LIVERMORE -- How many firefighters does it take to change the Livermore light bulb?
None, because it never burns out!
The riddle may be a bit tired, but the object of its affectionate punchline is not.
For more than a century, the 4-watt "Centennial Light" -- believed to be the world's longest-burning bulb -- has hung from the modest rafters of Fire Station No. 6 in Livermore.
Notwithstanding other groan-inducing jokes that are bound to follow (including some made recently on Comedy Central's "The Colbert Report"), the light's 110th year of illumination will be celebrated this weekend in style.
Fans from all over the globe are expected at the free event, which will feature book-signings, a film screening, fire trucks, heritage costumes, antique displays, live music, a balloon drop and even a birthday cake.
The fun kicks off Friday with a showing of "Century of Light," a movie about the bulb, at 7 p.m. at the Vine Cinema, 1722 First St. The free party will be from noon to 4 p.m. Saturday at Station 6, 4550 East Ave.
Manufactured by Ohio-based Shelby Electric Company, legend has it that Livermore Power and Light Company owner Dennis Bernal donated the bulb to the fire department in 1901. Volunteers recalled first seeing it lit in the department's hose cart on L Street. Shortly after, it was moved to Station No. 1 on First and McLeod streets and eventually to the East Avenue firehouse.
A community bash was held 10 years ago when it turned 100. Since then, the bulb -- monitored 24/7 by a webcam -- has been the subject of two children's book and featured in two documentaries.
Political satirist and TV host Stephen Colbert plugged it on his show earlier this month (Go to http://vimeo.com/24888314 to see the clip).
"Century of Light" director Chris Lepps will be at the party to answer questions. Cosima Dannoritzer, European director of "The Light Bulb Conspiracy," another film in which the bulb is depicted, will "attend" via live video chat from Spain.
Bulb book authors -- KPIX-TV anchor Juliette Goodrich, "The Little Light Shines Bright;" and Janet Nolan, of Chicago, "The Firehouse Light" -- will also attend.
For details, go to www.centennialbulb.org.
Jeanine Benca covers Livermore. Contact her at 925-847-2125.