In the same way that time decays your memories of times past, the weather and the environment can physically decay objects in much the same way, be that by corrosive weather conditions or erosive strong sunlight. A while back I placed a random selection of photo prints up on the wall of my back garden with the aim of seeing how they would decay in that environment over a period of 12 months.
The prints were pegged to a piece of old fishing net I found on the beach and initially in the spring not much seemed to happen apart from a little fading of colour. After a wet summer the edges started to wear and some of the prints began to show water damage but it wasn’t until the winter snow and cold the prints really showed wear. One very cold morning I found a huge icicle on one of the prints and the rest covered in snow. In the final months the net fell on the floor due to high winds so it remained there until the summer of 2011 when the experiment ended, 12 months after it began.