Welcome to Wikipedia

the free encyclopedia that anyone can edit

Picture of the Day
About Wikipedia

Picture of the Day

An oblique shock is a shock wave that, unlike a normal shock, is inclined with respect to the direction of incoming air. It occurs when a supersonic flow encounters a corner that effectively turns the flow into itself and compresses. This photograph shows an oblique shock at the nose of a Northrop T-38 Talon aircraft, made visible through Schlieren photography.

Photograph credit: NASA & US Air Force (J.T. Heineck, Ed Schairer, Maj. Jonathan Orso, Maj. Jeremy Vanderhal)

Recently featured:

About Wikipedia

Wikipedia (IPA: /ˌwikiˈpiːdi.ə/ or /ˌwɪkiˈpiːdi.ə/) is a multilingual, web-based, free content encyclopedia project. Wikipedia is written collaboratively by volunteers from all around the world. With rare exceptions, its articles can be edited by anyone with access to the Internet, simply by clicking the edit this page link. The name Wikipedia is a portmanteau of the words wiki (a type of collaborative website) and encyclopedia. Since its creation in 2001, Wikipedia has grown rapidly into one of the largest reference Web sites on the Internet.

In every article, links will guide you to associated articles, often with additional information. Anyone is welcome to add further information, cross-references, or citations, so long as they do so within Wikipedia's editing policies and to an appropriate standard. One need not fear accidentally damaging Wikipedia when adding or improving information, as other editors are always around to advise or correct obvious errors, if needed, and the Wikipedia encyclopedia software, known as MediaWiki, is carefully designed to allow easy reversal of editorial mistakes.