Rainbow pride flags

Make a rainbow for Pride

race, gender, human rightsJohn Gordon, Content DeveloperJun 18, 2020

It’s Pride Month, everyone!

Pride Month is all about celebrating the dignity, equality, and accomplishments of lesbian, gay, bisexual, transgender, and queer people. It’s a joyous affirmation of the value and the rights of people whose value and rights have historically been denied and oppressed—part of the reason June is Pride Month in the US is to commemorate the Stonewall Riots of June 1969, when protesters fought back against targeted police raids on New York City’s gay community.

The rainbow flag is one of the most recognizable symbols of Pride, and you can help celebrate by making your own rainbow decoration with one of these science projects. There are many variations of the flag, each using different colors and numbers of stripes to symbolize different groups and aspects of the LGBTQ+ community, so don’t worry about getting your decoration exactly “right.” However it turns out, it can be your unique celebration of your neighbors, your friends, your family, or yourself!

Want to make a big, bright rainbow inside your home . . . but you think your parents, roommates, or landlord just maaaybee don’t want you splashing paint all over the walls? This activity lets you paint with light!

Watch the video for the full instructions, but you’ll need:

  • Water

  • A bowl

  • A small mirror (small enough to fit in the bowl)

  • A flashlight or cellphone (or some strong sunlight—I made the rainbow in the photo with a sunbeam in my kitchen)

The host of the video explains what’s happening, but the short version is that the white light of your flashlight (or the Sun) is made up of all colors (or wavelengths) of light blended together. The light bends when it hits the water, but the different colors/wavelengths bend at slightly different angles, causing them to separate. The separated light hits the mirror and reflects out of the bowl as a rainbow!

A quick science note on the video—the host’s explanation is good, but the video accidentally mislabels amplitude as wavelength. Amplitude is the distance from the top of a wave to its bottom, and wavelength is the distance from the top of one wave to the top of the next wave!

Want to make a little, bookmark-sized rainbow? Try this “thin films” activity.
You can find detailed instructions here, but to get started you’ll need:

  • A shallow dish or pan

  • Strips of black paper

  • Clear nail polish

“Thin film” materials create an iridescent rainbow effect because the thickness of a reflective material changes the way different colors of light reflect. Here, the super thin layer of clear nail polish on the paper has tiny variations in thickness, so colors reflect differently across the variations. This is the same reason oil or gas on a puddle can look like a rainbow; the oil spreads out into a very thin layer on top of the water, creating an uneven reflecting surface.

(Image from Pussreboots on Flickr, CC-BY 2.0)

How about experimenting with food coloring to make a rainbow in a jar? Try this activity!
Or for a similar experiment that uses a pan of milk instead of a jar of water, try this activity!

All you need for these are:

  • Food coloring

  • Water or milk

  • A glass jar or dish

  • Shaving cream (for the jar activity)

  • Paper towels (for cleanup)

These won’t last long as decorations, but they’re pretty and fun, and you can learn about how colors and materials mix!

If you want to make some marbled rainbow cards, check out this activity! This one requires more materials and will take longer to complete, but you can make some nice cards to give out for Pride. You’ll need:

  • Two large plates

  • Shaving cream (NOT gel)

  • Liquid food coloring (at least two different colors)

  • White paper or card stock

  • Medical dropper/eye dropper

  • Scissors

  • Spoon

  • Toothpick

  • Jumbo craft stick

  • Paper towels

  • Spray bottle

  • Water

  • Iron (optional)

  • Vegetable oil (optional)

  • Rubbing alcohol (optional)

For more on the history of the rainbow Pride flag and the artist who designed the first version, check out this online exhibition.

And if you want to learn about LGBTQ+ people working in science today, take a look at this post Being out in STEM!

Have a happy, safe, and fun Pride month!