A rapid, violent, and uncontrolled release of energy as a result of a chemical or nuclear reaction, which causes a blast wave or shock wave. This is a sharp pressure pulse. An explosion is also accompanied by noise, heat, and light. An explosion as the result of a chemical reaction can be due to a deflagration in which the reaction front moves at less than sonic velocity, whereas a detonation is a chemical reaction that is extremely rapid and the reaction front moves into the unreacted material greater than sonic velocity, resulting in considerable blast damage.