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
Hauksbee GeneratorItems 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:
- Take the PVC pipe on hold it on one end.
- Hold the wool, fur or silk around the pipe, without your hand touching the pipe.
- The rub the material up and down the pipe quickly, until you hear a crackling sound. Note: The results will subject to the humidity.
- Rub the charged pipe along the fluorescent bulb.
- Write down your observations.
Explanation:
When a electron hit the phosphorus molecule, they become excited and release a photon (light)