Have you ever wondered what thunder looks like? Thanks to a series of tests conducted last summer near Gainesville Florida, you can now take a look at the inside of a lightning strike.
Whether you’ve spent your life dreaming of becoming a storm chaser or hiding under the bed every time a clap of thunder comes along, there is some very cool science involved in the study of storms. Thunder is still a relatively mysterious phenomenon, but it is known that the loud booming sound results from a shockwave of heated air created by lightning.
To capture a data image of thunder, scientists from the Southwest Research Institute (SwRI) used a rocket wrapped in conductive wire to “lure” the lightning along a predictable path and trigger a strike nearby. Microphones were placed on the ground to record sounds associated with the strike in a technique that is sometimes known as “ranging.” Maher A. Dayeh, a researcher with SwRI, then took the recordings and used them to make images of sound waves. Dayeh noted that at first, the images looked like “a colorful piece of modern art that you could hang over your fireplace.” Once lower-frequency sounds had been filtered out, the resulting pictures included a series of red and orange curves that represent thunder.
What exactly do the images show? They’re measurements of the amount of energy produced by the strike, and among the first to provide so much detailed information on thunder’s energetic footprint. These results, along with a long-exposure photograph of a lightning strike were presented at a meeting of the American and Canadian geophysical studies in Montreal. The photograph depicts not one, but nine return strikes as the lightning moves upwards off the ground faster than the human eye can see. Since artificial lightning tends to move in a different pattern from natural lightning, the researchers are now interested to see how a strike that was not purposefully induced would differ.
Activity: Try your hand at long-exposure photography. A long-exposure photograph is generally achieved by keeping the aperture of a camera’s lens open for an extended period of time to capture the blur of a moving object. You’ll need a camera (either film or digital) with a long-duration shutter speed and a tripod. An easy place to start is with traffic light trails, since cars move at a much, much slower rate than a bolt of lightning.
Jobs: Climatologist, meteorologist
Photo Credit: Creative Commons