A blast wave is a powerful wave of pressure that travels outward from an explosion. It occurs when a sudden release of energy creates a rapid increase in air pressure, followed by a drop in pressure. This wave can cause significant damage to structures and can be felt over large distances, depending on the size of the explosion. Blast waves are commonly associated with events like nuclear explosions, chemical explosions, and large fireworks. The intensity of a blast wave decreases with distance from the explosion, but it can still pose serious risks to people and buildings in the vicinity.