LEDs let archaeologists see the past in a new light

An archaeological excavation is a little like eating a layered cake: Once you have removed a layer, you cannot put it back. The problem becomes even trickier if two layers look almost exactly the same. Researchers from Aarhus University and Moesgaard Museum in Denmark have now developed a relatively inexpensive multispectral imaging system that gives archaeologists more ways of looking at the soil before they dig into it.