Micrumpulmini unleashed by methane bubbles seem to trigger the fatuous fires, the flames above swamps and cemeteries at the center of many legends.
The souls of the deaths blocked in Purgatory, or those of unbalanced children: there are only two of the popular legends traditionally associated with fatuous fires, the flames a little detached from the ground that on summer nights happened to observe, at least until a century ago, in correspondence with marsh, ponds or old cemeteries.
After decades of assumptions, now a research published in the magazine Pnas He concluded that to turn on these trembling and spectral lights they could be microscopic electric discharges that are formed between gas and air bubbles.
Guts with sparks
For some time it has been suspected that to feed the fatal fires are methane and phosphine (a highly flammable gas) produced by the decay of the organic material present in the bursts, or in the old coffins not carefully sealed. Less clear, however, was what triggered the combustion process of these gases in the beginning.
To shed light on this mystery was the research group of Richard Zare, a chemist of Stanford University who in the past has already shown how from the collision of tiny bubbles of water, of dimensions of a few nanometers or micrometers (millionths or thousandths of a millimeter), can be created microscopic lightning. In the past, the scientist has gone to hypothesize that this type of reaction may have had a role in generating, in the primordial broth of the land of origins, the chemical bricks indispensable for life.
Fire from the water?
Now, Zare and his team have experienced experimentally that from the clashes between methane bubbles and air inside a tank of water in the laboratory there are spontaneous electrical discharges: scientists call them microfulmines and think they play a role in catching the fatal fires.
The researchers used an nozzle to shoot methane microbolle mixed with air in the water and studied their collisions with a high -speed camera and other tools to measure the charges produced. As explained on Sciencewhen the bubbles are found in the interface between water and air, the electric charges on their surface separate: on the smaller bubbles, negative charges accumulate, on the larger, positive ones, and this difference generates electric fields on small distances that trigger micro -miguline.
“Nobody thinks that water can be connected to the fire,” said Zare. «It is thought that the water turns it off. Nobody had explained to us that starting from the water, a spark can be created and setting fire to something: this is new ».
The high -speed camera filmed the small flash of light created by the collision bubbles, while other tools detected the ultraviolet light derived from the fluorescence of formaldehyde, a compound produced when it burns methane.
A convincing explanation (but perhaps not definitive)
Other scientists believe that this is an interesting explanation, although perhaps not the last one, on the origin of the fatuous fires. The results also seem to give reason in part to the Italian physicist Alessandro Volta, who in addition to inventing the pile was the first to discover the origin of the methane gas.
It was aimed at demonstrating, at the end of the 18th century, studying the water of the reeds on the banks of Lake Maggiore, that methane gas was not a product of mineral origin, but organic, and to call it “Flatable native air of the marshes“.” He hypothesized that they were lightning to cause these fatuous fires, and in a certain sense he was right, “concludes Zare.” But they are not lightning in the sky; but those who are unleashed in the droplets “.
