How do you summarize the past 50 years of discoveries in science, technology, engineering, medicine and mathematics? That kind of challenge would be daunting for any one person - but fortunately, we have a huge crowd of science fans to help with the task.
Coming up with the top 50 sagas in science is one of the ways that the Council for the Advancement of Science Writing plans to mark its 50th anniversary in 2010. The council began its work in 1960, in the wake of the first satellite launch, to help researchers and writers get the word out about the new era in science and technology that was dawning back then.
The end of the year is a fitting time to review the highlights of the past 12 months, and the end of the decade provides an opportunity to look back at the top stories of the previous 10 years. But the chance for a 50-year perspective doesn't come along too often, so the rules have to be different.
For this list, we're focusing on research milestones in science and its allied fields – the kinds of things that have been covered at CASW’s annual “New Horizons in Science” meetings. We’re also going with a wide focus that touches upon the broad themes that have generated headlines through the years.
To engineer a list of 50 science sagas that are evenly distributed over five decades, you need to combine some developments and separate others. For example, a single item on this list encapsulates five decades of particle physics, while no fewer than eight items document the revolution in genetics.
You won’t find listings for events in the realm of science, space and medicine that may have generated huge headlines but did not involve advances in research - for example, the Challenger shuttle disaster of 1986 and the Columbia tragedy of 2003. However, we are including the Sputnik launch in 1957, in part because it seemed to serve as a fitting start for CASW’s historical timeline.
This list draws upon the input of CASW board members, but it’s not set in stone – at least not yet. We welcome your comments about breakthroughs we may have missed. Perhaps there are some science sagas we’ve addressed in a single phrase that deserve a more extended mention. Or maybe there’s a better way to explain the significance of a particular science saga. Whether you love the list or hate it, please let us know what you think. Your input will be considered when we create a more interactive, multimedia-laden version of the timeline for the 50th-anniversary observances in 2010.
1. Satellites: Russia launches Sputnik, opening the space race. America responded with the 1958 launch of Explorer 1, the first satellite to produce a significant scientific return—namely, the discovery of the Van Allen radiation belt. The first successful weather satellite (TIROS 1) and the first communication relay satellite (ECHO) were launched in 1960. The space race and the satellite revolution kicked scientific and technological progress into high gear—and created greater demand for science news coverage.
2. ‘The Pill’: First oral contraceptive is introduced. The Food and Drug Administration's approval of Enovid-10 ushered in the era of "the Pill." Few medications have had such a widespread impact on society and social norms.
3. The laser: First working laser is put into operation. Theodore Maiman's optical-light ruby laser followed up on earlier research by Charles Townes and Arthur Schawlow, who developed the first maser (microwave amplification by stimulated emission of radiation) in 1954. The 1964 movie “Goldfinger” may have portrayed it as a killer ray, but the device came to have user-friendly applications ranging from eye surgery to DVD players to supermarket checkouts.
4. Cracking the DNA code: Biochemist Marshall Nirenberg and his colleagues publish the first of a series of papers laying out how DNA's genetic code is translated within the cell. The cracking of the code built upon Watson and Crick's discovery of DNA's double helix almost a decade earlier, and opened the way for the genetic revolution to come.
5. Plate tectonics: Geologists Harry Hess and Robert Dietz propose that seafloor spreading and subduction are basic parts of the mechanism for plate tectonics - a finding that led to the rapid acceptance of the tectonic theory behind Earth's large-scale geologic changes. The study of paleomagnetism led scientists to conclude that Earth's magnetic poles periodically reversed, providing an important geological dating method.
6. The environmental movement: Marine biologist Rachel Carson's masterwork, Silent Spring, is published. The environmental concerns voiced in the book helped spark a grassroots movement that led the federal government to create the Environmental Protection Agency in 1970 and phase out the use of DDT in 1972.
7. Quasars: The first quasar—quasi-stellar radio source—is discovered by Dutch astronomer Maarten Schmidt. Scientists eventually determine that quasars are compact regions in the center of active galaxies that mark the presence of a supermassive black hole. The discovery was a key turning point in our understanding of galactic development and structure.
8. Quarks and all that: The quark model of particle physics is proposed. The ideas put forth by physicists Murray Gell-Mann and George Zweig touched off a decades-long quest to find the subatomic particles that matched the theory, including the J/Psi particle (found in 1974), the W and Z bosons (1983) and the top quark (2004-05). The quest continues today at America's Fermilab and Europe's Large Hadron Collider, where scientists hope to detect the Higgs boson, the last particle predicted by the Standard Model.
9. Big bang's afterglow: Cosmic microwave background radiation is discovered by radio astronomers Arno Penzias and Robert Wilson, an achievement that earned them a Nobel Prize in 1978. The background radiation serves as the fossil imprint of the big bang and has helped astronomers determine the geometry of the universe. The Cosmic Background Explorer (COBE), launched in 1989, was a landmark space mission that followed up on Penzias and Wilson's discovery by mapping variations in the background radiation.
