Dear Science,
I live in the attic of a building on 14th Avenue East and Denny
Way, which means I am at the peak of Capitol Hill. Often, my stereo
receiver will pick up radio signals. The noise overwhelms my regular
music, and I can’t use my personal recording equipment without it being
tainted by radio waves, which totally sucks because I am anxious to
record my music. I have a hunch the noise comes from the huge towers on
17th Avenue and Pine Street. Why is this happening, and more
importantly, how can I make the noise stop?
Beamed Into My Head
The towers at 17th and Pine are a good hunch. Hug the next
electrophysiologist, neurologist, or physicist you meet; the
solution they use should also work for you.
Let’s talk about radio for a moment. Any changing electrical field
creates a magnetic field. This magnetic field can then spread out, as a
wave. When this electromagnetic wave hits any conductor—an
antenna, a metal fence, or your microphone wire—the magnetic
field gets converted back into a current. If it happens in rabbit
ears attached to a television, something good and wondrous has
happened and you can watch TV. If it happens in the wires in your
attic, you start hearing voices. Bummer.
Imagine you’re living at the end of the 19th century, when
all of this was worked out in Scotland, Italy, and New York. “With
electricity we can make these waves, invisible waves, that pass through
everything, including you. Then way over here, we can turn these
waves, that travel somehow right through walls, back into electricity.”
You’d probably ask for a drink, or a pitchfork. People still
don’t feel quite right about all this, as evidenced by the whining by
some living under high-voltage power lines. If radio were invented
today, San Francisco would probably ban it.
Today, we live in a world bathed in radio waves—waves we
didn’t ask for, that are constantly passing through everything. Your
attic, at the top of a hill and right next to transmission towers, is
particularly susceptible. What can we do?
Shielding! When the electromagnetic wave hits something
metal, the creation of the current uses up the wave. So, if we put what
you want kept free of radio waves inside a metal box, disco! (Yes,
aluminum-foil hats do work. Well, sort of. The neck gets in the
way.) In fact, it doesn’t even need to be a solid metal barrier. A wire
mesh will absorb all waves of a wavelength longer than the openings in
the mesh. As a bonus, such a mesh cage—deemed a Faraday cage,
after British chemist Michael Faraday—will also allow you to
breathe. A Faraday cage keeps your microwave from killing you and it
can keep your recordings free from interference.
Oscillatingly yours,
Science
Send your science questions to
dearscience@thestranger.com.
