August 26, 2022

Painting by Gravity

Practice Newton’s Law of Inertia at home! All you need is some paint, water, paper and let gravity do the work! Just a warning, it could get a little messy.

In this Discovery on Demand activity, we are focused on the integration of Newton’s Law of Inertia and design by conducting a pendulum paint pour (which is as cool as it sounds!).

Newton’s First Law, or the Law of Inertia, states that an object in motion will stay in motion unless acted upon by another force. In our case, that force will be gravity.

pendulum is a fixed object, hung from a point where it can freely swing back and forth due to the force of gravity, converting its energy into motion—also described as potential energy to kinetic energy.
This project may get a little messy, so you might want to try it outside or make sure you have a drop cloth or old newspapers to put on the ground.

The amygdala is a bundle of important nerve cells deep inside the brain. Everyone has two amygdales—there’s one in each half of the brain. The amygdala works with the parts of the brain that control memory, behavior and emotion, and this tiny group of cells packs a big punch when it comes to emotions, especially stress and fear.

Most people don’t like to feel scared, but humans are fascinated by it! Think of all the spookiness in the month of October. The rush of energy and emotion people get by being scared can be enjoyable in controlled situations, like a scary movie or an amusement park ride.

No matter the source of the scare, the amygdala’s role is the same. The amygdala is like a bridge connecting two very different parts of the brain: the part that controls the body functions you aren’t aware of (like breathing) and the part that “thinks” for you.

This means that when your amygdala gets information that tells you something scary is happening, it can send signals that make your heart race and your breathing get faster, making you feel scared!

Time to Set Up: 15 minutes

Time to Create: Endless!

Ages: All


  • A frame for your pendulum—this can be two chairs facing back-to-back and a broom or a long stick/pole. Make sure your stick is secure before starting this activity to avoid big messes.
  • A paper or plastic cup
  • Something to poke a small hole in your cup
  • Water-based, washable paint
  • Water (for diluting your paint)
  • Two paperclips
  • Scissors
  • Masking tape
  • A washer or sinker for weight
  • String
  • A large piece of paper or a canvas

Design is very similar to science and engineering in that we can keep trying different approaches until we get the desired result. If this activity does not work the way you want it to the first time you try it, identify the problem, correct it and then try it again!


1. Set up the pendulum by attaching a string to the center of the stick/pole at the top.

2. At the end of the string, tie your washer so that it’s about a foot off the ground. You don’t want the washer too close to the ground because you will be attaching your cup to it, and you don’t want it to drag on the ground.

3. Using a pencil, poke a small hole in the bottom of the cup and two holes on the top directly across from one another. Now, take some masking tape and seal off the bottom hole.

4. Use two paper clips to attach the cup onto the washer on the top holes.

5. Position your large piece of paper or canvas below the pendulum.

6. To prepare your paint, mix two parts paint with one part water. It doesn’t have to be perfect; you just want to make sure the paint is runny enough so that it won’t clog the bottom hole in the cup, but thick enough that it won’t all leak out the moment you unplug the hole. Pour the paint-water mixture into the pendulum cup.

7. When you’re ready, hold the cup up, pull off the tape that is plugging the hole and let it go to start swinging.

Test this activity as many times as you would like with different colors to create a variety of pendulum paint masterpieces! Share your creations on social media by tagging @discoveryplacescience.