How come light travels in straight lines but radio waves spread out?

Answer:
Light and Radio Waves are both forms of Electromagnetic radiation, and propagate at c (that is, the speed of light, 3*10^8m/s). Both light and radio waves can travel in straight lines, or by spreading out, depending on how they are made. For example, a radio dish and a light bulb can both spread out light and radio waves in 360 degrees.
First answer by ShannonMacca. Last edit by ShannonMacca. Contributor trust: 17 [recommend contributor recommended]. Question popularity: 1 [recommend question].