A Shadow of Things to Come

A shadow gives visible evidence of the existence of an object upon which light of one kind or another falls. Take that object away and there will be no shadow. Turn off that light, or place something between that object and the source of light, and the shadow of that object will disappear. A shadow gives proof of the existence of the object, even when the object itself cannot be seen. Someone may be walking closely behind you, while you are looking forward. But the shadow of that person makes...