When something glows from being heated, it emits light in all parts of the spectrum, but will always peak somewhere. For household lamps that still use glowing metal filaments, the bulbs all peak in the infrared, which is the single greatest contributor to their inefficiency as a source of visible light. Our senses detect infrared only in the form of warmth on our skin. The LED revolution in advanced lighting technology creates pure visible light without wasting wattage on invisible parts of the spectrum. That’s how you can get crazy-sounding sentences like: “7 Watts LED replaces 60 Watts Incandescent” on the packaging.
The two versions of him were related the way a body and its shadow were. Connected, yes. Each inextricably related to the other, yes. But not the same thing.
