The phenomenon you're referring to is often cited by some individuals as evidence against the notion of a curved Earth. However, it is important to understand that this phenomenon can be explained by the properties of light and the limitations of human perception, rather than refuting the concept of a curved Earth. Here's an explanation:
Atmospheric Refraction: Light rays passing through the Earth's atmosphere can be refracted or bent due to variations in air density. This phenomenon is particularly noticeable near the Earth's surface. When light travels from a less dense medium (such as air) to a denser medium (such as water or denser air closer to the surface), it bends toward the denser medium. This bending of light allows objects to become visible even when they are technically below the line of sight.
Viewing Angle and Perspective: When viewing distant objects through a telescope, the viewing angle and perspective can play a role. As the observer looks through the telescope, the light entering their eye or camera lens can be influenced by atmospheric conditions and refraction, allowing them to see objects that would otherwise be obstructed due to the Earth's curvature.
However, it's important to note that these optical phenomena do not fundamentally negate the concept of a curved Earth. They are well-understood effects explained by the laws of physics. Over vast distances or when observing large areas, the curvature of the Earth becomes evident and observable. For example, when viewing ships at sea, their hulls disappear first due to the curvature of the Earth, and only the masts or taller structures remain visible.
Scientifically, numerous observations, measurements, and experiments provide overwhelming evidence for the Earth's curvature. Satellite images, photographs from space, and circumnavigation of the Earth are just a few examples that consistently support the concept of a spherical Earth.