The Lava Lamp

No modern decoration better symbolizes the psychedelic 1960s than the lava lamp, which spewed colored blobs in a mesmerizing undulating pattern. The lamps were a hit with counterculture groups, especially hippies, during a tumultuous time of antiwar protests, shocking political assassinations, and a frenzied space race.

Although it might look like real lava, the "lava" in liquid motion lamps isn't lava at all but a special type of wax. The blobs form through a process called Archimedes' principle, which relies on the interaction of two different fluids. The fluids are carefully chosen based on their densities so one tends to float in the other. The lamp works because the heat from a light bulb tucked inside warms the less dense wax, which rises to the top. Once it gets far enough away from the bulb, the wax cools, becomes denser again, and sinks back to the bottom.

Besides the basic ingredient of water and wax, which the original patents list as ingredients, manufacturers add various chemicals to the mixture to achieve their desired lava effect. The ingredients, which are kept confidential, include agents that keep the wax from breaking into bubbles and clumping together as it's heated, and other additives to promote faster rising, more freely floating blobs. According to Haggerty Enterprises, the only official U.S. manufacturer of Lava Lite lamps, the company has sold over seven million lamps worldwide. The lamps are still a popular decorative item and can be found in many shops and dorm rooms.lampe lave