Figure of the month: 9 square metres

A seasoned blacksmith is able to hammer a single ounce of fine gold into a flat, transparent surface of 9 square metres with a thickness of 0.000018 cm. Alternatively, this ounce of fine gold – one ounce, by the way, is exactly 31.103 grams – could also be used to make the thinnest possible wire. It would be 80 kilometres long and have a circumference of only 5 micrometres, which is roughly 1 million times finer than an average human hair.

There is no other element on Earth that can be similarly stretched and compressed. Speaking of Earth: encompassing our planet once with gold wire would require a mere 500.9 troy ounces of the precious metal, which would have a weight of 15.58 kilograms.

Gold scores in both fashion and space travel thanks to its malleability

Gold is one of the rarest and, therefore, most precious commodities. For thousands of years, it has been a preferred element in the production of jewellery and fashion accessories. In addition to its singular colour and lustre, gold owes its appeal to its malleability. Without the nearly unlimited elasticity of the precious metal, the price of a gilded picture frame, for example, would be immeasurably expensive. For ornamental use, such as costume jewellery, door handles or fittings, pure gold is processed into gold leaf and alloyed with other metals for stability, as pure gold can be bent manually with little effort.

Gold is also irreplaceable in all kinds of technical areas, even in space travel, where wafer-thin layers of gold on the outside of the space capsule and the visors of astronaut helmets protect against the very dangerous solar radiation in space and ensure stable temperatures within the spaceship. What is more, gold in its most extended, i.e. molecular form, is used in space as a substitute for lubricants between the moving parts of a space capsule, because organic substances such as oil would deform in a vacuum and quickly be destroyed by the intense space radiation. It is for these reasons that gold is also built into all satellites orbiting Earth.

Indispensable asset in various future technologies

Almost all modern electronic devices would be unimaginable without gold. This is due to another special feature of the precious metal: it is practically imperishable and, unlike other electrical conductors, it does not react with oxygen. Electrical wires and contacts in electronic applications are therefore coated with a wafer-thin layer of gold. This is the only way to guarantee a reliable, sustained flow of current at low voltages of 10 volts or less, as is common in many modern electronic devices. This is also the reason why smartphones would not work without gold, as their charging voltage is usually around 5 volts. As regards other excellent electrical conductors such as silver or copper, a minimal oxide layer is formed on their surfaces, which electrical current can only overcome with significantly more than 10 volts.

Nor will future technologies such as self-driving cars  be able to work without gold, and the same is true for innovative wireless applications in industry and consumer electronics as well as for smart wearables such as watches or clothing that detect and analyse physical activity. Additional advantages: gold is not subject to ageing processes, it can be recycled almost indefinitely and practically reused without degradation of quality.

Arnulf Hinkel
Financial journalist