What is a light bulb?
Q: What is a light bulb?
A: A light bulb is an electronic device that produces light from electricity.
Q: What are some uses of a light bulb?
A: A light bulb can be used to light a dark space, show an electronic device is on, direct traffic, provide heat, and for many other purposes.
Q: How many light bulbs are in use?
A: Billions of light bulbs are in use, some even in outer space.
Q: What did early people use for light before the invention of the light bulb?
A: Early people used candles and oil lamps for light.
Q: Who invented the electric arclight?
A: Humphry Davy invented the electric arclight in the early 1800s.
Q: Who invented the more efficient incandescent lightbulb?
A: Thomas Alva Edison, Joseph Swann, and several others in the 1880s invented the more efficient incandescent lightbulb.
Q: What kind of light bulb became the main kind for the 20th century?
A: The incandescent light bulb became the main kind for the 20th century, thanks to improved vacuum pumps and better materials made them shine longer and brighter late in the century.
