![1990s Mathmos Astro](https://upload.wikimedia.org/wikipedia/commons/f/f2/1990s_Mathmos_Astro.jpg)
A lava lamp is a decorative
lamp
Lamp, Lamps or LAMP may refer to:
Lighting
* Oil lamp, using an oil-based fuel source
* Kerosene lamp, using kerosene as a fuel
* Electric lamp, or light bulb, a replaceable component that produces light from electricity
* Light fixture, or li ...
, invented in 1963 by British entrepreneur
Edward Craven Walker, the founder of the lighting company
Mathmos
Mathmos is a British company that sells lighting products, most famously the lava lamp invented by its founder Edward Craven Walker. It is headquartered in its factory in Poole, Dorset.
Company history
The Astro lamp, or lava lamp, was in ...
. It consists of a bolus of a special coloured wax mixture inside a glass vessel, the remainder of which contains clear or translucent liquid. The vessel is placed on a base containing an
incandescent light bulb
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows. The filament is enclosed in a glass bulb with a vacuum or inert gas to protect the filament from oxida ...
whose heat causes temporary reductions in the wax's density and the liquid's surface tension. As the warmed wax rises through the liquid, it cools, loses its buoyancy, and falls back to the bottom of the vessel in a cycle that is visually suggestive of
pāhoehoe lava, hence the name. The lamps are designed in a variety of styles and colours.
Lava lamps are often associated with
hippie culture
A hippie, also spelled hippy, especially in British English, is someone associated with the counterculture of the 1960s, originally a youth movement that began in the United States during the mid-1960s and spread to different countries around ...
and
cannabis culture
Cannabis culture describes a social atmosphere or series of associated social behaviors that depends heavily upon cannabis consumption, particularly as an entheogen, recreational drug and medicine.
Historically cannabis has been used an entheo ...
.
Operation
![Blue Lava lamp](https://upload.wikimedia.org/wikipedia/commons/0/0e/Blue_Lava_lamp.JPG)
A classic lava lamp contains a standard incandescent or
halogen lamp
A halogen lamp (also called tungsten halogen, quartz-halogen, and quartz iodine lamp) is an incandescent lamp consisting of a tungsten filament sealed in a compact transparent envelope that is filled with a mixture of an inert gas and a small ...
which heats a tall (often tapered) glass bottle. A formula from a 1968 US patent consisted of water and a transparent,
translucent
In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable scattering of light. On a macroscopic scale (one in which the dimensions a ...
, or opaque mix of mineral oil,
paraffin wax
Paraffin wax (or petroleum wax) is a soft colorless solid derived from petroleum, coal, or oil shale that consists of a mixture of hydrocarbon molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and begins to m ...
, and
carbon tetrachloride
Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC, carbon tet in the cleaning industry, Halon-104 in firefighting, and Refrigerant-10 in HVAC ...
.
[ DISPLAY DEVICE, Smith David George, Mar. 4, 1965]p. 2, line 30 The clear water or mineral oil can optionally be coloured with translucent
dye
A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution an ...
s.
Common wax has a
density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...
much lower than that of water and would float on top at any temperature. However, carbon tetrachloride is denser than water (also
nonflammable
A combustible material is something that can burn (i.e., ''combust'') in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable mat ...
and
miscible
Miscibility () is the property of two substances to mix in all proportions (that is, to fully dissolve in each other at any concentration), forming a homogeneous mixture (a solution). The term is most often applied to liquids but also applies ...
with wax) and is added to the wax to make its density at room temperature slightly higher than that of the water. When heated, the wax mixture becomes less dense than the water, because it expands more than water when both are heated.
p. 1, lines 40 & 45 It also becomes fluid, causing blobs of it to ascend to the top of the lamp. There, they cool, increasing their density relative to that of the water, and descend.
p. 1, line 47 A metallic wire coil in the bottle's base breaks the cooled blobs'
surface tension
Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to f ...
, allowing them to recombine.
Since 1970, lava lamps made for the US market have not used carbon tetrachloride, whose use was banned that year due to toxicity. Haggerty, their current manufacturer, has stated that their current formulation is a
trade secret
Trade secrets are a type of intellectual property that includes formulas, practices, processes, designs, instruments, patterns, or compilations of information that have inherent economic value because they are not generally known or readily asc ...
.
The underlying
fluid mechanics
Fluid mechanics is the branch of physics concerned with the mechanics of fluids ( liquids, gases, and plasmas) and the forces on them.
It has applications in a wide range of disciplines, including mechanical, aerospace, civil, chemical and bio ...
phenomenon in lava lamps is a form of
Rayleigh–Taylor instability
The Rayleigh–Taylor instability, or RT instability (after Lord Rayleigh and G. I. Taylor), is an instability of an interface between two fluids of different densities which occurs when the lighter fluid is pushing the heavier fluid.
Drazin ( ...
.
The bulb is normally 25 to 40 watts. It generally takes 45–60 minutes for the wax to warm up enough to form freely rising blobs, when operating the lamp at standard
room temperature
Colloquially, "room temperature" is a range of air temperatures that most people prefer for indoor settings. It feels comfortable to a person when they are wearing typical indoor clothing. Human comfort can extend beyond this range depending on ...
, and as long as 2 to 3 hours if the room is cooler.
