The Ultimate Lava Lamp Quiz

Liquid motion lamps made their first appearance in the United States in the 1960s.

There are three components: the lamp, the substance making up the floating blobs, and the substance the blobs float in.

Immiscible means mutually insoluble, meaning that liquid A won't dissolve or mix with liquid B.

Oil and water is a classic example of an immiscible compound, as the oil always rises to the top.

You will see two distinct layers of liquid. The higher density liquid will be on the bottom, pushing the lower density liquid to the top.

So that the blobs can alternate between rising and sinking, you need substances with similar densities.

To change the density of a substance, you change its temperature. Heating it causes the molecules to expand, making it less dense, and cooling it makes it more dense.

When you heat water it expands greatly, because applying heat causes the molecules to spread apart.

The heat turns it into a liquid that is less dense than the liquid it is floating in, and so it rises to the top of the lamp

Because it is now away from the heat source, it cools down slightly. This makes it less dense than the liquid it is in, and so it sinks downward.

Englishman Edward Craven Walker came up with the idea, though it's not certain whether he based it on something he saw in a pub or when developing a complicated egg timer.

The most simple combination is to use oil for the blobs and mixture of 70- and 90-percent rubbing alcohol for the liquid. Even so, you will need to experiment to get the right balance of alcohol.

Don't use a bulb hotter than 40 watts, as it can be hazardous to overheat chemical substances.

It can be expensive to purchase all the materials and it can be dangerous to combine and heat chemical substances.

Edward Craven Walker called his original invention the Astro Lamp.