One problem with a new technology is deciding what to call it. Although "electromagnetic radiation" is the formal scientific term for what Heinrich Hertz produced with his spark transmitter, numerous other descriptive phrases were also used, including various permutations of "Hertzian waves", "electric waves", "ether waves", "spark telegraphy", "space telegraphy", and "wireless". Eventually, the official term "radio" was adopted at the 1906 Berlin Radiotelegraph Convention, but it took many years before the synonyms like "wireless" generally disappeared from usage in the United States. (Recently "wireless" has made a comeback in "wireless telephones", but these still use electromagnetic radiation, and actually consist of a small radio transmitter and receiver.)
Radio News, January, 1925, page 1165:

Radio  vs.  Wireless
"I SEE that you have installed a wireless set," I said to a well educated neighbor of mine.
    "No," he answered, "it's a radio." I concealed the utter disgust I felt for this man and his stupidity, and hurried home to write about the "difference" between radio and wireless. There ain't none such, that's all. Wireless or radio, whichever you wish to call it, has put more people in the bug-house and living room than any other mechanical cussing-machine.
    But radio and wireless--there must be a big difference; they're spelled a little different. I hate to disappoint and disillusion some of you who have counted so much on a "big difference." But just brace yourselves and prepare for the shock: THERE IS NO DIFFERENCE BETWEEN RADIO AND WIRELESS EXCEPT THE SPELLING.
    Wireless does not mean sparks, noise, lots of switches and neighborhood feuds. Wireless means communication without the use of wires other than the aerial; the ether and ground taking the place of wires. Radio means exactly the same thing: it is the same process. Now communication by wireless waves may consist of an SOS message from a ship at sea or the communication may be simply the reception of a wheezing soprano. It does not become something different in either spelling or meaning just because you can understand one and can't the other. When broadcasting was being experimented with, back in 1915, they called these experiments "wireless telephone." But today the same thing is being done only on a wholesale basis, and for no reason at all the name has been changed to "radio." But radio is not a new word and its real meaning isn't broadcasting of music or speeches. Radio is simply the process of communication by either voice or telegraphic code by using the ether and ground in place of direct wires. Thus, don't say you "have a radio" in your house. What you mean is that you have a radio receiver or a wireless receiver in your home. If you think that there's any difference between a radio receiver and a wireless receiver then how do you explain hearing code signals on your so-called "radio"? No, there's no difference; the same circuits that the ships and amateurs use for reception of radio telegraph or wireless telegraph signals will be found in a so-called "radio." The famous "Reinartz Circuit" was originally made for the reception of code signals, not soprano broadcasts.
    So get it straight now, that the thing you have in the living room that makes noises like the victrola is not "a radio," but a "radio receiver," or "wireless receiver"; the two terms are synonymous. The code signals which sometimes justly drown out a political speech should not be called "wireless," for that is too broad a term. Call it "wireless telegraph" or "radio telegraph." The jazz band music you hear is NOT "radio." It is "radio telephone" or "wireless telephone," music. If this is the radio age let us learn the correct classification of the various branches, instead of making one or two words put on various disguises for the many parts they are supposed to play.