The Science of Dating Old Photographs

We all have old family photos that are a bit blurry or faded. But imagine if those photos were over a hundred years old and held clues to major historical events. In the world of Infotosearch, a photo isn't just an image. It is a physical object made of silver and chemicals. Over time, those chemicals move around. Scientists call this silver halide diffusion. By studying how that silver has spread out, they can tell exactly how old a photo is and what kind of air it has been