10 - THE ORIGIN OF THE SOLID-STATE
FROM THE TRANSISTOR DO THE IC

In 1887,The German physicist, Heirich Rudolph Hertz, put the whole subject of electromagnetic radiation on a firm basis in a serie of classic experiments thus establishing the foundation that the so called radio waves did exist and certainly behave similarly to light waves in a way they could be reflected, refracted and also polarized.
As those new Hertzian radiations could not be perceived directly by human senses, it was necessary to provide some means for detecting or indicating their presence.
At the beginning of the Electronic age, many physical phenomena were employed by the reserachers thus originating obscure radio wave detectors which soon were replaced by crystal or proto-semiconducting materials.

Fig. 242 a survey on early types of devices used for Hertzian radiation