Editing Implosion (mechanical process) (section)

{{Short description|Destruction of objects by self-collapsing}}
{{Refimprove|date=June 2023}}
[[Image:Explosion and implosion.svg|right|thumb|200px|In an [[explosion]] (top), force radiates away from a source. With implosion (bottom), the object collapses upon itself (generally being crushed by an outside force).]]

'''Implosion''' is the collapse of an object into itself from a pressure differential or gravitational force. The opposite of [[explosion]] (which expands the [[volume]]), implosion reduces the volume occupied and concentrates [[matter]] and [[energy]]. Implosion involves a difference between internal (lower) and external (higher) pressure, or inward and outward forces, that is so large that the structure collapses inward into itself, or into the space it occupied if it is not a completely solid object.{{Citation needed|date=April 2011}} Examples of implosion include a submarine being crushed by [[Fluid pressure#Hydrostatic pressure|hydrostatic pressure]]<ref>{{Cite news |date=2023-06-22 |title=Titanic sub: OceanGate co-founder fears there was an 'instantaneous implosion' |language=en-GB |work=[[BBC News]] |url=https://www.bbc.com/news/world-us-canada-65992567 |access-date=2023-06-22 |archive-date=2023-06-22 |archive-url=https://web.archive.org/web/20230622180847/https://www.bbc.com/news/world-us-canada-65992567 |url-status=live }}</ref> and the collapse of a [[star]] under its own [[gravitational collapse|gravitational pressure]]. 

In some but not all cases, an implosion propels material outward, for example due to the force of inward falling material rebounding, or peripheral material being ejected as the inner parts collapse. If the object was previously solid, then implosion usually requires it to take on a more [[density|dense]] form—in effect to be more concentrated, compressed, or converted into a denser material.