How Does the Magic Yellow First-Down Line Work?

Sportvision
Sportvision

If you attend a Super Bowl party on Sunday, you’ll probably hear at least one casual football viewer ask, “How do they get that yellow first-down line on the field?” While “magic” is a fine answer in its own right, the real explanation is a bit more technologically intense. Let’s have a look at the background and mechanics behind every football fan’s shining beacon: the yellow first-down line.

According to Allen St. John’s 2009 book The Billion Dollar Game: Behind the Scenes of the Greatest Day in American Sport - Super Bowl Sunday, the first-down line actually emerged from the ashes of one of sports broadcasting’s bigger debacles: the FoxTrax system for hockey, which was designed by a company called Sportvision. FoxTrax—which hockey fans no doubt remember as the much-maligned “technopuck” that debuted in 1996—employed a system of cameras and sensors around a hockey rink to place a little blue halo around the puck.

FoxTrax wasn't a great fit for NHL broadcasts: Hockey purists hated the intrusion into their game, and casual fans didn’t flock to hockey just because the puck was suddenly easier to follow. However, the system inspired producers to think of new ways to insert computerized images into live sports broadcasts.

The idea of using a line to mark the first down in football was a natural extension, and Sportvision debuted its 1st and Ten system during ESPN’s broadcast of a Bengals-Ravens tilt on September 27, 1998. A couple of months later, rival company Princeton Video Image unveiled its Yellow Down Line system during a Steelers-Lions broadcast on CBS. (Sportvision is still kicking, and ESPN acquired all of PVI’s intellectual property in December 2010.)

BUT HOW DOES IT WORK?

It takes lots of computers, sensors, and smart technicians to make this little yellow line happen. Long before the game begins, technicians make a digital 3D model of the field, including all of the yard lines. While a football field may look flat to the naked eye, it’s actually subtly curved with a crown in the middle to help rainwater flow away. Each field has its own unique contours, so before the season begins, broadcasters need to get a 3D model of each stadium’s field.

These models of the field help sidestep the rest of the technological challenges inherent to putting a line on the field. On game day, each camera used in the broadcast contains sensors that record its location, tilt, pan, and zoom and transmit this data to the network’s graphics truck in the stadium’s parking lot. These readings allow the computers in the truck to process exactly where each camera is within the 3D model and the perspective of each camera. (According to How Stuff Works, the computers recalculate the perspective 30 times per second as the camera moves.)

After they get their hands on all of this information, the folks in the graphics truck know where to put the first-down line, but that’s only part of the task. When you watch a football game on television, you’ll notice that the first-down line appears to actually be painted on the field; if a player or official crosses the line, he doesn’t turn yellow. Instead, it looks like the player’s cleat is positioned on top of an actual painted line. This effect is fairly straightforward, but it’s difficult to achieve.

To integrate the line onto the field of play, the technicians and their computers put together two separate color palettes before each game. One palette contains the colors—usually greens and browns—that naturally occur on the field’s turf. These colors will automatically be converted into yellow when the line is drawn on to the field.

All of the other colors that could show up on the field—things like uniforms, shoes, footballs, and penalty flags—go into a separate palette. Colors that appear on this second palette are never converted into yellow when the first-down line is drawn. Thus, if a player’s foot is situated “on” the line, everything around his cleat will turn yellow, but the cleat itself will remain black. According to How Stuff Works, this drawing/colorizing process refreshes 60 times per second.

All this technology—and the people needed to run it—wasn’t cheap at first. It could cost broadcasters anywhere from $25,000 to $30,000 per game to put the yellow line on the field. Sportvision had to deploy a truck and a four-man crew with five racks of equipment. The cost has come down since then, and the process is now less labor-intensive. One technician using one or two computers can run the system, according to Sportvision, and some games can even be done without anyone actually at the venue.

Now you can explain it to everyone at your Super Bowl party during one of the less-exciting $5 million commercials.

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This post originally appeared in 2011.

What Exactly is Christmas Tree Flocking?

iStock.com/Spiderstock
iStock.com/Spiderstock

Of the many curious holiday traditions (figgy pudding? wassailing?), one of the oddest has to be spraying down small trees with a mixture of adhesive and cellulose fibers to satisfy our longing for a white Christmas.

That’s what’s happening when you adorn a tree with artificial snow, otherwise known as flocking. And yet, when decorated and lit up, there’s something beautiful and warmly nostalgic about a well-flocked Christmas tree. Here’s how professionals manufacture this Christmas miracle.  

The History of Flocking

We’ve been trying to get that snowy look on Christmas trees for longer than you might think, dating back to the 1800s using substances like flour or cotton. A 1929 issue of Popular Mechanics recommended varnish, corn starch, and flakes of the silicate mineral mica. 

But tree flocking as we know it really caught on in the late 1950s and 1960s, along with aluminum trees and other glitzy (if not natural-looking) decor of the post-war boom. General Mills marketed Sno-Flok home kits, to be applied using a gun that attached to a vacuum cleaner.

Such home kits are not so popular these days, says Tom Leonard, owner of Peak Seasons, one of the country's largest manufacturers of Christmas tree lots supplies and tree flock. Flocking itself, however, has retained a level of appeal. “Sunbelt states use a lot of it because there’s no snow there,” Leonard tells Mental Floss. “It’s tremendously popular. The West Coast, the South, and the Southeast, the vast majority of it is sold in those zones.”

