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What you need to know about EMP weapons

170 points| flyingkiwi44 | 9 months ago |aardvark.co.nz

206 comments

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[+] ufmace|9 months ago|reply
I'm not sure about most of this. The great majority of the articles and stories about this I've read trace back to layman speculation and disaster porn fiction written by people who have never claimed to actually be informed about how these things work. There's damn little stuff out there that traces back to actual experiments with real hardware. Probably most of the serious experiments are by various militaries and are highly classified. I've seen some more believable stuff suggesting that most consumer electronics and automobiles are not vulnerable at all to the much-fictionalized high-altitude nuclear EMP.

Either way, the author of this article does not cite any sources or relevant experience, and he doesn't include any biographical information about himself to judge how qualified he is to speak on such subjects. There's not much reason I see to take this any more seriously than any piece of fictional disaster porn you could buy on Amazon.

I don't know the truth for sure myself, but hopefully we all know better than to believe everything we read, especially about subjects like this where there appears to be very little hard science published.

[+] Animats|9 months ago|reply
There's plenty of unclassified info available. Start here.[1] This is an overview document from Defense Acquisition University, a unit of DoD. It's a painful PowerPoint. You have to plow through a lot of really boring military documents to get the details.

EMP doesn't address small devices much. Small devices with no wires connected are not very vulnerable, because the energy is mostly at somewhat longer wavelengths, meters or tens of meters. Worry about cell towers, not cell phones.

Other than the power grid people, the civilian sector doesn't look at EMP hardening much any more.

[1] https://www.dau.edu/sites/default/files/Migrated/CopDocument...

[+] hxorr|9 months ago|reply
I happen to be from the same town as this guy. He is well known for building his own ramjet-powered cruise missile.

I don't know about recently but he was actively involved in the local RC airplane club for quite a while if I recall correctly.

His website is well worth checking out, he has a very extensive technical knowledge.

[+] jvanderbot|9 months ago|reply
https://en.wikipedia.org/wiki/Starfish_Prime

> Starfish Prime caused an electromagnetic pulse (EMP) that was far larger than expected, so much larger that it drove much of the instrumentation off scale, causing great difficulty in getting accurate measurements. The Starfish Prime electromagnetic pulse also made those effects known to the public by causing electrical damage in Hawaii, about 900 miles (1,450 km) away from the detonation point, knocking out about 300 streetlights,[1]: 5 setting off numerous burglar alarms, and damaging a telephone company microwave link.[6] The EMP damage to the microwave link shut down telephone calls from Kauai to the other Hawaiian Islands.[7]

This was a 1 Mt bomb 10x as far from the surface as the article discusses.

All that to say, it's plausible.

[+] tomxor|9 months ago|reply
> wrap that in aluminium foil, making sure that the ends are folded over and pressed down hard to provide good inter-layer contact

I've tried this many times, it's impossible to prevent gaps without welding it shut. Obviously I wasn't testing with an EMP or nuke, but trying to block 2.4GHz WiFi... But that is well within the E1 range the author states.

I think the problem with folding is it's too uniform, it's still too easy for waves to propagate through the humanly imperceptible gaps with only a few reflections.

The only method I found that worked consistently was to wrap many layers randomly overlapping and crumpling previous layers. My theory as to why this works is through self interference due to creating a long signal path with highly randomised reflections... No idea if that would help cancel out EMP.

[+] Workaccount2|9 months ago|reply
Let me tell you something from first hand field experience with faraday cages...

They attenuate signals, they do not block them. The common verbiage is to say "faraday cages block EM radiation", so people naturally assume that it blocks EM radiation. But I learned the hard way while doing compliance testing that no, they do not block EM radiation, they just weaken it (and it's highly frequency dependent on top of that.)

[+] ttshaw1|9 months ago|reply
You shouldn't need to prevent gaps entirely. You only need to make sure there are no holes larger than roughly the wavelength of the radiation you're trying to block. Which, for 2.4GHz wifi, is about 125mm. I think what you saw is that a single layer of foil isn't enough skin depths thick to block radiation sufficiently at that frequency.
[+] Calwestjobs|9 months ago|reply
1. google how many lightning strikes are there per day

2. google how many millions of miles/kilometers of electric wires is hanging in air all over the world providing people with electricity

3. do not google how many of those millions of lightning strikes PER DAY disabled those billions of miles of wires per day, by applying energy bigger than nuclear EMP. do not google that.

