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"Bomb blast" redirects here. For the Bollywood movie, see Bomb Blast (1993 film).
"Explosions" redirects here. For the Ellie Goulding song, see Explosions (song). For the American post-rock band, see Explosions (band).
For other uses, see Explosion (disambiguation).
Detonation of 16 tons of explosives.
Gasoline explosions, simulating bomb drops at an airshow.
Black smoke from an explosion rising after a bomb detonation inside the outside Nahr al-Bared, Lebanon.
Detonation of a MICLIC to destroy a 1km in depth blast resistant minefield in Iraq.

An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases. Supersonic explosions created by high explosives are known as detonations and travel via supersonic shock waves. Subsonic explosions are created by low explosives through a slower burning process known as deflagration. When caused by a man-made device such as an exploding rocket or firework, the audible component of an explosion is referred to as its "report" (which can also be used as a verb, e.g., "the rocket reported loudly upon impact".)




Animal bodies can also be explosive, as some animals hold a large amount of flammable material such as animal fat. This, in rare cases, results in naturally exploding animals.[citation needed]


Among the largest known explosions in the universe are supernova, which result when a star explodes from the sudden starting or stopping of nuclear fusion, and gamma ray bursts, whose nature is still in some dispute. Solar flares are an example of explosion common on the Sun, and presumably on most other stars as well. The energy source for solar flare activity comes from the tangling of magnetic field lines resulting from the rotation of the Sun's conductive plasma. Another type of large astronomical explosion occurs when a very large meteoroid or an asteroid impacts the surface of another object, such as a planet.


Main article: Explosive material

The most common artificial explosives are chemical explosives, usually involving a rapid and violent oxidation reaction that produces large amounts of hot gas. Gunpowder was the first explosive to be discovered and put to use. Other notable early developments in chemical explosive technology were Frederick Augustus Abel's development of nitrocellulose in 1865 and Alfred Nobel's invention of dynamite in 1866. Chemical explosions (both intentional and accidental) are often initiated by an electric spark or flame. Accidental explosions may occur in fuel tanks, rocket engines, etc.

Electrical and magnetic

A high current electrical fault can create an 'electrical explosion' by forming a high energy electrical arc which rapidly vaporizes metal and insulation material. This arc flash hazard is a danger to persons working on energized switchgear. Also, excessive magnetic pressure within an ultra-strong electromagnet can cause a magnetic explosion.

Mechanical and vapor

Strictly a physical process, as opposed to chemical or nuclear, e.g., the bursting of a sealed or partially sealed container under internal pressure is often referred to as a 'mechanical explosion'. Examples include an overheated boiler or a simple tin can of beans tossed into a fire.

Boiling liquid expanding vapor explosions are one type of mechanical explosion that can occur when a vessel containing a pressurized liquid is ruptured, causing a rapid increase in volume as the liquid evaporates. Note that the contents of the container may cause a subsequent chemical explosion, the effects of which can be dramatically more serious, such as a propane tank in the midst of a fire. In such a case, to the effects of the mechanical explosion when the tank fails are added the effects from the explosion resulting from the released (initially liquid and then almost instantaneously gaseous) propane in the presence of an ignition source. For this reason, emergency workers often differentiate between the two events.


In addition to stellar nuclear explosions, a man-made nuclear weapon is a type of explosive weapon that derives its destructive force from nuclear fission or from a combination of fission and fusion. As a result, even a nuclear weapon with a small yield is significantly more powerful than the largest conventional explosives available, with a single weapon capable of completely destroying an entire city.

Properties of explosions


Explosive force is released in a direction perpendicular to the surface of the explosive. If a grenade is in mid air during the explosion, the direction of the blast will be 360°. If the surface is cut or shaped, the explosive forces can be focused to produce a greater local effect; this is known as a shaped charge.


The speed of the reaction is what distinguishes an explosive reaction from an ordinary combustion reaction. Unless the reaction occurs very rapidly, the thermally expanding gases will be moderately dissipated in the medium, with no large differential in pressure and there will be no explosion. Consider a wood fire. As the fire burns, there certainly is the evolution of heat and the formation of gases, but neither is liberated rapidly enough to build up a sudden substantial pressure differential and then cause an explosion. This can be likened to the difference between the energy discharge of a battery, which is slow, and that of a flash capacitor like that in a camera flash, which releases its energy all at once.

Evolution of heat



Initiation of reaction

A chemical explosive is a compound or mixture which, upon the application of heat or shock, decomposes or rearranges with extreme rapidity, yielding much gas and heat. Many substances not ordinarily classed as explosives may do one, or even two, of these things.

A reaction must be capable of being initiated by the application of shock, heat, or a catalyst (in the case of some explosive chemical reactions) to a small portion of the mass of the explosive material. A material in which the first three factors exist cannot be accepted as an explosive unless the reaction can be made to occur when needed.


Fragmentation is the accumulation and projection of particles as the result of a high explosives detonation. Fragments could be part of a structure such as a magazine. High velocity, low angle fragments can travel hundreds or thousands of feet with enough energy to initiate other surrounding high explosive items, injure or kill personnel and damage vehicles or structures.

Notable explosions

Chemical explosions

Nuclear testing

Use in war

Volcanic eruptions


Classical Latin explōdere means "to hiss a bad actor off the stage", "to drive an actor off the stage by making noise", from ex- (“out”) + plaudere (“to clap; to applaud”).. The modern meaning developed later:[3]

  • Classical Latin: "to drive an actor off the stage by making noise" hence meaning to "to drive out" or "to reject"

In English:

  • Around 1538: "drive out or off by clapping" (originally theatrical)
  • Around 1660: "drive out with violence and sudden noise"
  • Around 1790: "go off with a loud noise"
  • Around 1882: first use as "bursting with destructive force"

See also


  1. ^ Kissane, Karen (2009-05-22). "Fire power equalled 1500 atomic bombs". The Age. Melbourne. 
  2. ^ Dubnikova, Faina; Kosloff, Ronnie; Almog, Joseph; Zeiri, Yehuda; Boese, Roland; Itzhaky, Harel; Alt, Aaron; Keinan, Ehud (2005-02-01). "Decomposition of Triacetone Triperoxide Is an Entropic Explosion". Journal of the American Chemical Society. 127 (4): 1146–1159. doi:10.1021/ja0464903. PMID 15669854. 
  3. ^ wikt:explode#Etymology