By DONNA URSCHEL
During a recent lecture at the Library of Congress on the origins of life and the universe, two Nobel Prize-winning scientists discussed many mind-boggling concepts. The most spectacular involved a golf ball.
John C. Mather, whose work in physics helped cement the Big Bang theory of the universe, said, “The entire observable universe, if you were to run the (Big Bang) movie backwards, could have been stuffed into a ball as big as a golf ball. Now that’s shocking. But, if you’re talking about the universe, it’s going to be shocking whatever it is.”
How could this entire observable universe fit into that little bitty ball? Mather said, “Well, number one, space is almost completely empty. Stars are extremely far apart. We cannot imagine any way currently available to get to the nearest one, besides the sun…. Next, atoms are almost completely empty. The atomic nuclei are tiny compared to the size of atoms. And if you squeeze hard enough on the particles of an atom, they come apart and are made of even smaller things called quarks.
“So you can imagine taking the entire universe, running the movie backwards, squeezing and squeezing and squeezing until it mushes into the size of a golf ball.” At that point, said Mather, he is not sure what the ball would be like, because the laws of nature and physics would no longer apply. “It’s a great mystery and not one we will answer today.”
Mather, 2006 Nobel Laureate in Physics, and Craig C. Mello, 2006 Nobel Laureate in Physiology or Medicine, discussed cosmology and genetics in two lectures delivered at the Library on July 26 before a standing-room-only crowd. Both presentations were sponsored by the John W. Kluge Center and the Science, Technology and Business Division of the Library of Congress and the American Association for the Advancement of Science (AAAS).
The program, called “On the Origins of Life and the Universe: An Afternoon with 2006 Nobel Laureates Craig Mello and John Mather,” can be viewed at www.loc.gov/today/cyberlc/feature_wdesc.php?rec=4106. Mather’s lecture was titled “From the Big Bang to the Nobel Prize,” and Mello’s was “Life on a Cosmic Scale: From the Primordial Soup to a Nobel Prize-Winning Worm.”
“Astronomers can look back in time. We can look at things as they used to be. We have an idea there was a Big Bang explosion 13.7 billion years ago. We have a story of how galaxies and stars were made. It’s an amazing story,” said Mather, a chief scientist at NASA, who is an astrophysicist in the Observational Cosmology Laboratory at Goddard Space Flight Center. He leads the James Webb Space Telescope science team.
Mather served as project scientist for NASA’s Cosmic Background Explorer (COBE) satellite, which measured the spectrum of heat radiation from the Big Bang. As principal investigator for the Far Infrared Absolute Spectrophotometer on COBE, he showed that the cosmic microwave background radiation has a blackbody spectrum within 50 parts per million, confirming the Big Bang theory with extraordinary accuracy. Mather shared the Nobel Prize in Physics with George F. Smoot, a professor at the University of California at Berkeley.
How did we get from the Big Bang to the complex structures of stars and galaxies? The answer, in short, is gravity. Gravity is a long-range attractive force, pulling materials together to make stars and galaxies. Mather said, “Gravity makes it possible for us to be here.”
Mather presented a timeline of the 13.7 billion-year-old universe. Three minutes after the Big Bang, “primordial neutrons latched onto primordial protons and made atomic nuclei for helium.” Mather said, “That was the end of the nuclear reaction.” The Big Bang produced hydrogen and helium, the future substance of stars.
The universe expanded and cooled for the next 389,000 years. At that point, according to Mather, the primordial electrons found atomic nuclei to latch onto and became the ordinary gases hydrogen and helium. With the gases, light and heat radiation were released, and the first stars were born. They lasted about 3 million years before they self-destructed. Then galaxies formed and merged.
The sun and Earth were formed 4.5 billion years ago. “Many amazing things happened in the history of the Earth,” Mather said. Continents formed and moved around, and the Earth was pelted with debris from the early solar system. The last big chunk of debris hit the Yucatan Peninsula 100 million years ago. “Earth was a nasty place then. It was bombarded a lot,” Mather said.
Mammals became dominant 55 million years ago. Between 1 and 2 million years ago, humans and other present-day mammals, the ones we see at the zoo, came into existence. About 400 years ago, Galileo perfected the telescope, observed celestial bodies and launched the field of astronomy. In 1905, Albert Einstein changed the concept of space and time with his theory of special relativity, and in 1958, NASA was founded.
Mather said that in the far future, the sun will get larger; it will be too hot to sustain life on earth. The sun will then use up all its nuclear fuel and will eventually darken and go out. Dark energy, a negative pressure that causes gravitational repulsion, is causing the universe to accelerate. The universe is expected to get bigger and bigger, darker and darker. The galaxies will get farther away. Mather said, “In 100 billion years, the universe will be a very strange place.”
Mather described the composition of the universe as 4 percent atoms, 23 percent dark matter (matter of unknown composition that does not emit or reflect radiation) and 73 percent dark energy.
Astronomers will be learning more about the universe when NASA, in cooperation with the European Space Agency and the Canadian Space Agency, launches the James Webb Space Telescope in 2013. It will be two and a half times larger than the aging Hubble Space Telescope and will operate for five to 10 years. Finding the first galaxies that formed in the early universe will be one of many objectives for the new telescope.
While Mather spoke of the big picture, Mello directed the focus of the audience to the DNA and RNA of a transparent worm the size of a comma. Experiments on these worms led to his Nobel Prize-winning research on RNA interference (RNAi), a fundamental mechanism for controlling the flow of genetic information. Mello said RNAi promises to revolutionize medicine.
“It’s important to get this message out to leaders in Washington, D.C. We can understand and intervene with disease on the genetic level,” said Mello, who stressed the need for further funding of medical research.
Mello is the Blais Professor of Molecular Medicine and an investigator with the Howard Hughes Medical Institute at the University of Massachusetts Medical School. He shared the 2006 Nobel Prize in Physiology or Medicine with Andrew Z. Fire of Stanford University.
“The most important activity scientists can do is talk to each other, share ideas and get closer to the truth,” Mello said. “Andy and I talked to each other. We knew the work was hard and we knew it was worth doing.”
The road to success, according to Mello, is persistence, and starting new projects as often as one can. “The fun thing in science is discovering you are wrong—wrongedy, wrong, wrong—and going from there.”
Mello, Fire and their colleagues, however, were very right in 1998 when they reported that double-stranded RNA could induce sequence-specific gene silencing. RNAi occurs in plants, animals and humans. RNAi can spread between cells and can even be inherited. It is of great importance for the regulation of gene expression, and it may lead to many novel therapies in the future.
Mello said, “RNA interference is the mechanism for searching, finding and turning off a gene expression.”
“I like to use the Google analogy. RNAi is a lot like Google, the huge repository of information, and what happens when you want one piece of information. RNAi is a way for the cell to search rapidly through tons of information and find the matching sequences,” said Mello, who grew up in the Washington, D.C., area and attended Fairfax High School in Virginia.
How is RNAi changing medicine? Mello asked. “It’s improving the understanding of gene regulation … We have a better understanding of how cancer works … It’s speeding research on gene pathways involved in disease, and it can be used as a drug platform that directly targets gene expression.”
Mello said, “RNAi brings a lot of hope to so many people who are sick. People are contacting me almost daily, asking if RNAi could work for them.”
Despite many stellar discoveries, there are no cures yet for major diseases. “The pace is picking up in biomedical research, and I urge you to support further funding for NIH [the National Institutes of Health] and all sciences,” Mello said. “But we have a lot of work to do.”
Donna Urschel is a public affairs specialist in the Library’s Public Affairs Office.