Why dont they pass through wood, brick, metl, and other stuff? I think it would de better if they could pass through matter except water, coal, wax and few oter elements.
Real neutrons can easily pass through thin metal or concrete walls, but can be absorbed by graphite.
Neutrons simulate atomic particles: The cant pass through because, in real life, they are deflected by these materials. However, some materials are of a lesser densitiy and allow the neutrons to pass through.