Objects

Made things, and what their material tells you about when and how they were made.

• Aluminium beverage can

  Half a gram of metal thinner than a hair holding three atmospheres, and the most successful recycling loop there is.

• Bronze socketed axe

  A cast bronze axe head with a hollow socket for the haft — the characteristic tool of the later Bronze Age.

• Catalytic converter

  A ceramic honeycomb coated with platinum, palladium and rhodium — the single largest use of the platinum group metals, and the reason city air stopped getting worse.

• Hand axe

  The longest-used tool design there has ever been — over a million years, across three continents, and nobody is certain what it was for.

• Incandescent lamp

  A wire heated until it glows — and the object that created the tungsten industry, then made itself illegal.

• Joint replacement

  Three materials in one device, each chosen against a different failure — and it fails from the debris rather than the load.

• Lithium-ion cell

  Lithium ions shuttling between two hosts — and the object that turned a list of obscure elements into a geopolitical argument.

• Pencil

  Graphite and clay fired into a rod and glued inside a slat of cedar — and there has never been any lead in one.

• Printed circuit board

  Copper foil on woven glass in epoxy — the substrate every electronic thing is built on, and the reason electronics could be manufactured rather than wired.

• Smartphone

  About sixty elements in something the size of a hand — the most materially complex object most people own, and the one they own most casually.

• Solar panel

  Mostly glass and aluminium by weight, and a fraction of a millimetre of silicon that does the work — with a silver paste on top that is its own supply problem.

• Stained glass window

  Metal oxides dissolved in glass, held in lead, and the reason medieval Europe knew a great deal about colouring materials.

• Transistor

  The most manufactured object in history by an enormous margin, and the reason silicon is refined further than any other material.

• Turbine blade

  One metal crystal, grown to the shape of an aerofoil, film-cooled and ceramic-coated so it can run several hundred degrees above the temperature its alloy melts at.

• Wind turbine blade

  The largest composite structures made, built to last twenty-five years, and there is still no good answer to what happens to them afterwards.