Here's why:

* Light: Light is an electromagnetic wave and travels at the fastest speed possible in the universe, approximately 299,792,458 meters per second (about 186,282 miles per second).

* Sound: Sound is a mechanical wave that needs a medium (like air, water, or solids) to travel. It travels much slower than light, at about 343 meters per second (767 miles per hour) in air at room temperature.

Example: You see lightning before you hear thunder because the light from the lightning bolt reaches you much faster than the sound waves.