The Science of Flocking

So what exactly is flocking? At its core, flocking means attaching tiny fibers to a surface to create texture (the process is also used in fashion, home decor, and crafts). The Peak Seasons recipe includes paper pulp as fiber, corn starch as adhesive, and boron as a flame retardant—there’s a safety benefit to flocking.

And the company makes a lot of it. Leonard says they're the largest manufacturer of flock in the United States and Europe. “I don’t want to share [how much], but we sell lots of flock. I mean truckloads and truckloads.”

Based in sunny Riverside, California, Peak Seasons starts with paper and a grinder. “It’s like a big roll of toilet paper and it weighs a ton and you feed it into a machine and it comes out a powder,” Leonard says. The exception is certain bright colors—flock comes in white, black, pink, ice blue, royal blue, red, green, gold, and purple—which require cotton fibers instead of paper to hold the dye. The final product is almost like baby powder, shipped all over the country in large, cement-bag-sized bags.

From there you need to affix the stuff in a nice even coat, which is where flock machines like the Mighty Sno-Blower come in. They’re basically big tanks that hold varying amounts of flock depending on the model, plus a mechanism at the bottom to fluff up the powder. The machine then pumps the powder through a hose, and a gun at the end mixes it with a mist of water.

And that’s how flock is born.

The Art of Flocking

You don’t have to go with a professional flocker, or even use manufactured flock. There are all sorts of DIY recipes that include things like soap flakes or even desiccated coconut flakes. But if you do go pro, you want to be in the hands of someone like Paul Iantosca, who has been flocking trees in the Boston area for 20 years.

Flocking one tree in bright purple (white is still most popular), Iantosca first sprays it down with water. Then, in an area closed off with plastic sheeting, he fires up the blower and blasts the tree evenly with what looks like a purple fog. The stuff gets everywhere. He wears a mask to keep it out of his nose, but some high-volume flockers wear full protective coveralls. 

The tricky part to flocking is that you can’t tell if you got it right until it dries. When it goes on, it’s cold and wet like paste. But as it dries, the Christmas magic kicks in and it puffs up, turning into fluffy white (or, in this case, purple) fuzz firmly affixed to the needles.

There are, of course, pitfalls. Not enough water, and the flocking falls off and makes a huge mess. A flocked tree can’t get wet a second time. “It won’t dry again. It’s disgusting actually,” Iantosca says. Also, when you flock a tree, the color highlights its flaws. A janky tree turns into a weird, uneven shrub.

But if you get it right and string it up with lights, you’ve got a real stunner on your hands. Iantosca’s had flocked trees for his own home for the past 10 years and his kids won’t let him go back.

“When you plug that thing in, it absolutely glows inside," he says. "It’s unbelievable.”

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Why Do Fruitcakes Last So Long?

iStock
iStock

Fruitcake is a shelf-stable food unlike any other. One Ohio family has kept the same fruitcake uneaten (except for periodic taste tests) since it was baked in 1878. In Antarctica, a century-old fruitcake discovered in artifacts left by explorer Robert Falcon Scott’s 1910 expedition remains “almost edible,” according to the researchers who found it. So what is it that makes fruitcake so freakishly hardy?

It comes down to the ingredients. Fruitcake is notoriously dense. Unlike almost any other cake, it’s packed chock-full of already-preserved foods, like dried and candied nuts and fruit. All those dry ingredients don’t give microorganisms enough moisture to reproduce, as Ben Chapman, a food safety specialist at North Carolina State University, explained in 2014. That keeps bacteria from developing on the cake.

Oh, and the booze helps. A good fruitcake involves plenty of alcohol to help it stay shelf-stable for years on end. Immediately after a fruitcake cools, most bakers will wrap it in a cheesecloth soaked in liquor and store it in an airtight container. This keeps mold and yeast from developing on the surface. It also keeps the cake deliciously moist.

In fact, fruitcakes aren’t just capable of surviving unspoiled for months on end; some people contend they’re better that way. Fruitcake fans swear by the aging process, letting their cakes sit for months or even years at a stretch. Like what happens to a wine with age, this allows the tannins in the fruit to mellow, according to the Wisconsin bakery Swiss Colony, which has been selling fruitcakes since the 1960s. As it ages, it becomes even more flavorful, bringing out complex notes that a young fruitcake (or wine) lacks.

If you want your fruitcake to age gracefully, you’ll have to give it a little more hooch every once in a while. If you’re keeping it on the counter in advance of a holiday feast a few weeks away, the King Arthur Flour Company recommends unwrapping it and brushing it with whatever alcohol you’ve chosen (brandy and rum are popular choices) every few days. This is called “feeding” the cake, and should happen every week or so.

The aging process is built into our traditions around fruitcakes. In Great Britain, one wedding tradition calls for the bride and groom to save the top tier of a three-tier fruitcake to eat until the christening of the couple’s first child—presumably at least a year later, if not more.

Though true fruitcake aficionados argue over exactly how long you should be marinating your fruitcake in the fridge, The Spruce says that “it's generally recommended that soaked fruitcake should be consumed within two years.” Which isn't to say that the cake couldn’t last longer, as our century-old Antarctic fruitcake proves. Honestly, it would probably taste OK if you let it sit in brandy for a few days.

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