[+] davidmurdoch|9 months ago|reply
I need to test flaky cell phone connectivity issues and tried the same thing. Aluminum foil did not cause packet loss. But a microwave (not running) in a building with a metal roof in a room surrounded by metal filing cabinets did the job.
[+] WalterBright|9 months ago|reply
You can experiment by putting a cell phone in various kinds of faraday cages and seeing if it rings when called.
[+] downrightmike|9 months ago|reply
Why not try a large Stanley cup? Double layered, top seals shut, pretty easy to get a hold of.
[+] nancyminusone|9 months ago|reply
>You can also forget about the inverse square law to protect you

No, you don't get to ignore physics because the source is not a point source

>Very large area of EMP

How large?

>Induces currents in any conducting material

So does a magnet falling off my fridge. What magnitude of currents, at what distance, in what sized conductor?

>During E1 the frequencies are so high

How high are they?

There can be radio waves strong enough to fry a silicon chip. There can be radio waves strong enough to melt glass vacuum tubes. This article provides no parameters by which one can make these calculations.

You might as well say "don't get nuked" which is admittedly sound advice.

[+] pjc50|9 months ago|reply
Yeah, this reads like alarmism with no numbers.

It's been a long time since atmospheric nuclear testing, but the US did carry out a bunch of tests to measure such effects, and it would be good to dig up the numbers from them.

[+] ianburrell|9 months ago|reply
My understanding is that nearby nuke and high altitude produce different EMP. The nearby one destroys electronic, but less of concern since close to nuclear blast. The high altitude one covers a large area, but it is more like solar flare, causing current in large conductors and primarily affecting the grid.

The problem is that the recent government studies that say high altitude can hurt electronics are all made by alarmists. When we should be focusing effort on grounding the grid, both for EMPs and for flares.

[+] giardini|9 months ago|reply
nancyminuson says: "...There can be radio waves strong enough to melt glass vacuum tubes..."

Well, if it will melt glass vacuum tubes then it will likely smoke my a* - and my brain along with it. (Just following the directive: "...bend over and kiss your a* goodbye!")

[+] jajko|9 months ago|reply
I would expect this depends on yield, distance, any existing shielding (ie rebar in concrete), height of explosion and so on. Article doesn't discuss any specific bomb, hence no need for specific numbers.
[+] lenerdenator|9 months ago|reply
1) Don't worry about it. If one goes off over a NATO country or Russia/China, you'll soon have much, much bigger problems to worry about.

2) There is no 2)

[+] yabones|9 months ago|reply
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.
[+] spacebanana7|9 months ago|reply
Not all uses of nuclear weapons necessarily escalate to the doomsday maximum exchange scenarios. There are many interesting points of equilibrium in between.

For example - if far right extremists took over Turkey and attacked Russia, then Russia nuked a Turkish airbase, what would the US/UK/France do? It's not actually that obvious.

[+] muzani|9 months ago|reply
But I don't live in any of those places. Also I believe India-Pakistan has nukes too. And possibly Israel-Iran. North Korea too? The peace loving nations are well within fallout range.

My biggest fear with MAD is that it only takes a single irrational leader, and we've seen so many of them lately.

[+] jnurmine|9 months ago|reply
I agree about not worrying about it, but one should be aware -- awareness about something is not equal to worrying about something.

Awareness of something is the first step in adapting. One can adapt beforehand, or, one can adapt afterwards; with more limited resources, necessitated by circumstances, under more time pressure, with more suboptimal tools, and so on.

It is unquestionable that an EMP would have an extreme impact in all aspects of society and the lives of people. Preparations on macro and micro level can mitigate some of the problems that would follow. And preparations require awareness.

[+] diggan|9 months ago|reply
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.

From the first paragraph:

> maybe it's time to look at the damaging effects of the electromagnetic pulse that follows a nuclear detonation.