Once the wax is molten, the lamp should not be agitated, or the two fluids may
emulsify
An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Altho ...
, and the fluid surrounding the wax blobs will remain cloudy rather than clear. Some recombination will occur as part of the normal cycle of the wax in the container, but the only way to recombine all of the wax is to turn off the lamp and wait for a few hours. The wax then settles back to the bottom, forming one blob once again. Severe cases can require many heating-cooling cycles to clear.
In 2015, a new design was introduced that uses
ferrofluid
Ferrofluid is a liquid that is attracted to the poles of a magnet. It is a colloidal liquid made of nanoscale ferromagnetic or ferrimagnetic particles suspended in a carrier fluid (usually an organic solvent or water). Each magnetic particle ...
in place of wax.
History
British entrepreneur
Edward Craven Walker had the idea for the lava lamp in 1963 after watching a homemade egg timer, made from a cocktail shaker filled with liquids, as it bubbled on a stovetop in a pub. He hired British inventor David George Smith to develop the device and the chemical formula it required. Smith is credited as the inventor on the original for a "Display Device" filed and assigned to Craven-Walker's company in 1965, and subsequently issued in 1968.
Craven Walker's company, Crestworth, was based in
Poole
Poole () is a large coastal town and seaport in Dorset, on the south coast of England. The town is east of Dorchester and adjoins Bournemouth to the east. Since 1 April 2019, the local authority is Bournemouth, Christchurch and Poole Counc ...
,
Dorset
Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset (unitary authority), Dors ...
, United Kingdom. He named the lamp "Astro" and had variations such as the "Astro Mini" and the "Astro Coach" lantern.
In 1965, Adolph Wertheimer and Hy Spector were intrigued by Walker's product when they saw it at a German trade show. They bought the American rights and began the Lava Manufacturing Corporation in
Chicago
(''City in a Garden''); I Will
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to sell what they called the Lava Lite Lamp. In the late 1970s, US rights were sold to Larry Haggerty, who created a subsidiary of his company, Haggerty Enterprises, called Lava World International, which produced American lava lamps for over 30 years.
In 2003, American lava lamp maker Lava World International (formerly Lava-Simplex-Scribe Internationale) moved its production to China. In 2008, it was acquired by Talon Merchant Capital and its name was changed to Lava Lite LLC. As of 2016, lava lamps were being sold under Lifespan brands in North America. In 2018, the 'Lava Lamp' brand was acquired by toy and gift maker Schylling Inc. of North Andover, MA. who continue to hold the US trademark rights to both the shape and name of LAVA lamp.
When the American rights were sold, Craven Walker retained the rights for the rest of the world, and took on two business partners in the late 1980s,
Cressida Granger
Cressida Granger is a British entrepreneur. She is the owner and managing director of Mathmos, the lighting company founded by Edward Craven Walker, inventor of the lava lamp. Career
Granger took over Mathmos in 1989 and won two Queens Awards f ...
and David Mulley. They eventually took over the company and changed its name to
Mathmos
Mathmos is a British company that sells lighting products, most famously the lava lamp invented by its founder Edward Craven Walker. It is headquartered in its factory in Poole, Dorset.
Company history
The Astro lamp, or lava lamp, was in ...
in 1992. Edward Craven Walker remained a consultant to them until his death in 2000. Mathmos continues to make Lava Lamps and related products. They have won two Queens Awards for Export, and the Best Multi-Media prize at the Design Week awards. Astro lava lamp was launched in 1963 and celebrated its 50th anniversary in 2013.
Mathmos lava lamps are still made in the original factory in Poole, Dorset.
See also
*
Lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...
*
Lavarand, a
random number generator
Random number generation is a process by which, often by means of a random number generator (RNG), a sequence of numbers or symbols that cannot be reasonably predicted better than by random chance is generated. This means that the particular out ...
that used lava lamps
*
Plasma globe
A plasma globe or plasma lamp is a clear glass container filled with a mixture of various noble gases with a high-voltage electrode in the center of the container.
When voltage is applied, a plasma is formed within the container. Plasma filam ...
*
Bubble light
A bubble light is a decorative device consisting of a liquid-filled vial that is heated and illuminated by an incandescent light bulb. Because of the liquid's low boiling point, 39.6°C (103.3°F), the modest heat generated by the lamp causes the ...
References
Further reading
*
External links
How Do Lava Lamps Work?- from
The Straight Dope
"The Straight Dope" was a question-and-answer newspaper column written under the pseudonym Cecil Adams. Contributions were made by multiple authors, and it was illustrated (also pseudonymously) by Slug Signorino. It was first published in 1973 in ...
How Liquid Motion Lamps Work- from
howstuffworks.com
HowStuffWorks is an American commercial infotainment website founded by professor and author Marshall Brain, to provide its target audience an insight into the way many things work. The site uses various media to explain complex concepts, termin ...
What exactly is the goop inside a lava lamp?- from Technology Connections
Lava lamps creators mark 50 years of 1960s icon- BBC News
The history of the original lava lamp- Flow of lava
{{Artificial light sources
Products introduced in 1968
1960s fads and trends
1970s fads and trends
Brands that became generic
British inventions
Hippie movement
Novelty items
Articles containing video clips
Types of lamp
20th-century inventions