|MLA Citation:||Bloomfield, Louis A. "Question 850"|
How Everything Works 16 Jul 2018. 16 Jul 2018 <http://howeverythingworks.org/print1.php?QNum=850>.
Like any electromagnetic wave, a microwave has a wavelength (the spatial distance between adjacent wave crests) and a period (the temporal spacing between adjacent wave crests). The electric current that a microwave propels through a metal travels about one microwave wavelength during one microwave period. Therefore, the current can work its way around a hole in the metal only if the hole is significantly smaller than the microwave wavelength. The amplitude of the microwave doesn't matter—increasing the amplitude of the microwave just makes more current flow.