Well, Kripke can pat himself on the back for his alleged adherence to physics all he wants, but nothing I've seen in any of the exhausting number of trailers and promos for this show have shown a mechanism for or conditions of the global blackout that is at all consistent with EMP.
- The lights go out in a domino-like sequence similar to a rolling blackout, but first local near Illinois, across North America, then worldwide in the span of eight minutes. It's not a series of nuclear or e-bomb
explosions and then instant and simultaneous lights out in the affected regions (and you would need numerous bombs to blackout the entire world).
- The mechanism for the blackout seems to be some kind of computer virus or electronic signal rather than a nuclear explosion, as power can be activated and deactivated at will with a flash drive override device hidden in a pendant.
- If the source of the blackout was nuclear, people would know that was the cause of the EMP and would begin repairing and rebuilding infrastructure and gradually restore power. However, whatever is causing the blackout on the show renders that impossible. It's not a one time event, it's a continuous signal or virus that prevents repair or reactivation of any electronic device without the override in the pendant I mentioned above.
- Important government and military facilities are hardened against EMP, and yet in this show they are all rendered useless and the government is as powerless to act as anyone else. For some bizarre reason the massive stocks of rifles, shotguns, handguns, and (most) grenades the military has which have no electronic parts and would be in perfect working order don't work in the universe, because everyone's been reduced to using swords, arrows, and muskets for some reason in one of the most heavily armed countries on Earth.
So, no, unless there's some kind of magical signal that can't be detected yet can shut down all power systems worldwide (it would have to be mounted on a series of satellites to blanket the Earth yet also would never come down despite no longer being serviced, refueled, replaced, or monitored), or a virus that can interface with every computer system around the world and take over non-networked electronic devices, there's no "realistic" explanation for the blackout on this show, and it's certainly not regular EMP.