Why does a container full of water appear shallow?
Answer: When a container is filled with water, it appears shallower when viewed from above. This is because water is a dense medium and air is a light-medium. Hence the diffracted rays coming from the bottom of the container are refracted from the denser medium to the thinner medium and become more diffracted. Extending the diverging rays backwards creates a faint reflection of the bottom of the container above the surface. Because of this, the pot full of water appears less deep.