There are so many mysteries is this world, so we all decide which ones we want to solve in our own lifetimes.
Because you can’t make time for them all.
If you’re out there wondering why you never learned the difference between AM and FM radio, well, you’re not alone.
First, you have to know how radio stations that still use traditional broadcasting methods get music and/or words to our stereos.
They begin with a carrier signal and a radio wave that has a constant frequency and amplitude. The information or music they record is encoded into the carrier wave by changing those variables.
The mixed signal is them sent out by large transmitters to be picked up by listeners. Their radios use a demodulator that converts the signal back into sound waves.
AM stands for amplitude modulation, so stations that broadcast AM alter the amplitude of the carrier wave in order to encode information.
FM stands for frequency modulation, so those stations adjust the frequency of the carrier wave.
One is not necessarily better than the other, but AM does have a significant issue that can deter some – and it’s that there are a lot of radio waves out there similar to those used by AM stations, but that comes from other sources.
Power lines, lightning, even the Sun can create waves that interfere with the ones going out to AM radio stations.
This doesn’t happen with FM stations, because the frequency can’t be confused the way the amplitude can – plus there’s a greater bandwidth.
People still choose to use AM radio because of its longer wavelengths. That means it has a larger range than FM and can more easily penetrate the concrete jungles that are modern cities.
This is why emergency messages typically go out on AM frequencies.
So, there you have it.
Go forth and conquer your next trivia night!
If you thought that was interesting, you might like to read about the mysterious “pyramids” discovered in Antarctica. What are they?