The effect of a 10 Hz and 8 kV AC electrical field on a flame.
The effect of a 10 Hz and 8 kV AC electrical field on a flame. Park, et al./CC BY 4.0

For nearly as long as modern humans have been around, we’ve been really into fire. Today, it’s the subject of entire fields of scientific study. Scientists are still trying to figure out exactly how flames work, and new discoveries could lead to innovations that might make extinguishing flames easier, or render combustion in industrial settings more efficient. In order to do any of that, fire scientists need to be able to see exactly what’s happening in a flame.

A research team from Saudi Arabia has developed a new method for generating 3D images of flames when they’re exposed to electrical fields. When electrodes are placed on each side of a flame, an “ionic wind” is created—charged particles in the flame move toward the electrodes, and the behavior of a flame can change based on the voltage and current applied to the electrodes. To track the ionic wind, the researchers trained a special argon laser on a flame, added reflective particles to the fire, and then tracked the light that bounced back.

The effects of an AC electrical field on flames.
The effects of an AC electrical field on flames. Park, et al./CC BY 4.0

“We used a smoke generator [to add particles to the flame], but we had to control the timing of the smoke generation very carefully so that we didn’t disturb the main flow. It was a time-consuming step requiring a lot of patience,” study coauthor Min Suk Cha said in a press release. But the care paid off and produced images that are not only useful for understanding how fire behaves, but also mesmerizing for the rest of us.