What you need to know about EMP weapons (opens in new tab)

> Worry about cell towers, not cell phones.

The grounding is usually required to meet a standard and is tested during the towers installation. There are also coaxial surge arrestors and isolators that get used along the span.

Some of the site to site communications equipment has no ground component other than a PoE switch. The ethernet interface, radio, and antenna are all in a single packaged unit installed at height on the tower.

I did run through the whole thing. It doesn't actually say anything at all about what is or is not vulnerable, it's just a bunch of military standards and procedure about how to test for things and what to test, and some vague stuff about potential ways to protect things and what large military hardware they'd like to test.

Curiously, all of the links people have thrown out in this thread seem to prove exactly what I said - there's damn little available to the public in the way of documented experiments on real hardware for EMP susceptibility.

I don't have any really solid cites for it offhand, but it has been my understanding that small devices aren't vulnerable. I don't know EMPs specifically, but I have been involved in standard EMI testing for approval of consumer-grade electronics, so I know there's already a fair amount of testing for and shielding against EM interference with everyday consumer electronics.

Okay, that's very cool! I don't mean to trash this guy at all, he may well be a real expert in some fields.

However, it is a failure mode that people who are really smart and qualified about one thing can assume they are equally smart and qualified about a bunch of other fields that require their own specific expertise. Alas, it doesn't work that way.

There's nothing wrong with not knowing about some specific technical subject. It is a red flag though when someone takes it as a threat to their identity and self-worth to acknowledge that they don't know much about some particular subject, even if they do know a lot about a different subject.

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.

Note that this testimony is a persuasive presentation, an effort to persuade congress to allocate additional spending for EMP protection. Mr. Wood may indeed be qualified to speak on the subject, but this aspect necessarily colors his speech. It's not like there's a shortage of cases of decently qualified people exaggerating the risks of something in order to get more funding and status for themselves and their pet programs.

What I'd really like is hard data on what is or is not actually vulnerable to these hazards and to what extent, based on hard proof rather than fear-mongering by interested parties, which this doesn't get us any further towards.

From messing about with MR scanners:

An MR Faraday cage attenuates the RF signal about 100db (according to the engineer who built it). Phones work as long as the door is open 1mm or so. Blue tooth works through the cage just fine. Wifi doesn't work very well anywhere near the cage.

MR scanners get nice pictures with the scan door open, but the if the scanner next door has its door open (so 2x scanners running with door open), images are wrecked.

Also, the coastguard sends you grumpy letters if you leave the door open and scan (at 3T).

"(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.

yes, this has been studied: https://web.archive.org/web/20100708230258/http://people.csa...

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

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...

You don't need to google. Simple experience tells you which continent is well prepared to EMP problems, and which not. Where do you have to protect your consumer electronics from lightning strikes and where not? In Europe and Russia you don't have to.

Related, today I learned that modern Android self-sabotages by refuses to reconnect to wifi if location is disabled.

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

> The problem is that the recent government studies that say high altitude can hurt electronics are all made by alarmists.

Was just thinking about how electronics back in the 80s and 90s tended to die from static electricity and similar very often, as they didn't have much built-in protection.

These days almost all transistors and microcontrollers have built-in overvoltage protection, and all serious circuits adds additional external protection like TVS diodes and such, especially for anything connected to cables (which would act as antennas).

So I'm guessing the area which an EMP is effective could be lower these days compared to back in the 80s and 90s?

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.

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/

I think you have to be pretty close to the actual fireball to die within 20ms, and most fireballs would be air bursts 1km altitude or higher.

As I understand it the main reason there isn't instant disintegration out to hundreds or thousands of meters is that as soon as enough initial gamma and X-rays turn surrounding material into plasma most of the energy released goes into fireball formation because the plasma is virtually opaque to all EM and the fireball grows in volume as a plasma until expansion reaches equilibrium with compressed surrounding air, everything at the plasma/gas interface is incandescent and radiates as a black body of ~10,000C which transfers a lot of heat but not sufficient to atomize many centimeters thick objects unless they are very close.

Portions of the towers that suspended initial nuclear tests survived, for example.

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.

>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.

The problem with this strategy is that the "instant death zone" is much much smaller than the "3rd degree burns over 100% of your body" zone.

I don't share your fatalism, but I can't criticize it. It is an understandable position. With that said, if your desire is truly to remove yourself from existence in the aftermath of such an event it is better to have some plan to do so already laid in. The majority of immediate casualties will not be deaths, you are very likely to regret relying on the weapons.

That would also grant you the chance to reconsider whether the resulting world is actually not worth living it -- or at very least to confirm that it is in fact so bleak.

> 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 think it’s important to understand fictional stories, even reasonable speculative ones, will usually have very little to do with actual reality. Don’t base your choices on what you saw in a movie.

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.

nuclear war is a lot more survivable than people make it out to be. if you can get your hands on enough clean water to hide in a basement for a week you'll basically be ok

Fuck that. I’m going to resist dying. I am going to keep those around me, alive.

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

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.

One has to recognize the genre of "Threads" and "The Day After" - they represent suffering porn that has little to do with how actual disasters play out. In "Threads", the way people suddenly lose the ability to speak and rapidly turn into cavemen after a nuclear strike is comical. Kids grunt instead of talk, everyone shuffles around like zombies, and basic things like farming or using tools just vanish. How is anyone supposed to take that seriously? Is that how Cologne, Dresden, Würzburg and Pforzheim, or Hiroshima and Nagasaki looked a decade after they had been destroyed in Allied bombing raids? The truth is that even after infrastructure gets bombed back to the Middle Ages, life remains surprisingly normal, and people quickly rebuild.

Hiroshima in 1957, about a mile from the epicenter of the nuclear strike: https://img.i-scmp.com/cdn-cgi/image/fit=contain,width=1024,...

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.

Russia may be kinda sorta next to North Korea, technically.

But you know who is really next to North Korea and has nukes? China.

It seems weird that Russia would even particularly care to be involved in this scenario, frankly.

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

Yeah, so how are we on the verge of nuclear war?

> your desktop pc already is inside of metal enclosure designed to minimize EM emissions, per UL/CE requirements for electronic devices.

Many desktop PCs have enclosures with one or more sides made of glass or acrylic. That does not seem "designed to minimize EM emissions" to me.

Anyone using that exercise in melodramatics as their basis for probability of nuclear war deserves to be laughed it and subsequently ignored.

Doomsday clock is not an estimate of nuclear risk these days, but includes risks like climate change.

It's kind of like WWI.

Where some minor player commits some act and the entire Western-Russo world spirals out into war. Only this time we use nuclear weapons instead of trenches and cannons.

Would be an interesting case study for Brazilian historians in the future.

Somehow I don't see those as related. Any use of nukes will not be an act of rationality. That's the utter stupidity behind this belief in MAD keeping us safe.

I'd replace "some analysts" with "some alarmists". And unless you're in the hyped-up headline business, the attack fell well short of "devastating".

Plus, the pre-attack triad cred of the https://en.wikipedia.org/wiki/Tupolev_Tu-95 bombers was pretty limited. Notice that they are turboprops. From the 1950's. Hitting hard against the western nuclear powers (US/UK/France) ain't in their talent set.

> it's not impossible that they will eventually.

Please stop believing the ridiculous Russian propaganda.

Using even a single tactical nuclear weapon would be game-over for Putin's Russia.