Why Your Christmas Lights Always Get Tangled, According to Science

iStock
iStock

A Christmas tree isn't a Christmas tree without those pretty colored lights, right? OK, no problem. You stored them in a box marked "Xmas lights" 11 months ago. You know where the box is. Now you just have to open the box, grab the lights, and—

That's where it gets tricky. Unless you're very lucky, or extremely well organized, the lights are likely all tangled up; soon you're down on your hands and knees, struggling to untangle a spaghetti-like jumble. (And it's not just you: A couple of years ago, the British grocery chain Tesco hired temporary "Christmas light untanglers" for the holiday season.) But why are Christmas lights so prone to tangling in the first place—and can anything be done about it?

IT'S KNOT AN EASY PROBLEM TO SOLVE

There are really two separate problems, explains Colin Adams, a mathematician at Williams College in Williamstown, Massachusetts and the author of The Knot Book, an introduction to the mathematical theory of knots. First, the cord on which the lights are attached is prone to tangling—just as headphone and earbud cords are (or, in the past, telephone handset cords).

Several years ago, physicists Dorian Raymer and Douglas Smith, then at the University of California, San Diego, did a study to see just how easily cords can get tangled. They put bits of string of various lengths in a cube-shaped box, and then mechanically rotated the box so that the strings tumbled around, like socks in a dryer, repeating the experiment more than 3400 times. The first knots appeared within seconds. More than 120 different types of knots spontaneously formed during the experiment. They also found—perhaps not surprisingly—that the longer the string, the more likely it was to become knotted (few knots formed in strings shorter than 18 inches, they noted). As the length of the string increased, the probability of a knot forming approached 100 percent.

The material that the string (or cord) is made of is important too; a more flexible cord is more likely to tangle than a less flexible one. And while the length of the cord matters, so does its diameter: In general, long cords get tangled more easily than short ones, but a cord with a large diameter will be less flexible, which reduces the risk of knotting. In other words, it's the ratio of length to diameter that really matters. That's why a garden hose can get tangled—it's relatively stiff, but it's also very long compared to its diameter.

But that's not the end of the story. If a cord has a metal wire inside it—as traditional Christmas lights do—then it can acquire a sort of "natural curvature," Jay Miller, a senior research scientist at the Connecticut-based United Technologies Research Center, tells Mental Floss. That means that a wire that's been wrapped around a cylindrical spool, for example, will tend to retain that shape.

"Christmas lights are typically spooled for shipping or packing, which bends metal wire past its 'plastic limit,' giving it natural curvature approximately the size of the spool it was wound around," Miller says. Christmas lights can be even harder to straighten than other wound materials because they often contain a pair of intertwined wires, giving them an intrinsic twist.

And then there's the additional problem of the lights. "Christmas lights are doubly difficult, once things get tangled, because there are all of these little projections—the lights—sticking out of them," Adams tells Mental Floss. "The lights get in the way of each other, and it makes it very difficult to pull one strand through another. That means once you're tangled, it's much harder to disentangle."

IS THERE ANY HOPE FOR A TANGLE-FREE CHRISTMAS?

What, then, can be done? One option would be for manufacturers to make the cord out of a stiff yet elastic material—something that would more readily "bounce back" from the curvature that was imparted to it while in storage. A nickel-titanium alloy known as Nitinol might be a candidate, says Miller—but it's too expensive to be a practical choice. And anyway, the choice of material probably makes little difference as long as the lights still protrude from the cord. Perhaps the biggest breakthrough in recent years has been the proliferation of LED "rope lights" that don't employ traditional bulbs at all; rather, they use LEDs embedded within the rope-like cord itself. Of course, these can still get tangled up in the manner of a garden hose, but without those pesky protrusions, they're easier to untangle.

A simpler solution, says Adams, is to coil the lights very carefully when putting them away, ideally using something like twist-ties to keep them in place. (Martha Stewart has proposed something similar, using sheets of cardboard instead of twist-ties.)

Meanwhile, the mathematicians have some advice if you find yourself confronted with a hopelessly tangled, jumbled cord: Find one of the "free" ends, and work from there.

"Eventually," Adams assures us, "you will succeed."

10 Electrifying Facts About Michael Faraday

iStock
iStock

This world-changing genius was born into poverty on September 22, 1791. Fortunately for us, Michael Faraday refused to let his background stand in his way.

