Why do Microwaves Make the same patterns as cathedral windows..? Magnetrons use their geometry to create a resonance that constructively interferes and produces frequencies in the Megahertz range. Microwaves can damage DNA in these frequencies, but perhaps cathedrals were doing the opposite. The ambulatory of the cathedral shares the same geometry as the magnetron, and when the silent resonance of the cathedral is amplified, the geometry of the rose window is produced. If amplifying the wrong fr