What is the best lava lamp? It seems that no matter how much culture changes, there’s always a demand for the retro, which is why the playful visuals of a lava lamp never seem to go out of style.

Since it tends to be associated with the shaga- delic 1970s, it is hard to believe the lava lamp is celebrating its 40th birthday. But although it seems somewhat younger, the ultimate retro “light ...