Over the last few years, at the kinds of conferences where the world’s technological elite gathers to mainline caffeine and determine the course of history, Google has entertained the crowds with a contraption it calls Liquid Galaxy. It consists of eight large LCD screens, turned on their ends and arranged in a circle, with a joystick at the centre. The screens display vivid satellite imagery from Google Earth, and the joystick permits three-dimensional “flight”, so that stepping inside Liquid Galaxy feels like boarding your own personal UFO, in which you can zoom from the darkness of space down to the ocean’s surface, cruising low over deserts, or inspecting the tops of skyscrapers. (The illusion of real movement is powerful; your legs may tremble.) You can swoop down to street-level in Cape Town, spot ships in the Mekong river, or lose yourself in the whiteness of Antarctica.

But you don’t, of course. What you do – or what I did, anyway, but watch anyone using Google Earth for the first time, and you’ll see they do the equivalent – is to hurtle across continents to the semi-detached house on the outskirts of York where you grew up, to peer down at a street you know well. In an era of previously unimagined opportunities for exploring the far-off and strange, we want mainly to stare at ourselves.