Shadows are created by a physical object blocking light from reaching another object beyond the interfering object. Analyzing my established environs I decided to show what happens when light from another direction interferes.
I had two sources of light (three if you count window light, but that is unimportant here) one is my dorm light in the ceiling providing a constant source of light, the other is a lamp that has three stages of brightness.
Using a Juicy Fruit gum travel cup as the shadow creating object I took four pictures. One with the lamp off and three at its various brightness stages. Even with the camera readjusting to compensate for the light one can see the increasing dampening of the shadow.
The more I increase the intensity of the lamps light the more it directly attacks the shadow, dampening it. We see this effect often if we’re on a street or sidewalk at night and there are multiple street lights on.