Book 8, Question 3 · Video
Why Is the Night Sky Dark If There Are So Many Stars?
The night sky is dark even with so many stars because the universe has a limited age, so light from the farthest stars has not reached us yet. The universe is also expanding, which
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What Crafty Clover says in this video
Intro
Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why is the night sky dark if there are so many stars?
The Big Idea
The night sky is dark because space is mostly empty, and stars are very, very far apart! Their light spreads thin across huge distances, so the gaps between stars look black. Dark sky means empty space between distant suns!
Far Apart
Step one: stars are far apart. Between one star and the next there are trillions and trillions of kilometres of space. That is a lot of empty room!
Thin Light
Step two: the light spreads out. Light from a star spreads in every direction, like ripples in a pond. By the time it reaches us, only a tiny speck of it is left, so each star is a faint dot.
Dark Gaps
Step three: the gaps look black. There is nothing bright in the spaces between stars, so our eyes see darkness there. That gives us tiny sparkles on a dark blanket.
A Closer Look
Let's take a closer look! Stars are shining suns. They are separated by enormous distances. The space between them is almost completely empty. So the sky between the dots stays dark.
Quick Facts
Quick facts! There are more than 100 billion stars in our galaxy alone. Even so, the nearest star besides the Sun is more than 4 light-years away. Far away stars look like dots, not floodlights. Use a flashlight carefully, and ask a grown-up first.
Think Like a Scientist
Now, think like a scientist! With a grown-up, poke tiny pinholes in a piece of paper and cover a flashlight with it. Shine it on a dark wall. You will see tiny lights with dark gaps between them, just like the night sky! Share what you discover with a grown-up.
Outro
Tiny lights with dark gaps in between. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!