Question

2 eggs cook in a frying pan, which is sitting over a gas burner.
Is thermal energy being transferred from the metal pan to the eggs by radiation in this image? Why or why not?

Answer 1

Mostly no — not by radiation in any important way. When the egg is sitting on the hot metal, heat flows across the contact surface by conduction (atoms, electrons and phonons transferring kinetic energy). Convection from the hot air/steam and a very small amount of thermal radiation are also present, but conduction through the touching surfaces dominates because direct contact gives a much larger heat flux than emission/absorption of infrared radiation.