" We have entered the Age of Light. The ages of steam and coal are long gone. With oil clinging to power, light is emerging as our deus ex machine. Light goes where nothing else can, gets there faster than anything else could, and brings back the images. If there are limits to light, other than its cosmic speed limit, we have not tested them. If there is a final answer to the question "What is light?" we have not found it. "
― Bruce Watson , Light: A Radiant History from Creation to the Quantum Age