Here's how it works:
* Atmospheric Refraction: Light bends as it passes through different mediums, like air. When sunlight enters the Earth's atmosphere at a low angle (near the horizon), it passes through a greater amount of air. This bending of light causes the Sun's image to be stretched vertically.
* The Illusion: The bottom of the Sun's disk is refracted more than the top, making it appear elongated vertically. This creates the impression of an oval shape.
Important Note: The Sun is actually a sphere. The oval shape we see is just an optical illusion created by the way light interacts with the atmosphere.
