1709 – Glowing discovery

1709 – Glowing discovery – Francis Hauksbee Francis Hauksbee, also known as Francis Hauksbee the elder, experimented with mercury after hearding of the account that the french astronomer Jean Picard in 1675 had observered a faint glow while caring a mecury barometer.

He discovered that mercery in a glass cantainer exposed to static electricitity can glow bright enough to read by.   This is called electroluminescence.

Francis Hauksbee make a modified static electric generator like Otto von Guericke’s, which had mercury in the glass ball with a partial vacuum.  When it was spun and a hand placed on it, it gave off light.

Experiment – Glowing discovery

HauksbeeHauksbee Generator

Items needed:

  • 1 foot of PVC pipe
  • Wool, fur or silk
  • small fluorescent bulb (like a compact fluorescent or 6″ bulb). A long fluorescent bulb will work, but is more dangerous.

The experiment:

  1. Take the PVC pipe on hold it on one end.
  2. Hold the wool, fur or silk around the pipe, without your hand touching the pipe.
  3. The rub the material up and down the pipe quickly, until you hear a crackling sound. Note: The results will subject to the humidity.
  4. Rub the charged pipe along the fluorescent bulb.
  5. Write down your observations.

Explanation:

When a electron hit the phosphorus molecule, they become excited and release a photon (light)

Leave a Reply