Atmospheric refraction is the bending of light as it passes through the Earth's atmosphere. This occurs because the atmosphere is made up of layers of air with varying densities caused by differences in temperature and pressure. As light travels through these layers with different refractive indices, it bends gradually, resulting in the light not traveling in a straight line but following a curved path. This bending of light explains several observable phenomena such as the apparent shift in the position of celestial objects (e.g., stars appearing higher than their actual position), the twinkling of stars, and mirages. It is similar in principle to how light bends when passing between air and water or glass, but in the atmosphere, this change is gradual due to the continuous variation in air density with altitude. Atmospheric refraction is important in astronomy and navigation, as it affects how objects are seen near the horizon and requires corrections for accurate observations.
