CLOSE
Original image
iStock

Why Does Snow Squeak When You Step On It?

Original image
iStock

With Winter Storm Jonas expected to dump tons of snow on a large swath of the East Coast over the next few days, you might be trying to figure out if you have enough bread, milk, and eggs (and booze!) at home to get through the weekend. We’re also pondering another important question—why is snow, which is so quiet when it’s falling out of the sky, so loud on the ground, squeaking, creaking, and crunching under our boots? (If you’re not from a snowy part of the country, you can hear what we’re talking about in the video below).

Snow is made up of ice crystals. While ice is a solid, it actually has a thin (as in, a few nanometers) quasi-liquid layer (QLL) on its surface. Michael Faraday, better known for his work on magnetism and electrochemistry, first suggested this idea in the 1850s. While scientists have confirmed it since then, the origins and many of the characteristics of the QLL are unclear.

One thing we do know, though, is that the thickness of the QLL depends on temperature. When snow is warmer, the QLL around all those ice crystals is softer. When you step on the snow, the National Snow and Ice Data Center explains, you compress the crystals, but the liquid allows them to quietly slide past each other. When snow is colder and the QLL is stronger, there’s more friction between the crystals, and they don’t slide so easily. When you step on colder snow, the crystals rub against each other and also break, making that familiar squeaking sound.

Around 14 degrees Fahrenheit seems to the dividing line between squeaky and non-squeaky snow. Temperatures in the region getting hit by Jonas will be well above that through the weekend, so we’re probably in for a quiet storm.

Original image
iStock
arrow
Big Questions
What Is the Difference Between Generic and Name Brand Ibuprofen?
Original image
iStock

What is the difference between generic ibuprofen vs. name brands?

Yali Friedman:

I just published a paper that answers this question: Are Generic Drugs Less Safe than their Branded Equivalents?

Here’s the tl;dr version:

Generic drugs are versions of drugs made by companies other than the company which originally developed the drug.

To gain FDA approval, a generic drug must:

  • Contain the same active ingredients as the innovator drug (inactive ingredients may vary)
  • Be identical in strength, dosage form, and route of administration
  • Have the same use indications
  • Be bioequivalent
  • Meet the same batch requirements for identity, strength, purity, and quality
  • Be manufactured under the same strict standards of FDA's good manufacturing practice regulations required for innovator products

I hope you found this answer useful. Feel free to reach out at www.thinkbiotech.com. For more on generic drugs, you can see our resources and whitepapers at Pharmaceutical strategic guidance and whitepapers

This post originally appeared on Quora. Click here to view.

Original image
iStock
arrow
Big Questions
Do Cats Fart?
Original image
iStock

Certain philosophical questions can invade even the most disciplined of minds. Do aliens exist? Can a soul ever be measured? Do cats fart?

While the latter may not have weighed heavily on some of history’s great brains, it’s certainly no less deserving of an answer. And in contrast to existential queries, there’s a pretty definitive response: Yes, they do. We just don’t really hear it.

According to veterinarians who have realized their job sometimes involves answering inane questions about animals passing gas, cats have all the biological hardware necessary for a fart: a gastrointestinal system and an anus. When excess air builds up as a result of gulping breaths or gut bacteria, a pungent cloud will be released from their rear ends. Smell a kitten’s butt sometime and you’ll walk away convinced that cats fart.

The discretion, or lack of audible farts, is probably due to the fact that cats don’t gulp their food like dogs do, leading to less air accumulating in their digestive tract.

So, yes, cats do fart. But they do it with the same grace and stealth they use to approach everything else. Think about that the next time you blame the dog.

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

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios