The Reason Behind Those Brightly Colored Balls Along Power Lines

If you've ever driven past those colorful balls strung up along a power line, you might have wondered about what purpose they serve—a thought that usually disappears as soon as the balls have faded from your rearview mirror. Though we sort of wish they were rogue holiday decorations local governments forgot to take down, the truth is that they’re actually used for aircraft safety.

According to electric utility company Edison International, the balls are called visibility marker balls (or just marker balls, for short), and they help make power lines more obvious to low-flying aircraft like planes and helicopters. Though you might not have realized it, you usually spot marker balls near mountain passes, deep valleys, major freeway crossings, and airports—all locations where aircraft tend to fly at low altitudes, running the risk of getting tangled up in the hard-to-see cables.

The Federal Aviation Administration regulates these marker balls and details their specifications in the Advisory Circular No. 70/7460-1L [PDF]. The diameter of the balls must be at least 36 inches on wires that cross canyons, lakes, and rivers, but the FAA allows 20-inch spheres on power lines fewer than 50 feet above ground level and within 1500 feet of an airport runway end. They should be spaced evenly at roughly 200-feet intervals along regular wires, and with less space (30- to 50-feet) intervals on wires near runway ends.

If there are fewer than four marker balls on a given wire, they should all be “aviation orange,” the fluorescent hue you probably associate with some communication towers. Otherwise, they should alternate between orange, white, and yellow to provide the highest level of visibility to approaching aircraft.

According to a 1983 article from United Press International, the marker balls first gained popularity in the early 1970s, when Arkansas’s then-governor Winthrop Rockefeller noticed electric wires whiz by as his aircraft started to land and decided something should be done to make them more obvious to pilots. The article also notes that the benefits go beyond aviation—the markers also help geese and boats steer clear of inconspicuous cables.

If you’re wondering by what magic the marker balls get installed on hard-to-reach power lines, it sometimes takes one helicopter and a very plucky technician. Check out the video below from T&D World to see exactly what that looks like. (The especially thrilling bit starts around 2:10.)

Now that one road-related mystery has been solved, find out the function of those black tubes sometimes stretched across the road.

[h/t Edison International]

Koalas Aren’t Bears, So Why Do People Call Them ‘Koala Bears’?

Arnaud_Martinez/iStock via Getty Images
Arnaud_Martinez/iStock via Getty Images

If you—with no prior knowledge of koalas or pouched animals in general—spotted a tree-climbing, leaf-munching, fur-covered creature in the wild, you might assume it was a small bear. That’s essentially what happened in the 18th century, and it’s the reason we still call koalas “bears” today, even when we know better.

In the late 1700s, English-speaking settlers happened upon a small animal in Australia that looked like a small, gray bear with a pouch. It was soon given the scientific name Phascolarctos cinereus, which is derived from Greek words meaning “ash-gray pouched bear.” Essentially, naturalists had named the unknown animal based on its appearance and behavior, and people didn’t realize until later that the presence of a pouch is a dead giveaway that an animal is definitely not a bear.

According to Live Science, koalas and bears both belong to the same class, Mammalia (i.e. they’re mammals). Then their taxonomic branches diverge: koalas belong to an infraclass called Marsupialia. Marsupials, unlike bears, give birth to their offspring when they’re still underdeveloped, and then carry them around in pouches. Even if koalas look just as cuddly as bear cubs, they’re much more closely related to other marsupials like kangaroos and wombats.

Over time, people adopted a name that the Aboriginal Darug people in Australia used for the animal, koala.

But bear still stuck as a modifier, and scientists never went back and replaced arctos (from arktos, Greek for bear) in its genus Phascolarctos with something more accurate. So, technically speaking, koalas are still called bears, even by scientists.

Wondering how you can help the lovable non-bears survive Australia’s wildfires? Here are 12 ideas.

[h/t Live Science]

The Reason Why Button-Down Shirts Have Loops On the Back

Erin McCarthy
Erin McCarthy

The apparel industry has presented a number of intriguing mysteries over the years. We’ve previously covered why clothes shrink in the wash, deciphered the laundry care tags on clothes, and figured out why shorts cost as much as pants. But one enduring puzzle persists: What’s with that weird loop on the back of button-down shirts?

The loop, which is found on many dress shirts for both men and women, is a small piece of fabric that typically occupies the space between the shoulder blades, where the yoke (upper back) of the shirt meets the pleat. While it can be an excellent way to annoy someone by tugging on it, history tells us it originally had a much more pragmatic function. The loops first became popular among naval sailors, who didn’t typically have much closet or storage space available for their uniforms. To make putting away and drying their shirts easier, the loops were included so they could be hung from a hook.

The loops didn’t remain exclusive to the Navy, however. In the 1960s, clothing manufacturer GANT added what became known as a locker loop to their dress shirts so their customers—frequently Ivy League college students—could hang the shirts in their lockers without them getting wrinkled. (The loop was originally placed on the back of the collar.) Later, students repurposed the loops to communicate their relationship status. If a man’s loop was missing, it meant he was dating someone. Women adopted an apparel-related signal, too: wearing their boyfriend’s scarf to indicate they were taken.

Particularly enthusiastic partners would rip the loop off spontaneously, which became a bit of a trend in the ‘60s. At the time, women who had crushes wearing Moss brand shirts complained that their loops were so strong and secure that they couldn’t be torn off.

For people who wanted to have a loop without ruining a shirt, one mail-order company offered to send just the loops to people in the mail.

You can still find the loops on shirts today, though they don't appear to have any social significance. Should you find one that's torn, it's probably due to wear, not someone's relationship status.

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