[RFEngineer]

“And yes, a well designed EMP device may not be visible.”

There is no way to detonate a nuclear device in the atmosphere and conceal it.

[dhs12345]

Visibly? But I agree, there are ways to detect it without actually seeing it with the human eye. And that is the point. The damaging frequencies are not in the visible band but outside the visible band.

Actually, if you were to design an EMP device, why waste the energy on the visible band of em? Maybe the fact that it is visible is only incidental and the IR and UV bands that might affect electronics are on either side of the visible band. There is xray, microwave, etc. (smaller wavelengths) and as you know the sensitivity of a circuit is based on geometries (physical loop area), distance, amplitude.

There are two levels of compliance — recovery and non-recovery. Overwhelming a circuit to cause the device to reset and reboot (if it has the smarts to recover), and actual damage.

Not good if my driverless car is cruising down the highway at 70 mph and the processor has to reboot vs is fried. Moot either way because you'd be dead.