Which wave phenomenon is characterized by spreading out as they encounter obstacles?

The phenomenon characterized by spreading out as waves encounter obstacles is diffraction. When a wave passes through a narrow opening or around an edge, it bends and spreads out into the region behind the obstacle. This behavior occurs with all types of waves, including sound waves, light waves, and water waves.

For example, when sound waves travel through a doorway, they spread out in the room rather than just traveling straight through the opening. This allows us to hear sounds even when we are not directly in line with the source, illustrating how waves can change direction and spread into new areas.

Understanding diffraction is essential in various applications, such as in the design of audio systems, optical devices, and even in telecommunications, where maximizing signal reach often depends on the diffraction of waves around obstacles.