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]

Amazon’s Big Fall Sale Features Deals on Electronics, Kitchen Appliances, and Home Décor

Dash/Keurig
Dash/Keurig

If you're looking for deals on items like Keurigs, BISSELL vacuums, and essential oil diffusers, it's usually pretty slim pickings until the holiday sales roll around. Thankfully, Amazon is starting these deals a little earlier with their Big Fall Sale, where customers can get up to 20 percent off everything from home decor to WFH essentials and kitchen gadgets. Now you won’t have to wait until Black Friday for the deal you need. Make sure to see all the deals that the sale has to offer here and check out our favorites below.

Electronics

Dash/Amazon

- BISSELL Lightweight Upright Vacuum Cleaner $170 (save $60)

- Dash Deluxe Air Fryer $80 (save $20)

- Dash Rapid 6-Egg Cooker $17 (save $3)

- Keurig K-Café Single Coffee Maker $169 (save $30)

- COMFEE Toaster Oven $29 (save $9)

- AmazonBasics 1500W Oscillating Ceramic Heater $31 (save $4)

Home office Essentials

HP/Amazon

- HP Neverstop Laser Printer $250 (save $30)

- HP ScanJet Pro 2500 f1 Flatbed OCR Scanner $274 (save $25)

- HP Printer Paper (500 Sheets) $5 (save $2)

- Mead Composition Books Pack of 5 Ruled Notebooks $11 (save $2)

- Swingline Desktop Hole Punch $7 (save $17)

- Officemate OIC Achieva Side Load Letter Tray $15 (save $7)

- PILOT G2 Premium Rolling Ball Gel Pens 12-Pack $10 (save $3)

Toys and games

Selieve/Amazon

- Selieve Toys Old Children's Walkie Talkies $17 (save $7)

- Yard Games Giant Tumbling Timbers $59 (save $21)

- Duckura Jump Rocket Launchers $11 (save $17)

- EXERCISE N PLAY Automatic Launcher Baseball Bat $14 (save $29)

- Holy Stone HS165 GPS Drones with 2K HD Camera $95 (save $40)

Home Improvement

DEWALT/Amazon

- DEWALT 20V MAX LED Hand Held Work Light $54 (save $65)

- Duck EZ Packing Tape with Dispenser, 6 Rolls $11 (save $6)

- Bissell MultiClean Wet/Dry Garage Auto Vacuum $111 (save $39)

- Full Circle Sinksational Sink Strainer with Stopper $5 (save $2)

Home Décor

NECA/Amazon

- A Christmas Story 20-Inch Leg Lamp Prop Replica by NECA $41 save $5

- SYLVANIA 100 LED Warm White Mini Lights $8 (save 2)

- Yankee Candle Large Jar Candle Vanilla Cupcake $17 (save $12)

- Malden 8-Opening Matted Collage Picture Frame $20 (save $8)

- Lush Decor Blue and Gray Flower Curtains Pair $57 (save $55)

- LEVOIT Essential Oil Diffuser $25 (save $5)

Sign Up Today: Get exclusive deals, product news, reviews, and more with the Mental Floss Smart Shopping newsletter!

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

Why Do Dogs Like to Bury Things?

Dogs like to dig.
Dogs like to dig.
Nickos/iStock via Getty Images

If you’ve ever found your dog’s favorite toy nestled between pillows or under a pile of loose dirt in the backyard, then you’ve probably come to understand that dogs like to bury things. Like many of their behaviors, digging is an instinct. But where does that impulse come from?

Cesar's Way explains that before dogs were domesticated and enjoyed bags of processed dog food set out in a bowl by their helpful human friends, they were responsible for feeding themselves. If they caught a meal, it was important to keep other dogs from running off with it. To help protect their food supply, it was necessary to bury it. Obscuring it under dirt helped keep other dogs off the scent.

This behavior persists even when a dog knows some kibble is on the menu. It may also manifest itself when a dog has more on its plate than it can enjoy at any one time. The ground is a good place to keep something for later.

But food isn’t the only reason a dog will start digging. If they’ve nabbed something of yours, like a television remote, they may be expressing a desire to play.

Some dog breeds are more prone to digging than others. Terriers, dachshunds, beagles, basset hounds, and miniature schnauzers go burrowing more often than others, though pretty much any dog will exhibit the behavior at times. While there’s nothing inherently harmful about it, you should always be sure a dog in your backyard isn’t being exposed to any lawn care products or other chemicals that could prove harmful. You should also probably keep your remote in a safe place, before the dog decides to relocate it for you.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.