Marcos André via Flickr Creative Commons // CC BY 2.0
Marcos André via Flickr Creative Commons // CC BY 2.0

Scientists Explain How Your Shoes Untie Themselves

Marcos André via Flickr Creative Commons // CC BY 2.0
Marcos André via Flickr Creative Commons // CC BY 2.0

You know you tied your shoelaces properly. You know you did. Yet halfway down the block, you feel your sneaker slipping away from your foot. How could a knot untie itself? Scientists using slow-motion cameras may have figured it out. They published their report in the journal Proceedings of the Royal Academy A.

There are two classic shoelace knots. There’s the “rabbit comes out of the hole, runs around the tree, and returns to his hole” loop-and-pull, and then there’s the crossed-loop bunny ears approach. (Rabbits have apparently cornered the market on shoelace knots.) Both knots are prone to unraveling under strain, although bunny ears are generally considered the more secure option.

Mechanical engineers at Berkeley wondered what was producing the two knots’ different success rates. Their interest, said co-author Christopher Daily-Diamond, goes well beyond untied cross-trainers. “If you can start to understand the shoelace,” he said in a statement, “then you can apply it to other things, like DNA or microstructures, that fail under dynamic forces. This is the first step toward understanding why certain knots are better than others, which no one has really done."

The first step was to catch the knots in the act of coming undone. The researchers trained a high-speed camera on a treadmill, then co-author and runner Christine Gregg put on her sneakers and got moving.

By slowing down the camera and analyzing the physics of Gregg’s footfalls, the research team was able to spot the conspirators tugging away at those poor, unsuspecting knots. The first was the violence of each footfall, as Gregg’s shoes smacked against the treadmill with seven times the force of gravity. This impact stretched and pushed the knot. And while it was weakening, the whipping motion of the bow’s loops and ends simultaneously pulled the strands apart. These two forces combined untied Gregg’s well-formed knots.

"You really need both the impulsive force at the base of the knot and you need the pulling forces of the free ends and the loops," Daily-Diamond said. "You can't seem to get knot failure without both."

The researchers noted that knot failure is not inevitable; often it takes one specific jolt to the laces to start the unraveling clock. “[Your] laces can be fine for a really long time,” Gregg said, “and it's not until you get one little bit of motion to cause loosening that starts this avalanche effect leading to knot failure.”

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25 Incisive Facts About Jaws
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Daah dun, daah dun, daah dun, dun dun, dun dun, dun dun. Today is the 43rd anniversary of Steven Spielberg’s original blockbuster, Jaws. Here are 25 fascinating facts you may not have known about the Oscar-winning shark flick.

1. THE BOOK COULD HAVE BEEN CALLED SOMETHING ELSE.

The film is adapted from author Peter Benchley’s bestselling novel of the same name, which Benchley based on a series of shark attacks that occurred off the coast of New Jersey in 1916 and after an incident where a New York fisherman named Frank Mundus caught a 4,500-pound shark off the coast of Montauk in 1964. Other title ideas Benchley had before settling on Jaws were “The Stillness in the Water,” “The Silence of the Deep,”  “Leviathan Rising,” and “The Jaws of Death."

2. THE BOOK’S AUTHOR MAKES A CAMEO IN THE MOVIE.

Benchley himself can be seen in a cameo in the film as the news reporter who addresses the camera on the beach. Benchley had previously worked as a news reporter for the Washington Post before penning Jaws.

Steven Spielberg also makes a cameo in the movie: His voice is the Amity Island dispatcher who calls Quint’s boat, the Orca, with Sheriff Brody’s wife on the line.

3. STEVEN SPIELBERG GOT THE DIRECTING JOB BECAUSE OF DUEL.

Spielberg was chosen to direct Jaws by producers Richard Zanuck and David Brown (who had also worked with the then-28-year-old director on his 1974 film The Sugarland Express) because of his film Duel, which featured a maniacal trucker terrorizing a mild-mannered driver. The producers thought the movie was thematically similar to the story for Jaws, making Spielberg a great fit.

4. THERE’S NOT A LOT OF JAWS IN JAWS.


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The shark doesn’t fully appear in a shot until one hour and 21 minutes into the two-hour film. The reason it isn’t shown is because the mechanical shark that was built rarely worked during filming, so Spielberg had to create inventive ways (like Quint’s yellow barrels) to shoot around the non-functional shark. 

