Lava lamp

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A lava lamp is a decorative lamp that creates moving blobs inside a glass bottle. It was invented in 1963 by British entrepreneur Edward Craven Walker, who later founded the Mathmos company. The bottle holds wax and a clear liquid; a small bulb at the base heats the mixture. As the wax heats, it becomes lighter and rises through the liquid; it cools, becomes denser, and sinks back down, producing slow, glowing blobs that look like lava. The lamp comes in many colors and shapes and became a symbol of 1960s and 70s counterculture.

The basic recipe has changed over time. Early versions mixed water, mineral oil or another liquid with wax, and sometimes carbon tetrachloride to adjust density. Carbon tetrachloride is toxic and was banned for US use in 1970, so modern lamps do not use it. The exact mix is a trade secret. The effect relies on a Rayleigh–Taylor instability: hot, rising blobs meet cooler liquid and merge as they move. If you shake the lamp while the wax is melted, the fluids emulsify and the lamp looks cloudy; once it settles, the blobs reform.

In 2015, a design using ferrofluid instead of wax was introduced. The Lava lamp’s history includes several business moves. Walker observed a bubbling egg timer in a pub, which inspired the idea. Crestworth released the first Astro lava lamp in 1963. US and UK rights passed through several companies, including Lava Manufacturing Corporation, Lava World International, and Lava Lite LLC, before production moved to China in 2003 and later changes in ownership. In Britain, the company was renamed Mathmos in 1992 by Walker and partners Cressida Granger and David Mulley; Walker remained a consultant until his death in 2000. Mathmos continues to make lava lamps in Poole, Dorset, and has won design awards, including recognizing the Astro lamp’s 50th anniversary in 2013.