RE: Another Look At Ultrarich Preppers: How Would Their Methods Work? (Part 1)

An EMP attack is wonderful science-fiction.
However, it is not real.

Take your pretty picture of the affected area by altitude of detonation.
30, 120, 300 miles.

What you do not see there is that ... lets assume they had a device that would make an EMP that would take out computers at 30 miles away. And this is a big assumption.

The one at 120 miles would need to be (120^2 - 30^2) times more powerful.
13,500 times more powerful!!!

At 300 miles, it would need to be (300^2 - 30^2) = 89,910 times more powerful.

Energy transmission of this kind falls off at the square of the distance. And any of the EMP possible devices that I know of are across the street distances. Not even 30 miles.

Also, the electrical grid deals with nearby lightening strikes all the time. Real EMPs.

What will happen is thus: A black flag event. Detonate a large blast somewhere, then send a signal to shut down the electrical grid, computers and smartphones. (Yes, these all have a govern-cement back door to turn them off.) And then blame it on an EMP from whichever boogyman they wish.

That could be. But are you sure your math is right? Square-of-the-distance only applies when the energy is propagated in all directions. (For example: it would apply perfectly to an H-bomb detonated in outer space.)

If that math were to hold up, the area of the 120-miler would be much larger than the 30-miler. Since it isn't, there's a focusing effect that's in play.

Here's what Wikipedia has to say:

In July 1962, the US carried out the Starfish Prime test, exploding a 1.44 megaton bomb 400 kilometres (250 mi) above the mid-Pacific Ocean. This demonstrated that the effects of a high-altitude nuclear explosion were much larger than had been previously calculated. Starfish Prime made those effects known to the public by causing electrical damage in Hawaii, about 1,445 kilometres (898 mi) away from the detonation point, knocking out about 300 streetlights, setting off numerous burglar alarms and damaging a microwave link.[8]

Starfish Prime was the first success in the series of United States high-altitude nuclear tests in 1962 known as Operation Fishbowl. Subsequent tests gathered more data on the high-altitude EMP phenomenon.

The Bluegill Triple Prime and Kingfish high-altitude nuclear tests of October and November 1962 in Operation Fishbowl provided data that was clear enough to enable physicists to accurately identify the physical mechanisms behind the electromagnetic pulses.[9]

The EMP damage of the Starfish Prime test was quickly repaired because of the ruggedness (compared to today)[10] of Hawaii's electrical and electronic infrastructure.[citation needed]

The relatively small magnitude of the Starfish Prime EMP in Hawaii (about 5.6 kilovolts/metre) and the relatively small amount of damage (for example, only 1 to 3 percent of streetlights extinguished)[11] led some scientists to believe, in the early days of EMP research, that the problem might not be significant. Newer calculations[10] showed that if the Starfish Prime warhead had been detonated over the northern continental United States, the magnitude of the EMP would have been much larger (22 to 30 kV/m) because of the greater strength of the Earth's magnetic field over the United States, as well as its different orientation at high latitudes. These calculations, combined with the accelerating reliance on EMP-sensitive microelectronics, heightened awareness that EMP could be a significant problem.

https://en.wikipedia.org/wiki/Nuclear_electromagnetic_pulse