1. HE WAS LARGELY SELF-EDUCATED.

In Faraday's boyhood home, money was always tight. His father, James, was a sickly blacksmith who struggled to support a wife and four children in one of London's poorer outskirts. At age 13, young Faraday started helping the family make ends meet. Bookseller George Ribeau (sometimes spelled Riebau) took him on as an errand boy in 1804, with the teen's primary job being the delivery and recovery of loaned-out newspapers.

Shortly after Faraday's 14th birthday, Ribeau offered him a free apprenticeship. Over the next seven years, he mastered the trade of bookbinding. After hours, Faraday remained in Ribeau's store, hungrily reading many of the same volumes he'd bound together.

Like most lower-class boys, Faraday's formal schooling was very limited. Between those bookshelves, however, he taught himself a great deal—especially about chemistry, physics, and a mysterious force called "electricity."

2. A 300-PAGE NOTEBOOK LAUNCHED HIS SCIENTIFIC CAREER.


Wikimedia Commons // CC BY 4.0 

Sir Humphry Davy (above) left a huge mark on science. In the year 1808 alone, the man discovered no less than five elements, including calcium and boron. An excellent public speaker, Davy's lectures at the Royal Institution consistently drew huge crowds. 

Twenty-year-old Faraday attended four of these presentations in 1812, having received tickets from a customer. As Davy spoke, Faraday jotted down detailed notes, which he then compiled and bound into a little book. Faraday sent his 300-page transcript to Davy. Duly impressed, the seasoned scientist eventually hired him as a lab assistant. Later in life, Davy was asked to name the greatest discovery he'd ever made. His answer: "Michael Faraday."

Tension would nevertheless erupt between mentor and protégé. As Faraday's accomplishments began to eclipse his own, Davy accused the younger man of plagiarizing another scientist's work (this rumor was swiftly discredited) and tried to block his admission to the Royal Society.

3. IF IT WEREN'T FOR FARADAY, WE MIGHT NOT HAVE ELECTRIC POWER.

On September 3, 1821, Faraday built a device that ushered technology into the modern era. One year earlier, Danish physicist Hans Christian Ørsted had demonstrated that when an electric current flows through a wire, a magnetic field is created around it. Faraday capitalized on this revelation. Inside the Royal Society basement, he began what was arguably his most groundbreaking experiment by placing a magnet in the bottom of a mercury-filled glass container. Dangling overhead was a wire, which Faraday connected to a battery. Once an electric current was conducted through the wire, it began rotating around the magnet.

Faraday had just built the world's first electric motor. How could he possibly top himself? By building the world's first electric generator. His first experiment was comprised of a simple ring of wires and cotton through which he passed a magnet. By doing so, he found that a current was generated. To this day, most electricity is made using the same principles.

4. FARADAY INVENTED THE RUBBER BALLOON.


iStock

By today's standards, his early models would look shabby. Made via pressing two sheets of rubber together, Faraday's balloons were used to contain hydrogen during his experiments. Faraday created his first in 1824 and was quick to praise the bag's “considerable ascending power.” Toy manufacturers started distributing these the following year.

5. HE'S ALSO THE GRANDFATHER OF MODERN REFRIGERATORS.

In 1823, Faraday sealed a sample of chlorine hydrate inside a V-shaped tube. As he heated one end and cooled the other simultaneously, the scientist noticed that a peculiar yellow liquid was starting to form. Curious, he broke open the tube. Without warning, a sudden, violent explosion sent glass shards flying everywhere. Mercifully uninjured, he smelled a strong scent of chlorine in the air.

It didn't take him very long to figure out what had happened. Inside the tube, pressure was building, which liquefied the gas. Upon puncturing the glass, he'd released this pressure and, afterwards, the liquid reverted into its gaseous state. This sudden evaporation came with an interesting side-effect: it cooled down the surrounding air. Quite unintentionally, Faraday thus set the stage for the very first ice-making machines and refrigeration units.

6. HE BECAME AN ANTI-POLLUTION CRUSADER.

Britain's industrialization came at a malodorous price. As London grew more crowded during the mid-1800s, garbage and fecal matter were dumped into the River Thames with increasing regularity. Naturally, the area didn't smell like a rose. In 1855, Faraday penned an oft-reproduced open letter about the problem, imploring the authorities to take action. “If we neglect this subject,” he wrote, “we cannot expect to do so with impunity; nor ought we be surprised if, ere many years are over, a hot season give us sad proof for the folly of our carelessness.”

Just as Faraday predicted, a broiling summer forced Londoners of all stripes to hold their noses. Dubbed “the Great Stink,” the warmer months of 1858 sent the Thames' rancid odor wafting all over the city. Parliament hastily responded with a comprehensive sewage reform bill. Gradually, the putrid stench began to dissipate.

