Why is the Edison effect an important milestone in history?

         In one of his experiments, Thomas Alva Edison discovered that electrons can flow from one metal conductor to another, through a vacuum. This discovery was later named as the Edison Effect.

         Sometime in the early 1880s, Edison and his team were working to find a light bulb filament. Their carbonized bamboo filament did well, but even so, carbon deposits were seen inside the bulb after hours. That was when he noticed that the carbon came from the end of the filament which was attached to the power supply. It looked as though it was flying through a vacuum onto the walls!

          Edison realized that there was electric charge flowing not just through the filament, but through the evacuated bulb as well.

          Although Edison was right about the flow, he could not find the reason behind it. He moved on to other experiments.

           Later, it was proved that Edison, with his experiment, discovered the basis of the vacuum tube. And the modified light bulbs were later used to control the flow of electrons through vacuum.