Last month, Science selected the opportunities presented by research on embryonic stem cells as the latest of our Breakthroughs of the Year (Science, 17 December 1999, pp. 2238 and 2267). That discovery, like all scientific research, was possible only because of the previously accumulated body of scientific information, hypotheses, and tools of observation. Our annual selections of Breakthroughs are intended to draw attention to significant scientific achievement. But knowing that any annual retrospective is both temporally and substantively shortsighted, Science begins with this issue a “Pathways of Discovery” series as part of our yearlong special coverage of the transition into the next millennium.
For the remainder of 2000, the second issue of each month will include an essay portraying the pathways of discovery in exciting areas of investigation ranging from quantum physics to cosmology and from genomics to atmospheric sciences. For each topic covered, all of them coordinated by Contributing Editor Ivan Amato, distinguished scientists will review what they see as the major past heuristic accomplishments along the intellectual pathway they presently traverse, and they'll imagine the downstream terrain of that pathway through extrapolation from discoveries unfolding now.
The opening essay of this series, by Stephen Jay Gould (p. 253), is a provocative approach to the question of what distinguishes the scientific way of knowing about the world and what it is about that way of knowing that is all too human. Gould sees a false dichotomy in today's “science wars” between scientist-realists and humanist-relativists who question whether scientific truth has any special standing among other claims of truth. His assessments will prepare readers of subsequent essays for the mix of rational and nonrational influences that continually shape the ever more-revealing worldview scientists have been building.
To help lay out our year of Pathways essays, in this issue we have assembled a graphical timeline of major past events and agents of discovery. The points along the way were drawn from initial selections by Science's editors and then refined and vetted with the help of historians of science (the editors retain credit for any errors, omissions, or overemphases). From this overarching timeline of discovery, an at least arguable origin for each of the 11 essay topics to follow can be seen (p. 230). Each essay will include a more focused timeline depicting pathways of discoveries germane to the topic. In addition, through collaboration with the Encyclopedia Britannica, their Web site (www.britannica.com) will enrich each month's essay with links to unique historical and other informational resources.
These timelines serve as convenient simplifications of the spectacular and progressive accumulation of insight and understanding scientists have achieved. A more detailed visual metaphor of this progress would look like an intricate circulatory system with multiple ever-finer branchings that often interconnect with other parts of the nexus. Science has indeed become a process of continuous specialization, yet each new capillary of investigation contributes to the overall understanding. As some of our essays will show, like that on genomics by Eric Lander and Robert Weinberg slated for March, each new branch of science can open wondrous new opportunities while posing societal challenges that will require vigilance and insightful management.
The unavoidable consequence of focusing on the pathways we have chosen to highlight in this series is the obligatory omission of the many, many other important pathways of discovery that deserved equal recognition in our homage to the past. Recognizing that a truly comprehensive portrayal of science's leading edges was beyond our resources, we opted for some themes that have figured prominently in our pages over the past decade as examples of the flows of ideas and technologies within and between the various pathways of science.
For this editor, the most remarkable conclusion to emerge from this exercise was the realization* that in the millennium we are about to leave, humanity's knowledge of its place in the universe has moved from St. Thomas Aquinas's view that knowledge was of two types—that which man could know and that which was “higher than man's knowledge” and not to be sought through reason—to the belief begun with Newton's Principia that our universe and all within it are indeed knowable. We eagerly await readers' views of our Pathways.
Pathways of Discovery
To help readers negotiate Science magazine's yearlong series, Pathways of Discovery, we compiled this timeline. It leaves out far more than it includes, but we hope it—along with Stephen Jay Gould's provocative essay on page 253 and this issue's editorial by Science Editor-in-Chief Floyd Bloom—will give readers an idea of what to expect from this series. A schedule of the essay topics appear below.
Pathways of discovery are only smooth and linear when the nuanced and tortuous history of science is brutally edited to fit into a finite space. The items to the right represent the countless twists, turns, ironies, contradictions, tragedies, and other unkempt historical details that have synthesized into the far more complex and multitextured reality of the scientific adventure.
