The Wise Book of Whys (12 page)

Why Hair Only Grows to a Certain Length

Hair length is completely controlled by the length of the anagen phase of your hair
follicle. How long this phase lasts is determined mostly by genetics, but it can also be affected by hormones and extreme stress. But in the end, there is a chemical signal that ultimately controls the exact growth cycle.

Following the anagen phase is the catagen phase
. It isn’t yet known what triggers the catagen phase, but once it is triggered, the outer part of the root is cut off from its nutrient supply (blood), as well as the cells that produce new hair, thus your hair stops growing. This phase lasts about three weeks.

Next up comes the telogen phase where the follicle is in a resting state and your hair is now a “club hair
,” completely dead down to the root. During this stage, these hairs are relatively easy to pull out (as can happen while brushing/combing/washing your hair), but if they manage to last long enough, they’ll eventually be pushed out by a new hair as the cycle begins again.

Obviously hairs on your arms or legs have a very different anagen period than hairs on your head, thus why your leg hair doesn’t grow two feet long without trimming
. Further, different people, thanks mostly to their genetics, have differing lengths of the anagen period for a given body part compared to other people. For the hair on your head, the average length of the anagen phase is about 2-7 years. For your arms, legs, eyebrows, etc., this phase usually lasts just 30-45 days. However, in extreme cases which are quite rare, some people have anagen periods for their heads as short as most people’s anagen phases for their arms and legs. For these people, their hair never naturally grows more than a few inches long. The opposite is also true for people whose anagen phase can last decades for their scalp hair.

At any given time about 85 to 90 percent
of your hair is in the anagen phase, 1 to 2 percent is in the catagen phase, and 10 to 14 percent is in the telogen phase. However, extreme stress can trigger the anagen phase to stop prematurely and hair can rapidly progress to the telogen phase, even as much as 70% of the hair on your body. When this happens, the majority of your hair that should still be growing can fall out all at once.

Under normal circumstances, though, you can get a rough estimate of how long your anagen phase is based on how long your hair gr
ows naturally without cutting off a given area. First, assuming your hair isn’t already as long as it can get, measure your hair length, then exactly a month later measure it again and note the difference. Now you have your growth rate (usually about 1 centimeter every 28 days or 1 inch every 71 days). So if, without cutting, the hair on your head eventually grows 16 inches long max, then your anagen phase lasts: (inches*period per inch). So using the average of 1 inch every 71 days, (16 inches * 71 days/inch) = approximately 1,136 days or 3.11 years.

As to why when you cut hair, it will always grow back to its maximum length, this is just because when the cycle restarts, new hair comes in that can grow to the maximum length, eventually replacing the old hair that will be shorter than it could have been because you cut it.

As you might have guessed from the fact that hair growth is completely controlled by what’s going on under the surface, within your hair follicles, and that genetics and hormones are the primary things determining hair growth length, which are in no way affected by shaving, shaving does not in any way alter your hair growth rate, nor does it alter the color of the hair, contrary to popular belief.

Why Rice Krispies
“Snap, Crackle, and Pop”

The popping is a result of the walls of the Rice Krispies kernels fracturing. There are two prevalent theories as to the exact process that results in this fracturing, and it’s entirely possible that both are occurring.

Rice Krispies, also known as “Rice Bubbles
,” in some countries, are created by preparing rice in such a way that it will “pop” like popcorn during the cooking process, albeit much less dramatically. This popping puffs up the kernels. When the rice is finished cooking, most of the Rice Krispies will have thin solid walls with hollow, sealed, areas inside where air pockets have formed.

In the first theory of what causes
the fracturing of the walls, the sudden temperature shift caused by adding cold milk to the Rice Krispies causes the air inside the hollow pockets to contract suddenly, which, in turn, fractures the thin walls of the Rice Krispies, creating the noises.

The second theory also involves the fracturing of the thin walls, but by a different mechanism. The thin walls of the Rice Krispies have very strong bon
ds between the starch molecules due to the high heat the Rice Krispies were prepared at. When you add cold milk, the sudden shift of temperature puts a high amount of stress on these bonds, due to uneven absorption. This is actually the exact same thing that happens when you pour hot water over a frozen windshield. This dramatic temperature shift causes both the glass in the windshield and the walls of the Rice Krispies to shatter.

Why Yo
ur Nose Runs When It is Cold Outside

On an average day, a typical person’s nose will produce about one quart of mucus/fluid (just under one liter). Most all of this snot generally gets passed back into your throat and swallowed, often without you even really being conscious of it. When you’re breathing cold air though, the rate of mucus production goes up significantly, causing some of that snot to come out the front of your nose, rather than back in your throat.

