How a lava lamp works
Guy Macon
_How does a lava lamp work?_ by Doug Gelbert
A lava lamp works on an easy-to-comprehend physical premise.
The ingredients that work the magic inside a lava lamp are a
trade secret.
Many a veteran exited World War II eager to make up for lost
time and begin working at making his fortune in the post-war
consumer boom. Edward Craven Walker, a Singapore native who
flew reconnaissance missions for the Royal Air Force, was no
different.
One day, while visiting a pub in Hampshire, England, he
became fascinated by an egg-timer on a shelf behind the bar.
The timer was essentially a blob of solid wax suspended in a
clear liquid in a cocktail shaker. Drop the shaker into the
boiling water with your egg and when the wax melted and
floated to the top, the egg was done. As Walker looked at
the egg timer, he saw the lava lamp.
He sought the inventor of the egg timer and discovered that
he had died without patenting it. He spent the better part
of the next 15 years perfecting a way to mass-produce his
'astro lamp.' The theory behind his novelty lamp was
relatively simple - enclose two liquids which are similar in
density and insoluble in one another and apply heat.
The most common insoluble liquids are oil and water.
However, the oil is nowhere near dense enough to achieve the
desired result. What chemicals did Walker use? The recipe is
a trade secret, only the manufacturers of lava lamps know
the exact ingredients. Like the secret formula for
Coca-Cola, scientists can analyze and approximate the
chemicals but can not duplicate the exact recipe.
Once Walker determined the liquids, he assembled his lava
lamp to apply heat via a light bulb in the base. The heavier
of the two liquids absorbs the heat first and begins
expanding. It becomes less dense and this 'lava' rises. As
it rises in the lava lamp it moves further from the heat
source and cools down enough that it once again becomes
heavier than the liquid in which it is suspended and it
falls back towards the base. Since heat absorption and
dissipation is a slow process, all the motion takes place in
slow motion. The lava also is injected with special
chemicals that make it easy for the wax to plop into blobs
when it is stretched to the breaking point. When the lamp is
off, this heavier liquid squishes onto the bottom. The exact
concoction of this potion is what eludes amateur lava lamp
constructionists. If the liquids and chemicals are not
perfectly balanced the result is an explosion of tiny
bubbles or a flow up the side of the container.
By 1963 Walker had all this figured out and began
manufacturing his Astro lamps in a factory in the south of
England. He unveiled it at a novelty convention in Hamburg,
West Germany in 1965. Two American entrepreneurs purchased
the American rights and renamed it the Lava Lite. The
amorphous blob light was an immediate hit in the psychedelic
1960s. Soon more than seven million lava lamps were being
sold each year.
Just as quickly, the fad ended. Before the 1970s were over,
yearly sales were less than 10,000. Most people forgot about
lava lamps unless they were spotted at a garage sale. But
like the lava lamp itself, the cycle of sales was not over,
just sinking to the bottom. In the early 1990s, original
lava lamps from a generation before became cherished
collectibles and sales of new lava lamps once again measured
in the millions annually.
Written by Doug Gelbert
--
Guy Macon
<http://www.GuyMacon.com/>