Right now, invisible signals are flying
through the air all around you.
Beyond the spectrum of light
your eyes can see,
massive radio waves as wide as houses
carry information between computers,
GPS systems, cell phones, and more.
In fact, the signal your phone broadcasts
is so strong,
if your eyes could see radio waves,
your phone would be visible from Jupiter.
At least your special eyes would be able
to see this if the sky
wasn’t flooded with interference
from routers, satellites, and, of course,
people flying who haven't put their
phones on airplane mode.
You see, this setting isn't
to protect your flight,
it's to protect everyone else
in your flight path.
Cell phones connect to networks
by emitting information
in the form of electromagnetic waves;
specifically, radio waves,
which occupy this band of the
electromagnetic spectrum.
These radio waves come
in a range of wavelengths,
and let’s imagine your special eyes
see the various wavelengths
as different colors.
When you make a call,
your phone generates a radio wave signal
which it throws to the nearest cell tower.
If you're far from service,
your phone will expend more battery power
to send a higher amplitude signal
in an effort to make a connection.
Once connected, this signal is relayed
between cell towers
all the way to your call’s recipient.
Since your call isn’t the only
signal out here,
cell towers managing the calls assign
each phones involved their own wavelength.
This specific color ensures you’re not
picking up other people’s calls.
It’s even slightly different
from the wavelength
your phone is receiving information on,
so as not to interfere
with that incoming signal.
But there are only so many
colors to choose from.
And since the advent of Wi-Fi,
the demand for ownership of these
wavelengths has increased dramatically.
With all these signals in the air and
a limited number of colors to assign,
avoiding interference is
increasingly difficult.
Especially when cell towers receive
too many signals at once,
such as during regional emergencies, when
everyone's trying to use their phones.
But other sources of interference
are more preventable,
like phones searching for signals
from thousands of meters in the sky.
Phones on planes are very
far from cell towers,
so they work overtime to send
the loudest signals they can
in search of service.
But since planes travel so quickly,
the phones might find themselves much
closer to a cell tower than expected—
blasting it with a massive signal
that drowns out those on the ground.
So when you fly without
using airplane mode,
you’re essentially acting
as a military radio jammer—
sending out giant radio waves
that interfere with nearby signals.
Even on the ground, almost all our
electronics emit rogue radio waves,
slowing down our internet
and making our calls choppy.
This leads consumers to pay
for more bandwidth,
pushing service providers to take
over more of the radio spectrum,
and eventually, send more satellites
into the sky—
creating a vicious cycle that could
eventually blot out the stars.
Though, even without these satellites,
this system is threatening
our relationship with the cosmos.
Radio telescopes used for astronomy
rely on a specific band of wavelengths
to see deep into space.
However, while this range
is supposedly protected,
the cutoffs aren’t enforced.
For example, the Very Large Array can see
signals throughout our solar system
from 1 to 50 GHz.
But if it tries looking for signals
below 5 GHz,
its search could be drowned
out by a sea of phones on 5G networks.
Today, nowhere on Earth
is truly radio quiet.
Satellites relaying signals
around the globe
have blanketed the planet in radio waves.
But there are a few places
with less crowded skies,
where radio telescopes
can look deep into space.
Here, we can see the black hole
at the center of the Milky Way,
and uncover the secrets of galaxies
up to 96 billion light years away.
Well, so long as we’re
not blinded by phones
sending signals from first class.