10. Heart transplants: First human-to-human heart transplant is performed. Dr. Christiaan Barnard's operation in South Africa prolonged his patient's life by only 18 days, but helped set the stage for rapid progress in medical transplantation techniques. Stanford heart surgeon Norman Shumway was an early pioneer in transplant medicine, and Denton Cooley and Domingo Liotta made a significant contribution in 1969 with the first human implantation of an artificial heart.
11. Moon landing: Humans make first landing on the moon. The Apollo series of moon surface missions, beginning with Apollo 11's Neil Armstrong and Buzz Aldrin, marked the climax of the decade-long U.S.-Soviet space race and also led to fresh scientific insights into the origins of Earth and the moon.
12. Internet: First node is connected on ARPAnet, the predecessor to the modern Internet. What began as an research project to develop a nuke-proof communication system ended up revolutionizing academic exchange - and eventually modern society. Twenty years after the Internet's birth, CERN's Tim Berners-Lee brought the global network to a higher level with the invention of the World Wide Web.
13. Oncogenes: First cancer-causing gene is discovered in a chicken retrovirus. In 1976, J. Michael Bishop and Harold Varmus described the mechanism by which proto-oncogenes mutate and give rise to cancer—a discovery that earned them the Nobel Prize in 1989.
14. Medical scanners: First CT scanner is created. Computerized tomography X-ray scanners not only revolutionized medical imaging, but also presaged other imaging techniques such as magnetic resonance (MRI and functional MRI) as well as positron emission tomography (PET). Such techniques have been put to wide application in medical diagnosis and neuroscience, and even archaeology and paleontology.
15: Recombinant DNA: Stanford biochemist Paul Berg creates the first recombinant DNA molecule, pointing the way to genetically modified organisms and gene-based medical therapies. The technique proved so powerful and controversial that it led to a 1975 conference at California's Asilomar Conference Center, where scientists voluntarily agreed on research restrictions. The Asilomar conference itself stands as a milestone in scientific accountability.
16. Human ancestors: Paleoanthropologist Donald Johanson discovers the 3.2 million-year-old fossil skeleton of a human ancestor dubbed "Lucy" in Ethiopia. The australopith find serves as the best-known milestone in a long line of hominid discoveries also including the Laetoli footprints in Tanzania (1976), the Toumai skull in Chad (2002) and Ardipithecus in Ethiopia ("Ardi" found in 1994, characterized in 2009).
17. Countering the ozone threat: Chemists F. Sherwood Rowland and Mario Molina propose that chlorofluorocarbons may affect Earth's ozone layer—a hypothesis that was borne out over the following decade, particularly with the identification of the Antarctic ozone hole in 1985. Concerns about CFCs led to a phase-out of their production mandated by the 1987 Montreal Protocol. The Rowland-Molina research and its impact set a precedent for the current debate over greenhouse-gas emissions.
18. Pictures from other planets: NASA's Mars Viking probes land on Mars and send back the first color pictures from another planet. The twin missions follow up on the Soviet Venera 9 and 10 missions, which transmitted black-and-white images from Venus in 1975.
19. Deep-sea life: Biologists discover a rich ecosystem surrounding deep-sea hydrothermal vents along the Galapagos Rift. The discovery dramatically changed scientists' views on the conditions required for life on Earth, sparked new ideas about the potential undersea origins of life and led astrobiologists to consider the possibility of life in extraterrestrial settings such as the subsurface oceans of Europa (a moon of Jupiter) and Enceladus (a moon of Saturn).
20. Farthest frontier: NASA launches the twin Voyager probes, following up on the Pioneer interplanetary missions with a grand tour of the solar system. Both craft flew past Jupiter and Saturn. Voyager 2 flew past Uranus and provided the first up-close look at Neptune. Voyager 1 is now the farthest-flung object ever made by humans. Both Voyager spacecraft probes carried a "Golden Record" with recordings of Earth imagery, sounds, speech and music.
21. Test-tube babies: The first baby conceived through in-vitro fertilization is born in England. The method is a boon to couples with fertility problems. Since then, an estimated 3.5 million "test-tube babies" have been born using assisted reproductive technology. But the method is not without controversy, as illustrated by the furor over the birth of octuplets to "Octomom" Nadya Suleman in 2009.
22. Data encryption: MIT's Ron Rivest, Adi Shamir and Leonard Adleman describe the RSA public-key encryption method, which draws upon prime factorization to provide a means of secure communications. The encryption method serves as the foundation for applications ranging from military communications to Internet commerce.
23. Farewell to smallpox: The World Health Organization announces that smallpox has disappeared worldwide. The infectious disease killed untold millions over the course of centuries, and its eradication through widespread vaccination was a crowning achievement in public health.
