What you need to know about EMP weapons

It should be understood that the largest impact of the Starfish Prime test, knocking out streetlights, was the result of a very specific design detail of the street lights that is now quite antiquated (they were high-voltage, constant-current loops with carbon disc arc-over cutouts, and the EMP seems to have caused some combination of direct induced voltage and disregulation of the constant current power supply that bridged the carbon disks). The required repair was replacement of the carbon disks, which is a routine maintenance item for that type of system but of course one that had to be done on an unusually large scale that morning. The same problem would not occur today, as constant-current lighting circuits have all but disappeared.

In the case of the burglar alarms, it is hard to prove definitively, but a likely cause of the problem was analog motion detectors (mostly ultrasonic and RF in use at the time) which were already notorious for false alarms due to input voltage instability. Once again, modern equipment is probably less vulnerable.

Many of the detailed experiments in EMP safety are not published due to the strategic sensitivity, but the general gist seems to be along these lines: during the early Cold War, e.g. the 1950s, EMP was generally not taken seriously as a military concern. Starfish Prime was one of a few events that changed the prevailing attitude towards EMP (although the link between the disruptions in Honolulu and the Starfish Prime test was considered somewhat speculative at the time and only well understood decades later). This lead to the construction of numerous EMP generators and test facilities by the military, which lead to improvements in hardening techniques, some of which have "flowed down" to consumer electronics because they also improve reliability in consideration of hazards like lightning. The main conclusion of these tests was that the biggest EMP concern is communications equipment, because they tend to have the right combination of sensitive electronics (e.g. amplifiers) and connection to antennas or long leads that will pick up a lot of induced voltage.

The effects of EMP on large-scale infrastructure are very difficult to study, since small-scale tests cannot recreate the whole system. The testing that was performed (mostly taking advantage of atmospheric nuclear testing in Nevada during the 1960s) usually did not find evidence of significant danger. For example, testing with telephone lines found that the existing lightning protection measures were mostly sufficient. But, there has been a long-lingering concern that there are systemic issues (e.g. with the complex systems behavior of electrical grid regulation) that these experiments did not reproduce. Further, solid-state electronics are likely more vulnerable to damage than the higher-voltage equipment of the '60s. Computer modeling has helped to fill this in, but at least in the public sphere, much of the hard research on EMP risks still adds up to a "maybe," with a huge range of possible outcomes.

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"(and it's highly frequency dependent on top of that.)"

Well, sure. Can people inside the cage see outside? (Or a hypothetical person for a small cage.) If so, then clearly, not all frequencies are being blocked. A lot of "Faraday cages" are explicitly designed for radio and deliberately let other frequencies, particularly the visual range, through.

In fact we all have direct experience with that. Our microwaves use a Faraday cage to keep them in. But we can still see through the mesh, and you can tell that the inside can see out because outside light can go in and bounce back out. (That is, while there's probably a light in your microwave, it's obviously not the sole source of light.) Blocks microwaves well, but visible light goes right through the holes.

That seems intuitive, though. EM radiation is either reflected or absorbed, and optimizing for that requires both a pretty complex understanding of RF behavior and generally knowing that materials are generally radiopaque and radiolucent at different frequencies and wattages.

Sometimes we're trying to keep things (eg- information) outside from getting in, and other times we want to prevent things inside from getting out. There are practices to optimize for both that don't rely on "blocking".

Well, I am not sure how you expect redneck prepper types to pick up on enough RF theory to manufacture homemade metamaterials.

Your microwave oven is pretty good at attenuating 2.45 GHz signals.

Do you want to link your answers for comparison? The lightning strike issue seems to be mostly fuses with occasional more serious events. https://ewh.ieee.org/soc/pes/lpdl/archive/4_Bill_Chisholm_pa...

Starfish Prime blew streetlight fuses 900 miles away. I don't think lighting can do that.

I truly, really, forcefully recommend reading the novel "Warday" by Witley Strieber and James Kunetka It takes place in the early 90s, several years after an accidentally limited nuclear exchange between the United States and the USSR. The story traces the journey of two reporters crossing the devastated country and chronicling the stories of survivors and how they got by, while also slowly developing the journalists' own survival narratives.

In a very well written, visceral way, this novel showcases the barbarities that even such a limited nuclear can unleash on a society, like few others I've read. On the other hand it also underscores the hopeful recovery efforts that people are capable of.

