How fast does light travel?

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Light is a type of energy, and it moves very fast! It moves so quickly that when you turn on a light switch, you can’t even tell that the light from a lamp or light bulb has to travel to fill up a room.

It does travel though. Just like an ocean wave, it takes time for the energy to get from one place to another. In the case of light, it travels over 186,000 miles in a second! That number of miles is a bit large to even imagine, but that means the energy of light could loop around the Earth seven times in about as long as it takes you to say, “Mississippi.”

by   (whyzz writer)
  • Exploration

    Seeing back in time

    Even though light travels super fast, it can still take light awhile to get from certain far away places to our eyes. Some of the farthest-away objects that we can see with our eyes are the stars!

    The next closest star to Earth after the Sun is Proxima Centauri. It’s so far away that light takes about 4.2 years to get from the star to our eyes! That means that the light we’re seeing is 4.2 years old! We see what the star looked like 4.2 years ago, so if a big change happened there today, we wouldn’t know for 4.2 years, when the light reaches us!

    Imagine if someone looked at you today and saw what you looked like 4.2 years ago. How old were you then? How much have you changed? When we look at the night sky, we’re seeing very old light. It’s like looking back in time!


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