In what manner do radio waves propagate away from the source?

Radio waves propagate away from the source in a straight line in all directions at once due to their nature as electromagnetic waves. When a radio transmitter emits these waves, they radiate outward spherically from the source, similar to how light spreads from a bulb. This omnidirectional characteristic allows radio waves to cover a vast area around the transmitter. Factors such as obstacles or the earth's curvature can affect how effectively these waves are received, but the fundamental propagation pattern remains as radial and straight-line from the point of origin.