'Living concrete' covers buildings in moss

To some people, a lichen-covered facade is an evocative sign of history; to others, it's a mess. But to a team at the Universitat Politècnica de Catalunya, it's a way of regulating buildings' temperature and improving air quality.

Celebrating the bar code

They’re so ubiquitous, we keep forgetting they’re truly everywhere, but we see the bar code on practically everything we buy.