4th century B.C.: Aristotle rejects the atomism of Leucippus and Democritus in favor of the five-element material system—earth, air, fire, water, and ether. Atomism doesn't surface seriously for 2000 years. Meanwhile, the four-element philosophy spurs alchemical thought and practice. The power of authority often still poses obstacles to new ideas.
9th to 15th centuries: The flow of science and technology is mostly into Europe from Islam and China. Among the innovations diffusing westward: paper, chemical technology, glassmaking, the compass, shipbuilding, and gunpowder. In the 15th century, the centers of science and technology begin shifting to the West.
1543: Copernicus helps begin the scientific revolution with his heliocentric theory of the universe. Yet he retains the perfect circularity of orbits demanded by Platonic idealism and Ptolemaic astronomy. His work embodies both a radicalism that unlocks new knowledge and a conservatism. These together account for much of the progressive nature of scientific knowledge.
1633: The Holy Inquisition threatens Galileo Galilei with torture unless he renounces heliocentrism. He acquiesces but is confined to house arrest for the rest of his life for previously defying Church authority by publicly promoting the theory. The Galileo affair has since represented—in the most dramatic fashion—the tension between scientific and religious authority.
17th century: Even as Isaac Newton ascends to become an icon of the scientific revolution, he devotes 1 million words and countless hours of his intellect to the practice of alchemy. The ability of the human mind to simultaneously entertain contrary belief systems is a perennial source of wonder.
c1900: Shortly after Röntgen discovered x-rays, the French physicist, René Blondlot, claimed discovery of what he called “N-rays.” Other scientists confirmed his observations. Papers were published. Trouble was, N-rays didn't exist. This episode has become a classic case of “pathological science” in which self-deception, wishful thinking, and selective use and negligence of data can lead scientists astray.
1926: Alfred Wegener's theory of continental drift submerges due to the lack of support from his peers (to say the least). Forty years later, moving continents were established as scientific fact. The critical attitude always has been central to the scientific process, but it also can lead to the premature rejection of good ideas. This episode also is testimony to the faith among scientists that the truth will come out.
World War II: Often known as “the physicists' war,” WWII demonstrated tight links between science, technology, and national security. Synthetic rubber, radar, proximity fuses, and the fission bomb all emerged from the most extensive government-supported R&D program in history. After the war, this new R&D infrastructure evolved into its present form.
1953: Without Rosalind Franklin's crystallographic data of DNA, James Watson and Francis Crick wouldn't have determined that molecule's structure when they did. The two of them and Franklin's senior co-worker, Maurice Wilkins, shared a Nobel Prize for the discovery. Franklin never received official credit for her contribution, and her role was written out of early historical accounts. Franklin represents the struggle for professional parity that women have waged, and continue to wage, in the scientific community.
The 20th century—The Janus Face of Science
Science has never been a value-free enterprise, and its double-edgedness expressed itself with a sobering regularity this century. Before there was “better living through chemistry,” there were clouds of death-dealing chlorine on the Western Front of World War I. The next World War and the Cold War ushered in the awesome power of nuclear fission and fusion and a new kind of apocalyptic angst. Then came Rachel Carson. She alerted the world to global-scale ecological threats that can come with wide-scale environmental releases of synthetic chemicals. Her point was reiterated in the 1970s and 1980s when industrial activity and products were linked to planet-altering threats like ozone holes and global warming. Now, the growing ability to understand and manipulate our own genetic foundations opens up almost utopian medical possibilities. But that gleamy-eyed future only comes with the threat of unnerving compromises ranging from genetics-based job discrimination to the possibility of literally bumbling with the genetic constitutions of all generations that follow this one. Science has entangled itself within the most important values there are, and that brings with it unprecedented responsibilities for scientists of the next millennium.
Acknowledgments: Guidance for this graphic came from many books and other documents, as well as from the following historians: Robert Friedel, Naomi Oreskes, Steven Dick, Garland Allen, Spencer Weart, Sara Schechner, and James Fleming. The editors reserve credit for any remaining errors of fact or interpretation.
↵*A. Lightman, New York Times Magazine, 19 September 1999, p. 94.