A ripple tank doesn't actually demonstrate refraction. Refraction is the bending of waves as they pass from one medium to another, like light passing from air to water. While a ripple tank does produce waves, these waves are confined to the same medium (usually water).

Here's why a ripple tank can't demonstrate refraction:

* No change in medium: The waves in a ripple tank are always traveling through the same medium - water. For refraction to occur, the waves need to pass from one medium to another, like from water to glass or from air to water.

* Similar wave speed: The speed of the waves in a ripple tank is relatively constant throughout the tank, as the depth of the water is usually uniform. Refraction happens because the speed of the wave changes as it enters a new medium.

What a ripple tank DOES demonstrate:

* Wave reflection: Waves bouncing off obstacles, like a barrier in the ripple tank, show reflection.

* Wave diffraction: Waves spreading out as they pass through an opening (like a slit or gap) show diffraction.

* Wave interference: When two waves meet, they can interfere, creating patterns of constructive and destructive interference.

To demonstrate refraction, you'd need a different setup:

* You could use a laser to create a beam of light and then shine it through a prism or into a tank of water. The light would bend as it passes from air to the denser medium, demonstrating refraction.

Let me know if you'd like to learn more about reflection, diffraction, or interference!