Nuclear weapons and electro-magnetic pulse ?

In a James Bond movie and ‘Until The End Of The World’ (plus many more probably) they deal with a nuclear explosion in the upper atmosphere that sends an electro-magnetic pulse out that essentially knocks all electronics out. How true is this? I’ve heard of it many times before, yet I don’t know how damaging it would actually be. Would 1 bomb knock out everything all over the world, or just the cone of space from explosion to surface? Would a terrorist group do more damage to the world by getting their hands on a bomb and setting it off above the earth instead of in a major metropolis? Anyone know the answer?


Yes, that is precisely what would happen should a nuclear explosion happen in our atmosphere. I’m not sure of the distance at which any particular explosion would affect, but here’s a sample of The Smaller Version. hope that helps somehow.

The column is, Is there a way to permanently silence somebody’s loud car stereo? Yeah, I think that the connection should be obvious, too.

Just within the last few days I read somewhere (maybe in a letter to the editor in the WSJ) that a single Chinese hydrogen bomb detonated high above the US would disrupt all electronic devices everywhere in the US. I don’t believe it for a minute. But I’m too lazy to hash out the straight dope right now.

Thre was a recent thread on this subject, but I can’t find it. There’s lots of links in that thread.

Here’s a few:

From Operation Dominic:

“Starfish Prime was successful. The Thor missile carried the test instrumentation and the W-49 warhead/Mk-4 RV payload to 248 miles. The test appeared quite spectacular from Hawaii (800 miles away) and at Kwajalein (1600 miles away), with impressive light displays from an artifical aurora lasting up to seven minutes. The electromagnetic pulse (EMP) from this test sent power line surges throughout Oahu, knocking out street lighting, blowing fuzes and circuit breakers, and triggering burglar alarms.”


"The effects of EMP from the Starfish event were observed in Hawaii, 1,300 kilometers east of the detonation. Street lights and fuses failed on Oahu and telephone service was disrupted on the Island of Kauai.

We have recently learned that Soviet scientists observed similar disruptions following their high-altitude tests. In one test, all protective devices and overhead communication lines were damaged at distances out to 500 kilometers. The same event saw a 1,000 kilometer segment of power line essentially shut down by these effects."

To imagine how EMP does damage, let’s take a common place example. Have you ever put metal in your microwave oven (tin foil and fork, etc. - btw, if you haven’t, don’t)? The arcing that results is quite similar to an EMP blast. Except a fusion bomb pumps out lots more energy on lots more wavelengths.

I saw a show on TV where an EMP was put to good use in a prototype police gadget designed to stop high-speed pursuits.

Basically, you have a little four-wheeled cart hooked underneath the front bumper of the police car. When deployed, an solid-fuel amateur rocket engine (I think it was a D or E) fires up and sends the device zooming forward to zip underneath the bad guy’s car. When it detects (don’t know how) that it is under the engine, it fires an electromagnetic pulse upwards, knocking the engine out cold.

I don’t know if this only works on cars with electronic ignitions; they didn’t say.

As far as I know the device has not been deployed in the field, but if you watch any cop shows on TV, it’s about time they got it out there!

Along those same lines, I read an article somewhere explaining how the US took out the Iraqi power grid with Tomahawk’s armed with an ‘EMP Munition’

The Soviet 58-megatonner appears to have been designed to do just that: shut down the entire continental U.S. power grid with an EMP with only a couple well-placed shots.

BigJoe wrote:

No need to go nuclear, just use carbon thread:

Andrew Warinner

JonF said

That’s scary stuff, especially when you consider that the device was only about 1.5 Megatons. New York City could be blown to bits, and I wouldn’t give a damn. But if I lost power as a result, that would make me sad.

Thanks folks. I’m getting a slight feeling that although it does work, it is still a ‘focused’ area (although still quite large). One bomb couldn’t knock out the world. Plus it seems that while a ton of stuff would be affected, many things would not be- powerlines and street lamps yes, but servers and terminals in the basement no.

And saying bye-bye to New York would be a pity…But I’d get over it too! :slight_smile:

Anything with a computer chip that’s not shielded would be toast.

Granted, a computer in your basement is better shielded than one in a second story bedroom, but that additional amount of shielding would be negligible if the bomb went off within 100-125 miles.

At least those’re the numbers we train to.

Sorry, as ChiefScott pointed out, servers and terminals and anything containing integrated circuits would be toast. Operation Dominic was in 1962; there weren’t large numbers of solid state electronic devices around to be affected. Integrated circuits are much more susceptible than the electromechanical switches and relays that were affected.

You keep mentioning shielding…What exactly do you mean? Some Farady(sp? or different name) cage type thing, or just inside a lead box?

Gimme a couple of minutes Tomcat and let me call one of the squadrons aboard.

I know they use shielding, but it isn’t lead. That is too heavy a metal for aircraft.

For shielding from radiation, you want something dense, like lead. For shielding from EMP, you want a good conductor. A relatively thin layer of silver would probably do it, and if you can arrange the cooling (and if anyone can, it’s the military), any thickness of superconducting material would offer total shielding.

This will only work on newer cars with fuel metering computers. It stalls the engine…

EMT from an overhead Nuclear detonation is a real threat. I bet you didn’t know that our (the US’s) ground based nuclear defenses are backed up with manual firing systems consisting of vacuum tube circuits–just incase our chips get wiped out.

I heard that an EMP will knock out chips, but not vacuum tubes. So if the PC goes down, rest assured that EINIAC still works.