Other Activities to Try
Gravity in a Bottle – Liquid Art in Motion

Inspired by: Galaxy in a Bottle – One Little Project

Theme: Explore how gravity pulls and separates liquids of different densities while creating a mesmerizing “galaxy” in a bottle.
https://www.youtube.com/shorts/udFanT1i6zY

Objective:Learners will explore how gravity affects liquids of different densities and viscosities while layering and creating a swirling galaxy in a bottle.

Materials Needed
  • Clear plastic water bottle or small jar (with lid!!!)
  • Water
  • Baby oil or clear cooking oil
  • Cotton balls
  • Glitter and/or star-shaped confetti
  • Liquid watercolor or food coloring (multiple colors)
  • Optional: Sequins, glow-in-the-dark stars, or fine glitter

Instructions:

Discuss Gravity First (Short & Simple):
  • Gravity is what pulls everything toward the center of Earth—including water and oil.
  • Liquids that are heavier (more dense) will sink, and lighter ones will float.
  • In space, there’s microgravity—liquids float and swirl!(Show a short video or image of liquid floating in space if you like.)

Start Layering the Galaxy:
  • Add a layer of cotton balls to the bottom of the bottle to create a cloudy, nebula-like texture.
  • Carefully pour in some water mixed with food coloring and glitter.
  • Add a few more cotton balls, then pour in oil. Watch how the layers separate.
  • Repeat layers of cotton, colored water, and oil. Try layering different colors of water each time.
  • Seal the bottle tightly.

Tilt and Observe:
  • Have learners tilt, swirl, and gently shake the bottle. Watch what sinks, what floats, what swirls.
  • Ask them to look closely at how gravity pulls the water down and the oil separates to the top.

Reflection Questions:
  • “Which liquids stayed on top? Which sank to the bottom? Why?”
  • “What would happen if there was no gravity? Would the layers stay still or mix everywhere?”
  • “What did gravity help create in your bottle?”

Gravity Demonstration
This activity gives learners a hands-on way to see how gravity works—especially how it causes objects to orbit bigger ones (like the Earth around the Sun or the Moon around the Earth).

What You Need

  • A stretchy cloth (like a fitted sheet or spandex fabric)
  • A large ball (like a tennis ball or heavy rubber ball)
  • Smaller balls or marbles
  • Optionally: string and a ball for a second version

What to Do
  • Set up your "space fabric":Stretch the cloth over a table or have a few kids or adults hold the corners so it forms a tight, taut, flat surface.
  • Place your “sun” in the center:Put the heavy ball in the middle—it will make a dip in the cloth like a gravity well.
  • Send planets into orbit:Roll marbles or small balls around the dip. With the right speed and angle, they’ll spiral in or even “orbit” for a bit before falling in!
What It Shows
  • Gravity pulls things toward the most massive object.Just like the cloth curves around the heavy ball, space bends around stars and planets.
  • Orbits happen because of motion + gravity.When you roll a marble, it wants to go straight, but gravity keeps tugging it in—resulting in a curved path.
Alternate Version (No Cloth Needed)
  • Ball & String Orbit Model:Tie a small ball to a string. Swing it in a circle around your hand.→ Your hand is the Sun, the string is gravity, and the ball is a planet in orbit.
Discussion Questions:
  • “What do you think would happen if the Sun disappeared?”
  • “Why don’t the planets fall into the Sun right away?”
  • “What happens when the planet moves too slowly or too fast?”

Video Demo (playlist is found here)

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