[+] cogogo|9 months ago|reply
El Eternauta on netflix is an Argentine sci-fi series based on an old comic recently released. It is very well done. Best series I’ve watched in a while. Avoiding any real spoilers it pretty much kicks off with an EMP frying all modern electronics and the grid.
[+] amit9gupta|9 months ago|reply
The book Nuclear War: A Scenario Hardcover by Annie Jacobsen should be essential reading for all politicians and those profiteering from the Military Industrial Complex

https://www.amazon.com/Nuclear-War-Scenario-Annie-Jacobsen/d...

[+] sbierwagen|9 months ago|reply
I read it and was not impressed.

It starts with North Korea launching two ICBMs against DC and a nuclear plant in California. Interceptors fail and the warheads hit their targets. This is unlikely, but possible. The launch is explicitly irrational, the act of a mad dictator.

In response, the US counterstrikes with Minuteman, despite having perfectly serviceable air deliverable nukes. Russia detects the launch, and the imprecision of their own early warning systems along with North Korea being next to Russia, they conclude that the US is attacking them. They do a massive launch, the US does a massive launch, worst possible assumptions for a 10C nuclear winter, four billion dead.

The only thing I learned from the book is that if you roll 1 over and over and over again, the worst can happen. But we already knew that?

[+] BryanLegend|9 months ago|reply
I read it and it's completely biased to a worst imaginable scenario. Not likely to reflect any real world at all.
[+] schiffern|9 months ago|reply
Shame to see such (otherwise excellent) writing fraught with mistaken SI usage, as defined by the authoritative SI Brochure.[0] It's a small thing that makes any writing feel less credible.

Hopefully the author sees this post and can correct it. The author is using British English so I have preferred that convention. I include a second option which at least corrects any mistaken abbreviations, but the first option is always the correct version.

  >tens or hundreds of Km
"tens or hundreds of kilometres" or "tens or hundreds of km"

  >30Km
"30 kilometres" or "30 km"

  >10nS
"10 nanoseconds" or "10 ns"

  >Khz to low Mhz
"kilohertz to low megahertz" or "kHz to low MHz"

  >hundreds of mS
"hundreds of milliseconds" or "hundreds of ms"

  >a few Khz
"a few kilohertz" or "a few kHz"

[0] https://www.bipm.org/en/publications/si-brochure/

[+] tronicjester|9 months ago|reply
To prevent nuclear war YouTube has now blocked videos related to faraday cages.
[+] hollerith|9 months ago|reply
>The world's longest-running online daily news and commentary publication . . . The opinion pieces presented here are not purported to be fact . . .

No thanks, I'll wait for factual information.

[+] hcfman|9 months ago|reply
Hey don't knock mister Simpson. He's an icon. I'm amazed he's still going.
[+] ctippett|9 months ago|reply
Genuine question, what happens to any commercial aircraft in the vicinity of such a detonation? Are they at a high enough altitude to avoid the EMP blast or can we expect them to lose all electronics?
[+] olelele|9 months ago|reply
I heard from a pretty crazy audio engineer in Berlin that there are miniature vacuum tubes from Soviet jet fighters that function as replacement in microphones bc they are vibration resistant. The jets were designed to survive emp.
[+] paulnpace|9 months ago|reply
There are also old Mercedes turbo diesels with mechanical fuel injection. I'm pretty sure those would survive an EMP, although I'm assuming things like starter motor circuit works (is it even possible to push start a diesel?).
[+] mrbluecoat|9 months ago|reply
A great, but chilling, read on this topic is 'One Second After', by William R. Forstchen
[+] amelius|9 months ago|reply
It doesn't answer the most basic question: how many layers of tinfoil do I need?
[+] mikewarot|9 months ago|reply
Given the contemporary rules about RF emissions, fairly robust shielding practices are the norm now. I suspect most consumer electronic devices would be fine.

The exception would be things like HF ham radio, etc.

[+] sandworm101|9 months ago|reply
Title is misleading. Article only dicusses nuclear emp issues with zero mention of the plethora of non-nuclear emp weapon options.
[+] timcobb|9 months ago|reply
> As we sit, possible poised on the verge of a nuclear conflict in the Northern Hemisphere

Am I missing something? Should I be worried?

[+] charintstr|9 months ago|reply
The Ukraine conflict has frequently raised nuclear fears mostly due to Russian nuclear sabre rattling. But this has been happening since 2022 and it’s hard to see anything going hot anytime soon
[+] 1970-01-01|9 months ago|reply
Datacenters hate this one weird trick!