An Engineering Girl in the Warring States: Flirting with a Frenzied Mozi and Making Lu Ban Weep

[The Mohist Engineer: Mortise and Tenon] An Engineering Student in the Warring States: Flirting with Mozi and Making Lu Ban Cry

One afternoon in 444 BCE, I woke up in a pile of corpses.

My name is Ma Jingyi, and I’m a doctoral student in materials mechanics. The first person I killed, I killed with the principle of the lever.

The next day, I met Mozi. He was repairing a broken cart. I told him he was doing it wrong. He glanced at me as if I were a piece of wood he found somewhat interesting.

It took me many years to understand that look.

We used counting rods to solve equations on the ground. When we solved them, we looked at each other and smiled. All around us were the stench of corpses and the smoke of battle, but in that moment, the world was clean.

Someone asked him what sort of relationship a mortise and a tenon had.

He said, “Heat it until it’s red, then force it in. Once it cools, you can’t pull it out. That’s what it means to entrust someone with your life.”

He didn’t look at me.

And I didn’t look at him.

But I knew what he meant.

Physics textbooks two thousand four hundred years later call it an “interference fit.” In the Warring States period, I called it...

Never mind. It doesn’t matter.

What matters is that I still remember the scorched smell in the workshop that day.