What’s going on here is the blood supply to your nose increase
s as a response to the cold air, via tiny blood vessels in your nose dilating to increase the blood flow. This helps keep your nose warm as you breathe, as well as begins to warm the cold air you’re breathing before it enters your lungs.

This increased blood flow doesn’t just help warm the air though, it also has a side effect of providing a lot more blood
than normal to the glands that produce the mucus in your nose. This, in turn, causes them to start producing snot at a much higher rate than normal, which causes your nose to run when you’re breathing the cold air.

Once you’re back in a warm air environment, the blood vessels in your nose will constrict and the glands that produce the mucus/liquid mix will go back to their normal rate of around four cups of snot per day.

Why A Dollar is Called a “Buck”

As with many etymologies, the exact root of this word is difficult to say with one hundred percent certainty. However, the leading theory is extremely plausible and backed up by a fair bit of documented evidence. Specifically, it is thought that a dollar is called a “buck” thanks to deer.

One of the earliest references of this was in 1748, about 44 years before the first U.S. dollar was minte
d, where there is a reference to the exchange rate for a cask of whiskey traded to Native Americans being “5 bucks”, referring to deerskins.

In yet another documented reference from 1748, Conrad Weiser, while traveling through present day Ohio, noted in his journal that someone had been “robbed of the value of 300 Bucks.”

At this time, a buck skin was a common medium of exchange. There is also evidence that a “buck” didn’t simply mean one deerskin, but may have meant multiple skins, depending on quality. For instance, skins from deer killed in the winter were considered superior to those killed in the summer, due to the fur being thicker.

It is thought that the highest quality skins were generally assigned a one to one value with one skin equaling one buck. In contrast, for lower quality skins, it might take several of them to be valued at a single buck
. The specific value for given sets of skins was then set at trading.

In addition
, when the skin was from another animal, the number of skins required to equal a buck varied based on the animal and the quality of the skins. For instance, there is one documented trade where six high quality beaver skins or twelve high quality rabbit pelts each equaled one buck.

This use of skins as a medium of exchange gradually died off over the next century as more and more Europeans moved in and built towns and cities
. Once the U.S. dollar was officially introduced after the passing of the Coinage Act of 1792, it quickly became the leading item used as a medium of exchange, but the term “buck” stuck around and by the mid-nineteenth century was being used as a slang term for the dollar.

Why It’s Traditional to Christen a Ship By Smashing a Bottle of Champagne Against the Hull

While today breaking a bottle of champagne over the hull of a ship is considered tradition before launching a vessel in certain countries, particularly Britain and the United States, people have been performing ceremonies at launches seemingly as long as humans have made boats.

Like today, this was essentially for the hope of good fortune on the ship’s voyages. For instance, one of the earliest known references to a similar practice when launching a ship goes all the way back about 5,000 years ago when a Babylonian stated, “To the gods I caused oxen to be sacrificed,” before launching a new ship he’d made.

The ancient Greeks, Romans, and Egyptians also called upon their various gods to protect a new ship and her crew upon its in
itial launch. For example, the ancient Greeks, during their launch festivities, would drink wine to honor the gods and pour water on the ship as a sort of blessing.

The religious aspects of ship christening remained well into more modern times, particularly in Catholic nations. For example, there’s an account of a ship christening by
the Knights of Malta in the seventeenth century that describes two friars boarding a new warship, praying, and sprinkling holy water all around the ship before deeming her seaworthy and sending her out into the water.

After the Protestant Reformation, kicking off in earnest after Martin Luther’s 1517 “Ninety-Five Thesis”, certain nations in Europe did away with
some aspects of the religious part of the christening. Rather than use religious leaders for this task, members of the monarchy or military leaders would take over the christening duties.

For instance, 65 years before the above Knights of Malta reference, in 1610, the Prince of Wales was present at the christening of the Prince Royal. In this instance, there was a standing cup on board the ship, which is just a large and expensive
cup made of some precious metal, usually silver. The Prince took a ceremonial sip of the wine in the cup before throwing the rest of the contents across the deck. The cup was then thrown off the side of the ship to be caught by a lucky observer.

Late in the seventeenth
century, the standing cup ceremony was replaced with breaking a bottle of wine over the bow. This switch was in part because the cups were extremely valuable and the British navy was growing rapidly; it just wasn’t practical to continue to give the expensive cups away every time a ship was launched.

As for the switch from wine to champagne, it’s thought that preferences simply switched with the times. Champagne came to be seen as an “aristocratic
” choice -for a time in the nineteenth century being more popular than wine among many elite –and, therefore, considered the best option for ship christening. The tradition of using it has stuck around ever since in certain countries.