Ball lightning created in the lab

Researchers in Germany have generated beautiful examples of ball lightning in vitro. Sometimes seen hovering over the ground during thunderstorms (and occasionally confused with a UFO), ball lightning is a mysterious spherical, glowing, ball of energy that scientists believe could be plasma. The plasma clouds that these scientists created were around 20 centimeters across and lasted for half a second. From New Scientist:

 Data Images Ns Cms Dn9293 Dn9293-1 650Earlier this year, Israeli scientists created plasma balls by using microwaves to vaporise various materials, but Gerd Fussmann and his colleagues (at the Max Planck Institute for Plasma Physics and the Humboldt University in Berlin) used a different approach that they believe comes closer to the natural phenomenon.

"It is likely that lightning flashes and water interact to produce ball lightning," says Fussmann. "We therefore use a short, high-voltage discharge of 5000 volts to vaporise some of the water in a glass tank and create the plasma ball."

The tank contains two electrodes, one of which is insulated from the surrounding water by a clay tube. The high voltage causes enormous currents of up to 60 amps – over 200 times those needed to cause death – to flow through the water for a fraction of a second. These enter the clay tube, causing the water there to evaporate and a luminous plasma ball – consisting of ionised water molecules – to rise from the surface.

Link to New Scientist article, Link to previous BB post about making "ball lightning" in your kitchen