Discover, February 1, 1994

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Swear not by magnetic north–it drifts, takes long excursions, and sometimes even heads south. Earth’s patchy core may be to blame.

Although it has long served as a fixed reference for navigators, Earth’s magnetic field is anything but static. Over the course of decades and centuries, in what is called secular variation, the pattern of the field drifts randomly, such that at a given geographic location the direction a compass needle points may change by tens of degrees. Every 30,000 years or so things get more extreme: the magnetic poles suddenly begin shifting toward the equator, only to snap back into place.

Continue reading “Inconstant Field” →

Discover, January 31, 1994

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Something strange was in the air in 1993. In January the average worldwide level of ozone in the stratosphere was in a record-breaking slump; in the summer northern hemisphere levels reached new regional lows; in September the notorious ozone hole over Antarctica returned, nearly twice as deep as ever before. And although carbon dioxide continued to accumulate in the atmosphere, aggravating the greenhouse effect, temperatures were actually cooler than normal in the summer, particularly in the interiors of continents–which may or may not have helped precipitate the Midwest’s disastrous floods, depending on whom you talk to.

Continue reading “Pinatubo Lives” →

Discover, January 31, 1994

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Quantum mechanics has many assaults on common sense to answer for–telepathic particles, for instances, and wormholes to other universes. These bits of weirdness are now old hat. But last March a team of physicists from the United States, Canada, France, and Israel added a new one: teleportation.

At first, it might seem as if teleportation is merely a problem of technology rather than fundamental physics. With a few technical breakthroughs, you might imagine, you’d be able to teleport over to a friend’s house for dinner simply by stepping into a scanner that would record all the pertinent information about the atoms making you up–their positions, their bonds with other atoms, their energy levels, and so on.

Continue reading “Getting There Is Half the Fun” →

Discover, January 31, 1994

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No one likes to be the bearer of bad tidings. But Alan Ferrenberg, a physicist at the University of Georgia, has discovered that bad news is a great way to draw people to talks. This past year Ferrenberg got the rapt attention of fellow physicists by showing them how science’s supply of random numbers is badly contaminated with order.

Random numbers are as crucial to science as they are to a game of craps; they form the basis for computer simulations of everything from collapsing stars to expanding universes, from the aerodynamics of fluids to the vagaries of stock market fluctuations.

Continue reading “Infected with Order” →

Discover, December 1, 1993

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Half the CO2 we pump into the atmosphere doesn’t stay there, which is good. But climatologists wish they knew where it’s going.

Climatologists have a rather large problem with their bookkeeping. Human beings release about 7 billion metric tons of carbon, in the form of carbon dioxide, into the atmosphere each year. (A metric ton equals 2,204 pounds.) Yet the amount of CO2 in the atmosphere rises annually by only 3.4 billion tons. Where does that remaining 3.6 billion tons go? This is not just a problem for climatological green eyeshades: the fate of the missing CO2 could bear directly on the course of global warming in coming decades.

Continue reading “The Case of the Missing Carbon” →