Why is the Sky Blue?

Trap a sunset. Flip it blue. 

Have you ever looked up and wondered… why is the sky blue in the daytime and orange at night? Turns out, it’s not just colors—it's light, particles, and a little sky magic you can make yourself. Let’s flip the sky in a jar!

• 1 clear jar or drinking glass
• Water (fill almost to the top)
• 1 tiny drop of milk (no more!)
• Flashlight (or phone light)
• Spoon
• A dark room or corner

Time Needed: About 10 minutes
(2 minutes setup, 8 minutes exploring and flipping your sky)

1. Make your sky potion.
Fill the jar with water and stir in just one small drop of milk.

This adds tiny particles—like dust in the real sky.
 

2. Lights out—flashlight on!
Go into a dark room. Shine your flashlight through the side of the jar.

Look from the other side. Do you see a soft blue glow? That’s your daytime sky!
 

3. Flip your view!
Now move your head to look from the top of the jar—or from behind the flashlight.

BOOM! The light changes to orange or red—just like a sunset!
 

4. Switch back and forth.
Look from the side = blue.
Look from the top = orange.

Flip it again and again. You're controlling the sky with your eyes!
 

5. Try your own twist.
Add a second drop of milk—do the colors change faster or slower?
Try shining your flashlight at different angles.
Try a dimmer flashlight. What changes?

Name your sky potion!

• Sunset Swirl
• Blue Blaze Brew
• Starshine Mix
• Or invent your own!

Lightning Round Challenge:
Explain the sky flip to someone in 10 seconds or less. Can you do it?
Try it as a race: who can flip the sky colors the fastest?

You don’t just talk about why the sky changes color—you actually see it happen in a jar. This is real science you can control with your eyes, a flashlight, and a single drop of milk.

Sunlight is made of all the colors of the rainbow, but it doesn’t travel equally.
Blue light scatters more, which is why the sky looks blue during the day.
At sunset, the light travels farther—only red and orange make it through.

By doing this experiment, kids will:

• Explore light scattering and atmospheric science
• Use real tools like observation, testing, and comparison
• See how science explains what we see every day!

• What did the blue light remind you of?
• Did changing your angle make the color stronger or weaker?
• What surprised you the most about how the light moved?
• Why do you think the real sky flips colors every day?