Terrellas had been used up until the late 20th century to attempt to simulate the Earth's magnetosphere, but have now been replaced by computer simulation.
allynh wrote:In the Tripod link Sparky had, there is an ad to a place that makes large plasma globes.
Museum Sized 22" Tall Plasma Globe - Red Plasma Effect - 15" Diameter Ball | Specialty Toys Direct
http://www.st-amz.com/Museum-Sized-22-T ... gwodjzANaw
The pressure of the gas mixture plays a large part in determining the shape of the plasma effect. In general, the higher the pressure of the gas, the thinner and more sharp the plasma arcs will be. The lower the pressure, the wider and softer the arcs will be. When the pressure is low enough, a unique effect becomes possible
at reduced power levels, somewhat like a glowing aurora borealis around the electrode core.
Plasma globes got their name because they really do contain “plasma.” Plasma is often referred to as the “fourth state of matter.” It is the most common state of matter in the universe—the stars themselves are made of it. Plasma occurs when a gas becomes electrically charged (or “ionized”) and the electrons begin to break off from the atoms and move around freely. Unlike a typical gas, plasma is electrically conductive and responds strongly to the effects of electromagnetic fields. Applying an electromagnetic field to plasma can cause it to form into structures such as filaments, beams, and double layers. These structures are what give shape to the moving tendrils of light that you see in the plasma globe.
Users browsing this forum: starbiter and 1 guest