By Shining a Laser From the Ground, Researchers Could Easily Measure Earth's Magnetic Field
Firing Lasers at the Sky Dmitry Budker lab/UC BerkeleySatellites, step aside To map the earth's magnetic field, scientists usually take readings from one of a number of satellites, a process that is expensive and often less-than accurate. Physicists at UC Berkeley have a better idea: measure the earth's magnetic nuances using a single ground-based laser to examine the spin of sodium atoms 56 miles up in the sky. There are a variety of reasons for mapping the Earth's magnetic field--geophysicists use the data to study the planet's interior, oil and gas companies use it to hunt for energy deposits, and climatologists use it to study changes in the atmosphere. Studying the atmosphere, it turns out, should inform scientists about changes in the earth's magnetic field as well. The magnetic field of the planet at a given locale influences the rotation of the atoms in that locale, and by studying that spin with...