Magnetic Fields

Vacquier obituary: An obituary of geophysicist Victor Vacquier Sr. in Saturday's California section gave an incorrect name for a tool he invented to detect magnetic fields. It is the flux gate magnetometer not the flux magnetometer.

The sun has been unusually quiet lately, with fewer sunspots and weaker magnetic fields than in nearly a century. A quiet sun is good for Earth: GPS systems are more accurate; satellites stay in orbit longer; even the effects of human-caused global warming are marginally reduced, though just by three-tenths of a degree at most. It's all a normal part of the strange but regular cycles of the sun's activity. Scientists don't know why it happens, but for humankind, they say, it's probably a good thing.

It comes as no surprise to Southern Californians that solid Earth moves. But until recently, geologists believed that these periodic rumblings were mostly skin-deep. Outbreaks such as earthquakes, volcanoes and violent weather were confined to the surface, like a bad complexion. Hidden beneath the layers of crust and mantle, they felt, the planet had an inner serenity.

Halfway through its two-year reconnaissance mission to Jupiter, the Galileo spacecraft has found a mysterious dusting on the supposedly dead moon Callisto that one NASA scientist said "makes you want to go up and sweep it off." The discovery that these "dust slides" are erasing craters on Callisto's surface was completely unexpected, said planetary scientist Kelly Bender of Arizona State University during a press briefing at the Jet Propulsion Lab in Pasadena on Thursday.

Jupiter's biggest moon, Ganymede, is surprisingly like Earth in some ways, with a magnetic field and probably a molten iron core, researchers report in the Dec. 12 issue of the journal Nature, citing data from the orbiting Galileo spacecraft. The results are considered important because they provide more information about what a planet needs to generate a magnetic field.

Were it not for the watchful eyes at the Food and Drug Administration, you might see bumper stickers like this across Southern California and beyond: MAGNET THERAPY= WORLD HEALTH, WORLD PEACE From backaches to headaches and tennis elbow, from poodles with broken legs to bridge-club women rump-sprung from sitting too long, controversial "magnet therapy" is being employed increasingly these days as an alternative to mainstream medical approaches.

Scientists from NASA's Goddard Space Flight Center reported in Nature that they have found direct evidence for the theory that sunspots--mysterious dark patches on the sun's surface--are caused by curved magnetic fields that stick out from the sun like croquet wickets. The number of sunspots rises and falls in an 11-year cycle of solar activity that can disrupt radio communications on Earth and might also affect Earth's climate.

Scientific computer visualization is a dramatic way to take complex mathematics and turn it into something you can see on a computer screen. Meteorologists, for example, can study the inner workings of thunderstorms or tornadoes without leaving the lab. But sometimes a solid model gives researchers a different perspective on a scientific 3-D set of data that complements the insights made possible from a computer graphics display.

The ubiquitous little white anti-theft tags attached to millions of compact discs and cassettes are causing a rift in the music industry as retailers search for better ways to fight shoplifting. To prevent theft, most music products are protected by tags that will activate an alarm if they pass through an electronic gate at a store's exit. The tags are deactivated at the point of sale, so that in theory, only stolen items will cause the alarm to go off.

Claudia Gonson of the Magnetic Fields opened the band's two-hour show Sunday at the Music Box @ Fonda by welcoming the capacity crowd to "sleepy performances night." Was this a sly dig at the seated audience's relatively muted enthusiasm? Several fans evidently thought so and quickly sent up a cheer to demonstrate devotion. "No, it's OK," Gonson said. "We like the quiet." In fact, they need it.