Definitely a fun note :). I think I heard it first from a Jay Leno youtube video where he was showing his amazing collection of steam powered machinery.

This is from the article, but governors also played a role in kicking off modern control theory! """ In 1868, James Clerk Maxwell studied when these oscillations grow or die away in his paper “On Governors”[https://www.damtp.cam.ac.uk/user/gold/pdfs/teaching/old_lite...]. This became one of the beginnings of modern control theory. """

Indeed, and of course "governor" in Greek is κυβερνήτης (kubernetes).

tbh, any time i've said it i've been referring to testicles, but thanks for the helpful excuse in future.

Similar to balls to the walls (or similar). Coming from the analog aviation controls I believe.

Example, throttle controls on a Dogulas DC3. All engine controls forward is the typical convention for full power. (At sea level, neglecting the altitude effect on required engine fuel/air mixture.)

https://www.douglasdc3.com/dc3throt/dc3throt.htm

That said, i'm sure the pilots were aware of the double entendre

Balls to the van der Waals

Engaging in a little hydrogen bonding, eh?

I suppose this is also the less colorful true origin of "balls to the wall" than the phrase itself suggests?

Nope. Balls to the wall refers to the balls on the end of throttle levers in aircraft cockpit.

Going balls to the wall means pushing the throttle and mixture all the way in to the firewall/instrument panel for maximum power.

Nit: I believe this originated with locomotives, predating aircraft by quite a bit!

Every source I can find says it was a mid century phrase first found written in the 1960s from pilots. Pre aircraft locomotives would have been steam driven. Largely operated by a complex series of valves, mostly rotating so no wall to push them to. They did have a governor balanced by rotating balls, which when at full RPM would be fully extended, or: balls out.

https://www.thedrive.com/news/the-phrase-balls-to-the-wall-c...

> When the engine slows, the balls fall and open the cock again.

The choice of wording makes me suspect that they intended both entendres. ;)

Euphemisms are weird, what was originally intended as a way of saying a thing without actually saying that thing, becomes the unspeakable thing in the first place. and the original meaning fades.

The one I like is why do we use birds to refer to female anatomy? I also heard something the other day and had an epiphany, but the sort you can't really tell anyone. "Oh... it means pouch that makes so much more sense, it's not a cat."

and i suppose “fuck” is actually an acronym for “fornicating under command of king,” right?

For Unlawful Carnal Knowledge is the acronym I've encountered most

While fun and satisfying, this is extremely unlikely to be true.

The first attested use is from 1945, on the nose of a P-47 Thunderbolt flown by Captain Milton Thompson of the 509th Fighter Squadron. And his art was exactly what you'd expect: a charging bull with the words "balls out".

Maybe he's thinking of "balls to the wall"?

Could be, for which the first attested use is in 1965 or so. Still doesn’t help.

There is also a steam engineers term called "high-balling" which referred the little ball in the steam pressure gauge used in the early days. So high-balling was travelling at high speed.

plausibly related to a "high ball" (cocktail glass shape, or slang for a personal-use amount of cocaine)

What about the phrase "testicles out"?

That one, although widely believed to refer to the steel balls in a centrifugal governor of a steam engine, actually refers to testicles.