It doesn’t really have to be strictly scientific, but I’m looking for places where people are forced to endure calculus or at least strenuous algebra using English units.
Tell me about your own work that uses English units.
When I studied nuclear power in the Navy, every single calculation was performed in pounds force, pounds mass, gallons, feet, British thermal units, horsepower, and so forth. Even though this was many years ago, the English units seemed just as out of place back then as they would today.
Mostly, we did thermodynamics calculations in these units. It wasn’t really as bad as it would seem, though the unit analysis was very dicey. I recall that there was a “proportionality constant” that related pounds force to pounds mass that we used whenever things weren’t working out – “Why don’t you try throwing the proportionality constant in there, that might fix it…”
There’s nothing like whipping out the conversions from watts to horsepower to BTUs, all so you can better look things up in your handy-dandy steam tables. Oh yes, the temperatures were all in this previously-unknown-to-me scale called Rankine (it is to Fahrenheit what Kelvin is to Celsius).
It happens all the time in the engineering world. FWIW, electrical engineering units are metric definitions, but since about every dimension is named for a dead scientist, this is obscured.
I do some controls work, so relating volts and amps to ft-lbs and oz-ins od torque is common. Being drilled in English-metric conversion is Freshman Engineering 101, so it’s second nature.
The conversion for lbm to lbf is lb[sub]f[/sub] = lb[sub]m[/sub]*32.2ft/sec[sup]2[/sup], BTW.
Well, a lot of civil and structural engineering is done is English units, leading to some irrritating conversions. On bridge layout sheets here in Texas, we use degrees, minutes, and seconds for the angles which I find immensely annoying to have to convert everytime I need to do some trig…
The radius of the earth varies from 3950 statute miles at the poles to 3963 statute miles at the equator. I often use the value of 3960, because it’s an exact ratio (3/4) of 5280, the number of feet per statute mile. This simplifies certain astrodynamics calculations, where it’s necessary to convert between feet and statute miles.
I got the idea for this from the fact that there are exactly 1852 meters in a nautical mile. In astrodynamics, even small rounding errors can be a problem. Being able to use this exact ratio eliminates a lot of them.
In my line of work we often have to convert Curies to Becquerels and vice-versa, it is annoying and seems so random. Also there’s plenty of converting acres to square meters or hectares. Why can’t we just get rid of that stupid system already? I hate hate hate converting degrees C to F or F to C and inches to cms…argh!!
I forgot to mention that I flunked Thermodynamics twice before I switched to Electrical Engineering (EEs didn’t have to take Thermo), in part because I could not remember to convert from lbm to lbf. Well, that and I spent my sophomore year f***ing off instead of going to class.
Man, I’m so glad we did our statics stuff in metric… SI is soo much easier than, say, remembering to distinguish between lb-f and lb-m. I still remeber the incredulous looks when we were introduced to the ‘slug’.
On the other hand I remember when the Poster Formerly Known As Anthracite would discuss power-plant thermodynamics in US Customary Units. Wow…
When I started writing those converters over 6 years ago, I wondered if anyone would visit the website because those BTU’s, nautical miles, acres, gallons, pounds, etc so were so out-of-date then. Surprisingly, they are still alive and well today as they have been for centuries. So much for progress.
Incidentally, the converters are very user-friendly. None of that “from - to” foolishness. Visit one and you’ll see what I mean.
Yes, shameless self-promotion I know but it is free - no advertising - no pathetic pleas for money or to visit my sponsors - no popups.
I took a class on agricultural water management back in college, and English units were still almost ubiquitous. Especially memorable were the acre-foot and the acre-inch, i.e. the amount of water necessary to cover an acre in one foot or one inch of water. There was of course some giant conversion factor to convert this to gallons, and then you could figure out how many miles of pipe you would need depending on how big the pipe was and how many gallons per minute it was delivering. It was actually a very interesting course, and I suppose in an agricultural context an acre-foot is useful, but I’m sure that hectare-meters would be easier to work in. They being exactly 100,000 cubic meters and converting easily to liters and all.
I measure temperatures in keV (kilo-electron-volts), radiation flux densities in units called Janskys, and surface brightnesses in units called Janskys/beam. I don’t think I’ve used a single SI unit since I started my PhD!
Wolfy Great link. Thanks.
Oh BTW, I was messing with the Ultra Converter[sup]tm[/sup]. Why Jupiter diameters and not the other planets? (IANAAstronomer)
That’s quite interesting actually. It’ll do Moon diameters, Jupiter diameters and Solar diameters, but not Earth diameters. Solar diameters (or rather radii) are useful when taking about the sizes of other stars, Moon diameters, are presumably useful for talking about the smaller planets (but I’d use Earth diameters for that, really). Presumably the Jupiter diameters give us a middling length scale?
But I’m an extragalactic astronomer – the smallest units I use are kilo-parsecs!
Up until I took Thermodynamics, all of my engineering courses stressed the importance of SI units, and basically ignored English units. Right now it’s a pretty even mixture of both. Needless to say, I keep links to several coversion programs on hand.
Angua & NutMagnet
As far as I know the UltraConverter™ will convert Earth Diameters.
The reason for choosing the diameters of the Moon, Earth, Jupiter and the Sun is that these are objects with which most people would have some familiarity. I chose Jupiter for the only planet (besides Earth) because it is the largest. I included these “non-standard” units in order to give some perspective when people make conversions.
Right now I’m at a power plant (or at least at the hotel next to it…) helping to install a multi-million dollar controls upgrade, which involves installing a super-advanced AI system to use “learning” to predict and adjust how to control the entire plant to reduce pollution and increase efficiency.
And displayed up on the wireless $12,000 plasma monitors are a whole array of US Customary Units - Btu, ft, lbf, lbm, in.w.g., psi, and even the Satanic half-breed of Btu/kWh.
