What do we use glass for?

Glass starts your day with a sparkle: a glance at your watch, a gaze through the glaze at the sun or the rain, a frown in the mirror, a song from the shower, as you wash with water trickling down warm from the  solar panels on the roof. Glasses pack the breakfast table, which might, itself, be made from smoked glass, and there are bottles and jars of all shapes and colors. Making breakfast in your kitchen, you might be using a glass-ceramic cooktop or a  microwave with a metal-lined window to keep the waves inside. Maybe you're watching croissants warm through the Pyrex oven door? (And is that a glass teapot?)

When you check your email over breakfast (bad habit), speed-of-light Internet data zips  to your home through optical fibers, just as sunlight streams through the heat-reflective windows that keep you cool. You read the words through the glass LCD panel of your laptop or the toughened gorilla glass of your smartphone, both charged by solar energy from photovoltaic panels on the roof. Talking heads are muttering at you through the TV screen in the corner.

Then you set off for work or school, in a glass-wrapped car, bus, train (perhaps even helicopter), hunched under low-energy lamps covered by glass to make them last. If you're driving, the highway you're roaring down could be made from aggregates and asphalt including recycled glass; even the white stripes down the middle use tiny glass beads to make them shine in your headlights. Maybe you drop in the bank or the post office on your way, smiling at the cashier behind her bulletproof window, as you make a quick copy of your driving licence (which you carelessly leave behind on the glass plate of the photocopier).

If it's a modern building, your office or school might be a mini glass cathedral; we think of glass as brittle and fragile, but toughen it the right way and you can make walls, floors, roofs, and staircases from it; shops show their wares through huge, laminated panels, polished to perfection.

And that's only a tiny selection of the things glass does for us. There are loads more places you'll find it hiding, from the bulbs in  thermometers and the cermet fillings in teeth to the fiberglass hulls of boats, the "sandpaper" we use for decorating (which is often glasspaper), and even the strain gauges that warn us when buildings are cracking. Clear, clean, attractive, unreactive, cheap, strong, and effective. What more could you want? Glass is one of those magic materials we absolutely take for granted; everywhere and nowhere—"invisibly transparent," so we don't even notice that it's there!