Industrial · The edge of physics
Smoke-Blind Fire Watch & Post-Hot-Work Sentinel
People wish WiFi could feel the heat of a fire starting after welding work.
We publish what we will not claim — that is how you can trust the rest.
Why the physics says no
Hot rising air changes radio waves so little that the effect is lost in the noise — WiFi simply cannot sense temperature. It is true that smoke does not block WiFi, but there is no thermal signal there to read in the first place.
In the physics: A developing heat source drives a buoyant convective plume; the turbulent hot-air column has a refractive-index deficit that fluctuates, producing characteristic low-frequency amplitude scintillation (0.1-10Hz, distinct spectral slope from human motion) on RF paths crossing it. Smoke and dust are RF-transparent, so the observable survives when optics are gone. Meanwhile presence detection confirms whether a human fire-watcher is actually posted.
Reviewer's verdict: The core observable - RF scintillation from a hot convective plume - is negligible at cm wavelengths; hot-air density changes produce sub-0.1 degree phase perturbation over indoor paths, far below the CSI noise floor. Smoke being RF-transparent is true but irrelevant when there is no detectable thermal signal. WiFi cannot sense temperature.