It is theoretically IMPOSSIBLE for any electromagnetic impulse to pass through any conductive barrier, even the metallic screen wire on the old “screen door”.
It is called the Faraday effect and such enclosures are “Faraday Cages”. I remember photos of a physicist sitting on a stool inside one while a LIGHTNING GENERATOR blasted huge bolts and arcs all around. He was completely untouched.
Has some exception to this basic principle of physics been repealed???
Just asking...
We would do well to take a few billions of wasted EBT monies and put it into EMP protection for our grids. It might be good insurance to prevent most of us from starving to death in case of such an event.
“...It is theoretically IMPOSSIBLE for any electromagnetic impulse to pass through any conductive barrier, even the metallic screen wire on the old “screen door”...”
I’ve taught courses on this stuff...and your theory is correct...but remember that any small holes with conductors (wires, etc) leading into the “protected” space will allow the pulse (or at least selected frequencies of that pulse) to enter and do damage.
our entire electrical grid would be fine if it was inside an electrical cage - but the overhanging wires you see are vulnerable to EMP
They could send enough current back into the generators to fy them too even if they are inside a cage
While I'm on the subject: we all need a little drama in our lives, some more than others. When the prepper circuit got ahold of the EMP issue, the excitement started. An EMP attack, it was held, would not only send the entire United States back to the 19th century but would also paralyze the entire government.
Recently, I was on a prepper blog reading a post about how to set up a Faraday cage. One of the commenters there politely corrected the urban legends (i.e., about using old microwaves) and explained how to build a proper Faraday cage. It turns out that this fellow was a soldier, and his tips came from the U.S. Army experimenting and testing Faraday cage units to find out what'll work and what won't.
If you're interested, he said that the only sure-fire Faraday cage was a solid box made of (preferably) copper or aluminum that, when closed, conducted electricity as if it had been welded shut. It has to be grounded with a nine-foot copper rod hammered into the earth and welded to the box itself through copper wire. The Army was buying conducting gaskets to make sure its own Faraday cages were up to snuff.
There's one aspect of the prepper world I'd like to call attention to: a kind of insider's-club attitude. It's SOP in the prepper world to not only believe that the "sheeple" will remain unprepared and helpless, but also that the U.S. government will too. I guess they're used to being ignored. The idea that soldiers, officers and out-of-the-spotlight bureaucrats will read the same material that they do, let alone take some action, doesn't even seem to occur to them.
For example, I'm quite sure that the D.C. Establishment knows all that we know about the coming debt crisis, if not more. They don't do anything about it because the person who sticks his neck out is going to have it chopped off by the electorate. So, both sides have a mutual non-action pact: they're waiting until the crisis erupts before they'll do something about it. Then, but not until then, they'll swing into action.
Not that the above paragraph is all that reassuring! I read somewhere that the TSA was blueprinted in the late Clinton Administration, so it was already "on the shelf" on 9/11. This claim makes sense, as government usually takes a long while to get anything off the ground. [Some of you may remember common-sensical solutions, like "arm the pilots," being ignored or dismissed out of hand.] It's a sure bet that FedGov has a similar contingency plan in the case of a debt crisis...or in the case of an EMP attack.
As for whether it's the best option...well, you know the track record of FedGov.
The worst effect is not on what is naturally shielded, or intentionally shielded. The problem is that the long lines of the electrical grid, both transmission and distribution are pretty much perfect antennae for the various EMP pulses.
Modern cars, well grounded appliances and the natural shielding of commercial structures might indeed save electronics.
But the electric grid will go down. Without electricity USA society will collapse in three to nine days. It will take longer to get even portions of the grid back up.
I have lost the link but a British economist/ sociologist wrote a great paper that was essentially “ 9 days from the Middle Ages “. It covers how society collapses rapidly and why.
So as you read about EMP bear in mind the real danger is that you and your family would have 3-9 days before you live in a 12th century, pre-industrial age that shifts rapidly from event to realization to chaos to barbarism/feudalism. How long recovery and reorganization takes is a worthy debate.
90%+ population loss is the general prediction target, mostly and rapidly in urban population areas. “No city can feed itself” is an axiom. Neither can it water or fuel itself.
Two worthy titles are indeed ‘One second after’ and the movie Remnants.
Net: if the grid goes down you have <72 hours to get to a place out of urban areas. After 48 hours travel will be dangerous and lethal after 72. 9 days to have everything to survive for 90 days, then perseverance and perspiration to go on til reorganization and recovery take hold.
The worst effect is not on what is naturally shielded, or intentionally shielded. The problem is that the long lines of the electrical grid, both transmission and distribution are pretty much perfect antennae for the various EMP pulses.
Modern cars, well grounded appliances and the natural shielding of commercial structures might indeed save electronics.
But the electric grid will go down. Without electricity USA society will collapse in three to nine days. It will take longer to get even portions of the grid back up.
I have lost the link but a British economist/ sociologist wrote a great paper that was essentially “ 9 days from the Middle Ages “. It covers how society collapses rapidly and why.
So as you read about EMP bear in mind the real danger is that you and your family would have 3-9 days before you live in a 12th century, pre-industrial age that shifts rapidly from event to realization to chaos to barbarism/feudalism. How long recovery and reorganization takes is a worthy debate.
90%+ population loss is the general prediction target, mostly and rapidly in urban population areas. “No city can feed itself” is an axiom. Neither can it water or fuel itself.
Two worthy titles are indeed ‘One second after’ and the movie Remnants.
Net: if the grid goes down you have <72 hours to get to a place out of urban areas. After 48 hours travel will be dangerous and lethal after 72. 9 days to have everything to survive for 90 days, then perseverance and perspiration to go on til reorganization and recovery take hold.
This Faraday cage experiment can be seen daily at the Museum of Science in Boston.
“It is theoretically IMPOSSIBLE for any electromagnetic impulse to pass through any conductive barrier, even the metallic screen wire on the old “screen door”.”
Maxwell begs to differ.
No. Go back to microwave engineering class.
The intensity on the far side of a cutoff waveguide is proportional to the inverse-square of the distance where the intensity is measured. Depending on the frequencies that make it up, and its intensity, EMP will cause some problems with screened electronics.
But that ain't the main problem.
The main problem is the so-called E3 pulse, the long-wavelength geomagnetic currents that are induced in the earth and in long electric wires. Those are powerful enough to burn out gigawatt power turbines. Ask the Russians about that one.
>even the metallic screen wire on the old “screen door”.
So what? Nothing is protected in this country except some military locations and maybe your stuff enclosed behind metal screens.
Hundreds of Major transformers and power stations would be wiped out along with most transport & communications in the country.
Literally every building and piece of equipment would be compromised.
The die off rate would be stunning before widespread relief could be obtained. - If it ever could.
Yes. It is the physics principle which states that if you stick to science and facts, you will succeed. That has been repealed by the government, which has instituted the policy where if you don't say what the government wants, you no longer get funded.
From 1945-1992 there were over ONE THOUSAND NUCLEAR BOMB TESTS done in the United States.
How many 'electrical grids' went down ?
So...hiding under a wooden desk wouldn't protect you from an EMP pulse, any more than it would from a nuclear fireball.
Wow. My teachers in grade school lied to me.