factor favoring the amateur observer is the change in our view of the universe caused by recent discoveries. The traditional Aristotelian view imagined the astronomical universe to be a sphere of unchanging peace and harmony. The earth alone
was perishable and violent, while the heavenly bodies were perfect and quiescent. This view was contradicted by a multitude of discoveries during the last four hundred years, beginning with the two exploding stars observed by Tycho Brahe and Johannes Kepler and with the mountains and valleys discovered by Galileo on the moon. In the last fifty years it became clear that we live in a violent universe, full of explosions, collapses, and collisions. The Earth now appears to be a comparatively quiet corner in a universe of cosmic mayhem. The 1994 bombardment of Jupiter demonstrated that our own solar system is not immune to cosmic violence. After this replacement of the old static view of the universe by a new dynamic view, the subject matter of astronomy is also transformed. Astronomy is less concerned with things that do not change and more concerned with things that change rapidly. The new emphasis on rapidly changing phenomena requires quick and frequent observation. Quick and frequent observation is a game that serious amateurs can play well. It is a game that amateurs can sometimes play better than professionals. It is a game that gives amateurs and professionals many opportunities for fruitful cooperation.

Ferris shows us a grand vision of the growing importance of amateurs, nimble, well-equipped, and well-coordinated, jumping ahead of the slow-moving professionals to open new frontiers. Some professional astronomers share this vision and welcome the help that amateurs can provide. But most professionals consider the efforts of the amateurs trivial. After all, the professionals with their big instruments and big projects are solving the central problems of cosmology, while the amateurs are finding pretty little comets and asteroids. The view of the majority of professionals was expressed by the physicist Ernest Rutherford, the discoverer of the atomic nucleus, who said: “Physics is the only real science, the rest is butterfly-collecting.” For most professional astronomers, the large-scale structure of the universe is real science, while comets and asteroids are unimportant details of
interest only to butterfly collectors. Butterfly-collecting is an amiable hobby, but it should not be confused with serious science.

The clash between the two visions of amateur astronomy, Ferris’s vision of amateurs as pioneer explorers and Rutherford’s vision of amateurs as butterfly collectors, has deep roots. It arises from an ancient clash between two visions of the nature of science. There are two kinds of science, known to historians as Baconian and Cartesian. Baconian science is interested in details, Cartesian science is interested in ideas. Bacon said:

Descartes said:

Modern science leapt ahead in the seventeenth century as a result of fruitful competition between Baconian and Cartesian viewpoints. The relation between Baconian science and Cartesian science is complementary. We need Baconian scientists to explore the universe and find out what is there to be explained. We need Cartesian scientists to explain and unify what we have found. Generally speaking, professional astronomers tend to be Cartesian, amateur astronomers to be Baconian. It is right and healthy that there should be a clash between
their viewpoints, but it is wrong for either side to treat the other with contempt. Ferris’s sympathies are on the side of the amateurs, but he portrays the professionals with respect and understanding.

Astronomy is the oldest science and has the longest history. For two thousand years it was studied in different ways in two disconnected worlds, the Western world of Babylonia and Greece and Arabia, and the Eastern world of China and Korea. Ancient astronomy in the West was predominantly Cartesian, culminating in the elaborate theoretical universe of Ptolemy, with the clockwork machinery of cycles and epicycles determining how the heavenly bodies should move. Astronomy in the East was Baconian, collecting and recording observations without any unifying theory. In both worlds, astronomy was mixed up with astrology and was mainly studied by professional astrologers. After a promising start, progress stopped and science stagnated for a thousand years, because neither Baconian science nor Cartesian science could flourish in isolation from each other. In the West, theory was unconstrained by new observations, and in the East, observations were unguided by theory.

Then came the great awakening in the West, when Bacon and Descartes together led the way to the flowering of modern science. The seventeenth and eighteenth centuries were the heyday of the scientific amateurs. During those two centuries, professional scientists like Isaac Newton were the exception and gentleman amateurs like his rival Gottfried Leibniz were the rule. Amateurs had the freedom to jump from one area of science to another and start new enterprises without waiting for official approval. But in the nineteenth century, after two hundred years of amateur leadership, science became increasingly professional. Among the leading scientists of the nineteenth century, professionals such as Michael Faraday and James Clerk Maxwell were the rule and amateurs Charles Darwin and Gregor Mendel were the exceptions. In the twentieth century the
ascendancy of the professionals became even more complete. No twentieth-century amateur could stand like Darwin in the front rank with Edwin Hubble and Albert Einstein.

If Ferris is right, astronomy is now moving into a new era of youthful exuberance in which amateurs will again have an important share of the action. It appears that each science goes through three phases of development. The first phase is Baconian, with scientists exploring the world to find out what is there. In this phase, amateurs and butterfly collectors are in the ascendant. The second phase is Cartesian, with scientists making precise measurements and building quantitative theories. In this phase, professionals and specialists are in the ascendant. The third phase is a mixture of Baconian and Cartesian, with amateurs and professionals alike empowered by the plethora of new technical tools arising from the second phase. In the third phase, cheap and powerful tools give scientists of all kinds freedom to explore and explain. The most important of the new tools is the personal computer, now universally accessible and giving amateurs the ability to do quantitative science. After the computer, the next-most-important tool is the World Wide Web, giving amateurs access to scientific papers and discussions before they are published, allowing amateurs all over the world to communicate and work together.

Astronomy, the oldest science, was the first to pass through the first and second phases and emerge into the third. Which science will be next? Which other science is now ripe for a revolution giving opportunities for the next generation of amateurs to make important discoveries? Physics and chemistry are still in the second phase. It is difficult to imagine an amateur physicist or chemist at the present time making a major contribution to science. Before physics or chemistry can enter the third phase, these sciences must be transformed by radically new discoveries and new tools. The status of biology is less clear. Mainstream biology is undoubtedly in the second phase, dominated by armies of professionals exploring genomes and analyzing
metabolic pathways. But there is a wide hinterland of biology away from the mainstream, where amateurs following the tradition of Darwin discover new species of wildflowers, breed new varieties of dogs and pigeons and orchids, and collect butterflies. The writer Vladimir Nabokov is the most famous of twentieth-century butterfly collectors, but there are many others not so famous who also discovered new species. A young friend of mine who went recently as a student to Ecuador discovered twelve new species of plants in the rain forest.