Vanishing Rods

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This is a quick activity/demonstration that introduces learners to the concept of index of refraction. Learners place stirring rods in a jar of water and notice they can see them clearly. They will be surprised when they place the stirring rods in a jar of vegetable oil and the rods appear practically invisible! This is a dramatic demonstration that effectively illustrates how light can bend and fool the eye. [Activity is publicly available through a web crawler capture on]

Quick Guide

Preparation Time:
Under 5 minutes

Learning Time:
Under 5 minutes

Estimated Materials Cost:
1 cent - $1 per group of students

Age Range:
Ages 8 - 18

Resource Types:
Activity, Demonstration


Materials List (per group of students)

  • Four or more Pyrex glass stirring rods
  • Two clear plastic or glass containers (like 16 ounce mason jars)
  • One container of Wesson Vegetable Oil
  • Tap water


  • Life Sciences
    • Human Senses and Perception
      • Vision
      • Perception
  • Physical Sciences
    • Vibration and Waves
      • Light and Optics
    • Light and Optics
      • Reflection and Refraction
  • The Nature of Science
    • The Scientific Process
      • Conducting Investigations


To use this activity, learners need to:

  • see
  • touch

Learning styles supported:

  • Involves hands-on or lab activities


Access Rights:

  • Free access



  • All rights reserved, Little Shop of Physics, 2009