Day 224
August 12, 2010Watching a Lava Lamp is a very soothing activity…..
The lamp contains a standard incandescent bulb which heats a tall glass bottle containing water (often with glycerol derived additive) and a transparent, translucent or opaque mix of wax and carbon tetrachloride (although other combinations may be used).
The wax is slightly more dense than water at room temperature but is less dense under warmer conditions. This occurs because wax expands more than water when both are heated. When heated, the wax becomes fluid, its relative density decreases, and blobs of wax ascend to the top of the device where they cool (which increases their density relative to that of the water’s) and then descend. A metallic wire coil in the base of the bottle acts as a surface tension breaker to recombine the cooled blobs of wax after they descend.
Singapore-born Englishman Edward Craven-Walker invented the lava lamp in 1963.
In 2004, Phillip Quinn, a 24-year-old of Kent, Washington, was killed during an attempt to heat up a lava lamp on his kitchen stove while closely observing it from only a few feet away. The heat from the stove built up pressure in the lamp until it exploded, spraying shards of glass with enough force to pierce his chest, with one shard piercing his heart and causing fatal injuries.