Making Glass Invisible

4.1 based on 321 ratings

Updated on Dec 09, 2011

Grade Level: 5th to 8th; Type: Physics


This experiment makes glass go completely invisible.

Research Questions:

  • What happens to light as it passes through glass?
  • Why are the edges of the glass still slightly outlined?

Glass is see-through, but usually you can still see that it is there. In this experiment we make glass go completely invisible.


  • Baby oil
  • Large clear glass bowl
  • Clear glass cup small enough to fit into the bowl

Experimental Procedure

  1. Fill the bowl with baby oil until the oil has a depth of slightly less than the height of the cup.
  2. Place the cup into the baby oil taking care not to allow oil to pour over into it. You can still see that the cup is in there, right?
  3. Now slowly pour baby oil into the cup. Observe the cup gradually disappearing as it fills with baby oil.

Terms/Concepts: refraction, light, speed of light, invisibility


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