This is believed to be the oldest surviving photograph made with a camera. It doesn't look like much at first: a blurry grey view of rooftops and buildings from an upstairs window at Niépce's estate in Burgundy, France.

To make it, Niépce coated a pewter plate with bitumen of Judea, a kind of asphalt that hardens when exposed to light. He put the plate in a camera at the window and waited. And waited. Estimates of the exposure range from several hours to a few days — which is why sunlight seems to fall on both sides of the buildings at once. The sun moved across the sky while the picture was being made.

Afterwards, he washed the plate with solvents; the unhardened bitumen dissolved, leaving an image.

Every photo on your phone, every film, every vintage snapshot in a shoebox, descends from this one grey plate. It's the first time the world held still long enough to be kept.