In 1830, nearly half of the mathematics class at Yale was expelled for refusing to use a blackboard in their exams.

Conic section problems are a particularly tricky part of learning geometry. Put simply, you can derive some important mathematical shapes by slicing up a cone: the parabola, the ellipse, and the hyperbola. These shapes have some surprising applications – mapping planetary orbits, for example – so they’re an important part of any math curriculum.

Up until 1825, students at Yale University could use their textbooks when being examined on conic sections. For any given problem, they could track down the appropriate diagrams in those textbooks and then use them as part of their solution. They still needed to find the correct diagram. They still needed to apply their learning. But all the tedium of actually drawing their own diagrams? That part, they could skip.

This was fine and good, right up until a newfangled invention hit Yale. The blackboard.

(Well, the blackboard was not new. In the United States, it dates back at least as far as 1801 – in a math lecture at West Point. But its use was not widespread until later in the century.)

Yale professors switched the assessment in 1825. Now, instead of using your textbook, you had to draw your answer on the blackboard. Pedagogically effective (“show your work”), but not at all popular. The students revolted.

Half of the second-year class refused to take the exam. This first Conic Sections Rebellion was short-lived. Yale responded by suspending them all; they were only readmitted when they withdrew their protests and promised to take the exam. But five years later, the rebellion was back and even stronger.

Once again the objection was the dreaded conic sections class. It began when nine students refused to draw diagrams rather than use their textbook. Another thirty five students (with that original nine, nearly half of the class) signed a letter stating that they would do the same. It was an impressive attempt at negotiation… but it backfired spectacularly.

Upon this, to their surprise, the authorities of the college, instead of further parlaying with them, promptly announced that their connection with the college was now terminated by their own action. Thus the forty-four disaffected members of the class were at once summarily cut off from all opportunity to make further disturbance.

Yale College

The United States may be a democracy, but Yale sure wasn’t. Amongst those expelled was Alfred StillĂ©. He would go on to be the president of the American Medical Association, but he never got back into Yale. And no students ever rebelled against conic sections again.

Mathematician here. An evergreen concern of math departments is that our blackboards not be taken away as buildings get renovated and all other departments say “finally rid of those useless blackboards”. At the Isaac Newton Institute they have boards in the elevator and restrooms, just in case.

I *love* mathematician blackboard culture. Chalk on the board has so many affordances that just aren’t possible with other tools – using the chalk’s edge to shade a large area, for example.

One of these days I’ll delve a bit deeper on the topic, perhaps do a post about Hagoromo Fulltouch.