Question

The setting sun is actually visible after it has dropped below the horizon due to the bending of light waves entering the atmosphere at a non-perpendicular angle to the surface, a process known as

Answer 1

The setting sun is actually visible after it has dropped below the horizon due to the bending of light waves entering the atmosphere at a non-perpendicular angle to the surface, a process known as refraction. 

Answer 2

Answer: Refraction

The bending of light waves entering the atmosphere at a non-perpendicular angle is called refraction. When the sun is setting, its light needs to pass through more of the atmosphere as being a very good prism to reach our eyes. Therefore, the sun appears to linger due to the refraction of our atmosphere.