Hacker News Reader

Comment by wyclif | Hacker News Reader

My Dad is a retired R&D chemist who worked at the DuPont corporation's Experimental Station. When I was a kid he would bring his old slide rules home from work when he got a new one, and at one point he explained to me how they work but I forgot it all long ago.

I still have the slide rules, so this post was a great rabbit hole to go down. In software there's no need for them but I still find them fascinating as a window into how engineers used to get their work done.

View on HN

> In software there's no need for them...

... but in the Real World they work pretty well for the sort of calculations you might need to do in the field (literally, in a field, sometimes) and don't require batteries, are reasonably waterproof, and reasonably robust if dropped.

The all plastic ones are intrinsically safe in a potentially flammable environment, they don't require power, they're an education in how most engineering materials in the real world have surprisingly wide tolerances so they are far more than accurate enough for most work, for people who learn graphically/visually they are the logical next educational step after counting on fingers.

They're pretty useful for teaching amateur people how to implement algorithms. Multiple ways to solve problems, some easier than others, some more efficient than others, with immediate rewards of faster higher accuracy.

> The all plastic ones are intrinsically safe in a potentially flammable environment

Never thought of that, and I used to work in an ATEX environment where calculators powered by watch batteries had to be carefully logged and carried across to a "safe" area inside a special (horribly expensive) Peli case.

Me neither. Similar to the drill floor on oil rigs where there's tracking of every tool in use to make sure it is non-sparking.

There were also all manner of specialty "slide rule" calculators of various kinds for special purposes. I used to have a bunch of them especially from the oil business. Don't know if I still have any at this point.

Somewhere I have a circular one for flight calculations that you velcro to the knee of your trousers.

Reply on news.ycombinator.com