Rainbow and Light Refraction Lab
Explore refraction with Snell’s law: light changes direction when it enters a different material, and different colours bend by different amounts (dispersion).
Before you try
What if raindrops were made of glass? Would rainbows look different?
Try it out
Interactive activity
Sign in to play
Use a Google account (yours or a parent’s) to unlock this simulator. We store only your name and email so your favourites and progress follow you.
Signing in needs an internet connection. Once you are signed in, simulators also work offline.
Free preview
Loading controls…
What happened?
Move a control to see what changes and why.
The beam is treated as a single ray meeting a flat surface. Real light spreads out, reflects a little at every surface, and raindrops are round rather than flat.
Something went wrong
This simulator could not load. Check your connection and try again.
Try these ideas
- Set the angle to 0°. Does the light still bend?
- Switch between water and diamond at the same angle and compare.
- Turn on white light and find which colour bends the most.
Why it works
Light travels more slowly in water or glass than in air, so when a beam enters at an angle it bends. The bigger the angle and the “denser” the material (higher refractive index), the more it bends. Diamond bends light the most, which is why it sparkles.
White light is a mix of colours. Each colour slows down a slightly different amount (violet bends more than red), so a prism or a raindrop spreads white light into a rainbow. This simulator draws the real refracted angle for each colour using Snell’s law.
Check your understanding
Question 1 of 3
What happens to light when it passes from air into water at an angle?
Which colour of light bends the most in a prism?
Which material bends light the most at the same angle?
Explain it in your own words
What changed? Why did it happen? Where might you notice this in everyday life?
For parents & teachers
- Put a pencil in a glass of water and look from the side. Why does it look bent?
- Ask: where is the Sun when you see a rainbow: in front of you or behind you?
- Spray a fine mist with your back to the Sun and look for colours.