Advocates of vertical farming say that growing crops in glassy skyscrapers would be a greener way to produce food. But the idea is still unproven, and growing plants indoors requires lots of artificial lighting. Does it really make sense?

Also in this Technology Quarterly:

Monitor - Retinal implants, aircraft without ailerons, the return of turboprops, a new type ofneedle, beefier batteries, a flying saucer dirigible, sniff…based interfaces, floating ships on cushions of air, liquid armour, and who won our Innovation Awards...

Difference engine - Bigger and better than WiFi

Vertical farming - Does it really stack up?

Inside story - Smart structures

Mini nuclear reactors - Thinking small

Satellite wars - Endangered birds

Brain scan - Making data dance