💡 How Fast Is Light?
6th Grade ⚛️ Physics
Light travels about 186,000 miles every second — the fastest speed in the universe.
Around the world 7 times
In one second, light could circle Earth about 7.5 times. Nothing we know can travel faster.
Light from the Sun
The Sun is about 93 million miles away, so its light takes about 8 minutes and 20 seconds to reach us. When you look at the Sun (never directly!), you see it as it was 8 minutes ago.
Light-years
Space is so big that we measure it in light-years — the distance light travels in one year, nearly 6 trillion miles. The nearest star after the Sun, Proxima Centauri, is about 4.2 light-years away.
Thunder and lightning
Light is much faster than sound. That is why you see lightning before you hear thunder.
Quick quiz
How fast does light travel?
About how long does sunlight take to reach Earth?
What is a light-year?