The explanation asks us to imagine shining a flashlight through a tree, first changing the flashlight brightness and then changing its color. The flashlight is

The explanation asks us to imagine shining a flashlight through a tree, first changing the flashlight brightness and then changing its color. The flashlight is an analogy for a radio transmitter. We all get that they work on same principle but just on different wavelengths. But regardless I can't shine the flashlight in my kitchen drawer at my radio and pick up a signal.