Neutral dust can get charged on its own

London, Apr 12 (ANI): Scientists have explained how lightning can occur even in the driest deserts- neutral dust can gain an electrical life of its own, according to a new theory.

It has long been known that clouds of neutral particles can sometimes gain a net charge, which can cause even the driest sand to generate lightning, and sugar refineries and coal-processing plants can experience unexpected explosions.

While most researchers have ascribed such events to static build-up, but Troy Shinbrot, a physicist at Rutgers University in Piscataway, New Jersey, was wondering how could sand and dust, which do not conduct electricity under normal conditions, generate fields strong enough to spark massive lightening bolts?

"These materials are insulators under very dry conditions, so where are the charges coming from?" Nature quoted him as saying.

After mulling over it for weeks, Shinbrot developed a theory. He began by visualizing the sand particles as party balloons.

In an electric field, he thought, the balloons would polarize, which means that each balloon would develop a positive and negative hemisphere.

He then thought about what would happen if a negative hemisphere from one balloon touched the positive hemisphere of another.

The touching hemispheres would neutralize, but each balloon's other hemisphere would not because they are in an independent electric field.

When the balloons parted ways, they would repolarize in the electrical field around them. But, as the balloons repolarize, the hemispheres that never came into contact with each other would gain an extra unit of charge.

In this way, the balloons could gain very, very high charges, even though they were initially neutral.

By Shinbrot's own admission, the idea of neutral particles charging through the act of neutralizing "just didn't seem right".

But when he began modelling his theoretical sand particles, he found that the idea held up.

Moreover, the models predicted optimal densities of particles where the effect should be most pronounced.

Shinbrot and his team tested their models with an experiment.

"This crazy idea seemed to work," he said.

The team's work appears online today in Nature Physics. (ANI)