They go back years, but I'd hazard a guess they started either in the Armed Services or science.
I've always thought there is a difference between an abbreviation and an acronym though.
The abbreviation is just one or more letters like "m" (metre), "USA" or mph ( miles per hour).
The acronym is an abbreviation that forms a contrived but enunciable "word" like your examples; or a real word contrived to form an abbreviation. E.g. "STEM" - I don't know if it's used in America but it is used in British education, and stands for "Science, Technology, Engineering and Mathematics", making me suspect that woolly word "Technology" is there to form the snappy word "STEM"!
I haven't heard of STEM Durdle but it could well be used in the technology fields. There is a certain lingo to various professions and that may be used here in the US as well. We have POTUS and SOTU f'r instance. Hazardous materials is referred to as hazmat. Is that an acronym? It's interesting to see how language develops and offshots from a base word not to mention slang patois colloquialisms. Thank you for your reply and Happy Wednesday! :)
Perhaps STEM is a purely British thing, and it refers to technical subjects within school curriculae.
All trades and professions have their "lingo" but it's not all abbreviated, though sometimes it needs to be to avoid frankly unwieldy constructions.
This is perhaps the most unwieldy I have seen. I found it in an inherited text-book on measuring sound, and discovered that it is the standard unit in science and industry for quoting the sensitivity of hydrophones (underwater microphones):
The value is a count of so-many deciBels referred to 1Volt per micro-Pascal.
(Don't worry if you don't understand it. It took me ages to gain some idea what it means, even though I am old enough to have used logarithms at school - deciBels are logarithmic.)
No, you can hardly expect a scientist to keep typing that lot, so it is shortened to:
so-many dB re1V/µPa
The "so-many" is a large negative number, like -200, too. The "µ" sign is the Greek letter "mu", and standard for the "micro-", or one-millionth, of any standard unit of measurement unit.
Now that is a pure abbreviation - you cannot enunciate it as an acronym.
"Hazmat", "POTUS" and "SOTU" are abbreviations, but they are also acronyms because you can speak them as words.
Happy Wednesday to you too!
++++
(Edited to correct typing errors.)
This post was edited by Durdle at February 5, 2020 6:58 AM MST
Did you forget to include what you were talking about Durdle? I see nothing of any great length in your reply. Do you mean that very short dB re1.....? I never worry about not understanding something m'dear. I have my limits as I think you've probably noticed by now. Sometimes it takes a kind patient person a few tries explaining something from different angles for me to finally "get it" and sometimes there is no way I can grasp it. Some things I get immediately. I expect everyone has blind spots...some of us have more than others but I am never embarrassed or upset about mine. I embrace them and hope I can get get rid of some of them over time.Of course they are always being replaced by new ones. So it goes! Thank you for your helpful reply Durdle! :)
No, I did think what I was writing, and did not mean it exclusively for physicists.
I gave that example purely as that - an example of abbreviations to avoid very unwieldy text constructions.
Although it was from Acoustics (the science of sound and vibration), I did not intend it as a lesson on that subject.
If you were to write that lot in full, it would become ridiculous because the Pascal (unit of pressure) in the middle of it all, is itself a complex, compound unit!
Durdle 