Take a look at your thumbnail. Now imagine a spot on the Sun that’s the same size as your thumbnail. This tiny spot would be really bright—as bright as a million candles shining all at once!
The Sun is our brightest and most important source of light. At any given moment, it sends out 383 billion billion megawatts of light energy. (That’s 383,000,000,000,000,000,000,000,000 watts!) Compare this to a light bulb in your home. It probably gives between 50 and 150 watts, so it has a lot less power.
Very little of the Sun’s light gets to us, because most of it speeds off into space, away from Earth. “Speed” is right—light is the fastest thing in the universe!
The few rays that do arrive mean life for every living thing on Earth. Without light, our world would be totally dark and so cold that everything would freeze solid. Life simply couldn’t exist without light.
