Who Invented the Sidewalk?


Before the 19th century, being a pedestrian in a major urban center meant taking a chance with your life every time you went outside. Without separate footpaths to protect them, pedestrians were forced to compete for space with animals, horse-drawn carts, carriages, wagons, and streetcars, running the risk of being mowed down or trampled. And if that doesn’t sound off-putting enough, horse dung and human urine flowed freely in the streets of European and American cities. According to David P. Jordan's Transforming Paris, the paving stones were covered in a slime so foul that the 19th century essayist William Hazlitt actually claimed he could recognize Parisians by their characteristic “light, jerking, fidgeting” gait, developed in order to navigate the fetid streets.


Why was this seriously gross state of affairs allowed to carry on for so long? According to Anastasia Loukaitou-Sideris's book on the subject, Sidewalks: Conflict and Negotiation over Public Space, the first sidewalks made their appearance around 2000 BCE in Anatolia (now Turkey), and there is evidence that both the ancient Greeks and Romans incorporated roadside pedestrian footpaths in their cities. The Romans even had a special name, semita, for their sidewalks. The fall of Rome in the 5th century CE ushered in a long, dark, sidewalk-less period in Europe, with sidewalks only making a comeback in the wake of the Great Fire of London in 1666, with some reconstructed streets featuring paved pedestrian walkways.

But sidewalks were still a rarity, the equivalent of urban amenities like rooftop pools today. In Paris, a handful of exclusive streets had limestone trottoirs, unconnected pavements that functioned almost like curbs to fend off traffic. The wide-scale revival of the sidewalk and its emergence as an integral feature of urban life can be attributed largely to the career of Georges-Eugene Haussmann, the man behind the massive rebuilding of Paris in the 1850s and 1860s.


The autocratic, self-styled Baron Haussmann (his title was never officially sanctioned) enjoyed almost limitless power and influence over the redesign of the city. Under his patron Napoleon III, he tore down the cramped, dark streets of medieval Paris and replaced them with wide, light-filled boulevards and block upon block of nearly identical apartment buildings with uniform facades. Flanking the grand boulevards were—you guessed it—sidewalks. But these were no ordinary sidewalks. They were “lined with benches, lush with trees,” according to Marshall Berman's All that is Solid Melts Into Air: The Experience of Modernity. They were the perfect stomping-ground for bourgeois Parisians, who turned up to stroll and mingle in droves. From little more than open sewers, city streets were transformed into places to see and be seen among the fashionable elite, redefining the experience of urban life in the process.

The prominence of sidewalks in Haussmann’s plan for Paris owed a lot to 19th century concerns over public health. Drawing on medical analogies, urban planners argued that a healthy city was a city that circulated—where traffic, fresh air, and people could move unimpeded through broad, artery-like roadways. By separating the flow of people from the movement of vehicular traffic, sidewalks contributed to the ordering and cleansing of the city. Paved surfaces for walking meant that pedestrians could avoid coming into contact with the effluvia of the streets, while the introduction of sewer and water systems simultaneously reduced the amount of liquid waste sloshing around the cobbles in the first place. The humble sidewalk became a potent symbol of hygiene and morality, the front line in the crusade against dirt.

Haussmann, always a big spender, was fired by Napoleon III in 1870 after critics accused him of extravagance (under Haussmann, the city’s municipal debt levels increased 15-fold). But his plan for Paris was hugely influential, with its key elements adopted by urban planners in Vienna, Barcelona, and, in the United States, the City Beautiful movement in Chicago and Washington, D.C. With the spread of Haussmann’s planning ideals, sidewalks finally assumed a ubiquitous role in city planning, with paved sidewalks a common feature of major cities by the late 19th century. By transforming city streets into spaces for leisure and consumption, sidewalks fundamentally changed the way we experience urban life.

Why Are Mugshots Made Public Before a Suspect is Convicted by the Court?

Jennifer Ellis:

Several reasons.

1. Mugshots can help find people when they have absconded, or warn people when someone is out and dangerous. So there is a good reason to share some mugshots.

2. Our legal system requires openness as per the federal constitution, and I imagine most if not all state constitutions. As such, this sort of information is not considered private and can be shared. Any effort to keep mugshots private would result in lawsuits by the press and lay people. This would be under the First and Sixth Amendments as well as the various Freedom of Information Acts. However, in 2016 a federal court ruled [PDF] that federal mugshots are no longer routinely available under the federal FOIA.

This is partially in recognition of the damage that mugshots can do online. In its opinion, the court noted that “[a] disclosed booking photo casts a long, damaging shadow over the depicted individual.” The court specifically mentions websites that put mugshots online, in its analysis. “In fact, mugshot websites collect and display booking photos from decades-old arrests: BustedMugshots and JustMugshots, to name a couple.” Some states have passed or are looking to pass laws to prevent release of mugshots prior to conviction. New Jersey is one example.

a) As the federal court recognizes, and as we all know, the reality is that if your picture in a mugshot is out there, regardless of whether you were convicted, it can have an unfortunate impact on your life. In the old days, this wasn’t too much of a problem because it really wasn’t easy to find mugshots. Now, with companies allegedly seeking to extort people into paying to get their images off the web, it has become a serious problem. Those companies may get in trouble if it can be proved that they are working in concert, getting paid to take the picture off one site and then putting it on another. But that is rare. In most cases, the picture is just public data to which there is no right of privacy under the law.

b) The underlying purpose of publicity is to avoid the government charging people and abusing the authority to do so. It was believed that the publicity would help protect people. And it does when you have a country that likes to hide what it is up to. But, it also can cause harm in a modern society like ours, where such things end up on the web and can cause permanent damage. Unfortunately, it is a bit of a catch-22. We have the right to know issues and free speech rights smack up against privacy rights and serious damage of reputation for people who have not been convicted of a crime. The law will no doubt continue to shake out over the next few years as it struggles to catch up with the technology.

This post originally appeared on Quora. Click here to view.

What Happens When You Flush an Airplane Toilet?

For millions of people, summer means an opportunity to hop on a plane and experience new and exciting sights, cultures, and food. It also means getting packed into a giant commercial aircraft and then wondering if you can make it to your next layover without submitting to the anxiety of using the onboard bathroom.

Roughly the size of an apartment pantry, these narrow facilities barely accommodate your outstretched knees; turbulence can make expelling waste a harrowing nightmare. Once you’ve successfully managed to complete the task and flush, what happens next?

Unlike our home toilets, planes can’t rely on water tanks to create passive suction to draw waste from the bowl. In addition to the expense of hauling hundreds of gallons of water, it’s impractical to leave standing water in an environment that shakes its contents like a snow globe. Originally, planes used an electronic pump system that moved waste along with a deodorizing liquid called Anotec. That method worked, but carrying the Anotec was undesirable for the same reasons as storing water: It raised fuel costs and added weight to the aircraft that could have been allocated for passengers. (Not surprisingly, airlines prefer to transport paying customers over blobs of poop.)

Beginning in the 1980s, planes used a pneumatic vacuum to suck liquids and solids down and away from the fixture. Once you hit the flush button, a valve at the bottom of the toilet opens, allowing the vacuum to siphon the contents out. (A nonstick coating similar to Teflon reduces the odds of any residue.) It travels to a storage tank near the back of the plane at high speeds, ready for ground crews to drain it once the airplane lands. The tank is then flushed out using a disinfectant.

If you’re also curious about timing your bathroom visit to avoid people waiting in line while you void, flight attendants say the best time to go is right after the captain turns off the seat belt sign and before drink service begins.

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