4. Time (Tribute to Atget)

How does time affect my camera?

I wanted to see if a digital camera could take two identical pictures.

I took two pictures of a fountain photographed by Eugène Atget in 1900.

Fountain, rue Garancière, Paris, 1900, Eugène Atget
Musée Carnavalet: Histoire de Paris, CC0 Paris Musées

On the computer, I calculated the difference between these two photos that seem to be identical. The result is an image:

As the difference between these two pictures is not zero, it means that the sensor of my camera cannot take two identical pictures.

Can I trust my camera to be consistent over time?