The elusive particle called the neutrino has led physicists on a merry chase ever since it was posited in 1930. Researchers have assumed that the ghostly neutrinos lack both charge and mass. But in a stunning announcement in June, an international collaboration running the Super-Kamiokande neutrino detector in Japan showed that these subatomic particles do indeed have a wisp of mass, and physicists are now scrambling to revise their view of how the universe is put together.

Physicists first began to suspect that neutrinos had mass when they aimed neutrino detectors at the sun and found fewer than expected. One possibility was that as neutrinos flew from their origin in the sun to the detector, they changed from one of three types to another type that eludes detection. By the laws of quantum mechanics, this can happen only if neutrinos have mass.

Super-Kamiokande, a 50,000-ton tank of water in which 11,200 light sensors detect the faint glow created when a neutrino slams into a water molecule, found strong evidence for such shape-shifting by tracking atmospheric neutrinos. These particles are the products of cosmic rays and so should rain down on Earth in equal numbers from all directions. But the detector found fewer neutrinos coming from Earth's far side than streaming down from above, presumably because far-side neutrinos change types during their longer route.

Thus at least one kind of neutrino must have mass. The results have spawned a furious debate over whether a new theory of particles is needed, and heated up a long-running argument over whether neutrinos are part of the unseen "dark matter" thought to make up much of the mass in the universe. 1998 marked a new understanding of the neutrino, but this wily particle is still a few steps ahead of the scientists pursuing it.

Beaming the Captain and his stalwart crew up to the bridge of the Starship Enterprise remains the stuff of science fiction, but this year physicists boldly went where no one has gone before, turning teleportation at the quantum level into lab reality.

In science fiction, teleportation moves people and things around, but in physics it means reconstructing a quantum state at a new location, so that information, rather than matter or energy, is moved about. Such information transfer lies at the heart of quantum computing, which offers the prospect of lightning-fast, superparallel calculations. This year physicists made great strides toward building such devices, "soldering" quantum links between ions, devising schemes to find and fix quantum data errors, and performing simple calculations.

The key to teleportation is the odd phenomenon known as quantum entanglement, in which the fates of two or more particles are entwined without physical contact. For example, when a single photon is split by a crystal, the two daughter photons retain a connection as they travel their separate ways: An action performed on one daughter will dictate the state of the other.

A year ago, teams using a roomful of lasers and mirrors in Innsbruck and in Rome teleported information on the quantum states of single photons. Then in October, a U.K.-Danish- U.S. group teleported information on the amplitude and phase of an entire light beam to another beam. In November, U.S. physicists teleported quantum information from the nucleus of a carbon atom to that of a neighboring hydrogen atom. This last feat hints at the real utility of teleportation--the reliable transmission of information between ions that serve as the elements of a quantum computer. That technology may be worthy of inclusion in a Star Trek episode: It's teleportation, Jim, but not as we know it.

Microchips are already the foundation of the electronics industry, but in 1998 chip technologies left their electronic roots behind and moved decisively into biology and other fields. This year the same miniaturization tools used to make computer chips were used to shrink and speed up everything from DNA sequencing equipment to diagnostics.

While major microelectronics firms entered the biochip business, teaming up with start-up companies to push commercialization, basic researchers forged new chip technologies. For example, this year researchers created a DNA-processing micromachine that may one day be able to sequence DNA. Already this chip, just a few centimeters on a side, can measure out precise amounts of DNA-containing solution, amplify DNA, chop it into small pieces, separate the fragments, and detect their size--all necessary steps in sequencing. Also this year, researchers at a California biotech firm developed a biochip that can screen a blood sample for cancer cells, bacteria, or other cell types and remove their DNA for analysis. Such tools could bring tests now done in the lab into the clinic.

Then there are the DNA chips themselves, in which researchers use arrays of immobilized DNA snippets to search out small genetic variations in genes or to detect RNA messages from the genes turned on in cells. Such chips could one day screen for genetic disease. Their foundations may be in electronics, but microchips have a bright biomedical future.

Researchers pushing the pace of discovery of new compounds put the pedal to the metal again this year. Powering the surge were advances in the high-speed discovery engine known as combinatorial chemistry, which allows researchers to assemble a handful of chemical building blocks into all possible combinations thousands of times faster than before.

Virtually all pharmaceutical companies now rely on combi chemistry to churn out a steady stream of hot prospects. In the field's meteoric climb, 1998 stood out as marked by especially rapid growth and explorations into new arenas. Two new journals were born, and a number of drug candidates, including one to treat inflammation, are now in clinical trials.

And this year, the research took off in new and unexpected directions. For example, one team used the technique to rapidly synthesize a collection, or library, of over 2.1 million complex organic compounds that resemble natural products such as antibiotics. Rather than laboriously test these molecules as drugs, researchers are scanning the library to develop a retinue of small compounds that can activate and deactivate target proteins at will. Such compounds may be new drugs and also may help biologists sort out the roles of the 100,000 or so cellular proteins.

Combinatorial chemists scored victories with other types of compounds, too. For example, U.S. researchers used a variation of the technology to find novel catalysts for fuel cells that convert methanol to electricity. Meanwhile, a Norwegian team created a library of hundreds of zeolites, solid materials shot through with tiny pores that are widely used in the chemical industry as molecular sieves. When the goal is to create new compounds, chemists seem to have hit on a winning combination.

The war on cancer is not a single fight but many far-flung skirmishes, and no superweapon has yet emerged to rout the enemy from all its hideouts. Nevertheless, 1998 saw a host of exciting developments in cancer prevention and treatment, suggesting that this feared enemy is at last losing ground.

The best way to beat cancer is to keep it from taking hold in the first place, and several types of prevention made a splash this year. Researchers can proudly point to a new use for the drug tamoxifen: This estrogen-like molecule was already in use as a breast cancer treatment and this year won rapid approval for prevention in high-risk women. Lower tech lifestyle advice seems to be having an effect too: The American Cancer Society announced in March that U.S. cancer incidence and death rates have been dropping since the early 1990s, due in large part to a drop in smoking.

Meanwhile, several promising therapies have emerged. In May, U.S. researchers announced that the antibody Herceptin significantly slows the growth of metastatic breast cancer. And a German team found that the antibody Panorex reduces colon cancer death rates.

False rumors of victory arise in any war, and 1998's award for most overhyped cancer cure goes to angiostatin and endostatin, proteins whose seemingly magical ability to shrink tumors--in mice--was lauded in The New York Times before the treatments were even tested in people. Still, therapies that adopt a similar approach--stopping the growth of a tumor's network of blood vessels--are showing some success in clinical trials, as are treatments such as cancer-killing viruses. The war against cancer goes on, but physicians now have a few new weapons to fight with.