Invented in 1963 by a great British inventor, entrepreneur and eccentric, Edward Craven Walker was also the founder of the British lighting company, Mathmos. At a certain moment in the late 1960s, the lava lamp came into lime light. Lava lamps are also called Astro lamps, Mathmos, the company under which the lava lamp was invented is a great British heritage brand founded earlier. Lava lamps have been in continuous British production for over 50 years, the company still takes orders from original 1960s-era owners need replacement bulbs. Since inception Mathmos has not only been working on the modalities of how do lava lamps work, they have also dabbled in screen savers, LED lights and other modern novelties, but the lava lamp has proven its staying power due to its worldwide popularity.
Craven Walker originally developed the lava lamp from a design for an egg timer he saw in a Dorset pub. He saw potential and set about perfecting it and turning into a lamp. He set up a laboratory in a small shed where he mixed ingredients in bottles of different shapes and sizes, then he discovered one of the best containers was a Tree Top Orange squash bottle and its shape defined the Astro Baby Lamp or Astro Mini as it was then called. Over the years the formula original timer were made with orange squash bottles. The Astro came into the market in 1963 was an instant hit becoming one of the defining products of the era.
The lava lamp - under the name Lava Lite- was introduced into the US in 1965. While the initial marketing strategy was not really welcoming, soon it caught up with the teeming younger generation with its undulating glow. By 1967, the Lava lite was being promoted all over the United States with hyperbolic copy that included lines like “like wild – way out!” and Erie, ghostly color plus scintillating, sinous motion… ever-changing – ever-different – never predictable amongst the rest, not so long before it became something of the household
HOW DO LAVA LAMPS WORK?
Firstly, how a lava lamp works may be subjected to its contents. The lamp basically consists of an oily special coloured wax mixture and water inside a transparent vessel the remainder of which contains clear or translucent liquid; the vessel is then placed on a box containing an incandescent light bulb whose heat causes temporary reductions in the density and viscosity of the wax. However, the wax is only slightly denser than the water; therefore it sinks when the lamp is cool. When the lamp is heated, the wax expands and floats, also the warmed wax rises through the surrounding liquid, cools, loses its buoyancy, and falls back to the bottom of the vessel in a cycle. The lamps are designed in different styles and colours.
The lava lamps as most people call it, is a perfect example of liquid motion lamps. The concept of how lava lamps work is solely based on the liquid contents which has different properties, in the lamp you have two liquids which are very close in density and polarity which makes them insoluble in one another. An expression comes saying “oil and water don’t mix”, that is just as suitable as saying oil and water are insoluble in one another. To simplify things, oil and water have very different densities, a volume of water weighs a lot more than the same volume of oil which is the actual basis why they are immiscible liquids, unfortunately they won’t work, so we make use of liquids that are very close in density and are insoluble. Not to search far, a waxy substance is most suitable to be used.
The chemistry behind is that the waxy substance and the water are incredibly close in their densities, the wax is slightly denser, the fact that they are so makes them immiscible compounds, a light bulb is placed under the mixture which heats the lamp up. When the lamp is heated, the dense wax expands and becomes less dense than the water in it. Because it is no longer the densest, it rises to the top of the glass section. When the wax is not directly exposed to the heat it cools, contracts and sinks back to the bottom. This occurs as a result of heat absorption and dissipation that are fairly slow processes, and the density changes we consider here are very minute. The substance used in the lamp is paraffin, paraffin is a wax-like hydrocarbon, the wax is not like beeswax which is an ester and the hydrocarbon used here is likely to have twenty to thirty carbons in the molecule. There are few variations of the lava lamp which include a colloid suspension. This kind of lamp uses the heat the same way, to move the liquid throughout the cylinder. Having the colloid gives the lamp “a swirling pearlescent effect”. There are also glitter lava lamps that use glitter instead of “lava”.
What Makes Lava Lamps flow?
If you can recall, there are two main components in the lava lamp: a wax compound and liquid compound. The wax is said to be a blend of paraffin and perchloroethylene (PERC aka dry cleaning fluid or brake part cleaner). The liquid part is a mixture of distilled water, pure salt, antifreeze (ethylene glycol) and a coloring agent. The two different blends are then sealed inside a heat-resistant glass container, which is then placed upon the heat or light sources usually a 40-watts or 50-watts light bulb. The exact ratios of all the components in both the water and wax elements need to be carefully calibrated to align their specific gravities to make the lava lamp work as expected and to not have the wax break up into little blobs or just hang in place.
HOW LAVA LAMPS WORK?