24. Killer asteroid: Luis and Walter Alvarez propose that a cosmic impact was responsible for the Cretaceous-Tertiary extinction that killed off the dinosaurs 65 million years ago. The hypothesis provided a focus for further scientific study into the causes of great extinctions. Cosmic impacts as well as the effects of climate change have come to be seen as the primary factors behind ancient die-offs.
25. Cosmic inflation: Inflationary big bang theory is put forward by Alan Guth to explain seeming contradictions in the scientific model for the universe's creation. Subsequent observations supported inflation as the leading explanation for what happened immediately after the universe's origin to create the seeds of cosmic structure.
26. HIV identified: French doctors isolate the virus that causes AIDS. The discovery of the human immunodeficiency virus marked the beginning of a continuing effort to develop treatments for a disease that was at the time seen as a death sentence.
27. Evo-devo: Researchers at the University of Basel and Indiana University independently discover homeobox DNA sequences within genes, which regulate patterns of development in a wide spectrum of organisms. Such work helped lead the way to evolutionary development ("evo-devo") studies that shed light on how different species are interrelated.
28. DNA decoders: Polymerase chain reaction technique for DNA analysis is developed by Kary Mullis, who won a Nobel Prize in 1993 for the discovery. PCR analysis has become the foundation of modern genetic research, touching on fields ranging from medicine and evolutionary biology to criminology.
29: String theory: The first superstring revolution begins. Theorists suggest that string theory—the idea that the most fundamental constituents of matter can be thought of as minuscule strings vibrating in multidimensional space—could resolve the inconsistencies between general relativity and quantum physics. The first superstring revolution (1984-85) set the precedent for the second superstring revolution (1994-97). Even today, string theory sparks debate over whether it could be a "theory of everything" ... or a "theory of nothing."
30. Nanotechnology: Buckminsterfullerene is created in the lab by Robert Curl, Harold Kroto and Richard Smalley. The soccerball-like C60 molecule was the first of several artificial carbon constructs that paved the way for innovations in nanotechnology such as carbon nanotubes. Other nanotech innovations, such as gold nanoparticles and quantum dots, appear to have medical applications - but nanotechnology has raised medical concerns as well.
31. Catching up with comets: Europe's Giotto mission observes Halley's comet up close. For the first time, humans were given a glimpse at the source of one of the most dramatic displays in the heavens - and, according to some theories, a primordial source for the stuff of life. Cometary studies continued with 2005's Deep Impact mission, which fired a "bullet" into the heart of a comet, and the Stardust mission, which brought samples of comet dust back to Earth in 2006.
32. High-temperature superconductors: The first high-temperature superconductor is discovered by Karl Mueller and Johannes Bednorz. The achievement earned them the Nobel Prize in 1987. High-temperature superconductors could eventually be used for more efficient power transmission and vehicle propulsion.
33. Witnessing a cosmic crash: Comet Shoemaker-Levy 9 smashes into Jupiter during one of the most widely watched astronomical events of the century. This was the first time astronomers predicted a planetary impact in advance. The event also had an impact on our own planet, pushing along efforts to catalog near-Earth asteroids and assess the threat they may pose.
34. Quantum computing quest: U.S. mathematician Peter Shor demonstrates a theorem for a procedure that could be used to crack the RSA cryptographic code using a computer based on quantum interference phenomena. Such a quantum computer was discussed in 1980 by Paul Benioff, and a year later by Richard Feynman. Since then, researchers have worked to construct quantum computing devices. In 2007, Canada-based D-Wave said it built the first practical quantum computer, but other researchers doubted whether the device was truly a quantum computer. In 2009 Google announced that D-Wave’s technology was being incorporated into its new image recognition system.
35. Math milestones: More than 350 years after Fermat's Last Theorem was proposed, British mathematician Andrew Wiles proves the claim that xn + yn = zn works for whole integers only if n is less than 3. The hard-won proof earns Wiles a $50,000 prize. Eight years later, reclusive Russian mathematician Grigory Perelman proves another long-running puzzle, the Poincare conjecture - but turns down a $1 million prize as well as the Fields Medal, mathematics' highest honor.
36. Alien planets: Astronomers detect the first extrasolar planet circling a normal star, 51 Pegasi. The discovery built upon 1992's detection of "pulsar planets," and pioneered techniques that have been used to find more than 400 extrasolar planets to date. The findings have led scientists to conclude that planets are much more common in the universe than previously thought.
37. First cloned mammal: Researchers announce the birth of Dolly the Sheep, the first mammal to be cloned from the adult cell of another animal. The achievement was followed by a string of other cloned species - ranging from dogs and cats to champion racing mules and rhesus monkeys. Dolly also touched off a long-running political and religious debate over human reproductive cloning.
