Explosion

An explosion is a fast increase in volume and increase in energy made available. It normally makes high temperatures and makes gases. Many natural events can make explosions, such as lightning, volcanic eruptions, meteors, and supernovae. People make explosions mostly by using chemical explosive materials.

A chemical explosion starts pressure waves in the medium where it happens. Explosions are categorized as deflagrations if the pressure waves are subsonic and detonations if they are supersonic. When a detonation happens, the resulting pressure waves are named shock waves.