Assign the candle project as an adjunct to such coursework covering such areas as cause-and-effect, Newton’s Law, momentum, gravity and electromagnetism. Split the students into teams to foster cooperation and brainstorming, and let them know how the assignment will be graded on creativity, science concepts and outcome.
Rube Goldberg once said that machines were a “symbol of man’s capacity for exerting maximum effort to achieve minimal results.” Motivate the class with a presentation of Goldberg’s original comic strips, or screen the 1953 Warner Bros. cartoon “Bully for Bugs,” in which matador Bugs Bunny hurriedly constructs a Rube Goldberg device — which includes the candle-like sequence of a match lit from a piece of sandpaper and igniting some TNT — to outsmart a charging bull. You can also bring in the classic game “Mouse Trap,” which relies heavily on Rube Goldberg inspiration.
Brainstorming a Rube Goldberg project can involve working in a linear fashion from start to finish, or strategizing in reverse: first deciding on the outcome, then working backwards to the start. The most basic candle concept is one in which the flame is blown out; this is easier for beginners and less risky than a project that lights the candle or moves a flame one from point A to point B. Help elementary-age students imagine the kind of air that causes a candle flame to go out. The blast of air might come from a popped balloon. A pin would do the popping. A toy car could transport the pin to the balloon. A track would guide the pin-laden car. Other “prequel” steps involve a means to get the car in motion, like a spring-loaded gate opened by a ball-bearing.
By middle school, students may wish to light the candle, which would involve steps to ignite a match, get the flame in proximity to the candle and hit the wick precisely. A team of eighth-graders spotlighted in Nucleus Learning used gears, a domino-line of falling cassette tapes, a zip-lining action hero figure, a foosball table, a vibrating cell phone that dispatches a marble and several inclines before a mousetrap ignites a match that lights the candle.
The suggested minimum number for a Rube Goldberg invention is six steps, though the candle-lighting contraption illustrated in the YouTube video “Best Rube Goldberg Contraption Ever,” in which a candle is lighted midway, is a huge, house-filling project involving dozens of items. Remind your students that their project needs to be portable enough to present in the classroom. For a tangible motivation to present a project, direct students to the Rube Goldberg Machine Contest, presented by Rube Goldberg Inc. This annual competition is open to all grades and skill levels.