Thick Glass Refraction
Purpose
Demonstrates that optical distortion depends on the refractive index ratio at an interface, not the absolute index. Immersing thick-walled glasses in water dramatically reduces distortion because \(n_{\text{glass}}/n_{\text{water}} \approx 1.13\) versus \(n_{\text{glass}}/n_{\text{air}} \approx 1.5\), revealing the true glass thickness and liquid volume.
Figure 1:
Top: In air, the thick glass walls are nearly invisible and the colored liquid appears to fill the entire bowl. Bottom: Surrounded by water, the reduced index contrast reveals the true wall thickness and smaller liquid volume.