Re ....aluminum foil on the walls......

Eugene Leitl (
Thu, 16 Sep 1999 21:29:55 -0700 (PDT)

There are digital pulse radio-based handheld SAR prototypes being evaluated for discovery of (breathing/moving) persons behind walls/doors for police use (shoot here, x marks the spot). Should such things come into widespread use I guess I wouldn't mind applying a little tinfoil to my appartment (just as in "Conspiracy Theory"), just in case.

Brian D Williams writes:
> Unfortunately foil on the walls or the wearing of foil especially
> on the head to protect against aliens is a classic sign of
> schizophrenia.
> A number of people who work at night including according to legend,
> Elvis, put foil on bedroom windows to completely darken it for
> sleeping during the day.

A partially aluminized polymer film on windows is actually pretty useful in heavily insolated areas of the world. Just don't sputter chrome on it...

> Unless it was properly grounded (Faraday shield) it would not form
> an effective shield against "radio waves" or microwaves, nor would
> it be an effective anti-Tempest defense. (Van Eck Radiation)

So you're telling me the cavity of a ~1 mm wall hollow sphere mounted on an insulator will be seeing EM radiation softer than xRay? Don't think so. (Unless you apply sufficient power to evaporate the conductive layer, that is).

Besides, it is hard enough to tinfoil a room without grounding the metal layer (unless you live in Teflonia).

There is currently some discussion on protecting a wearable computer against an EMP attack on the list. Strange that Dela Lu wasn't hardened against NEMP, but it certainly makes for more suspense in the story.