Cinema, Radio, and Television: Crash Course History of Science #29
Who Really Invented the Radio?
The First Radio Station
A Brief History of Radio
1944 ON THE AIR - History of radio broadcasting - Documentary
Radio is the technology of using radio waves to carry information, such as sound, by systematically modulating properties of electromagnetic energy waves transmitted through space, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.