A lava lamp is a decorative lamp that contains a mixture of oil and wax. When the lamp is turned on, the heat from the light bulb causes the wax to melt and rise to the top of the lamp. The oil then cools the wax and causes it to sink back down to the bottom of the lamp. This process creates a continuous cycle of motion that gives the lava lamp its characteristic appearance.
Lava lamps were first invented in the 1960s and quickly became popular due to their unique and calming effect. They are often used as nightlights or as a way to create a relaxing atmosphere in a room. Lava lamps are also relatively easy to repair, making them a good choice for people who want to save money on home repairs.