## Roots of Unity

Mathematics: learning it, doing it, celebrating it.

# Blackboards Make You Stupid (Or Is It Just Me?)

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It is unknown whether Einstein was subject to Blackboard Stupidity. In this picture, he appears to be far enough from the blackboard that BS effects should be minimal. Image: public domain, via Wikimedia Commons

I just finished my first week teaching after a few years out of the classroom. Whenever I teach, I'm struck by how much detail I need to put in my notes to make sure I don't say something absolutely ridiculous when I'm in front of the class. Even with careful preparation, I sometimes arrive back at my office wondering why I couldn't answer a question that perplexed me in class but suddenly seems so simple. The reason? Blackboards make me stupid, and they probably make you stupid too.

A quick search through stock photos reveals that the intelligence-suppressing powers of blackboards are well documented. But the exact amount that a person's intelligence decreases when he or she stands at the front of a classroom with a blackboard has only recently been determined—by yours truly.

This week, I came up with a preliminary formula that describes the troubling phenomenon of Blackboard Stupidity.

A completely not bogus formula for the Blackboard Stupidity, or BS, factor. Image: Evelyn Lamb.

In this formula:

n=number of students in the class;

s=number of hours of sleep you got last night;

p=number of hours of preparation you did for the class in the past three days;

m="morning factor"=number of hours before noon of the class start time;

How exactly to interpret this formula has not been completely determined yet—this is cutting-edge research, after all. It is clear that larger numbers are worse than smaller ones, but the exact relationship between Blackboard Stupidity and IQ is still unclear.

A quick look at this equation reveals that a person's distance from the blackboard is the dominant term. Halving your distance from the blackboard will quadruple your BS factor, whereas halving or doubling your number of students or amount of sleep will not have nearly as large an effect.

The BS factor should always be positive, although inspection of the formula shows that the denominator can be 0 if m is greater than s+p. If that is the case, you are definitely in trouble! Perhaps we should interpret a negative BS as an urgent warning that you really need to be getting more sleep and/or not working at a school that has classes at 4 am.

My BS formula is just a preliminary step in understanding and helping to mitigate the longstanding problem of Blackboard Stupidity. Further research is needed to make the formula more precise and answer some basic questions about the phenomenon. Do people ever fully recover from BS? Can people experience whiteboard-induced BS? Anecdotal evidence suggests they can, but no study has yet been conducted.

My research has not yet been published on vixra, but I hope to have a preprint available soon. In the meantime, feel free to help me identify BS factors I may have neglected, and please encourage your lawmakers to support funding for research on the sometimes debilitating and often humiliating condition of Blackboard Stupidity.

The views expressed are those of the author and are not necessarily those of Scientific American.