In December 2021, the volcano Hunga Tonga-Hunga Ha‘apai erupted, cascading ash and magma onto the islands and people of Tonga. It also sliced a 55-mile gash through the fibre optic cable that carried the internet between Tonga and the rest of the world, cutting the country off almost completely. ATMs didn’t work. Banks ended up having to fly a USB thumb drive with a spreadsheet to track people’s accounts. Businesses ground to a halt. At first, no one could even contact the outside world to let them know they were still alive.

The internet can feel intangible and immaterial; something wafting through the air or whimsically scattered across the electromagnetic spectrum. But Samanth Subramanian’s point in The Web Beneath the Waves is that there is a materiality to it. The internet has a place in the physical world too – in vast underground servers, for example – that we ignore at our peril. 

But perhaps the most important place of all is within the tiny lengths of glass running under our oceans, each no thicker than a hair and packed into bundles ‘no fatter than a garden hose’. These fibre optic cables are wondrous achievements of engineering, designed to allow information to bounce