Call them '60s relics or hippy home accessories, lava lamps have been casting their dim but groovy light on interiors for half a century, having hit shelves 50 years ago today.
A British firm began marketing their original creation in 1963. Since then, millions of models of the much-copied invention have been sold.
The design was created by British inventor Edward Craven-Walker, who was inspired by an odd-looking liquid-filled egg timer he saw in a pub.
The former World War II pilot then spent years transforming the concept into a home lighting accessory, having recognised the potential for such an invention during anything-goes '60s Britain.
"Everything was getting a little bit psychedelic," said Christine Baehr, the second of Craven-Walker's four wives. "There was Carnaby Street and The Beatles and things launching into space and he thought it was quite funky and might be something to launch into."
"I think it's really special to manufacture something that's been invented and made in Britain for 50 years," said Cressida Granger, who became involved with Craven-Walker's Crestworth firm in 1989, renamed it Mathmos in 1992 and gained sole ownership in 1999. Granger went on to enjoy a second wave of success for Craven-Walker's invention during the 1990s. Craven-Walker died in 2000.