You will hear Apollo astronauts occasionally say "all balls" or "five balls." After performing maneuvers, they would check their trajectory by taking fixes on stars using the telescope/sextant, this data would be fed into the guidance computer, which would compute their deviation from their intended course. If they were perfectly on their intended course, it would display a variation of 00000. "All balls." Perfectly accurate.
Another fun one is that in the phrase "three sheets to the wind" Sheets do not refer to the sails as many believe, they actually refer to the ropes that tie down the sales. So you lose a sheet, the sail becomes less predictable. If you lost 3 sails I think you'd just be dead in the water most times, not stumbling about
Patrick O'Brian has a bunch of opinions about these. "The devil to pay" was spreading pitch on, or paying, the hard-to-reach seam between deck and hull called the devil. At loggerheads means fighting with the long poles with a hot iron ball on the end , or loggerheads, used to heat pitch.
Another fun phrase with similar etymology is "pulling out all the stops". It comes from church organs, where the stops are all of the levers that can change the timbre
Going "balls out" refers to governors on steam engines which used centrifugal force on a pair of balls to regulate the speed of the engine. At full speed the balls were out at the maximum.
Have you ever accidentally stood on a ball (football/dodgeball) and tripped? If you have you may have an idea where the expression comes from.
You trip really hard.
Kind of like 'having one's balls in a vice'. It actually refers to the old days when ball bearings were made by hand. It was tedious work and the pressure to make ball bearings for the burgeoning industrial revolution was intense. They were cut out of metal and then polished smooth, secured in a vice. Hence, 'having your balls in a vice' meant being under intense pressure.
It's when your shaft is so damn deep that you can only barely make out your ball amidst the shaggy rough entanglement. Courses like Oakmont Country Club, Ko'olau, and Pinehurst are some examples that can challenge even top golfers.
As do many airplanes, in fact Cessna-style plunger throttle controls are relatively unusual.
The knobs on airplane throttles or thrust levers are also seldom spherical; it has happened but most are cylindrical. There's a whole section in FAR 23 that talks about how they have to be oriented in the cockpit, the shape and color of the knobs/handles etc. so pilots can tell them apart at a glance/by feel. For instance, when you first climb into a Cessna Skyhawk the position of the flap lever in front of the copilot's left knee feels kind of strange, almost everything is conveniently placed for the pilot, but the flaps are way over there. law requires the flap control to be to the right of the cockpit centerline, the gear lever must be to the left, but a Skyhawk has fixed gear.
You often hear steam engineers say "put the throttle on the ceiling" meaning apply full power. Diesel engineers will refer to "notch 8" as the highest power setting.
I guess it makes more sense than slamming your testicals against the wall.
In a way relating to human anatomy that has caused me to remove this phrase from my usage in recent years (because I worried how others would take it) the balls=testicles actually always made sense to me, but I'm not going to explain it.
However, now that I know what the most literal interpretation of the phrase actually is, I can feel safe using it again!