‘Microlightning’ might spark glowing will-o’-the-wisps, examine finds

Hovering blue flames that sparkle over bogs and marshes have impressed ghostly folktales for hundreds of years. Known as “will-o’-the-wisp,” “jack-o’-lantern,” “corpse candle” and “ignis fatuus” (“foolish fire” in Latin), the worldwide phenomenon has a spine-tingling historical past. But its origins may now have a scientific clarification: tiny flashes of lightning that ignite microscopic bubbles of methane.

Scientists have lengthy suspected that the will-o’-the-wisp’s spectral glow got here from a chemical response in gases launched by decaying natural matter. Methane, which is odorless, colorless and extremely flammable, is one such gasoline. Swamp gasoline is about two-thirds methane, and when methane reacts with oxygen, the oxidized methane glows blue-violet. However, methane doesn’t spontaneously ignite in oxygen’s presence.

New analysis means that the elusive will-o’-the-wisp is triggered when flashes of “microlightning” arc between electrically charged bubbles of methane in water. As a number of bubbles of methane oxidize and mix, they produce the will-o’-the-wisp’s eerie mild, in line with the authors of a examine revealed September 29 within the journal PNAS.

“There’s a paradox here: If you have a fire, you put it out with water. But little water droplets can make a fire,” stated senior examine creator Dr. Richard Zare, the Marguerite Blake Wilbur Professor of Natural Science and professor of chemistry at Stanford University in California.

Using high-speed cameras recording video at 24,000 frames per second, the examine authors captured flashes of electrical energy zipping between the surfaces of tiny charged bubbles. When oppositely charged bubbles got here collectively, electrons jumped from a negatively charged floor to a constructive one and generated a spark, Zare informed CNN.

“That’s lightning,” he stated. Though this lightning is at a minuscule scale, “it has enough energy to make all types of chemical reactions occur.” Future experiments with this mechanism may assist researchers develop extra sustainable strategies for widespread chemical processes, Zare added.

Other explanations for glowing will-o’-the-wisp lights don’t maintain up below scrutiny, Zare informed CNN. Proposals that the lights have been swarming bugs or birds carrying glowing fungus have been rapidly debunked. Static electrical energy wants dry circumstances to spark, which wouldn’t happen in swampy, water-logged ecosystems.

When the Italian chemist and physicist Alessandro Volta — who found methane in 1776 — instructed that lightning ignited methane in swamp gasoline to create will-o’-the-wisps, he was nearer to the reality than he suspected.

“He thought it was lightning in the sky,” Zare stated. “But no. It’s microlightning.”

In a previous examine, Zare and different researchers confirmed that charged water droplets measuring between 1 micron and 20 microns in diameter — smaller than the width of a human hair — may generate microlightning highly effective sufficient to type natural molecules. Billions of years in the past, this course of might have produced the constructing blocks of Earth’s earliest life.

The new experiments befell in a water-filled container. A microbubble generator pumped methane bubbles into the water by way of a nozzle. As the methane bubbles crammed the water, the scientists noticed microlightning flashes leaping between the surfaces of adjoining bubbles, resembling microlightning seen in earlier experiments with charged water droplets.

“The article puts forward a very interesting hypothesis and reports some evidence in support,” Dr. Alexei Khalizov, a bodily chemist and a professor of chemistry and environmental science on the New Jersey Institute of Technology, informed CNN in an e mail.

However, lingering questions accompany this clarification for the will-o’-the-wisp phenomenon, stated Khalizov, who was not concerned within the new analysis.

For instance, the researchers’ experiments used pure, deionized water, whereas actual swamp water is teeming with natural and inorganic compounds, Khalizov stated. Among these compounds are salts referred to as electrolytes, which may suppress cost separation between gasoline bubbles.

“Deionized water is a good insulator. Regular water is not,” he stated. “Will the reported phenomenon even occur in non-deionized water?”

And whereas the experiments present the presence of microlightning between bubbles, the glow was not reproduced at a degree that may be seen in a swamp. Nevertheless, Khalizov stated that “the process is still very intriguing” and that additional examine of microlightning may reveal their function in oxidizing hint gases launched on the sea floor — a few of which play a task in international warming.

Harnessing microlightning may current extra sustainable choices for chemistry, in line with Zare. “We’re doing this at room temperature without applying any external electric field and without necessarily having to add catalysts,” he defined.

One doable utility for microlightning may very well be triggering chemical reactions that cut back atmospheric methane, essentially the most considerable greenhouse gasoline after carbon dioxide. Methane makes up about 11% of greenhouse gas emissions globally and is about 28% stronger than carbon dioxide at trapping warmth.

“The question is: Can we really scale it up and make it commercial and industrial?” Zare requested. “That’s what I’m working on.”

Mindy Weisberger is a science author and media producer whose work has appeared in Live Science, Scientific American and How It Works journal. She is the creator of “Rise of the Zombie Bugs: The Surprising Science of Parasitic Mind-Control” (Hopkins Press).

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