Why Do Limbs 'Fall Asleep'?

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iStock

At some point, we've all experienced the sensation of "pins and needles"—that strange numbness that comes from applying pressure to our arms or legs. If you've ever wondered what causes it, or if it's dangerous, wonder no more.

We've got nerves running through our bodies that act as lines of communication between the brain and the other body parts, transmitting commands from the brain and relaying sensory information back to it for processing. With a "sleeping" limb, your nerves are going a little haywire because prolonged pressure has actually cut off communication between that limb and the brain. (The tingling sensation is technically called paresthesia.)

Pressure puts the squeeze on nerve pathways and blood vessels, so the nerves can't transmit signals properly, and the blood vessels can't bring oxygen and nutrients to the nerves. The cutoff interferes with the normal flow of information between the limb and the brain, and the signals going back and forth get jumbled. Some nerve cells stop sending info entirely, while others send impulses erratically.

The problem is compounded by the fact that our nerves are pretty specialized, and different kinds of nerves and sensory receptors receive different stimuli and transmit different information. (We've discussed another bodily oddity caused by this.) When the various signals get scrambled and aren't transmitted normally, the brain starts to misinterpret the info it's getting and generates an array of sensations, like warmth, numbness, and that tingling feeling.

When a limb falls asleep, we usually try to "wake it up" by changing positions. Blood flows back to the limb, giving a little boost to the misfiring nerves and making the tingling seem worse, but eventually the nerve signals begin to flow properly again. The pins-and-needles sensation is annoying for a few minutes, but it's a nice little prompt for us to relieve the pressure on a limb before serious nerve damage occurs.

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Why Are There 10 Hot Dogs to a Pack But Only 8 Buns?

tacar/iStock via Getty Images
tacar/iStock via Getty Images

Watching competitive eating champion Joey Chestnut cram dozens of hot dogs down his throat would make anyone crave a grilled log of processed meat this summer. But shopping for hot dogs can be a confusing experience. The dogs are typically sold in packs of 10, but the buns are sold in packs of eight. What's behind this strange dog and bun inequality?

According to the National Hot Dog and Sausage Council—yes, there is a National Hot Dog and Sausage Council—there’s a good reason for the discrepancy. For starters, distributors of hot dogs are almost always different from manufacturers of baked goods like rolls. The hot dogs are sold in packs of 10 because producers of meat (or meat-like) products selected that quantity when hot dogs started to sell at retail grocery stores in the 1940s. Oscar Mayer, which led the charge into direct-to-consumer hot dog packaging, sold hot dogs by the pound in accordance with how meat is typically priced. Having 10 dogs that weighed 1.6 ounces each seemed like the ideal distribution of weight.

Bakeries, meanwhile, have standards of their own. Buns and sandwich rolls are usually sold eight to a pack because the baking trays for the elongated buns are typically sized to fit that number. Two sets of four buns come off the tray, which is the reason why buns are often still attached to one another when you open a bag.

These standards were created independently of one another: Bakeries weren’t too preoccupied with hot dogs when they were settling on a four-roll tray standard, and hot dog manufacturers weren’t thinking about how difficult it would be for bakeries to break from their conveyor system to offer 10 buns to a pack.

It can be frustrating if you buy just one or two packages of each, but if you’re hosting a big enough party, the uneven number doesn’t matter. You just need to buy five packages of buns and four packages of hot dogs to have 40 matching pairs. No complicated calculations required.

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When Are the Dog Days of Summer?

Dorottya_Mathe/iStock via Getty Images
Dorottya_Mathe/iStock via Getty Images

The official “dog days” of summer begin on July 3 and end on August 11. So how did this time frame earn its canine nickname? It turns out the phrase has nothing to do with the poor pooches who are forever seeking shade in the July heat, and everything to do with the nighttime sky.

Sirius, the Dog Star, is the brightest star in the sky. The ancient Greeks noticed that in the summer months, Sirius rose and set with the Sun, and they theorized that it was the bright, glowing Dog Star that was adding extra heat to the Earth in July and August.

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