For anyone who appreciated those films, I can't imagine them disliking Warday. It's also delivers an unusually powerful emotional punch with its character development, well above the average for apocalypse literature.

One of the frighteningly realistic elements of the storyline is how it describes the nuclear bombardment as "moderate", at least compared to what was intended by the Soviets. However, because a large part of the fallout completely ruins the agricultural capacity of the country, the resulting development of widespread malnutrition turns a later flu epidemic into something truly murderous, causing far more death on top of what the bombs produced.

>Don't dig a hole to hide in, put your lawn chair on the roof and hope you're close enough to ground zero to get a peaceful and dignified end.

If Sarah Connor's dreams taught me anything, it's that there's an optimal middle ground to be had here.

You don't want to be exposed to the flash nor the heat pulse seconds later, because it's pretty much instant blindness followed by your skin melting off.

What you do want is the blast wave that sends large objects plus the pulverized debris with it in your direction, so you probably just get crushed instantly.

I'd only recommend the lawn chair part if you've got a protective suit and flash blinders, in which case the real question is what you're drinking and/or smoking at the time.

If there is a chance at survival, no matter how slim I would take it. Even if it brings me suffering at least I tried to escape death. Whether my end was peaceful or dignified is of no relevance to me, because I won't be around to regret my end.

> Yeah, what I've learned from films like "Threads" and "The Day After" is that you very much want to die in the first 20ms of a nuclear war. Don't dig a hole to hide in, put your lawn chair on the roof and hope you're close enough to ground zero to get a peaceful and dignified end.

That's all fine and dandy if you only have yourself to think about...

I have a nice view of the skyscrapers of a large city some 70 km to the North. Looking at it from my lawn chair probably won't kill me but it could make me blind.

That sounds like a good idea but the physics mean you have a far greater likelihood of painfully regretting that choice; "It seemed like a good idea at the time" will be no solace.

Using an example of a 350kt airburst on NukeMap[0], the fireball radius is 700m with an area of 1.53 km². The Thermal Radiation Radius with 3rd degree burns is 7.67 km with an area of 185 km². The Light Blast Damage Radius is 13.9 km with an area of 610 km². While the numbers will be different for different yields, the basic ratios will be the same.

This means that your person in the lawn chair is highly unlikely to get to unconscious bliss in 20ms. They are 120 times more likely to enjoy the full experience of 3rd degree burns and ~400 times more likely to get significant injury while still being alive.

It seems far better to take shelter and do all you can to survive intact, and help others. If the situation on the other side is intolerably bad, you'll likely be able to find ways to end your situation far less painfully vs being naked against a nuke blast.

[0] https://nuclearsecrecy.com/nukemap/

Funny that you mention "The Day After", I watched that movie in high school then went to lunch in a school that overlooks the Kansas City skyline.

No chance that had anything to do with the panic attack I had when Putin put his nuclear troops on high alert after invading Ukraine. No sir, not at all.

yup. "the survivors are the lucky ones" is fantasy.

You’re going to see the most strongly worded letter in the history of human civilization.

Responding to conventional weapons with a nuke ? Unlikely.

Turkey is a member of NATO.

I don't want to jinx it, but even the most deranged leaders don't want to rule over a nuclear wasteland. And they especially don't want to go down in their history as the worst person who ruined everything for their party.

> I mean, the article is about the EMP wave following a nuclear detonation, I'm not sure there are bigger problems after that, we're already pretty deep into "shit has hit the fan" at that point.

Sure we are in deep trouble, but at that point, but I disagree with your “not sure there are bigger problems after that”: the following problem would be a nuke exploding in your direct vicinity (instead of in high altitude/space where it caused an EMP).

A similar book of this category may be The 2020 Commission Report on the North Korean Nuclear Attacks Against the United States which describes how a series of events, which have separately happened in the past, may lead to NK launching nukes. But it is not framed as the irrational actions of a mad dictator, but a series of coincidences that suggest NK was itself being attacked.

It was not fun seeing the saber-rattling on Twitter after reading, as Twitter does have a significant part in the story.

The book says that that's exactly what it's supposed to be, to inspire people to talk about it. But (also from the book) the war games the USA runs around these situations always end in a massive nuclear exchange. Sure, some specific situations, like the Devil's Scenario, I would imagine might not reflect a real war, but the case the book is making is that reality is far more likely to be closer to the worst case than to a "best case" (whatever that means here).

I think this was a joke related to Jeff’s post xD