Believe it or not, that beloved 1960s relic that once cast a warm, unnatural glow on hippies everywhere is officially 50 years old today. And even though you may still see lava lamps churning away in basements scattered across the country, they are a very much a product of their time.

The original lava lamp—and the one that shot to fame—was dreamt up by a British inventor named Edward Craven-Walker, who found psychedelic inspiration in none other than a liquid-filled egg timer. Seeing the potential was just part of the equation, though, and it actually took Craven-Walker several years of tinkering before he managed to the perfect ratio of liquid densities that we've all come to know and love.

The beautiful dancing concoction you see when you look at a lava lamp is made up of two insoluble liquids with slightly different densities—the exact makeup of the liquids, however, is a carefully guarded company secret. As the heavier liquid heats up, the density decreases and allows it to rise to the top. Then, since the heat lamp is on the bottom, the liquid cools as it reaches the top of the lamp, increases in density, and begins to sink again—basic physics put to phenomenal effect. But where did the ramous rocket-shaped glass come from? Finally, though, the Astro Lamp was born—this shape being the one most will think of upon hearing the phrase "lava lamp." The epitome of what we now think of as retro-futurism, the sci-fi-inspired shape is a testament to a time when people were just as eager to reach out to the stars as they were to get back in touch with the Earth. The Astro Mini and the Astro Nordic (a strict cylinder) soon followed, and it wasn't long before Craven-Walker and his second wife, Christine Baehr, were told that none other than Ringo Starr was a proud Astro Lamp owner.

Even today, the company behind Craven-Walker's original invention, Mathmos, is still making their signature product using the same methods (at the same southwest Britain factory). And every so often, there's an invariable resurgence in the lamps' popularity as kids rediscover the magical mystery light. Craven-Walker, however, never got to see his legacy reach its half-century marker, as he passed away back in 2000. Still, although Craven-Walker may be gone, his legacy—thanks to the fact that pot-smoking teenagers never really seem to change—will live on.

Sources:

1. Gizmodo:
   50th Year of the Lava Lamp.