On Food and Cooking

around us is emitting at least some infrared
radiation all the time. The hotter an object
gets, the more energy it radiates in higher
regions of the spectrum. So it is that glowing
metal is hotter than metal that does not radiate
visible light, and that yellow-hot metal is
hotter than red-hot. It turns out that the rate of
infrared radiation is relatively low below
about 1,800ºF/980ºC, or the point at which
objects begin to glow visibly red. Cooking by
radiation is thus a slow process except at very
high cooking temperatures, those
characteristic of grilling and broiling near
glowing coals, electrical elements, or gas
flames. At typical baking and frying
temperatures, conduction and convection tend
to be more significant than infrared radiation.
But as the oven temperature goes up, the
proportion of heat contributed by the radiating
oven walls goes up with it. The cook can
control this contribution by moving the food
close to the walls or ceiling to increase it, or