38. Big bounce on Mars: Mars Pathfinder probe lands on Mars, marking a new era of interplanetary exploration two decades after Viking. Pathfinder blazed a trail for the even more wildly successful Mars Exploration Rovers, Spirit and Opportunity (which were both launched in 2003 and landed, like Pathfinder, cushioned by airbags). The Pathfinder mission also served as an early milestone in public interest in science as mediated by the Internet.
39. Dark energy: Two teams of astronomers studying distant supernovae determine that the expansion of the universe is accelerating, supporting a theoretical twist that Albert Einstein once called the "biggest blunder of my life." The discovery of the acceleration factor has sparked one of the biggest mysteries of contemporary cosmology: What is dark energy?
40. RNA interference: Biomedical researchers Andrew Fire and Craig Mello publish a study showing how small RNA molecules influence genetic pathways in C. elegans worms, opening up a new field of research into RNA interference. RNAi-based therapies could address a wide variety of illnesses, including AIDS, cancer, Huntington's and Alzheimer's disease.
41. Human embryonic stem cells: First human embryonic stem cells are isolated. Such cells can transform themselves into virtually any tissue in the body, raising hopes for new cell-based therapies. Because embryos were destroyed in the process of extracting the cells, the process touched off a years-long ethical and political debate, highlighted by federal funding limits in 2001. In 2007, two teams of researchers used genetic modification to transform ordinary skin cells into cells that appear to function like embryonic stem cells. The use of these reprogrammed cells, known as induced pluripotent stem cells or IPS cells, may resolve the ethical concerns.
42. Human genome decoded: The publicly funded Human Genome Project and privately funded Celera Genomics simultaneously publish the first working drafts of human genome in the journals Nature and Science, respectively. The genomic code was refined in succeeding years, providing a rich resource for studying the genetic origins of disease as well as tracing linkages in evolutionary biology.
43. Age of the universe: Using data from the Hubble Space Telescope, the Boomerang balloon flight and other data, astronomers determine the age of the universe to be 13.7 billion years—an estimate further refined by data from the space-based Wilkinson Microwave Anisotropy Probe.
44. Targeted cancer therapy: The Food and Drug Administration approves imatinib, marketed under the name Gleevec, as the first in a class of drugs that target the chemical mechanism behind the spread of cancer.
45. Titan revealed: Europe's Huygens lander descends through the smoggy atmosphere of the Saturnian moon Titan and sends back the first pictures of Titan's hydrocarbon rivers as well as its icy and possibly tarry surface. Huygens rode to Titan aboard the international Cassini orbiter, which continued to study Saturn and its moons. Another highlight of the Cassini mission was its observations of Enceladus' geysers of water ice, which led scientists to suggest the ice-covered moon possessed a subsurface liquid ocean and perhaps marine life forms as well.
46. Planets realigned: Astronomers discover an icy world in the Kuiper belt that is larger than Pluto, forcing the International Astronomical Union to draw up a much-debated definition of the term "planet" a year later. The definition reclassified Pluto and the newfound world (later named Eris) as dwarf planets, distinct from the solar system's eight major planets.
47. T. rex tissue: Paleontologists recover soft tissue from within the fossilized bones of a Tyrannosaurus rex, upending assumptions about the limits of fossil preservation. Analysis of the tissue turns up the signature of proteins similar to those found in the bones of chickens and ostriches, solidifying the linkage between dinosaurs and present-day birds.
48. Invisibility shield: Building on a formula proposed a year earlier, two teams of researchers announce the creation of "cloaking devices" that can cancel out the radiation reflected by an object and shield it from detection. Such devices are not as all-concealing as Harry Potter's cloak of invisibility, however. They are made from metamaterials that must be tailored for specific wavelengths and dimensions.
49. Tasting Martian water: NASA's Phoenix Mars Lander touches down in Mars' north polar region and samples the planet's water ice for the first time. Mission scientists say images of the probe's own lander legs appear to show droplets of liquid water stirred up during the landing. Phoenix's findings furnish the latest chapter in the decades-long scientific assessment of Mars' potential for life in ancient times.
50. Water on the moon: NASA sends a probe called Lunar Crater Observation and Sensing Satellite, or LCROSS, crashing into the moon. Weeks later, scientists report that an analysis of the impact debris confirms the existence of "significant" reserves of water ice. The mission followed up on indications from earlier probes (Clementine, Lunar Prospector, Chandrayaan 1, Cassini) and even from Apollo lunar samples. Some speculated that the findings could lead to a fresh round of lunar missions, but as the decade came to a close, NASA's plans for future exploration were still under review at the White House.
- By Alan Boyle, CASW treasurer and science editor for MSNBC.com
Illustration by Jenny Mottar for NASA. This material has been adapted for a series of Cosmic Log postings on MSNBC.com.