Understanding EMP

[amnite]

So I've heard alot about EMP(Electromagnetic Pulse). From everything they say an EMP will shut down any running electronics. I was curious:
A. Is it true? Does it really shut down Elecs?
B. How it does this.
C. An idea into what construction behind such a thing would be like.

Thx alot.
BTW This Site RULEZ.

[westfw]

The theory is that a large enough EMP would induce enough electrical surges on powerlines to knock out much of the electrical grid and many pieces of modern electrical gear connected to the grid, plus perhaps much of orbiting satellite electronics.

The proposed source of such a pulse is a high-yield thermonuclear weapon rather high in the atmosphere.

I don't know to what extent such things have been tested or actually analyzed, but of course Hollywood took the idea and ran with it, coming up with disasterous scenarios and spectacular special effects, forgetting that a lot of the stuff they're talking about already comes with protection built-in to cover smaller effects like lightning. Lightning is a pretty big deal in a lot of places, and it pretty much takes a direct strike to get anything close to the sorts of effects that they like to show in movies, conveniently forgetting actual physics and actual engineering practice...

Since the EMP thing started out as a military theory, you also have to presume that there are some features in place to prevent even nuke-caused EMPs from disrupting everything. For example, the Internet has it origins in research into "recoverable" communications Network architectures that would be capable of maintaining communications (between, say, the BANNED and Norad) even in the event that the middle of the country was glowing radioactive puddles...

Of course, if you want to see EMP-like behavior on a smaller scale, you can try to operate your HV electrostatics lab (Van de Graffs, tesla coils, and so on...) in the same space as your microprocessor lab.
The effects of a tesla coil demo in a typical hi-tech BANNED conference room can be pretty amusing (unless you work for the BANNED.)

[macegr]

I've experienced Tesla interference first hand...at the SF Maker Faire last year, I was in the "Dark Room" where most of the LED, video, and laser projects were set up. There was an array of Tesla coils and other spark generation equipment in one corner...I was going to be next to him, but they had to move the exhibit because they were under the fairgrounds Ethernet switch and causing havoc. Anyway, 90 feet across the room, the Tesla coil was still wreaking havoc with my project and several neighbor's projects. But it was fun

[eil]

Yes, EMP is certainly real. EMP is just a really huge momentary fluctuating magnetic powerful enough to induce a current into, well, just about anything. If the induced current is too much for the electronics to handle, they fry just like what would happen if you plugged your Arduino into a 120V outlet.

I worked on autopilot and guidance systems in the Air Force and EMP was part of our training, though the physics were obviously glossed over a bit. All military aircraft in service have some sort of EMP protection built in so that a nearby high-altitude nuclear explosion won't suddenly render the plane unflyable in mid-air. Mainly, this means that the really important systems either don't have sensitive electronics or those that do are very well-shielded from EMP.

For example, a few planes that I worked on had solid-state primary navigation and guidance systems. But the backup system would be run off vacuum tubes or even a gyroscope connected directly to an artificial horizon on the instrument panel.

Here's an aerial view of an Air Force EMP testing rig. I was stationed at this base and the rig is plainly visible from from the air. It's about a half-mile from the runway that's shared between the Air Force base and Albuquerque International airport.