I just read about two scientists from the University of Tel Aviv who created ball lightning in their laboratories using parts from a regular microwave oven. They took the microwave oven’s 600 watt magnetron and turned it into a sort of ray gun that they used to directionally shoot microwaves. The scientists, Eli Jerby and Vladimir Dikhtyar, call the gun a "microwave drill."
From the Tel Aviv U website:
Fireball Ejection from a Molten Hot Spot to Air by Localized Microwaves
Vladimir Dikhtyar and Eli Jerby* Tel Aviv University
A phenomenon of fireball ejection from hot spots in solid materials(silicon, germanium, glass, ceramics, basalt, etc.) to the atmosphere is presented. The hot spot is created in the substrate material by the microwave-drill mechanism.The vaporized drop evolved from the hot spot is blown up, and forms a stable fireball buoyant in the air.
Video of fireball here: http://www.eng.tau.ac.il/~jerby/Fireball%20floating.wmv
The two scientists zapped glass, silicon and other stuff, melting it. When they shut it off and pulled it away, it dragged some of the superheated material along with it, “creating a fire column that then collapsed into a bright fireball that floated and bounced across the ceiling of the metal enclosure,” according to a Fox news report.
"The fireball [looked] like a hot jellyfish, quivering and buoyant in the air," Jerby told the magazine LiveScience.
"Our experiment confirms to some extent the theory that ball lightning originates from hot spots in the ground created by normal lightning," Apparently, ball lightning happens when lightning strikes the ground and zaps the minerals in the soil. The vaporized nanoparticles could then link together into chains and form a fluffy ball of silicon that floats on the wind. The particles react with oxygen in the air and release light as they burn.
Readers are invited to comment with reports of their own microwave experiments.