* Early use of "radio": In the late 19th century, scientists studying electromagnetic radiation used the term "radiant energy" to describe this form of energy that travels in waves. This included the work of James Clerk Maxwell and Heinrich Hertz, who laid the groundwork for radio communication.
* From "radiant" to "radio": The term "radio" itself was first used in 1897 by the British physicist Oliver Lodge, who was experimenting with wireless telegraphy. He shortened the term "radiant energy" to "radio" because it was a more convenient and catchy term.
* Popularization of "radio": The term "radio" quickly gained popularity in the early 20th century as wireless telegraphy became more widely known. The development of the radio receiver and the broadcasting of radio programs further solidified the term "radio" as the common word for this technology.
So, while "radio" itself wasn't around until the late 19th century, it's rooted in the Latin word "radius", which captures the essence of how radio waves travel outward in all directions like spokes from a wheel.