If you do any caving you see this regularly. Deep deep in the cave wherever there’s moisture there’s moss. The tiny tiny amount of light that reflects/refracts

If you do any caving you see this regularly. Deep deep in the cave wherever there’s moisture there’s moss. The tiny tiny amount of light that reflects/refracts into the cave is enough to grow. You can’t really see in that level of light but as you shine the torch around moss everywhere. Hundreds of meters in and around multiple corners and that level of light is enough!