30 July 2004

Dr. John Barnes and his fountain of light

Forrest M. Mims III

High on the slope of Hawaii's Mauna Loa is a strange cluster of buildings. This facility is the famous Mauna Loa Observatory, and the scientist in charge is Dr. John Barnes.

Barnes has a variety of interests, but his specialty is probing the stratosphere with a powerful laser lidar that he designed and assembled. Once a week, he makes the long drive to the observatory to fire his laser into a black sky sprinkled with countless stars. The laser is fired in a rapid series of powerful pulses. It's impossible to adequately describe the brilliance of the beam as it forms a bright green line straight up to the zenith.

The image here was made by pointing the camera toward the beam and then moving the camera slightly toward the side while leaving the lens open. Each pulse of the laser left its image on the camera's digital sensor.