MANHATTAN’S INVISIBLE WALL

The Wire That Lets Jewish Residents Carry on Carrying

If you live in certain areas—New York City, for example—it’s probably not a great idea to look up at the sky as you walk up the streets and avenues. But if you do, assuming you don’t bump into anyone, you may notice something: a faint line shooting off lampposts, power line poles, and other tall roadside structures. That line is actually a wire, and it’s the border of an otherwise invisible wall around most of Manhattan.

To fully understand, you need to learn a bit about Judaism: The Sabbath—Friday night and Saturday—is intended to be a day of rest. That means you don’t do any work, which here can be defined in ways that aren’t immediately obvious to those of other faiths. For example, starting a fire, writing something down, tearing an object, and carrying something from one area to another. A prohibition on carrying seems sensible here: If you’re supposed to be resting, you probably shouldn’t be lugging objects home from work anyway.

But there are two important things to note here. First, the ban on carrying isn’t focused only on large, heavy items; it’s universal, meaning you can’t carry anything. That said, the ban isn’t on carrying altogether, just on carrying between two different areas. You can carry a glass of water from the sink to the table—that’s all within your house—but you can’t carry that same glass of water from the privacy of your home to somewhere public.

This rule causes problems, however. Let’s say you were on your way to synagogue on Saturday morning. You probably want to lock the doors to your house behind you and now have house keys that you need to take with you. Carrying your keys is a violation of the rule. So, a creative solution was in order. And that solution is called an eruv.

An eruv—“ay-roov”—is the invisible wall. Basically, the community gets together and agrees on an entire neighborhood that is one private domain, letting those observing the Sabbath carry items around this neighborhood as if they were in their own home. Eruvs are very common, at least in areas like New York City with a high density of observant Jewish residents.

But if you’re a believer who cares about the eruv from a religious perspective, whether the community has an eruv isn’t the end of the story. Even though the “wall” is primarily ritual, it still exists in tangible form—and those who observe take this seriously. If the wire isn’t up, the wall isn’t either. This can be hard to keep track of—the Manhattan eruv, for example, is miles long, which is way too much for any one person to monitor. As a result, the community runs a website with a status indicator displayed prominently.

BONUS FACT

Another invisible feature of New York City? The anti-theft features built into the light bulbs in the subways. The city’s transit system uses light bulbs with left-handed threaded screws in order to prevent theft. Instead of turning them to the left to loosen them, you need to turn them to the right. Sure, once you learn this, you can still steal the light bulbs, but they won’t work at your home. As subway history website NYCSubway.org explains, “Vandals who didn’t know this were surprised when they found that they would not screw into ordinary light fixtures.”