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]

The Reason Why Baking Makes You Feel Good, According to Psychologists

Liderina/iStock via Getty Images
Liderina/iStock via Getty Images

Whether you're nibbling a slice of zucchini bread or an extra-chewy chocolate chip cookie, it’s always fun to be the taste tester for a friend or relative who loves to bake. And, while eating products created with love (and sugar) probably makes you feel good, the baker is reaping some psychological benefits, too.

Studies have shown that creative activities like baking and knitting contribute to an overall sense of well-being. Boston University associate professor of psychological and brain sciences Donna Pincus told HuffPost that there’s “a stress relief that people get from having some kind of an outlet and a way to express themselves.”

Baking is also a great way to practice mindfulness, because it requires you to focus on following very straightforward directions in a specific order. In other words, most of the decisions have already been made for you, allowing you to concentrate on the details while nudging your mind away from the stressors and anxieties of your life outside the kitchen. Julie Ohana, a licensed clinical social worker and culinary art therapist, explained to HuffPost that baking is therapeutic because it helps you practice the “balance of the moment and the bigger picture.” While you’re measuring and mixing ingredients, you’re probably visualizing how they’ll all come together to create a fulfilling final product, and deciding how and when you’ll share it with others.

Sharing your desserts—altruistically rather than for attention or competition—is another mood-booster, making you “feel like you’ve done something good for the world, which perhaps increases your meaning in life and connection with other people,” Pincus said. It can also function as a mode of communication. Susan Whitbourne, professor of psychological and brain sciences at the University of Massachusetts, told HuffPost that “it can be helpful for people who have difficulty expressing their feelings in words to show thanks, appreciation, or sympathy with baked goods.”

If baking just isn’t for you, that’s OK, too—try one of these other stress-reducing tactics instead.

[h/t HuffPost]

The Reason Why Objects in a Car’s Side-View Mirror Are Closer Than They Appear

aydinozcanbaz/iStock via Getty Images
aydinozcanbaz/iStock via Getty Images

“Objects in mirror are closer than they appear.” It's a warning you see in basically every car, but why can't passenger-side mirrors display objects accurately? Well, it's actually a careful design choice made with safety in mind.

The way we see things is dependent on how light reflects off objects around us. An object's color, texture, shape, and other characteristics influence the direction and intensity of light that bounces off them. If the objects are reflected off an intermediate object, like a mirror, our perception of the original object may be distorted.

The shape of the mirror also makes a difference in our perception. In the U.S., passenger-side mirrors are convex (curved slightly outward), whereas driver-side mirrors are flat. A convex mirror placed on the passenger side reduces the driver's blind spots on that side of the vehicle by presenting a wider field of view, but it also makes other cars appear farther away due to a slight distortion caused by the shape. The flatter mirror on the driver’s side produces a more accurate depiction of what’s behind the car with a more narrow field of view, since light bounces off in the same direction that it hits the mirror and doesn't distort the reflection of the object.

When the two mirrors' reflections are combined in the driver's point of view, drivers have the ability to both see wider areas on the passenger side while keeping their eyes (mainly) on the road. The flat-convex combo has been the U.S. standard for years, though the U.S. Department of Transportation is looking into the safety benefits of two convex mirrors, which European cars usually sport.

For now, always remember to check your mirrors frequently, and look over your shoulder before you change lanes. (Don't forget your turn signal!)

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