Why Does the Sun Shine? (The Sun Is a Mass of Incandescent Gas) is an EP by alternative rock band They Might Be Giants, released in 1993. The EP is notable for being their first release with a full-band lineup, rather than only the two original members (John Flansburgh and John Linnell) performing. It was also released as a single on 7" vinyl.
All of the songs on the EP are cover versions, except for one. The title song is a cover of a song by Hy Zaret from Tom Glazer's 1959 album, Space Songs. The lyrics for the refrain appear verbatim in the 1951 Golden Guide "Stars". They Might Be Giants re-arranged the song in an uptempo version for their 1998 live album, Severe Tire Damage, and their 2009 children's album, Here Comes Science, on which they added the self-penned "Why Does The Sun Really Shine? (The Sun is a Miasma of Incandescent Plasma)", which corrects several factual inaccuracies in the original song. It was also included on the soundtrack to the children's game show Carmen Sandiego: Out of This World.
^Zim, Herbert S. and Baker, Robert H. (1951). Stars. NY: Golden Press. pp. 16 (1975 printing). "The sun is a mass of incadescent gas: a gigantic nuclear furnace where hydrogen is built into helium at a temperature of millions of degrees."