Why Can You Sometimes See Your Breath?

Chalabala/iStock via Getty Images
Chalabala/iStock via Getty Images

The human body is made up of about 60 percent water, meaning that when we breathe, we don’t just exhale carbon dioxide—we also exhale a certain amount of water vapor.

Water molecules need a lot of energy in order to remain in a gaseous form. When the warm water vapor molecules from your lungs reach colder air, they condense into “tiny droplets of liquid water and ice,” according to Wonderopolis. In fact, this process of condensation is also how clouds are formed.

But it’s actually relative humidity, not just temperature, that determines whether you can see your breath. The water vapor in your breath condenses into a liquid when it hits dew point—the temperature at which the air is saturated and can’t hold any more water in gas form. Since cold air can’t hold as much water vapor as warm air, you're much more likely to see your breath on a chilly day, but that's not always the case.

On more humid days, you may be able to see your breath even when it’s relatively warm outside. That’s because the air is already more saturated, making the dew point higher. And on especially dry days, even if it's cold outside, you may not be able to see your breath at all. Dry, unsaturated air can hold more water vapor, so you can huff and puff without seeing any evidence of it at all.

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In What Field Was Dr. Martin Luther King Jr. a Doctor?

Express Newspapers/Getty Images
Express Newspapers/Getty Images

Martin Luther King Jr. earned a doctorate in systematic theology from Boston University in 1955. He’d previously earned a Bachelor of Arts from Morehouse College and a Bachelor of Divinity from Crozer Theological Seminary. His dissertation, “A Comparison of the Conception of God in the Thinking of Paul Tillich and Henry Nelson Wieman,” examined the two religious philosophers’ views of God in comparison to each other, and to King’s own concept of a "knowable and personal" God.

In 1989, some three decades after King had earned his doctorate, archivists working with The Martin Luther King Papers Project discovered that King’s dissertation suffered from what they called a “problematic use of sources.” King, they learned, had taken a large amount of material verbatim from other scholars and sources and used it in his work without full or proper attribution, and sometimes no attribution at all.

In 1991, a Boston University investigatory committee concluded that King had indeed plagiarized parts of his dissertation, but found that it was “impractical to reach, on the available evidence, any conclusions about Dr. King's reasons for failing to attribute some, but not all, of his sources.” That is, it could have been anything from malicious intent to simple forgetfulness—no one can determine for sure today. They did not recommend a posthumous revocation of his degree, but instead suggested that a letter be attached to the dissertation in the university library noting the passages lacked quotations and citations.

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Who Is 'The Real McCoy'?

Inventor Elijah McCoy is may or may not be "The Real McCoy."
Inventor Elijah McCoy is may or may not be "The Real McCoy."
Ypsilanti Historical Society, CC BY-SA 4.0 via Wikimedia Commons

After taking a cool, carbonated sip of champagne from the Champagne region of France, you might say, “Ah, now that’s the real McCoy.” Sparkling wine from anywhere else is technically just sparkling wine.

The phrase “the real McCoy,” which can be used to describe any genuine version of something, has several possible origin stories. And while none of them mention champagne, a few do involve other types of alcohol.

According to HowStuffWorks, the earliest known recorded instance of the saying was an 1856 reference to whisky in the Scottish National Dictionary—"A drappie [drop] o' the real MacKay”—and by 1870, a pair of whisky distillers by the name of McKay had adopted the slogan “the real McKay” for their products. As the theory goes, the phrase made its long journey across the pond, where it eventually evolved into the Americanized “McCoy.”

Another theory suggests “the real McCoy” originated in the United States during Prohibition. In 1920, Florida-based rum runner Bill McCoy was the first enterprising individual to stock a ship with alcohol in the Caribbean, sail to New York, and idle at least three miles offshore, where he could sell his wares legally in what was then considered international waters. Since McCoy didn’t water down his alcohol with substances like prune juice, wood alcohol, and even turpentine, people believe his customers started calling his top-notch product “the real McCoy.” There’s no definitive proof that this origin story is true, but The Real McCoy rum distillery was founded on the notion.

There are also a couple other leading theories that have nothing to do with alcohol. In 1872, inventor Elijah McCoy patented a self-regulating machine that lubricated parts of a steam engine without the need for manual maintenance, allowing trains to run continuously for much longer distances. According to Snopes, the invention’s success spawned a plethora of poor-quality imitations, which led railroad personnel to refer to McCoy’s machines as “the real McCoy.”

Elijah McCoy’s invention modernized the transportation industry, but he wasn’t the only 19th-century McCoy who packed a punch. The other was welterweight champion Norman Selby, better known as Kid McCoy. In one story, McCoy decked a drunken bar patron to prove that he really was the famous boxer, prompting others to christen him “the real McCoy.” In another, his alleged penchant for throwing fights caused the press to start calling him “the real McCoy” to acknowledge when he was actually trying to win. And yet another simply suggests that the boxer’s popularity birthed so many McCoy-wannabes that Selby started to specify that he was, in fact, the real McCoy.

So which “the real McCoy” origin story is the real McCoy? The 1856 Scottish mention of “the real MacKay” came before Elijah McCoy’s railroad invention, Kid McCoy’s boxing career, and Bill McCoy’s rum-running escapades, but it’s possible that the phrase just gained popularity in different spheres at different times.

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