7. HE STARTED THE ROYAL SOCIETY'S CHRISTMAS LECTURE TRADITION.


Alexander Blaikley, Wikimedia Commons, Public Domain

Faraday understood the importance of making science accessible to the public. In 1825, while employed by the Royal Society, he spearheaded an annual series that's still going strong today. That holiday season, engineer John Millington delivered a set of layman-friendly lectures on “natural philosophy.” Every year thereafter (excluding 1939–1942 because of WWII), a prominent scientist has been invited to follow in his footsteps. Well-known Christmas lecturers include David Attenborough (1973), Carl Sagan (1977), and Richard Dawkins (1991). Faraday himself was the presenter on no less than 19 occasions.

8. BRILLIANT AS FARADAY WAS, HE STRUGGLED WITH MATH.

Towards the end of his life, Faraday's lack of formal education finally caught up with him. An underprivileged childhood had rendered him mathematically illiterate, a severe handicap for a professional scientist. In 1846, he hypothesized that light itself is an electromagnetic phenomenon, but because Faraday couldn't support the notion with mathematics, it wasn't taken seriously. Salvation for him came in the form of a young physicist named James Clerk Maxwell. Familial wealth had enabled Maxwell to pursue math and—in 1864—he released equations [PDF] that helped prove Faraday's hunch.

9. AS TIME WORE ON, HE STRUGGLED WITH MEMORY LOSS.

Michael Faraday
iStock

At the age of 48, Faraday's once-sharp memory started faltering. Stricken by an illness that rendered him unable to work for three years, he wrestled with vertigo, unsteadiness, and other symptoms. Following this "extended vacation" [PDF], he returned to the Royal Society, where he experimented away until his early 70s.

However, Faraday was still prone to inexplicable spurts of sudden giddiness, depression, and extreme forgetfulness. “[My] bad memory,” he wrote, “both loses recent things and sometimes suggests old ones as new.” Nobody knows what caused this affliction, though some blame it on overexposure to mercury.

10. EINSTEIN KEPT A PORTRAIT OF FARADAY IN HIS BERLIN HOME.

Fittingly, the father of modern physics regarded Faraday as a personal hero. Once, upon receiving a book about him, Einstein remarked, “This man loved mysterious Nature as a lover loves his distant beloved.”

Fossilized Fat Shows 550-Million-Year-Old Sea Creature May Have Been the World's First Animal

Ilya Bobrovskiy, the Australian National University
Ilya Bobrovskiy, the Australian National University

A bizarre sea creature whose fossils look like a cross between a leaf and a fingerprint may be Earth's oldest known animal, dating back 558 million years.

As New Scientist reports, researchers from the Australian National University (ANU) made a fortunate find in a remote region of Russia: a Dickinsonia fossil with fat molecules still attached. These odd, oval-shaped creatures were soft-bodied, had rib structures running down their sides, and grew about 4.5 feet long. They were as “strange as life on another planet,” researchers wrote in the abstract of a new paper published in the journal Science.

Another variety of fossil
Ilya Bobrovskiy, the Australian National University

Although Dickinsonia fossils were first discovered in South Australia in 1946, researchers lacked the organic matter needed to classify this creature. "Scientists have been fighting for more than 75 years over what Dickinsonia and other bizarre fossils of the Edicaran biota were: giant single-celled amoeba, lichen, failed experiments of evolution, or the earliest animals on Earth,” senior author Jochen Brocks, an associate professor at ANU, said in a statement.

With the discovery of cholesterol molecules—which are found in almost all animals, but not in other organisms like bacteria and amoebas—scientists can say that Dickinsonia were animals. The creatures swam the seas during the Ediacaran Period, 635 million to 542 million years ago. More complex organisms like mollusks, worms, and sponges didn’t emerge until 20 million years later.

The fossil with fat molecules was found on cliffs near the White Sea in an area of northwest Russia that was so remote that researchers had to take a helicopter to get there. Collecting the samples was a death-defying feat, too.

“I had to hang over the edge of a cliff on ropes and dig out huge blocks of sandstone, throw them down, wash the sandstone, and repeat this process until I found the fossils I was after,” lead author Ilya Bobrovskiy of ANU said. Considering that this find could change our understanding of Earth’s earliest life forms, it seems the risk was worth it.

[h/t New Scientist]

SECTIONS

arrow
LIVE SMARTER