
INFRARED_IRRADIATION
The Inverted Sun
Pure radiant assault from above. An incandescent element irradiates the exposed face with infrared flux scaling to the fourth power of its temperature, searing the zenith plane while the body below remains in shadow.
Voltage is near-maximal — the element glows past 800°C — but current flows only along the line of sight; shadowed faces receive almost nothing. Distance is the resistor: flux falls off sharply with every centimeter from the element.
j* = εσT⁴Where σ = 5.67×10⁻⁸ W·m⁻²·K⁻⁴ — radiant exitance scales with the fourth power of element temperature.
q = εσA(T₁⁴ − T₂⁴)Net transfer between glowing element and substrate surface.
This transmutation leans fire.
Radiant flux drives the exposed face past the browning threshold in seconds while the interior lags far behind. Amino acids and reducing sugars cascade into melanoidins across the irradiated plane only.
140°C – 180°CSurface lipids liquefy and migrate under direct infrared exposure, basting the zenith face. Rendered fat approaching its smoke point flares volatile aromatics — the signature broiler char.
Myosin and actin denature in sequence under the steep one-sided gradient, contracting the protein lattice and expelling juices if exposure outruns the thin-cut envelope.
Top-down radiant heat; short-distance, high-intensity finishing/cooking.
Broiling evolved from ancient cooking methods where food was placed near open fires, but as a distinct technique with overhead heatit became refined with the development of modern ovens in the 19th century. It gained particular popularity in American steakhouses in the 20th century as a way to quickly prepare steaks with a charred exterior while maintaining a juicy interior.