Final answer:
Rain on an aircraft windshield causes the view to appear distorted and blurry due to differing refraction of light by water and glass, and atmospheric conditions can further blur the image.
Step-by-step explanation:
Rain on the aircraft windshield can cause the view to appear distorted and blurry. This occurs because the rainwater and the glass have different optical properties, which affects how light passes through them. Light is refracted or bent differently by the water and the glass, leading to a distorted image of the object being viewed. This effect can be likened to looking through a glass of water, where the refraction of light by both the glass and the water alters how the viewed object appears. Moreover, atmospheric conditions such as turbulent air can further distort the view, often described as 'bad seeing' in astronomy, where celestial objects appear blurry due to the twisting and bending of light rays.