What Does Thunder Look Like?

There's still much to sort out about the science of thunder and lightning. Jessie Eastland [CC by 4.0]/Wikimedia

You can see the lightning from a storm and you can hear the thunder, but did you ever think that you could also see the thunder? Scientists at the Southwest Research Institute in San Antonio, Texas, have developed a method for converting the sound of a thunderclap into an image, and it could help to illuminate some of the mysteries that still surround the science of thunderstorms, reports CNET.

"Lightning strikes the Earth more than 4 million times a day, yet the physics behind this violent process remain poorly understood," said Dr Maher A. Dayeh, one of the scientists working on the project. "While we understand the general mechanics of thunder generation, it's not particularly clear which physical processes of the lightning discharge contribute to the thunder we hear. A listener perceives thunder largely based upon the distance from lightning. From nearby, thunder has a sharp, cracking sound. From farther away, it has a longer-lasting, rumbling nature."

For the study, a small rocket was tethered to a grounded copper wire and launched into a thundercloud. The wire gave the lightning a conductive channel to travel down while also providing researchers with a consistent and repeatable storm event to measure. The sound of the thunder was then captured using an array of 15 microphones placed about 310 feet from the rocket launch pad.

Researchers then converted the acoustic information into an image using post-signal processing and directional amplification of the data. The strange images generated from the process were difficult to decipher at first.

"The initial constructed images looked like a colorful piece of modern art that you could hang over your fireplace. But you couldn't see the detailed sound signature of lightning in the acoustic data," explained Dayeh.

Eventually they discovered that at higher frequencies a distinct thunder image could be picked out. The images are certainly surreal, but beautiful.

thunder images

The top two images depict the lightning event traveling along the copper wire. Meanwhile, the bottom ones show a visual representation of the sound of the thunder. This stunning visual data offers researchers another way of analyzing how lightning produces thunder.

Although it's slightly anti-intuitive to think about seeing sounds, remember that seeing and hearing are just different ways of representing sense data. This data can then be converted from one form to another. Such methods can occasionally allow us to see or hear things that we may not have been able to pick out otherwise.