Liquid Light

Coloured water/alcohol liquid in glass globes inside Galilean thermometers - an abstract macro study in form, light and colour.

A Galilean thermometer is a thermometer made of a sealed glass cylinder containing a clear liquid and several glass globes containing a water/alcohol mix of varying densities. The individual globes floats, rising or falling in proportion to their respective densities and the density of the surrounding liquid as the temperature changes. It is named after Galileo Galilei because he discovered the principle on which this thermometer is based, that the density of a liquid changes in proportion to its temperature, though he himself did not invent the thermometer itself.

The way the light and colour of one globe is reflected in the clear glass of another, enhances its shape and form and also gives it a fluidity and a sense of motion.

The strong directional lighting and reflection of light from the inner and outer edges of the glass surfaces makes them seem almost liquid or molten. It gives them an ethereal look. Photographically boring to look at from afar, close up these these scientific toys make great macro subjects.

They came in a range of sizes, the taller ones like the 15 inch one above being able to hold more globes and thus measure a wider range of temperatures. They were very popular novelties in the nineties though hardly ever seen these days, but can still be found for sale on the interweb if you search for them.