What was the key factor in thomas edison's success in designing the light bulb？what were some of the new things that were possible because of this invention？

The key factor in Thomas Edison success is discovering the carbon cardboard as a suitable element for his filament. This was the last and the most important thing in Edison design of the light bulb. Edison decided to use carbon filament after much testing because he discovered that the carbon filament will glow without burning.
Because of Edison invention, electricity light becomes a possibility and it is used for many things both in the homes and in the industries.