Technique · Fields
Lava
The slow, merging, stretching movement of lava-lamp wax, rising, wandering or swirling, drawn in different materials: wax, glass, chrome, gold, oil, marble, molten rock, jelly, velvet or ink.
Lava is a field drawn for every pixel by the graphics chip. Every piece on Synapse Drip is made from a recipe that layers techniques like this one, and you can change any of it in the Studio.
Good to know
- The wax in a lava lamp is a mixture of paraffin wax and other waxes and oils chosen so that the wax is a little lighter than the liquid when hot and a little heavier when cold; the liquid is mostly water with a little salt or alcohol.
- The blobs of a lava lamp move slowly because the wax is thick and its density differs from the liquid's by only a small amount; a lamp can take an hour or two to warm up before the wax first rises.
- The slow, random, never-repeating movement of a lava lamp is calming to watch, and the lamp has been sold since the 1960s; the same slow merging of soft forms turns up in title sequences and screensavers because it looks alive without being any particular creature.
- The movement is that of a lava lamp, made in 1963 by Edward Craven Walker, a British former pilot, who had seen a homemade egg timer of two liquids in a pub: the wax and the liquid are of almost the same density, so the small change in the wax's density when the bulb below warms it is enough to lift it, and at the top it cools, becomes heavier and sinks again.
The mathematics
- A blob that stretches into a long neck and then breaks into drops is following the Plateau-Rayleigh instability: a thread of one liquid in another is unstable to ripples as long as its circumference, and surface tension then pulls the ripples into drops; it is why a stream of water breaks into drops, and why a lava lamp's wax pinches off.
- Each of the 7 blobs adds a field of (r squared over e squared) to the power 2.6, where e is its distance from its centre measured along its own stretched axes, and the surface is where the sum is 1 or more; because the power is steep, a blob only joins another when it is close, and the join is a neck.
In art
- Light shows made with oil and water between glass plates, projected onto a wall, were a feature of 1960s rock concerts, and the moving, merging colours of this kind of picture are a small version of the same idea.
- Soft forms that merge and part in different materials, chrome, glass, gold, silk and jelly, are a staple of present-day abstract 3D art and wallpapers, because the same simple movement takes on a different character in each.
More ways to use it
Related techniques
Nebula and stars · Liquid · Droplets · Network · Terrain and maps · Neuron · Order to chaos · Fractal tree