Capillary Rainbow Walking Bridge

30 mins Ages 4-6 Indoor

A playful, screen-free adventure designed to spark curiosity, sensory exploration, and fine motor skills for kids aged 4 to 6.

Materials Needed

  • • Clear glass tumblers or jars (6 units)
  • • Heavy-duty paper towels (5 sheets)
  • • Food coloring (Red, Yellow, Blue) (1 set)
  • • Water (3 cups)

Pro Tips

  • → Ask your child to predict what will happen in the empty cups before the liquid reaches them.
  • → Fold paper towels into firm 1-inch strips so the liquid wicks upward efficiently.
  • → Leave the setup overnight so the final equilibrium level can be inspected the next morning.

Safety First

Place cups on a waterproof tray to protect tabletop surfaces from food dye.

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Step-by-Step Instructions

1

Step 1

Line up 6 clear glasses side by side. Fill cups 1, 3, and 5 with water; leave cups 2, 4, and 6 empty.

2

Step 2

Add red food coloring to cup 1, yellow to cup 3, and blue to cup 5.

3

Step 3

Fold 5 paper towels into thick vertical strips and bridge each adjacent pair of cups from lip to base.

4

Step 4

Observe the colored water creep vertically up the paper bridges and slowly drip into the empty vessels, mixing new colors.

What they are learning

Capillary action and fluid adhesion Subtractive color synthesis Scientific hypothesis formulation