How far does a space wave extend beyond the horizon?

A space wave extends beyond the horizon by a specific distance based on the concept of line-of-sight communication. This distance can be calculated using the geometric relationship between the transmitter, the receiver, and the curvature of the Earth. For radio waves, the rule of thumb states that the space wave can travel effectively about one-third farther than the line-of-sight distance to the horizon due to diffraction and the wave properties.

This means that if you were to determine the horizon distance, the space wave can extend approximately one-third of that distance beyond the horizon, allowing for effective communication even with obstacles. The factor of one-third is based on practical observational data from propagation studies, making it the most reasonable answer to the question about how far a space wave extends beyond the horizon.