Proof that a mysterious force called “dark energy” is pushing the universe to expand endlessly at a faster and faster rate has been selected as the “Breakthrough of the Year” by the editors of Science magazine.
The bizarre idea that some unknown force exists in the universe that is opposing gravity and flinging galaxies away from each other at an accelerating clip was first proposed in 1998. New studies in 2003 proved that the force does exist, and this discovery captured the top prize by the editors of Science as the year’s most important scientific development.
“It is one of the ultimate discoveries in basic science,” said Don Kennedy, editor-in-chief of the journal. “It stirs our imagination even though it challenges our ability to understand.”
“No longer are scientists trying to confirm the existence of dark energy,” the journal reported in its Friday issue. “Now they are trying to find out what dark energy is made of, and what it tells us about the birth and evolution of the universe.”
The editors also selected nine other research advances, ranging from gamma ray research to the evidence of global warming's effects to the effects of RNA on genes. All the selections, the journal said in a statement, were chosen “for their profound implications for society and the advancement of science.”
Expanding universe
Proof for the existence of the “dark force” came from two studies that probed the very early universe — back to less than 400,000 years after the Big Bang — and confirmed that the universe was expanding at a faster rate.
The Wilkinson Microwave Anisotropy Probe telescope analyzed the cosmic microwave radiation background, an echo from the Big Bang, and determined the age and composition of the universe. It confirmed that only 4 percent is ordinary matter, the stuff seen every day, and 23 percent is a cold, dark matter composed of unknown particles. The rest, some 73 percent, of the universe is dark energy.
The study also narrowed the proven age of the universe to 13.7 billion years, plus or minus a few hundred thousand years. Prior estimates had been between 12 billion and 15 billion years.
Another study, the Sloan Digital Sky Survey, mapped the distribution of a quarter-million galaxies and confirmed again the domination of dark energy.
Of the dark energy finding, the journal said: “It is, perhaps, a sign that scientists will finally begin to understand the beginning.”
Other categories
The editors of Science annually select the worst mistake made during the year in the world of research. For 2003, the Breakdown of the Year was the Feb. 1 loss of space shuttle Columbia. The spacecraft came apart while returning to Earth, scattering shattered pieces across east Texas. Seven astronauts were killed, and the remaining space shuttles were grounded while NASA corrects flaws in the craft and in the agency’s safety culture.
The shuttle is not expected to fly again until the fall of 2004.
The editors also noted the epidemic of severe acute respiratory illness, or SARS, that sparked worldwide worries and hit China and Canada particularly hard.
"The outbreak was a chilling reminder that new infectious diseases are always lurking in the woodwork — and they needn't sicken a lot of people to bring economies to their knees," Science's Martin Enserink wrote.
Among the “areas to watch in 2004” were three Mars landings, involving the British-built Beagle 2 probe and two NASA rovers; biodefense research; antiterror measures that may hamper open scientific exchange; a deluge of genomic data; advances in particle physics that may go beyond the Standard Model; the rise of open-access scientific journals; and a focus on soil science and its implications for agriculture and climate change.
The top 10 list
1. Illuminating the dark universe: Proof that all the galaxies and other bodies in the universe are moving away from each other at an accelerating rate, pushed by a force that astronomers now called “dark energy.” Two studies that analyzed light and radiation from an era just after the Big Bang proved that the universal expansion is real. One study also narrowed the age of the universe to about 13.7 billion years.
2. Decoding mental illness: Identifying the workings of certain gene variants that increase the risk of schizophrenia, depression and other mental illnesses that tend to run in families. Researchers found that one gene increases the risk of depression, but only when a person is also exposed to severe stress.
3. Is it warm in here? Growing evidence that global warming is beginning to affect the climate, ocean currents and animals and plants. There is new evidence of tying global warming to ice melting, droughts, falling plant production and changes in plant and animal behavior.
4. Still hot: The role of RNA in plants and animals, a field that was judged 2002's top breakthrough. RNA was once thought to act only as a messenger that followed the instructions of DNA in making amino acids within a cell. But new studies show that forms of RNA can also direct and alter the expression of genes, influencing stem cells and embryonic development.
5. Single molecules groove and glow: Expanded ability to monitor and manipulate single molecules. Powerful new imaging systems enable scientists to observe the actions of individual protein molecules within cells and membranes.
6. Cosmic blasts: Confirmation that gamma ray bursts, one of the most powerful releases of energy in the universe, are linked to supernovas, the explosion of massive stars. Observers connected a supernova explosion with a bright burst of gamma rays.
7. Spontaneous generation: Discovery that mouse embryonic stem cells can be prompted to transform into either sperm and egg cells, a finding that could advance the understanding of some types of infertility problems. But the discovery also raised the possibility, ethically troubling to some, that human embryonic stem cells one day could be used as a source of human eggs that could be used for cloning and other studies.
8. About face: Some high tech materials can bend light opposite to the direction that is normally seen. The discovery could lead to making higher quality lenses.
9. The little Y that could: The Y chromosome, which is the smallest of the human chromosomes and the one that determines the male gender, has duplicate genes that can be used if a new gene copy is required. This is unlike other chromosomes.
10. Starving cancer: A cancer treatment once hailed as the ultimate cure for the killer disease registered its first proven success in 2003. Antiangiogenesis drugs prevent tumors from building blood vessels needed to nurture cancer growths. The drug was found to prolong the lives of patients with advanced colon cancer. Some 60 different forms of antiangiogenesis drugs are now in clinical trials.