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What you need to know about EMP weapons

aardvark.co.nz

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Re: What you need to know about EMP weapons

#141

Post by saltcured »

palmotea wrote: post #102
yabones wrote: post #28

Earlier quoted context omitted.

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.

> 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...

OK, so you'll need a bigger roof and more lawn chairs...

Re: What you need to know about EMP weapons

#143

Post by southernplaces7 »

wat10000 wrote: post #118
southernplaces7 wrote: post #78

Earlier quoted context omitted.

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…

Finally, someone else who appreciates Warday! It's really good. And as far as I can tell, as a layman who reads way too much about this stuff, quite accurate in terms of what the sort of limited strike depicted in the book would do in the short and long term. (I have quibbles, such as what happens to San Antonio and Manhattan, but nothing major.) Highly recommended to anyone who like the genre.

I thought the book was both harrowing as hell, grim to the point of being close to a horror novel in some parts with its descriptions of what people went through, and also extremely moving. The scene where Streiber manages to visit the wreck of his Manhattan apartment was enough to bring tears.

I'm curious, What were your quibbles with Manhattan and San Antonio?

Edit, and yes, I've read that it was highly praised for realism. The authors really put their effort into making it as close to what things might really be like as possible. No hyperbole or dramatics, just the stark inevitable horror of even limited nuclear war and its effects

Re: What you need to know about EMP weapons

#144

Post by roenxi »

mopsi wrote: post #86
yabones wrote: post #28

Earlier quoted context omitted.

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.

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 anyon…

> 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,...

If the risk was a war involving bombs like Little Boy then there wouldn't be much to worry about beyond localised disaster. The issue is the weapons that are 2-3 orders of magnitude more powerful.

And you're referring to Germany, which that took casualties approaching something close to 10% of its population during WWII - so you're eyeballing a scenario where a country just lost 10% [0] of its population and saying it looks fine to you. That seems a weak argument that the damage is nothing we need to worry about. We can argue over whether nukes are going to kill 100%, 50%, 10%, etc of the population but frankly I don't see where you would want to go with that.

[0] Not from bombing, obviously, but the situation you're talking about is nonetheless one where Germany just suffered massive losses and you're saying you can't see that in a photograph after the cities were rebuilt so no worries if something worse happens.

Re: What you need to know about EMP weapons

#145

Post by dtgriscom »

tomxor wrote: post #15

> 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…

One of my more popular Physics Stack Exchange answers: https://physics.stackexchange.com/a/208520/82798

Re: What you need to know about EMP weapons

#146

Post by benlivengood »

yabones wrote: post #28
lenerdenator wrote: post #4

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)

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.

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.

Re: What you need to know about EMP weapons

#147

Post by wat10000 »

southernplaces7 wrote: post #143
wat10000 wrote: post #118

Earlier quoted context omitted.

Finally, someone else who appreciates Warday! It's really good. And as far as I can tell, as a layman who reads way too much about this stuff, quite accurate in terms of what the sort of limited strike depicted in the book would do in the short and long term. (I have quibbles, such as what happens to San Antonio and Manhattan, but nothing major.) Highly recommended to anyone who like the genre.

I thought the book was both harrowing as hell, grim to the point of being close to a horror novel in some parts with its descriptions of what people went through, and also extremely moving. The scene where Streiber manages to visit the wreck of his Manhattan apartment was enough to bring tears. I'm curious, What were your quibbles with Manhattan and San Antonio? Edit, and yes, I've read that it was highly praised for…

Mild spoilers here, I suppose!

It didn’t make sense that San Antonio would be targeted in the limited Soviet strike. It would be pretty far down the list, definitely not in the top 3. I believe Streiber has said as much, and that it was included because of the personal connection, and the reason given in the book (some military headquarters there?) was a weak excuse.

I can’t quite explain it, but it doesn’t feel right to me that Manhattan would be abandoned and salvaged like that. Seems like it would either be too dangerous for people to be there, or it would still be an actual city even if diminished. It seems like another thing done for the narrative and personal connection, to allow him to “return home” while also giving a reason he didn’t still live there.

But again, these are both minor points and really don’t detract from the work at all. San Antonio is little more than a bit of background flavor, and the story makes Manhattan well worth it.

Re: What you need to know about EMP weapons

#148

Post by o11c »

WalterBright wrote: post #134
tomxor wrote: post #15

> 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…

You can experiment by putting a cell phone in various kinds of faraday cages and seeing if it rings when called.

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

Re: What you need to know about EMP weapons

#149

Post by m463 »

o11c wrote: post #148
WalterBright wrote: post #134

Earlier quoted context omitted.

You can experiment by putting a cell phone in various kinds of faraday cages and seeing if it rings when called.

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

Just don't fall for the old "turn off any adblockers and enable javascript" trick.

Re: What you need to know about EMP weapons

#150

Post by lostlogin »

Workaccount2 wrote: post #41
tomxor wrote: post #15

> 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…

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 tha…

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).

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