4 ms·

You don’t use wood for light... wood burns at too low a temperature to be good for illumination, since radiant energy goes as temperature ^4, so in general lamp

• peteretep 6y ago
  > You don’t use wood for light Not for reading light, perhaps, but this starts with the contention that people had to go to bed when the sun set because you couldn’t see anything. Huddling around a fire into the night on the other hand is probably a human activity as old as fire itself.
  • bodhiandpysics1 6y ago
    obviously people stayed up at night before the invention of electric lighting (there is a reason we call it burning the midnight oil!). People generally however, didn't have open fires in their houses. For one thing, in the middle east, the southern mediterranian, India, and southern china, you don't need to burn fuel for heat. An open fire is also an inefficient way of heating a houser. People used enclosed ceramic or metal stoves, or put screens in front of open hearths to prevent energy from being lost as light. Also, while cutting wood isn't terribly time conusming, much of europe, particularly in the south and east, and almost all of central, southern, and western asia lacks good wood to burn for a fire! People, especially the poor, needed to conserve firewood for cold days, when they needed to be active, and couldn't bundle under covers
    • balfirevic 6y ago
      > to prevent energy from being lost as light. You don't lose any energy from fire just because it's emitted in visible spectrum.