MIT Study on Tin-Foil Hats :-)
Bill Stewart
bill.stewart at pobox.com
Thu Nov 10 11:43:21 PST 2005
The page was actually published in February, but showed up at www.fark.com
today.
(Hmm. Looks like Slashdot just got it also, so it'll probably
be a bit slow downloading. I've included the text here,
but the pictures make it worthwhile.)
http://people.csail.mit.edu/rahimi/helmet/
On the Effectiveness of Aluminium Foil Helmets:
An Empirical Study
Ali Rahimi1, Ben Recht 2, Jason Taylor 2, Noah Vawter 2
17 Feb 2005
1: Electrical Engineering and Computer Science department, MIT.
2: Media Laboratory, MIT.
Abstract
Among a fringe community of paranoids, aluminum helmets serve as the
protective measure of choice against invasive radio signals. We investigate
the efficacy of three aluminum helmet designs on a sample group of four
individuals. Using a $250,000 network analyser, we find that although on
average all helmets attenuate invasive radio frequencies in either
directions (either emanating from an outside source, or emanating from the
cranium of the subject), certain frequencies are in fact greatly amplified.
These amplified frequencies coincide with radio bands reserved for
government use according to the Federal Communication Commission (FCC).
Statistical evidence suggests the use of helmets may in fact enhance the
government's invasive abilities. We theorize that the government may in
fact have started the helmet craze for this reason.
Introduction
It has long been suspected that the government has been using satellites to
read and control the minds of certain citizens. The use of aluminum helmets
has been a common guerrilla tactic against the government's invasive
tactics [1]. Surprisingly, these helmets can in fact help the government
spy on citizens by amplifying certain key frequency ranges reserved for
government use. In addition, none of the three helmets we analyzed provided
significant attenuation to most frequency bands.
We describe our experimental setup, report our results, and conclude with a
few design guidelines for constructing more effective helmets.
Experimental Setup
The three helmet types tested
The ClassicalThe Fez
The Centurion
We evaluated the performance of three different helmet designs, commonly
referred to as the Classical, the Fez, and the Centurion. These designs are
portrayed in Figure 1. The helmets were made of Reynolds aluminium foil. As
per best practices, all three designs were constructed with the double
layering technique described elsewhere [2].
A radio-frequency test signal sweeping the ranges from 10 Khz to 3 Ghz was
generated using an omnidirectional antenna attached to the Agilent 8714ET's
signal generator.
The experimental apparatus, including a data recording laptop, a $250,000
network analyser, and antennae.
A network analyser (Agilent 8714ET) and a directional antenna measured and
plotted the signals. See Figure 2.
Because of the cost of the equipment (about $250,000), and the limited time
for which we had access to these devices, the subjects and experimenters
performed a few dry runs before the actual experiment (see Figure 3).
Test subjects during a dry run.
The receiver antenna was placed at various places on the cranium of 4
different subjects: the frontal, occipital and parietal lobes. Once with
the helmet off and once with the helmet on. The network analyzer plotted
the attenuation betwen the signals in these two settings at different
frequencies, from 10Khz to 3 Ghz. Figure 4 shows a typical plot of the
attenuation at different frequencies.
A typical attenuation trace form the network analyser
Results
For all helmets, we noticed a 30 db amplification at 2.6 Ghz and a 20 db
amplification at 1.2 Ghz, regardless of the position of the antenna on the
cranium. In addition, all helmets exhibited a marked 20 db attenuation at
around 1.5 Ghz, with no significant attenuation beyond 10 db anywhere else.
Conclusion
The helmets amplify frequency bands that coincide with those allocated to
the US government between 1.2 Ghz and 1.4 Ghz. According to the FCC, These
bands are supposedly reserved for ''radio location'' (ie, GPS), and other
communications with satellites (see, for example, [3]). The 2.6 Ghz band
coincides with mobile phone technology. Though not affiliated by
government, these bands are at the hands of multinational corporations.
It requires no stretch of the imagination to conclude that the current
helmet craze is likely to have been propagated by the Government, possibly
with the involvement of the FCC. We hope this report will encourage the
paranoid community to develop improved helmet designs to avoid falling prey
to these shortcomings.
Acknowledgments
The authors would like to thank Andy (Xu) Sun of the MIT Media Lab for
helping with the equipment, Professor George Sergiadis for lending us the
antennae, and Professor Neil Gershenfeld for allowing us the use of his lab
equipment.
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