A group of physicists in Brazil have managed to create luminous balls of burning silicon that behave much as ball lightning has been reported to behave.
Click the photo to see a brief video of artificial ball lightning.
Although the glowing balls fall to the floor rather than floating, as ball lightning reputably does sometimes, the hot blobs duplicate other typical phenomena such as
- Following erratic paths, randomly speeding up or slowing down
- Breaking into smaller balls
- Bouncing off of the ground and obstructions
- Scorching cloth and other objects they contact
The researchers, who hail from the Universidad Federal de Pernambuco and the Instituto Nacional de Pesquisas Espaciais, created the artificial ball lighting by touching an electrode to a wafer of pure silicon and heating it with a high electrical current. When they pulled the electrode away from the wafer, it created an arc that spewed out a cascade of burning silicon blobs roughly once in every thirty attempts.
The experiment may confirm the hypothesis that ball lightning forms when normal lightning vaporizes silicon out soil, wood, metals or plastics. Theoretically, the vaporized silicon forms a cloud of nanometer-sized particles that glows as it oxidizes in the atmosphere.
Although the artificial variety is too dense to float, the researchers plan to test whether varying conditions lead to buoyant ball lightning. They are also checking to see if winds or electric fields that may accompany lightning strikes could carry the glowing balls through the air.
The work was reported this week in the journal American Physical Society journal Physical Review letters.
Friday, January 26, 2007
Posted by Buzz Skyline at 1/26/2007 10:17:00 AM