From: "Timothy C. May" <tcmay@got.net>
Date: Sat, 5 Oct 1996 15:33:38 +0800
To: cypherpunks@toad.com
Subject: Electromagnetic Pulse
In-Reply-To: <Pine.3.89.9610040641.A14153-0100000@netcom14>
Message-ID: <v03007800ae7b96a03b48@[207.167.93.63]>
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At 8:58 PM -0500 10/4/96, snow wrote:
>Mr. Green wrote:
>> On Wed, 2 Oct 1996, Adamsc wrote:
>> > I have strong
>> > doubts that someone would come up with a non-nuke that could destroy stuff
>> > indiscriminately within a useably large area.
>> Fuel/air bombs.
>
>     Wouldn't work real good in a city, and would leave most computers
>inside buildings working just fine, especially given any predomanance
>of underground powerlines.


By the way, it's a myth of our age that nukes destroy electronics!

The infamous "electomagnetic pulse," or EMP, was discovered by the American
side in the Cold War only during the extremely high altitude bursts over
Johnson Atoll, circa 1962. (This is the test where streetlights in Hawaii,
a thousand or more miles away, were burned out, etc.)

EMP results from the prompt gammas from a nuclear explosion interacting
with the upper atmosphere to produce a wavefront of electromagnetic energy
as the gammas interact with the uppper ionosphere. Ground-level bursts have
no such effects, though I wouldn;t want to be close to one.

The key is that the effects of near-ground-level bursts are _extremely_
localized. Shocking so, no pun intended. The largest bomb in the U.S.
arsenal, believed to be 20 MT, might leave a crater several miles in
diameter, but would hardly be felt 30 miles away. Certainly almost no
electronic devices would be damaged, except if close to the blast center.

--Tim May

"The government announcement is disastrous," said Jim Bidzos,.."We warned IBM
that the National Security Agency would try to twist their technology."
[NYT, 1996-10-02]
We got computers, we're tapping phone lines, I know that that ain't allowed.
---------:---------:---------:---------:---------:---------:---------:----
Timothy C. May              | Crypto Anarchy: encryption, digital money,
tcmay@got.net  408-728-0152 | anonymous networks, digital pseudonyms, zero
W.A.S.T.E.: Corralitos, CA  | knowledge, reputations, information markets,
Higher Power: 2^1,257,787-1 | black markets, collapse of governments.
"National borders aren't even speed bumps on the information superhighway."