As I understand it, when there is a nuclear event, it generates x-rays followed by the EMP. The goal is to have warheads in flight to be able to continue to their target, so the strategy is to employ an NED. When an event is detected, the warhead shuts down its electronics for the duration of the EMP, and then powers back up.
With her NED, she uses an ASIC for detection. I might get some details wrong, but the ASIC has a physical array in it, and the x-rays flip bits in the array. When enough bits get flipped, one can infer a nuclear event. Because it is an ASIC it is really small, which has important advantages for space-born avionics.
I genuinely wonder if people who work on this kind of stuff feel conflicted about it regularly, or don't think about it, or feel strongly that they are doing good.
For my mom, at first she was very gung ho about it - arsenal of democracy and the importance of having a strong nation. Now she is having second thoughts, and is looking to follow her passion which is something in the education space.
I doubt this, since the EMP is moving at the speed of light, whereas the delay times inherent in most circuitry and the time required to power down most circuitry would be at least an order of magnitude (most likely more) larger.
Explosions, like all other macro scale phenomena are not instantaneous, they just appear so until an appropriately small time step is applied.
No, "X-Rays" travel at the same speed as the "EMP" - both travel at the speed of light. They're both part of the electromagnetic spectrum.