Where Does Static Come From?

If you’ve ever used an old-school radio or TV, I can't believe we have to say that now,
you’re probably familiar with static: that crackly, fuzzy noise
coming from the speakers or the random white dot pattern popping up on the screen.
Whether it’s on a radio or TV, this static shows up for the same reason -- unwanted electromagnetic
waves interfering with the real signal.
And some of those waves go all the way back to the Big Bang.
TV and radio antennas receive information from a broadcasting tower via electromagnetic
waves — specifically, radio waves.
But there are other waves in the atmosphere that accidentally get in the way.
Lightning storms, for instance, release large bursts of radio waves, and these waves interfere
with the signal.
The interference means your device ends up receiving a wave that’s slightly offset
from the original.
This messed-up signal will correspond to some random sound or pixel, so you hear a random
noise or see a small glitch.
Even when there’s no lightning, you’ll still receive some noise from other sources
-- like radiation from other electronics, or the radiation streaming out from the Sun.
You’ll even pick up some of the radiation left over from the Big Bang, called the cosmic
microwave background radiation.
Back in the day, if you tuned your TV so it was in between broadcasting channels, then
you’d really notice those other sources of radiation — they’d create random noise
and changing pixels on your screen.
But modern day devices don’t have that problem, mainly because they mostly use digital signals
instead of analog signals.
Digital signals also store more information in an electromagnetic wave, but they only
use particular, discrete values.
And if interference offsets that wave slightly, the TV can just guess what wave it was supposed
to be and correct it.
It takes pretty strong interference to change the wave enough to alter the TV’s interpretation,
so you’re much less likely to end up with noise.
For the most part, digital TV signals have replaced analog around the world, but analog
radio is still being used in lots of places. Like probably your car
So if you have an analog radio and it tends to get crackly, just remember: you’re getting
a little glimpse into lightning storms, the majesty of our Sun, and even into the beginning of our universe
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Where Does Static Come From?

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