One of the world’s oldest products faces the digital future

AFTER 4,000 years of development, you might assume that just about everything there is to be known about glassmaking has already been found out. Not so. Though the basic recipe of sand, soda and lime remains the industry’s core, first alchemists and then chemists have tinkered with the ingredients over the centuries to produce specialised products. For clarity and sparkle in tumblers and decanters, they added lead. For heat resistance in ovenware, they added boron. For a beautiful blue colour in drinking vessels and decorative bowls, they added cobalt. To increase the speed at which light traverses it, as may be useful in an optical fibre, they added germanium. To reduce that speed, they added fluorine. And so on.

So when, one day in 2006, Steve Jobs, the founder of Apple, came knocking on the door of Corning, one of the world’s biggest glassmakers and based in an upstate New York town from which it took its name, they were ready for him. The request was for a perfectly clear, tough and scratch-resistant glass to cover the screen of Apple’s newly designed “iPhone”. Jobs, being Jobs, wanted it in six months.