AM aerial at Feolin Ferry, Jura

This is the view looking north up the Sound of Jura. Notice the thin black line going diagonally from top left of centre down and right. I took the photograph through the car windscreen. When we first bought the car, we thought that the windscreen was cracked. It turns out that the wire they use as the aerial is now discreetly hidden in the glass. Electromagnetic radio waves make electrons oscillate and that is how that are detected. The movement of the electrons constitutes an alternating current. With AM, the amplitude of a given carrier frequency is changed to mimic the voices being carried. The wire represents one quarter of a wavelength. It is about 50cm long so a wavelength would be 2m. Frequency = wave speed/wavelength = 1.5 x 10^8 or 150 Megahertz.That would make it FM though!