Lightning and Van de Graaff

About Van de Graaff

Of Dutch heritage, Robert Jemison Van de Graaff was born in Alabama on December 20 1901. He went to University in Alabama, and later studied at the Sorbonne and then Oxford University.

By the time he was thirty, he had built two Van de Graaff generators, the second, larger one, was capable of producing millions of volts.

Van de Graaff Generators and Static Electricity

These electrostatic generators were designed to collect static electricity and store it.

They work by taking electrons from atoms. Atoms, the smallest “building blocks” of life, are made up of protons and electrons.

And some materials will lose electrons more easily than others. Van de Graaff generators are made to accumulate these “loose” electrons.

In their simplest form, the generators use a motor to turn a belt that goes around two rollers, one of which is metal. Imagine the fan belt in a car: instead of the belt being connected to a fan, it’s just connected around another roller. One of the rollers is housed inside a metal sphere that contains a metal comb that is barely touching the belt. As the belt rotates, the comb strips electrons from the metal rollers; the metal comb collects them as the belt turns and the comb transfers the electrons¬† to the metal sphere which houses them.

Here is a demonstration of a Van de Graaff Generator at Science World.

How lightning Works

The above demonstration given at Science World is creating small lightning bolts. Imagine that the large metal sphere is a cloud and is highly charged (with excessive amounts of electrons). Then along comes another object … a plane, another cloud or even Earth … but in a neutral state (does not have an excess of electrons).

… CRACK! …

The electrons between the two bodies are brought in to equilibrium.

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