Make a Rainbow

 

We usually see rainbows in the sky or in the air after it’s rained, but you can make a rainbow in your home any day you choose. You have everything you need in your house right now to make one.

You can make a rainbow in your living room (or bedroom or kitchen or playroom).

All you need are 4 simple materials:

water

mirror

sunlight (sunlight is better than artificial light for making rainbows)

and a clear bow or cup

(If you have a prism, this will also work really well for making rainbows at home.)

So how do these materials make a rainbow?

A rainbow happens when sunlight passes from air through another material like water or a prism and refracts (or bends). When the light passes through the new material, it changes speed and bends.

So why don’t you just see a bent ray of light?

Because each of the colors (or wavelengths) bends at a slightly different angle. This breaks the white sunlight into the seven colors of the rainbow.

This happens in nature when sunlight passes through water droplets in the air after it’s rained, but you can make this happen in your own home.

To make a rainbow at home, all you need to do is bend sunlight. Sunlight does work best, but you might be able to get a partial rainbow from a flashlight.

First, fill a clear bow with enough water to cover about half of a mirror. Next, prop your mirror at an angle in the water so that about half of it is under water.

Now place your bowl and mirror in direct sunlight so that the sunlight can pass through the water and reflect off your mirror. You might need to adjust your bowl a little to get the position right.

Now all that’s left to do is look out for a little rainbow on the floor, wall, or ceiling.

We were able to create this rainbow on our wall using our bowl and mirror.

And this one on our ceiling after adjusting the angle.

We experimented with different light sources reflecting onto different surfaces.

Here’s the rainbow we got from a flashlight reflecting off our mirror on the the fridge:

And our very small rainbow made from shining a flashlight through a glass of water.

How much fun is that?

Experiment with different light sources and surfaces at home and see what kind of rainbow you can make!

 

Looking for more cool science? Join the Free Trailblazer Club for more free science activities like the Make a Crystal Experiment.