Make a Pendulum Painting at Home

Get a little messy and turn a swinging cup of paint into a work of art.

 

Materials you'll need

• plastic cup
• utility knife
• string
• thumbtack
• tape
• acrylic paint (2 colors)
• water
• spoon
• paper
• large piece of cardboard
• something sturdy to hang your pendulum from

 

Step-by-step tutorial

Step 1: With a grown-up's help, use a utility knife to poke 4 evenly spaced holes around the top of a plastic cup, just below the rim.

Step 2: Thread string through the holes so the strands cross over the cup's opening. Gather the string ends together above the cup.

Step 3: Flip the cup over and use a thumbtack to poke a small hole in the center of the bottom.

Step 4: Cover the hole with a piece of tape for now so nothing leaks out.

Step 5: Lay a sheet of paper on a large piece of cardboard to catch any splatters. Hang your cup from something sturdy so it dangles above the paper.

Step 6: Pour paint into the cup, add water, and stir with a spoon until the mixture is runny.

Step 7: Peel off the tape and give the cup a push sideways to start it swinging. Watch it paint loops across the paper, then refill it with a second color and swing again to layer your design.

Learn more

Your cup is a pendulum, a weight hanging from a fixed point that swings back and forth. Every time the cup swings away from the middle, gravity pulls it back toward its lowest point. Pushing the cup sideways gets it moving in two directions at once, so instead of a straight line, it traces long ovals called ellipses. With each swing, air resistance and friction steal a little energy, so the ovals slowly shrink toward the center of the paper.

Pendulum art doesn't have to stay on the paper. The Pendulum Art Machine draws detailed geometric spirals that kids can turn into greeting cards and shrink-plastic keychains.