With its iPhones, watches and forthcoming smart glasses, Apple’s gadgets are increasingly becoming extensions of our minds and bodies. It’s the big tech dream – but could it turn into a nightmare?

By Alex Hern
Illustration by Steven Gregor

At the beginning of the Covid-19 pandemic, Apple engineers embarked on a rare collaboration with Google. The goal was to build a system that could track individual interactions across an entire population, in an effort to get a head start on isolating potentially infectious carriers of a disease that, as the world was discovering, could be spread by asymptomatic patients.

Delivered at breakneck pace, the resulting exposure notification tool has yet to prove its worth. The NHS Covid-19 app uses it, as do others around the world. But lockdowns make interactions rare, limiting the tool’s usefulness, while in a country with uncontrolled spread, it isn’t powerful enough to keep the R number low. In the Goldilocks zone, when conditions are just right, it could save lives.