Knight Rider: Electromagnetic Pulses

By Eric Wolff | November 20, 2008 7:03 pm

Screenshot from Knight RiderI can’t decide if electromagnetic pulses are scary. I mean, if Dark Angel was to be believed, a high-altitude electronic pulse could end civilization as we know it. If I put my trust in Ocean’s Eleven, then an EMP can be used to disrupt the entire power supply of an entire city. And in last night’s episode of Knight Rider, KITT used an EMP to knock out power to a casino. A weapon that can knock out an electronic grid could certainly do extraordinary damage to our infrastructure, on the one hand, but on the other, it doesn’t kill people directly or destroy buildings. And really, should we be trusting Hollywood on this subject in the first place?

Most of the time an EMP is associated with a nuclear warhead detonation, in which case most of the people in the blast area have bigger problems than dysfunctional electronics. But in the scenario proposed by these shows, someone has devised a weapon that provides the pulse without using a nuclear reaction. Flux compression Generator bombs harness the energy from a small explosion and convert it into an electromagnetic pulse.First takea coil of copper wire, and encase it in something very sturdy. Then run a lot of electricity through the coil,  which will generate a reasonably powerful magnetic field. Then set off a small explosion within the coil.  In broad terms (and there’s all sort of other small stuff going to actually make this thing work), the explosion will force the magnetic filed out through an opening in one end of the casing, causing the pulse. The pulse would be “tens of megajoules” in strength, easily enough to do a lot of damage to local electronics.

So, what would the effect of a pulse be? There’s no evidence that a pulse hurts people directly, but most of the people who have experienced one (i.e. the people living in Nagasaki and Hiroshima) were more worried about the nuclear blast than the EMP. Certainly electronics are quite vulnerable to an EMP because the copper and silicon act as lightning rods. High-voltage electricity runs up the wires and into the components, generating a power spike far beyond the ability of most surge protectors ability to handle. The circuit boards and microchips would be totally cooked. But the copper wiring itself isn’t especially damaged, and simple devices that use electricity, like lights and batteries, don’t necessarily suffer from an EMP. There’s a great video on the How Stuff Works website of a guy driving a car through an EMP. He drives at slow speed through the EMP generator. When it goes off, the car’s engine shuts down and he coasts to a halt. However, the brakes still work, the battery still works, and some of the dashboard lights are still on. The car dies because the computers that handle fuel injection and other engine functions shut down, but the battery still works.

An EMP like KITT’s would probably permanently destroy all the slot machines, the computerized door-lock touchpad, and a host of other stuff, but it might not actually turn off the lights, unless it hit the computers running the power generator. But a nuclear detonation is another matter. A 1998 paper published by the Federation of American Scientists notes the 1958 nuclear test explosion in the South Pacific that knocked out power in parts of Hawaii, hundreds of miles from the test area. It goes on to say that an explosion 500 km above Kansas could knock out electronics in the entire continental United States. And while it might not kill anyone directly, it would destroy the computers running hospital equipment, traffic signals, automobiles, and airplanes. Plus, it might kill the Internet.

OK, now I’m scared.

CATEGORIZED UNDER: Physics
MORE ABOUT: EMP, Knight Rider

Comments (8)

  1. Randy T

    ICBM sites are hardened to withstand all but a direct hit ground burst from a nuclear reentry vehicle. While the site is hardened and interior components are slung from hangers to handle a sudden lateral movement, the shielding from EMP is extensive and elaborate with wire mesh gaskets, metal electronics housing and straps to ground the EMP induced currents. Remember how everone thought the Soviets were so backwards when tube radar was found to be in the MIG fighter used by defector Victor Belinka? Tubes handle EMP much better that solid state electronics.

  2. Brian

    From what I understand, a high strength EMP is nothing to sneeze at.

    I heard years ago that there were real military plans to detonate nuclear explosives way high up in the ionosphere, specifically to generate an EMP. Being so high up there was no purpose to the blast other than the EMP itself. Apparently the specific atmospheric layer somehow enhanced the EMP dramatically (due to being ionized? I’m not at all clear on this).

    Also, induced current is nothing to sneeze at. It was induced current that knocked out the Hydro Quebec system in 1989. This one was caused by solar storm activity during a solar maximum.

    Your idea that simple electrical equipment won’t be damaged is simplistic here. Subject them to a high enough induced current and you’ll exceed their design limits. Sure, it’s just a light bulb and it will probably burn out. Remember that this is an area event though. If you’ve blown every light bulb on the continent then you’ve got a problem (and we haven’t yet discussed the other electrical damage).

    Hey, just remember the movie The Day the Earth Stood Still. It might be an awful lot like that.

  3. steve

    Hi,
    check out the d.v.d, “Nukes in Space”….Narrated by william shatner,directed by peter Kuran…Distributed by Magna Pacific, http://www.magnapacific.com.au
    During the cold war the u.s and the soviet union detonated up to 40 nuclear weapons in the outer atmosphere primarilly to test the affects on over the horizon radar.
    I think you may be shocked by what our goverments get up to….

  4. kelvin

    can i know which episode of knight rider you’re refering above? cuz i need the video of it for my physics work and stuffs. thanks

  5. Many thanks for share really decent informations. Your search engines is great.I am impressed by the information that you have on this weblog. It exhibits how well you understand this topic. Bookmarked this particular web page, will appear again for extra. You, my friend, awesome! I found just the details I previously explored everywhere and just wasn’t able to find. What a perfect internet site. Like this web-site your internet site is 1 of my new most-liked.I such as this knowledge shown and it has offered me some kind of idea to possess achievement for some reason, so keep up the very good do the job!

  6. AmandaK

    I agree with Glenda Zant, really great blog. I personally have been researching EMP for just a few months and it’s hard to find people who really know what they’re talking about. One really good blog that I constantly go back to is actually a radio blog show, though. They have a guest on their show and air every Wednesday. Next Wednesday the 31st, there’s a guy names Peter Huessy that’s going to be on their show. He’s going to be talking about EMP, state-sponsored terrorism, and other national security topics. It should be very informative. Here’s the link if you guys want to check it out: http://empactradio.org/pvp/episode64-peter-huessy/

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »