Magazine

September-October 2009

Current Issue

September-October 2009

Volume: 97 Number: 5

An illustration of the Sun's surface shows solar-flare activity, violent explosions that release huge amounts of energy and particles. Solar flares are powered by the sudden release of magnetic energy in the Sun's corona, caused by magnetic field lines traveling in opposite directions that cross and reconnect with each other. Magnetism is a major source of energy in galaxies across the universe, where the twisting and turning of material creates a dynamo effect that amplifies magnetic fields. The explosive release of magnetic energy, say from space storms interacting with the Earth's magnetosphere, can damage satellites and spacecraft, sicken astronauts and even disrupt power generation on the ground. Exactly what causes this phenomenon is still a matter of intense scientific study, as detailed by James Burch and James Drake in "Reconnecting Magnetic Fields." Cover illustration by Don Dixon/cosmographica.com.

In This Issue

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  • Environment
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Reconnecting Magnetic Fields

James L. Burch, James F. Drake

Physics

The huge amounts of energy released from the relinking of magnetic fields in outer space are both mysterious and potentially destructive

Taking Measure of Biofuel Limits

Thomas R. Sinclair

Agriculture Chemistry Economics Technology

When pinning hopes on biofuels, an energy-hungry world must adapt to plant production capacities and resource limits