WASHINGTON, D.C.--Experts from a variety of scientific fields gathered at AAAS headquarters yesterday to discuss some of the most pressing unanswered questions in science. As part of the 125th anniversary of Science, published by AAAS, four symposia addressed everything from the nature of the universe to the meaning of consciousness.
In the first session, "The Nature of the Cosmos," Vera Rubin, an astrophysicist at the Carnegie Institution of Washington, D.C., got things rolling with a whopper: "What is the universe made of?" In the 1970s, Rubin's measurements of rotating galaxies stunned physicists and forced them to conclude that the universe contains about 10 times as much mass as astronomers can see. Today, scientists still don't know what that "dark matter" is. Another major stumper was posed by S. James Gates, a string theorist at the University of Maryland, College Park. He wondered how scientists would fit all the forces of nature into a single mathematical framework. Answers may come from observatories being built to detect gravitational waves. And information theorist Neil Gershenfeld of Massachusetts Institute of Technology in Cambridge asked about the limits of conventional computing. "The interesting question," he said, "is not how physics limits computing, but how computing limits physics." Not only can computers transform research in still-unimagined ways, Gershenfeld predicted, but their powers of "digital fabrication" can help draw ordinary people around the world into the scientific process.
In the following session, "Memories, Consciousness and Human Life," three neuroscientists tackled the issues that make humans "uniquely human." Michael Gazzaniga of Dartmouth University in Hanover, New Hampshire, said some neuroscientists and philosophers contend that the problem of consciousness is just too hard for the human mind to comprehend--"like a nematode trying to figure out a dog." And we are hardly any better off when it comes to understanding memory, added Mortimer Mishkin of the National Institute of Mental Health (NIMH) in Bethesda, Maryland. How can a person retain the memory of a single event, such as a shopping trip, and retrieve it after a lifetime? Christopher Walsh of Harvard Medical School in Boston said several genes affecting brain development have been identified as "targets of evolutionary selection" and might lead to clues as to how humans got so brainy. But not any time soon: "We hope to have some preliminary answers in the next 25 years," he said.
In the third session, "Genes, Proteins, and Disease," four experts put their heads together to point geneticists in a new direction in their quest for causes of disease. It's time to look beyond genes and instead pay more attention to the complex network of gene products--RNAs, proteins, and the macromolecules they form--suggested Marc Vidal of the Dana-Farber Cancer Institute in Boston. Another participant, Kathleen Merikangas of NIMH, pointed out that more than ever before, genes need to be studied in conjunction with environmental factors. Bioinformatics will help researchers make sense of these facets, added Kenneth Buetow of the National Cancer Institute in Bethesda, Maryland. But a word of caution came from Ted Dawson of Johns Hopkins School of Medicine in Baltimore, Maryland, who warned against too much emphasis on assuming genetics always plays a key role in diseases, urging a continued respect for clinical work. In some cases, he said, instead of going from bench to bedside, "we may need to go from bedside to bench."
In the final discussion of the afternoon, "Sustainable Development," the panel agreed that overall population growth itself isn't going to be the major influence on the state of the world's ecosystems. Rather, as ecologist Stuart Pimm of Duke University in Durham, North Carolina, explained, the greatest change in impact will come from the 1 billion people--think China--whose living standards are poised to rival those of North Americans. Cheap and clean energy won't necessarily obviate the impact, noted James Salzman of Duke University Law School in Durham, because other problems such as habitat destruction would remain. The big challenge will be how to deal with the interaction of multiple threats, said William Clark of Harvard University.