Massachusetts Institute of Technology
Sign in | Create Account

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. If you don’t have an account yet, sign up now!

MIT Department of Physics Technical Services Group

MIT Department of Physics Technical Services Group

Category: Science | Updated over 1 year ago

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


Viewed
31722 times

More from MIT Department of Physics Technical Services Group

Moving Sand Cart Over a Rotating Surface

Moving Sand Cart Over a Rotating Su...

Added 5 years ago | 00:01:13 | 33299 views

MIT Physics Demo -- Centrifugal versus Centripetal Motion

MIT Physics Demo -- Centrifugal ver...

Added 6 years ago | 00:01:18 | 32997 views

Physics Demo -- Superconductor

Physics Demo -- Superconductor

Added over 6 years ago | 00:00:56 | 50790 views

Rubber and Glass Rods with Tinsel and Balloon

Rubber and Glass Rods with Tinsel a...

Added almost 6 years ago | 00:02:02 | 38216 views

Coupled Air Carts

Coupled Air Carts

Added over 5 years ago | 00:07:38 | 48700 views

Laser Diffraction and Interference

Laser Diffraction and Interference

Added over 5 years ago | 00:02:25 | 36615 views