6A40.70: Beer Mug Refraction
Description: This demonstrates refraction at an air/water surface. Reveals the tricks of bartenders.
- Medium sized plastic container
- Three different beer mugs
- Three different food colorings
- Place a drop or two of food coloring in each beer mug. Use a different color for each.
- Fill the beer mug up with water.
- Place them in the plastic container and spread them out.
- Fill the plastic container to about 2/3 the height of the beer mugs (See picture).
- Have students look at the setup.
- Explain that form the water-glass-air path, it looks like the liquid is almost to the side of the beer mug.
- When looking at the water-glass-water path, you can see the inside glass wall of each beer mug.
- This is a common trick used to make the buyer think they are getting more beer than they really are.