The Invisible Pink Unicorn (IPU) is the goddess of a parody religion used to satirize theistic beliefs, taking the form of a unicorn that is paradoxically both invisible and pink. She is a rhetorical illustration used by atheists and other religious skeptics, sometimes mentioned in conjunction with the Flying Spaghetti Monster. The IPU is used to argue that supernatural beliefs are arbitrary by, for example, replacing the word God in any theistic statement with Invisible Pink Unicorn. The mutually exclusive attributes of pinkness and invisibility, coupled with the inability to disprove t...

The visible spectrum is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 750 nm. In terms of frequency, this corresponds to a band in the vicinity of 400–790 THz. A light-adapted eye generally has its maximum sensitivity at around 555 nm (540 THz), in the green region of the optical spectrum (see: luminosity function). The spectrum does not, however, contain all the colo...

Microsoft Windows:Steam October 9, 2007PlayStation 3: Microsoft Windows:(retail stand-alone):Rest of WorldApril 11, 2008Xbox Live Arcade: October 22, 2008Mac OS X: May 12, 2010 }} | genre = Sci-fi puzzle-platform game | modes = Single-player | ratings = | platforms = Microsoft Windows, Mac OS X, PlayStation 3, Xbox 360 | media = DVD, digital download | requirements = → See Development section for requirements | input = Gamepad, keyboard and mouse }} Portal is a single-player puzzle-platformer developed by Valve Corporation. The game was released in a bundle package called The Orange Box...

"Lisa's First Word" is the tenth episode of The Simpsons' fourth season. It was first broadcast on Fox in the United States on December 3, 1992. In the episode, as the Simpson family gathers around Maggie and tries to encourage her to say her first word, Marge reminisces and tells the story of Lisa's first word. Elizabeth Taylor appeared for the voicing of Maggie's first word. The episode was directed by Mark Kirkland and written by Jeff Martin. After its initial airing on Fox, the episode was later released as part of a 1999 video collection: The Simpsons: Greatest Hits, and released aga...