SCIENCE IN PICS: The Mysterious Plasma Globe

By Christina Zhang
Christina Zhang
Christina Zhang
July 12, 2012 Updated: August 11, 2020
Epoch Times Photo
When touched, the strings of light concentrate onto the spot where your hand is. (Stephanie Lam/The Epoch Times)

The plasma globe (or inert gas discharge tube) is a strange object that appears to trap colorful strings of light constantly moving inside a transparent ball.

So how does it work?

First, a glass tube or sphere with a certain amount of air pumped out is filled with rare gases like argon or neon. Different gases produce different colored waves.

Next, high frequency electricity is sent through wire coils inside the globe. These currents are strong enough to push some electrons away from their atoms, creating an ionized phase called “plasma” within the enclosed space.

Due to the different voltages inside and outside the globe, the electricity travels to any area that is lower in voltage than the coils, effectively grounding it. This is why, when touched, the strings of light concentrate onto the spot where your hand is.

Scientist Nikola Tesla invented the plasma globe in the late 1800s, while experimenting with high voltage currents inside a tube that had some of its air sucked out.

The popular science toy available today is a version of Tesla’s invention, created in 1971 by Bill Parker, then a student at Massachusetts Institute of Technology.

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