Building Tools, Leaving Breadcrumbs
When I was seventeen, I tried to build a perpetual motion machine.
It was for a competition. The idea — quietly ridiculous, in retrospect — was that an arrangement of magnets, placed just right, could use their own attract-and-repel forces to keep turning each other. I had read enough physics to know roughly why it shouldn't work, but not quite enough to feel the weight of why it couldn't. So I built it anyway, convinced that if I got the geometry right, the thing would just keep going.
It didn't, of course. The magnets found a stable arrangement and stopped. The second law of thermodynamics, which I had heard about but not yet really believed in, quietly held the line.
So I pivoted. The project I actually entered was an automated whiteboard with sliding panels, so an older teacher wouldn't have to walk back and forth across the board while writing. This was the late 1990s, before smartboards. It was, looking back, the more honest of the two ideas — I'd stopped trying to cheat thermodynamics and started trying to make someone's working day a little easier.
What I remember more than that first failure is the feeling, going in, that I was the first person to attempt this. I wasn't, obviously. People had been failing at perpetual motion for centuries before me, with much better equipment and considerably more patience. But for those weeks of building, the problem felt like mine.
It took me years to realise that nothing in engineering is yours alone.
Standing on tools you didn't make
Almost everything an engineer reaches for in a working day was built by someone they will never meet.
The pipe flow equations I use to estimate pressure drops were worked out, painstakingly, by people in the late 1800s and early 1900s — Darcy, Weisbach, Colebrook — solving practical problems for canals and steam plants and water supply schemes. The jet engine that carried me to my first job interview is a direct descendant of Frank Whittle's stubbornness in the 1930s, when very few people thought a turbojet was worth the bother. The hand-calculator I still reach for to do quick checks contains, under the keys, decades of refinement from anonymous engineers at Hewlett-Packard and Texas Instruments.
I never met any of them. They built tools, and the tools outlived them.
The first physics teacher who taught me how to draw a free-body diagram had no idea that thirty years later, on some quiet afternoon between meetings, I would still be drawing the same diagram on the back of a notepad to convince myself that a piping support load made sense. They weren't writing software or publishing papers — just teaching, in front of a chalkboard. But they handed me a tool, and I am still using it.
Leaving breadcrumbs
Once you notice the lineage, the question turns the other way round.
If everything I use was built by someone before me, what am I building for whoever comes next?
The honest answer is small things. A spreadsheet that captures the assumptions I needed last time, so the next person doesn't have to reconstruct them. A short note explaining why a particular calculation was set up the way it was. A bit of code that makes a tedious check less tedious. A slightly clearer figure in a slightly clearer report.
None of this is the jet engine. None of it changes the world. But it is, I think, what most engineering actually consists of — a long chain of people leaving small, useful artefacts behind, and the next person picking them up.
The perpetual motion machine I tried to build at seventeen was the wrong idea. The energy you put in is the energy you get out, minus what you lose to friction and heat and time. But the meta-machine of engineering practice runs on a different principle. The tools you build, the notes you leave, the explanations you take time to write down — those keep moving long after you stop pushing.
So I try to write the note. I try to leave the spreadsheet in a state that someone else could pick up. I try to be the kind of engineer the seventeen-year-old in his bedroom would have been quietly grateful to find ahead of him.
The magnets settle. The breadcrumbs don't.
