This Invisible Entity

"What is radio?“ asks Alasdair Pinkerton at the beginning of his
newly published book "Radio: Making Waves in Sound", in which he
answers this question a dozen times or more. Depending on time,
place and perspective, it can mean the discovery of the natural
occurring electromagnetic waves, the technological inventions that
make use of these waves or a means of communication that has had
tremendous effects on our lives since more than a century. It can
also mean a medium of news and entertainment or the little box
itself that we turn on to tune in. Alasdair Pinkerton’s “Radio”
touches on all these aspects and shows beautifully that they are
entangled on various levels. He tells the history of radio as
stories of bold inventors, of uncanny coincidences and of political
oppression and liberation.