Massachusetts Institute of Technology
Sign in

Breakdown of Air

Grounding rod tips of different sizes are used to discharge a large Van de Graaff generator. The larger the curvature of the tip, the more charge must build up to break down the air, resulting in longer sparks. The electricity ionizes air molecules, releasing quick flashes of light.

A pointed tip barely sparks at all, but instead creates an electric field so strong that it forms a tiny ball of plasma just beyond the tip. This is known as "St. Elmo's Fire", and is just visible when all the lights are turned off.

Comments (0)

It looks like no one has posted a comment yet. You can be the first!

You need to log in, in order to post comments.

MIT Department of Physics Technical Services Group

MIT Department of Physics Technical Services Group

Category: Science | Updated over 6 years ago

Created
March 03, 2010 12:42
Category
Tags
License
Creative Commons Attribution-NonCommercial (What is this?)
Additional Files


Viewed
36855 times

More from MIT Department of Physics Technical Services Group

Balloons in Liquid Nitrogen

Balloons in Liquid Nitrogen

Added 8 years ago | 00:01:18 | 50356 views

Confetti and the Van de Graaff Generator

Confetti and the Van de Graaff Gene...

Added 8 years ago | 00:00:55 | 46340 views

MIT Physics Demo -- Levitating Magnet

MIT Physics Demo -- Levitating Magnet

Added almost 9 years ago | 00:00:47 | 45041 views

MIT Physics Demo -- Dipole Antenna

MIT Physics Demo -- Dipole Antenna

Added almost 9 years ago | 00:00:57 | 44728 views

Fluorescent and Neon Tubes in an Electric Field

Fluorescent and Neon Tubes in an El...

Added 7 years ago | 00:02:02 | 42159 views

Physics Demo -- Superconductor

Physics Demo -- Superconductor

Added 9 years ago | 00:00:56 | 57330 views