Refraction phenomena

Apparent depth. An oar (весло) partly under water looks bent when viewed from above. This phenomenon can be explained by referring to the laws of refraction, and the fact that the brain assumes (визнає) that light travels in straight lines and that the tip of the oar is at 0°. For the same reason, a person’s legs beneath the surface of water appear shorter than they really are when viewed from the air. Also, a stone on a riverbed appears closer to the surface than it really is.

Why the Sun looks oval. The sun loses its round shape when it is near the horizon. Light from the bottom of the sun travels a greater distance in the dense atmosphere than light from the top, so it is refracted more. Thus, the bottom of the sun looks flat and the sun appears oval.

Mirages

Black asphalt adsorbs a lot of heat from the sun on hot days, and warms the layer of air immediately above it. As a result, the density of the air close to the pavement is less than that of the air higher up. This causes light from the sky to be totally intern ally reflected. An image of the sky on the pavement looks like a puddle (калюжа) of water on the road.