October 2009

The explosive C4, a favorite for everything from demolition to terrorism to action movies, is in fact one of the safest explosives. How can an explosive be safe? If it’s hard to set off by accident. C4 is so stable that you can light it with a match (it burns but does not explode) or shoot it (it splatters but does not explode). To go bang, it requires a detonator that produces both heat and shock.

At the other end of the spectrum are mixtures that ignite simply from being scratched or knocked. There are obvious challenges in mixing, storing, and handling these substances so that they explode only when intended, yet they’re surprisingly common.

As the kite’s tether unspools, it spins an alternator that generates up to 40 kilowatts. Once the kite reaches its peak altitude, it collapses, and motors quickly reel it back in to restart the cycle. This spring, KiteGen started building a machine to fly a 1,500-square-foot kite, which it plans to finish by 2011, that could generate up to three megawatts—enough to power 9,000 homes.

Despite its gusty reputation as a “gas giant,” Jupiter’s blood-red clouds hide a dense, rocky core that’s perhaps 20 times as massive as Earth. That core blocks any spacecraft’s passage through the center of the planet, but even a detour through the clouds would be a disaster.

No matter how intelligent a robot might be, it’s nice knowing you can pull its plug to halt the anti-human insurrection. Whoops, not anymore. A new cohort of ’bots that make energy by gobbling organic matter could be the beginning of truly autonomous machines.

The first computer-generated model of an entire sunspot—a magnetic anomaly on the surface of the sun—tracks the magnetic fields in the area, helping researchers figure out how the sun releases energy around the spots. At the dark center, or umbra, the field is so strong—about 1,000 times the solar average—that it blocks the solar gases that typically bubble to the surface.

A new technology has made giant air cleaners in Swedish factories smaller and more energy-efficient, and now it’s doing the same for filters in your home. The innovation: paper.

Observing a star up close (putting aside for a moment how you’d get there or withstand its heat) is probably like sitting beside an enormous silent fire. Sounds—which are simply pressure variations in a medium such as air or water—can’t propagate in the vacuum of space, so the roiling surface of a star would make an impression on the eyes, but not the ears.

Who needs brakes? When you’re converting a junk-stuffed shopping cart into an electric joy-ride-mobile, they’re the last thing you worry about. MIT undergrad Charles Guan’s LOLriokart—the name is a mash-up of Web and videogame-speak—grew out of his membership in the MIT Electronics Society, a student engineering club. With no plans to build a vehicle, he looked around the club’s shop and spotted the shopping cart, some discarded wheels and an electric engine normally used in high-performance golf carts.

On October 7, 2020,shortly before dawn in northern Sudan, a trucker named Omar Fadul el Mula was praying at a remote teahouse in the Nubian Desert when a bright flash lit up the landscape. It was as if the world had switched from night to day. He sprung to his feet, ran around the small building, and saw a huge trail of dust and debris stretched high in the sky.

Features

The Race to 1,000 MPH

In the Black Rock Desert, a band of misfits is going up against the land-speed record holder to make history, and break the sound barrier—all while keeping the car and driver in one piece.
By Mike Spinelli

Meet the Asteroid Hunters

Boaters like spray and sun in their face, not exhaust. The first hybrid sport boat, courtesy of a co-designer of the Aptera electric car, delivers cleaner thrills.