The Reason Why Your Car's Tires Are Black

Daniel Kalisz, Getty Images
Daniel Kalisz, Getty Images

With the possible exception of some Big Wheels or other child transportation vehicles, most tires are black. You’d be hard-pressed to find a tire shop and come across a Goodyear or Michelin sample that’s any other color.

Natural rubber, however, is closer to an off-white shade, and early-model cars sported that lighter color. Early tire makers also often added zinc oxide to their natural rubber as a way to strengthen the material, resulting in white tires. But at some point, tire manufacturers decided to go darker. Why?

Jalopnik automotive journalist David Tracy pondered the question when he visited Detroit’s Ford Piquette Avenue Plant Museum and came across the white tires of a Ford Model T, a vehicle that began production in 1908. Tracy posed the question of the color transition to Michelin, which informed him that tires changed color when manufacturers began adding carbon black around 1917.

It wasn’t for cosmetic purposes. Carbon black—an elemental carbon made from the incomplete combustion of gas or oil and collected as particles—increases a tire’s durability, in part by blocking damaging UV rays that can cause rubber to crack, and by improving road grip. It also improves tensile strength, making tires more resistant to road wear.

Older tires that weren't treated with carbon black were good for 5000 miles before they needed to be replaced. Tires made with carbon black, meanwhile, could be driven for 50,000 miles or more.

There was another wrinkle: World War I led to a shortage of zinc oxide, as it was needed to make ammunition. That’s when carbon black became tire companies' go-to strengthening material (though zinc oxide does still play a role in the tire-making process today). Carbon black was initially supplied to tire manufacturer B.F. Goodrich by Binney & Smith, the company that produced Crayola crayons, which originally sourced the material for a line of ink pens.

Was that the end of the tire color evolution? Almost. Early on, companies decided to try and limit production costs by only adding carbon black to the treads, inadvertently creating the whitewall tire with a white sidewall and dark treads. The two-tone look is still popular among classic car collectors today.

[h/t Jalopnik]

Why You Should Never Charge Your Phone in Public USB Ports Without a USB Data Blocker

Creative-Family/iStock via Getty Images
Creative-Family/iStock via Getty Images

The USB charging ports that have popped up at airports, coffee shops, and even outdoor stations around cities in recent years are definitely a lifesaver when your smartphone is down to its last bit of juice. A dead phone is annoying at best and downright dangerous at worst, so it’s totally understandable why you’d jump at the chance to revive it at your earliest opportunity.

However, those public ports might not be as benevolent as they seem. According to Afar, hackers can load malware onto those stations—or on the cables left plugged into the stations—which can then deliver passwords and other data right from your device to the hacker’s. If you have used a public port recently, don’t panic; TechCrunch reports that these cases are fairly rare. Having said that, it’s definitely better not to risk it, especially considering what a nightmare it would be to have your identity stolen.

The Los Angeles County District Attorney’s Office explains that the easiest way to prevent becoming a victim of this type of scam, often referred to as juice-jacking, is simply to abstain from using public USB charging ports. Instead, invest in a portable charger, or plug your own charger into an actual AC power outlet.

But unoccupied power outlets are notoriously hard to come by in public places, and portable chargers themselves can also run out of battery life. Luckily, there’s a small, inexpensive device called a data blocker that will enable you to use public USB charging ports without worrying about juice-jacking. It looks a little like a flash drive with an extra slot, but it lacks the two wires usually found in USB chargers that can download and upload data. That way, your device will charge without transferring any information.

You can get two of them for $11 from Amazon here.

[h/t Afar]

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The Ingenious Reason Medieval Castle Staircases Were Built Clockwise

Shaiith/iStock via Getty Images
Shaiith/iStock via Getty Images

If you’re a fan of Game of Thrones or medieval programs in general, you’re probably familiar with action-packed battle scenes during which soldiers storm castles, dodge arrows, and dash up spiral staircases. And, while those spiral staircases might not necessarily ascend clockwise in every television show or movie you’ve watched, they usually did in real life.

According to Nerdist, medieval architects built staircases to wrap around in a clockwise direction in order to disadvantage any enemies who might climb them. Since most soldiers wielded swords in their right hands, this meant that their swings would be inhibited by the inner wall, and they’d have to round each curve before striking—fully exposing themselves in the process.

Just as the clockwise spiral hindered attackers, so, too, did it favor the castle’s defenders. As they descended, they could swing their swords in arcs that matched the curve of the outer wall, and use the inner wall as a partial shield. And, because the outer wall runs along the wider edge of the stairs, there was also more room for defenders to swing. So, if you’re planning on storming a medieval castle any time soon, you should try to recruit as many left-handed soldiers as possible. And if you’re defending one, it’s best to station your lefties on crossbow duty and leave the tower-defending to the righties.

On his blog All Things Medieval, Will Kalif explains that the individual stairs themselves provided another useful advantage to protectors of the realm. Because the individual steps weren’t all designed with the same specifications, it made for much more uneven staircases than what we see today. This wouldn’t impede the defenders, having grown accustomed to the inconsistencies of the staircases in their home castle, but it could definitely trip up the attackers. Plus, going down a set of stairs is always less labor-intensive than going up.

Staircase construction and battle tactics are far from the only things that have changed since the Middle Ages. Back then, people even walked differently than we do—find out how (and why) here.

[h/t Nerdist]

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