Over the years, a number of fans have suggested that 99% Invisible cover a series of strange concrete arrows found scattered across the American countryside. They date back to the 1920s and were used to help guide airmail planes across the nation. While in use, the arrows were painted bright yellow and were accompanied by towers that illuminated them by night. These things are really neat (and fun to find on maps) but, ultimately, there is not much more to the story — not enough around which to build an entire episode.
We come across ideas like this all of the time—great little potential anecdotes and seeds of stories that just don’t warrant a complete audio production. So for this episode, we have compiled some of these shorter stories into a series of conversations between Roman Mars and the show’s producers. Each one also comes with its own little origin tale—the place it was found, person who suggested it and/or reason it made sense to include as a mini-story.
The Squaring of Circleville by Sam Greenspan
While researching the story that would become the episode The Plat of Zion, producer Sam Greenspan was digging through academic databases at the University of California at Berkeley’s Environmental Design Library when he came across a curious citation in an article. In “The Mormon Village, Genesis and Antecedents of the City of Zion Plan” (1977), author Richard H. Jackson writes that most towns built west of Appalachia all developed fairly similarly—with the lone exception of Circleville, Ohio. That led Sam to another journal article from 1955, entitled “Redevelopment in the 19th Century: The Squaring of Circleville.”
Circleville, Ohio was established in 1810 by a local power broker named Daniel Driesbach. Driesbach decided to build on land that had two Native American earthworks—one in the shape of a square, one in a circle. Dreisbach took inspiration from the shapes of the low earthen walls, and decided that they would be the framework for his city.
He decided to build a circular grid.
The result was an urban layout that looked less like graph paper and more like the steering wheel of a pirate ship—spokes sticking out in all directions from a central plaza, with a concentric ring road wrapping around the plaza, and another ring road around that. Hence: Circleville.
To the dismay of the Dreisbach, however, the Circlevillians hated it. People complained that the round streets forced everyone to build on oddly-shaped lots. Eventually, they appealed to the state government, and in 1837 the Ohio State Assembly decided to ditch the circular grid.
The Circleville Squaring Company was deputized to de-circle Circleville.
It took nearly two decades but it worked. All that is left of the original circular plan are a few rounded buildings, the name of the town, and the city’s municipal seal.
The Dutch Reach by Kurt Kohlstedt
Each week, 99% Invisible publishes an array of new content in addition to the weekly podcast episodes, including multiple articles by staff as well as outside contributors. These cover the same thematic territory as 99pi audio pieces but tackle topics that are too short for episodes or ones that require visuals. If a story simply won’t work without graphics, videos or pictures, it can still be a great fit for the website. One of our most popular pieces this year was a short article written by Kurt Kohlstedt about something known as the The Dutch Reach.
Bicycle lanes can be a boon for cyclists but they can also land riders in the “door zone,” a dangerous area sandwiched between primary vehicle lanes and parked cars. In the long term, cities should continue designing better solutions to accommodate bicyclists, but in the meantime: drivers could learn a thing or two from a practice found in Europe. Retired doctor Michael Charney calls it the “Dutch Reach” and it addresses a serious problem on the streets of America where parking spots often sit right alongside unprotected bicycle lanes.
Basically, instead of using their door-side (left) arm, drivers reach over with their other (right) arm. This simple behavioral shift causes drivers to look back naturally and see whether or not there are oncoming bicyclists. The simplicity of the approach is part of its genius. It trades one basic habit for an easy alternative, a cheaper and faster fix than pricey and prolonged infrastructural overhauls. If this approach were integrated into driving education programs in the United States, it could become something so ordinary that people would not even call it The Dutch Reach — it would just be the way one opens a car door.
