EMP dangers? Maybe not so much.

The declassified nuclear test video above describes how the US first discovered electromagnetic pulse (EMP) and began to study it by detonating bombs in space above the Earth. The idea was to create a nuclear anti-ballistic missile (ABM) which could destroy incoming intercontinental ballistic missiles (ICBM's) or conventional bombers, using EMP rather than a direct hit, to fry the incoming missile's electronics. Such systems were indeed built, such as the Nike and Minuteman systems, which proved so effective that they were considered destabilizing and were banned by the ABM treaty of 1972.

Most people who follow the news have probably heard of Electro-Magnetic Pulse weapons, or EMP. The idea is that a surge of electrons, created by a nuclear blast or solar storm, would damage or disable electric circuits in the power grid, computers, and communications, sending society back to the Stone Age.

Indeed, there is a lot of evidence that such a surge could be a serious disaster, such as the infamous Carrington event in 1859, a solar storm which damaged the primitive telegraph system of the time and electrically shocked the operators. Another solar storm in the late 80's burnt out huge grid transformers in Canada, which required months to replace. But the real danger of an EMP is probably less in reality than theory.



A rather nerdy explanation of EMP. Note that the US does not manufacture large electric transformers any more-yet another example of how economic globalization has hollowed out the US's strategic depth.

The threat profile is that North Korea or Iran could detonate a single bomb in the atmosphere and thereby wipe out America's power grid and technology in one strike. It sounds scary until you begin to think it through. Obvious difficulties complicate carrying out such an attack. It would by no means be certain that one bomb could cause that kind of destruction, or enable an attacking country to escape retaliation.

For one thing, military systems have long been hardened against EMP, and the US is making lots of quiet progress hardening the grid. Since any protection against an unlikely EMP is essentially the same as protecting against a far more likely solar storm, there is plenty of motivation to improve EMP defense. There have been several fairly strong solar storms and coronal mass ejections (CME's) recently, none of which has brought down any significant portion of the grid- at least not yet.

There are so many factors an attacking State would have to get just right. The size, timing and placement of the bomb within the Earth's magnetic field is just one set of parameters. Since there are few possible suspects, there is little chance we would not quickly know who did it and retaliate accordingly.

An EMP surge is also not uniform in all directions, but skewed by magnetic fields and other factors. Destruction of equipment could be widespread but not everything in every place would be affected equally. The effects might not be severe enough to justify the risks posed to an attacker.

Defending against an EMP is actually not a complex proposition, merely an inconvenient one. Silly as it sounds, wrapping your cellphone in tin foil will deflect the 50 kilovolts per square meter surge and save your phone. As a radio operator, I have researched how to harden radios against EMP. The primary defense is the installation of electrical shunts, similar to lightning arrestors, in line with antennas and power cables. The more robust the electronics, the better it survives. Most old vacuum tube equipment is very survivable, while low voltage computer circuits are not. At least Armageddon will have good guitar amps for post-apocalyptic punk rockers.



This more elegant than the tinfoil wrap. I keep my radios and coax in metal cabinets anyway. Of course this only works if you know or suspect an EMP is coming. We do have hours of advance notice before solar storms or CME's strike.



This is what EMP does to a laptop and how a fine wire mesh Faraday cage is used to protect it.

As a ham operator I sometimes hear the whirling whistle of a relativistic electron spiraling down to the Earth along magnetic field lines. During a recent CME, the radio noise was tremendous, but didn't make communication impossible. Proper grounding, Faraday cages, and alternate power supplies are the best defense.

Here is a recent video about EMP. It's from a channel called City Prepper.
It's Paranoitainment!