Why a Dripping Faucet Makes That Maddening 'Plink' Sound—and How to Stop It

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iStock

In most cases, calling a professional is the best option when dealing with a stubborn faucet leak. With the right tools and knowledge, the problem isn't that difficult to solve. But when every other thought you have is interrupted by that incessant "plink" noise, even a few hours spent waiting for the plumber can feel like an eternity. A team of scientists recently looked at the mechanics that make that sound so annoying, and they've come up with a quick fix you can use to silence it before tackling the source.

The researchers from the University of Cambridge recently published their findings in the journal Scientific Reports. To get to the bottom of the annoying acoustics, they recorded a leaky faucet using a microphone, a hydrophone, and ultra-high-speed cameras. “A lot of work has been done on the physical mechanics of a dripping tap, but not very much has been done on the sound,” lead researcher Anurag Agarwal said in a press release. “But thanks to modern video and audio technology, we can finally find out exactly where the sound is coming from, which may help us to stop it.”

They found that the unmistakable "plink" comes not from the water droplet itself, but from an air bubble trapped beneath it. When a drop of water hits something, a cavity forms inside it. This cavity immediately recoils, creating a water column that splashes away from the surface that was hit. The cavity recoils so quickly that it leaves a small air bubble beneath the water.

Scientists already knew the physics, but until now it was unclear which part of the equation produces the dripping noise. The University of Cambridge team observed that it's not the impact of the droplet, the creation of the cavity, or the upward splash of water that make the sound: It's the air bubble, which vibrates and pushes sound waves through the air in a way that's uniquely grating to the ears.

The researchers were also able to identify a way to neutralize this effect without any fancy equipment. Just add some liquid soap to the bottom of the sink to change the surface tension of the water each time a droplet splashes. This slight adjustment is enough to stop the air bubble from forming and quiet the sound.

The constant noise keeping you up at all hours of the night isn't the only reason leaky taps are a pain. According to the Environmental Protection Agency, Americans lose 1 trillion gallons of water a year to leaks. Every year, the EPA runs Fix a Leak Week, a campaign aimed at getting homeowners to catch all the wasteful leaks on their property—not just the ones within hearing distance.

Is There An International Standard Governing Scientific Naming Conventions?

iStock/Grafissimo
iStock/Grafissimo

Jelle Zijlstra:

There are lots of different systems of scientific names with different conventions or rules governing them: chemicals, genes, stars, archeological cultures, and so on. But the one I'm familiar with is the naming system for animals.

The modern naming system for animals derives from the works of the 18th-century Swedish naturalist Carl von Linné (Latinized to Carolus Linnaeus). Linnaeus introduced the system of binominal nomenclature, where animals have names composed of two parts, like Homo sapiens. Linnaeus wrote in Latin and most his names were of Latin origin, although a few were derived from Greek, like Rhinoceros for rhinos, or from other languages, like Sus babyrussa for the babirusa (from Malay).

Other people also started using Linnaeus's system, and a system of rules was developed and eventually codified into what is now called the International Code of Zoological Nomenclature (ICZN). In this case, therefore, there is indeed an international standard governing naming conventions. However, it does not put very strict requirements on the derivation of names: they are merely required to be in the Latin alphabet.

In practice a lot of well-known scientific names are derived from Greek. This is especially true for genus names: Tyrannosaurus, Macropus (kangaroos), Drosophila (fruit flies), Caenorhabditis (nematode worms), Peromyscus (deermice), and so on. Species names are more likely to be derived from Latin (e.g., T. rex, C. elegans, P. maniculatus, but Drosophila melanogaster is Greek again).

One interesting pattern I've noticed in mammals is that even when Linnaeus named the first genus in a group by a Latin name, usually most later names for related genera use Greek roots instead. For example, Linnaeus gave the name Mus to mice, and that is still the genus name for the house mouse, but most related genera use compounds of the Greek-derived root -mys (from μῦς), which also means "mouse." Similarly, bats for Linnaeus were Vespertilio, but there are many more compounds of the Greek root -nycteris (νυκτερίς); pigs are Sus, but compounds usually use Greek -choerus (χοῖρος) or -hys/-hyus (ὗς); weasels are Mustela but compounds usually use -gale or -galea (γαλέη); horses are Equus but compounds use -hippus (ἵππος).

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

An Ice Age Wolf Head Was Found Perfectly Preserved in Siberian Permafrost

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iStock/stevegeer

Don’t lose your head in Siberia, or it may be found preserved thousands of years later.

A group of mammoth tusk hunters in eastern Siberia recently found an Ice Age wolf’s head—minus its body—in the region’s permafrost. Almost perfectly preserved thanks to tens of thousands of years in ice, researchers dated the specimen to the Pleistocene Epoch—a period between 1.8 million and 11,700 years ago characterized by the Ice Age. The head measures just under 16 inches long, The Siberian Times reports, which is roughly the same size as a modern gray wolf’s.

Believed to be between 2 to 4 years old around the time of its death, the wolf was found with its fur, teeth, and soft tissue still intact. Scientists said the region’s permafrost, a layer of ground that remains permanently frozen, preserved the head like a steak in a freezer. Researchers have scanned the head with a CT scanner to reveal more of its anatomy for further study.

Tori Herridge, an evolutionary biologist at London’s Natural History Museum, witnessed the head’s discovery in August 2018. She performed carbon dating on the tissue and tweeted that it was about 32,000 years old.

The announcement of the discovery was made in early June to coincide with the opening of a new museum exhibit, "The Mammoth," at Tokyo’s Miraikan National Museum of Emerging Science and Innovation. The exhibit features more than 40 Pleistocene specimens—including a frozen horse and a mammoth's trunk—all in mint condition, thanks to the permafrost’s effects. (It's unclear if the wolf's head is included in the show.)

While it’s great to have a zoo’s worth of prehistoric beasts on display, scientists said the number of animals emerging from permafrost is increasing for all the wrong reasons. Albert Protopopov, director of the Academy of Sciences of the Republic of Sakha, told CNN that the warming climate is slowly but surely thawing the permafrost. The higher the temperature, the likelier that more prehistoric specimens will be found.

And with average temperatures rising around the world, we may find more long-extinct creatures rising from the ice.

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