The link between rainfall and the duration of Roman emperors


There’s an interesting piece in The Economist about the link between rainfall and the rise and fall of Roman emperors.

One such lesson is how drought affected the stability of the Roman empire 1,500 years ago. In a new paper published in Economics Letters, Cornelius Christian of Brock University and Liam Elbourne of St Francis Xavier University identify a strong association between rainfall patterns and the duration in power of Roman emperors. The academics hypothesise that lower precipitation reduced crop yields, leading to food shortages and eventually starvation for soldiers stationed at the empire’s frontiers. As a result, troops were more likely to stage mutinies and assassinate their emperor.

The data, collected from oak tree rings, shows hungry troops peaking in revolts around The Gordian dynasty from 235 AD to 285. Invasions and the economic plight brought on by droughts were also contributors.

The academics combine data on assassinations—some 25 emperors were assassinated, roughly one-fifth of the total—with precipitation data collected from rainfall-sensitive oak-tree rings across the Roman frontier in France and eastern Germany.

Today’s natural disasters in California, Greece, and Japan due to heatwaves may not lead to overthrows, but they don’t augur well either.

It might be easy to dismiss the lessons from 1,500 years ago. Ancient Rome had little ability to store grain for long periods or irrigate crops. Yet, to this day, dictators rely on an obedient army to retain power. And more broadly, it has been long established that adverse weather causes economic shocks that lead to unrest, and even to civil war.

The history behind the modern definition of ‘average’

sats average human size

Everybody is unique, but on the whole, there’s still the average. Average height, average SAT score, there is even ‘average looking.’ From clothing to education to body features, there’s always been a standard.

According to 99% Invisible’s podcast ‘On Average,’ Belgian astronomer/mathematician Adolphe Quetelet discovered what we now know today as the ‘average’ when he aggregated the mean chest size of five thousand Scottish soldiers. Consequently, he took his philosophy and applied to other areas such as marriage and human lifespan, forever stamping his law of averages on the world, starting most notably with the Civil War.

The reason we have small, medium, and large clothing sizes today is that Abraham Lincoln needed a way to mass produce uniforms for the Union army. The US military would standardize both uniforms and airplanes in 1926, “the distance to the pedals and the stick, and even the shape of the flight helmets.”

However, with increased manpower required for World War II, the Air Force jettisoned the average American pilot for new planes with customizable seating, later adapted to account for female pilots such as five foot four Senior Air Force pilot Kim Campbell. She successfully flew her A10 Warthog to safety despite getting hit and losing all hydraulics during the aerial raid of Baghdad in 2003 Iraq.

So despite the continued standardization of certain clothing sizes and educational tests, today we are at least more flexible and egalitarian. You still have the option–albeit an expensive one–to order custom-made Nikes and a bespoke suit. The world is yours. Kind of.

Listen to ‘On Average’ from 99% Invisible


How Coffee Fueled the Civil War


Coffee did not win the war – Union material resources and manpower played a much, much bigger role than the quality of its Java – but it might say something about the victors. From one perspective, coffee was emblematic of the new Northern order of fast-paced wage labor, a hurried, business-minded, industrializing nation of strivers.

America’s Civil War didn’t just lead to the philosophy of pragmatism. It also resulted in an obsession with coffee.

Read How Coffee Fueled the Civil War

“Truth is what works”

“Truth is what works,” said the pragmatist William James.

Simple enough. But as Robert Talissee explains, you can’t take James’s advice at face value.

Beliefs are tools. A belief is like a hammer or a pair of scissors. It’s supposed to do things, behaviourally, it’s supposed to guide our actions. James thinks that the truth of a belief is to be understood in terms of the success it brings to our action when it serves as our guide.

Truth happens to an idea. First, we believe, and then we experiment. You can’t possibly confirm what’s true about your own beliefs and perceived faculties without taking some type of action to test them. What you think is true only becomes true through validation.

Positive results are at the heart of Pragmatist philosophy. But so are negative ones.

In Louis Menand’s book The Metaphysical Club, he explains how America’s Civil War — a failure in American democracy — was fought to show that democracy was indeed worth preserving.

Pragmatism is, therefore, a test of failure just as much it is a test to revalidate success and strengthen resolve. Pragmatists theorize that if your belief is strong enough, you’ll do everything you can do to uphold it to ensure repeated success. At the same time, if the experiments fail, then pragmatism fights to find something else that works.

Pragmatists endeavor to reach the best solution and keep improving until they get there, even if that means a completely different pivot. Pragmatism is also a community effort, as John Dewey later added. Your ideas are only so good that they get accepted by the wider community.

At the simplest, pragmatism can be described as “Truth is what works.” But as you can see from the complexity above, pragmatism allows for the truth to be continually tested and expanded until the solution of the moments rings true for all.