In 1902, the British physicist Oliver Heaviside independently postulated the existence of the ionosphere, a layer of the Earth’s upper atmosphere that is ionized by solar radiation. Heaviside theorized that this layer could reflect radio waves back to the Earth’s surface, thus enabling long-distance radio communication. This concept, along with similar ideas proposed by the American electrical engineer Arthur E. Kennelly around the same time, led to the term “Heaviside-Kennelly layer” being used to describe the ionosphere. The existence of the ionosphere was later experimentally confirmed, and it became a fundamental element in the understanding and development of radio wave propagation, significantly impacting both amateur and commercial radio communications.