A classic lava lamp contains a standard incandescent or halogen lamp which heats a tall (often tapered) glass bottle. A formula from 1968 U.S patent comprises of water and a transparent, translucent or opaque mix of mineral oil, paraffin wax, and carbon tetrachloride. The clear water or mineral oil can at times be coloured with transparent dyes. Common wax has a density which is much lower than that of water, and would causes it to float on top under any certain temperature. However, carbon tetrachloride is heavier than water and is added to the wax to make its density slightly higher than that of the water. When heated, the wax mixture becomes less dense than the water, because the wax expands more than water when both are heated. It also becomes fluid, and blobs of wax ascend to the top of the glass where they cool and then descend. A metallic wire coil in base of the bottle acts as a surface tension breaker to recombine the cooled blobs of wax after they descend.
Lava lamps in the US market since 1970 do not use carbon tetrachloride, because its use was banned due to its toxicity. The bulb is normally 25 to 40 watts. Generally, it will take 45-60 minutes for the wax to warm up enough to form freely rising blobs. Once the wax is molten, the lamp should not be shaken or else the two fluid may emulsify and the remaining fluid around the wax may become cloudy. After few hours the wax will settle at the bottom and the cycle begins again.
CHEMISTRY AND MECHANICS OF HOW A LAVA LAMP WORKS
The invention relates to the display device comprising of a transparent or translucent glass container for two components which upon the application of heat, which according give rise to display properties. During operation, the two components are in a liquid state, a first component which is suspended in the second component that are immiscible. The said display properties consist of the first component ascending under the influence of the heat circulation in the second liquid component to produce shapes and/or patterns which are fascinating and relaxing to observe, especially if at least one of the components is coloured and the container is illuminated by the heat source which may be an electric light bulb located under the container base. The first component is most likely a solid at room temperature and becomes liquefy at about 25 to 50 C, probably a wax. It may comprise a mineral oil such as Ondina 17 with light paraffin, carbon tetrachloride and a dye and paraffin wax, the second component being water of without a differently coloured dye. The initially solid first component is heavier at room temperature and is therefore located at the bottom, of the container and gets heat from the light bulb below. The second component becomes fluent and, upon continued heating, gives the desired display property. According to the invention, the water or second component contains an additive of a substance which has the effect of raising the coefficient of cubic thermal-expansion of the water alone.
HOW TO MAKE A HOMEMADE LAVA LAMP
As the chemistry and physics behind assembling a lava lamp might look like, coupled with the feelings of watching it glow, with its large coloured bubbles sinking and rising, you can make your own temporary lava lamp with household materials, it is very easy safe and looks very cute.
Needs: Flask or transparent plastic bottle, vegetable oil, water, food colouring, Alka-seltzer (A drug used for relieving heart burn).
What to do in steps
1. Fill the flask or plastic bottle almost to the brim with vegetable oil.
2. Fill the rest of the container with water. The water will sink to the bottom under the oil.
3. Add a few drops of food colouring: you can choose any colour you want. The food colouring is water-based, so it will also sink and colour the water is now at the bottom of the flask.
4. Break an alka-seltzer tablet into a few small pieces, and drop them in the flask one at a time.
5. Watch your lava lamp erupt into activity, as the reactions decelerates, simply add more alka-seltzer.
How did it work?
As I have emphasized, the lava lamp works based on two different basic scientific principles, density and polarity.
The density is the measurement of how compact a substance is- how much of it fits in a certain amount of space. If you measure an absolute equal volume of oil and water, you will find the water is heavier than the same amount of oil, this is because water molecules are packed more tightly and a cup of water actually has more mass than a cup of oil. Reason is because water is denser than oil, it will sink to the bottom when the two are out in the same container. Density is affected by temperature- the hotter a liquid is, the less dense it will be.
Water molecules are “polar” because they have a lopsided electrical charge that attracts other atoms. The end of the molecule with the two hydrogen atoms are positively charged whereas oil molecules are non-polar- they don’t have positive and negative charge, so they are not attracted to water molecules at all, that is why oil and water can never mix.
Real lava lamps use a polar and non-polar liquid just like our homemade. In a real one, however, the densities of the liquids are much closer together than vegetable oil and water, in that case a paraffin wax is used. The denser liquid sinks to the bottom, but the lava lamp light heats it up until it expands and becomes less dense, causing it to rise upward. As it gets farther from the light, it cools down, becoming denser again until it sinks; then the cycle starts all over.
In our home made lava lamp, an alka-seltzer tablet is used instead of a light bulb to power the lamp. The alka-seltzer reacts with the water to produce gas bubbles, which stick to the water droplets. The water and gas combo is however less dense than the oil, so they tend to rise to the top of the flask. At the top, the gas bubbles pop and escape into the air, allowing the dense water to sink back to the bottom again. An alka-selter tablet is re-introduced into the glass container to enable the process continue.