And this is just one example of many 99pi stories you will only find on the website. Fans of the show looking to dive into our extensive article archives can use this handy list to get started:
If architect, Renderings vs Reality
If urbanist, Clean City Law
If suburbanist, Ghost Boxes
If cyclist, The Dutch Reach
If activist, Guerrilla Bike Lanes
If ecologist, Invisible Fences
If artist, Olympic Architects
If humorist, 11 Feet 8 Inches
If numerologist, Floor M
If ponerologist, Architecture of Evil
If designer, Biohazard
If developer, Least Resistance
If driver, The Magic Roundabout
If shopper, Railway Market
If filmmaker, LA Misdirection
If geographer, Post-It Urbanism
If traveler, Paternoster Lifts
If engineer, Tilt & Turn
If continental, Fact Follows Fiction
If acoustician, Building the Wall
If historian, Tsunami Stones
If pedestrian, User Illusion
Looking to get a friend into 99pi in general? Here is another list designed to introduce people to episodes of the show.
The Big Zero by Emmett FitzGerald
Emmett FitzGerald is always on the lookout for a good sports story, and since he started working at 99pi he has been looking into stadiums. He hasn’t found one that is worth spending a whole episode on, but this is one of his favorites. There is a very unusual soccer stadium in the northeast Brazilian state of Amapá, a region that’s mostly dense rainforest. The capital city, Macapá, is so remote there are no roads connecting it to the rest of the country. Tourists do visit Macapá though, and one of the things that draws them there is its location — it sits precisely on the equator.
A giant red stripe runs down Avenida Equatorial, marking the world’s most famous latitude line. That equator also runs right into the city’s soccer stadium. The 10,000-person arena is officially called the Estadio Milton Corrêa after a local sporting bureaucrat, but everyone just calls it O Zerão, or: the Big Zero (after its notable latitude). And the stadium was built so that the equator runs perfectly down the midfield line of the pitch.
The Big Zero mostly hosts small Brazilian professional soccer clubs, but each match is a battle between hemispheres: north versus south. At least until half-time when the teams switch sides.
The Little Chirp by Delaney Hall
This story came to 99% Invisible from one of our listeners — Dr. Carrie Nugent. She is an asteroid scientist at CalTech and she has her own podcast called Space Pod. Our listeners write in all the time with story ideas and this one stood out. To understand the story, though, takes a bit of context.
Earlier this year there was a huge discovery in astronomy. Scientists with the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a signal. What their machines registered was effectively the sound of two black holes colliding and unleashing the energy of a billion trillion suns.
The signal they detected was faint because the black holes collided a billion years ago and the resulting gravitational wave had been traveling through space for all of those years, getting fainter and fainter along the way. By the time it reached us here on earth, it sounded like a little chirp. But despite all this, scientists managed to detect it.
Their discovery was enormously significant because it’s the first direct evidence of gravitational waves, which are ripples in space-time. These were predicted more than 100 years ago by Einstein in his general theory of relativity, which upended the known rules of physics. Instead of a static framework, Einstein theorized that matter and energy could actually distort the geometry of the universe, creating ripples of gravity. The gravitational waves LIGO detected, so many years later, confirmed his theory with empirical data.
But as Dr. Nugent, our listener, pointed out to us, there is a design angle that has not really been covered as much: the instrument that detected the sound is amazing and extremely sensitive. It’s also incredibly complex and difficult to describe on the radio. But there’s one element we wanted to focus on: how LIGO scientists went about minimizing environmental noise that might interfere with the signal they were trying to detect.
First, they isolated the instrument’s detectors in giant vacuums that would largely protect them from the vibrations and noises of the outside world. Then, on top of that, the experiment employed two environmental monitoring experts. Their job was to figure out how outside sound (rumbling trucks, falling trees, thunderstorms, howling wolves) might interfere with the experiment. These monitors played recordings near the detectors and documented their effects. They even had a staff member ride away on his motorcycle to determine if and how the rumbling motor would impact their measurements.
Over time, the monitoring team generated a huge library of what different kinds of sonic interference might do to the experiment. That way, when the genuine signal appeared they would know it was the real deal.
It is hard to convey how crazy it is that they were able to detect the signal from the black hole collision. It’s as if the scientists at LIGO measured the distance from earth to the nearest star outside our solar system to within the width of a human hair.
Have a question or story for 99% Invisible? We will be doing a follow-up to this episode with additional mini-stories based on listener inquiries and ideas. Feel free to ask or suggest something in a comment below!