5. IT TOOK A VERY LONG TIME TO MAKE.

Jaws was marred with so many technical problems (including the shark not working and shooting in the Atlantic Ocean) that the originally scheduled 65-day shoot ballooned into 159 days, not counting post-production.

6. AMITY ISLAND WAS ACTUALLY MARTHA’S VINEYARD.

To create the fictional town of Amity, the production shot on location in Edgartown and Menemsha on Martha’s Vineyard in Massachusetts. Strict land ordinances kept the production from building anywhere—Quint’s shack was the one and only set built for the movie, while the defaced Amity Island billboard had to be constructed and taken down all in one day. 

7. THE SHARK WEIGHED MORE THAN A TON.

The pneumatically-powered shark, designed and built by production designer Joe Alves, weighed in at 1.2 tons and measured 25 feet in length. Part of the reason that Martha’s Vineyard was chosen as a location was because the surrounding ocean bed had a depth of 35 feet for up to 12 miles offshore, which was perfect for scenes that required the mechanical shark rig to be rested on the shallow ocean floor.

8. SPIELBERG TOOK INSPIRATION FROM HIS LEGAL COUNSEL.

The director nicknamed the shark “Bruce” after his lawyer, Bruce Ramer, who also currently represents other celebrities like Demi Moore, Ben Stiller, and Clint Eastwood.

9. SOME GOOD, OLD-FASHIONED ELBOW GREASE HELPED CREATE THE OPENING SCENE.

The opening scene took three days to shoot. To achieve the jolting motions of the shark attacking the swimmer in the opening sequence, a harness with cables was attached to actress Susan Backlinie’s legs and was pulled by crewmembers back and forth along the shoreline. Spielberg told the crew not to let Backlinie know when she would be yanked back and forth, so her terrified reaction is genuine.

Spielberg went on to spoof his own opening scene for Jaws in his 1979 World War II comedy 1941. The scene features Backlinie once again taking a skinny dip at the beach, but instead of being attacked by a shark she’s scooped up by a passing Japanese submarine.

10. SOME EAVESDROPPING GOT ROY SCHEIDER THE LEAD.

Scheider got the part of Chief Martin Brody after overhearing Spielberg talking to a friend at a Hollywood party about the scene where the shark leaps out of the water and onto Quint’s boat. Scheider was instantly enthralled, and asked Spielberg if he could be in the film. Spielberg loved Scheider from his role in The French Connection, and later offered the actor the part.

11. RICHARD DREYFUSS WASN’T THE FIRST CHOICE TO PLAY HOOPER.

Spielberg initially approached Jon Voight, Timothy Bottoms, and Jeff Bridges to play oceanographer Matt Hooper. When none of them could commit to the role, Spielberg’s friend George Lucas suggested Richard Dreyfuss, whom Lucas has directed in American Graffiti. Dreyfuss would later accept the part because he thought he was terrible in the title role of the film The Apprenticeship of Duddy Kravitz a year earlier.

12. ROBERT SHAW WASN’T THE FIRST CHOICE TO PLAY QUINT.

When actors Lee Marvin and Sterling Hayden—the first and second choices to play the grizzled fisherman Quint, respectively—both turned Spielberg down, producers Zanuck and Brown recommended English actor Robert Shaw, whom they had previously worked with on 1973's The Sting.

13. A LOCAL MARTHA’S VINEYARD FISHERMAN WAS THE REAL QUINT.

Shaw based his performance of Quint on Martha’s Vineyard native and fisherman Craig Kingsbury, a non-actor who appears in the film as Ben Gardner. Kingsbury helped Shaw with his accent and allegedly told Shaw old sea stories that the actor incorporated into his improvised dialogue as Quint.

14. GREGORY PECK FORCED A SCENE TO BE CUT FROM THE MOVIE.

In early drafts of the screenplay, Quint was originally introduced while causing a disturbance in a movie theater while watching John Huston’s 1958 adaptation of Moby Dick. The scene was shot, but actor Gregory Peck—who plays Captain Ahab in that movie—owned the rights to the film version of Moby Dick and wouldn’t let the filmmakers on Jaws use the footage, so the sequence was cut.

15. THE BOOK WAS VERY DIFFERENT FROM THE MOVIE.

Early drafts of the screenplay featured a subplot where Hooper has an affair with Chief Brody’s wife, which was carted over from the book. Another detail left out of the movie from the book was that Mayor Vaughn was under pressure from the mafia, not local business owners, to keep Amity’s beaches open because of their real estate investments on the island. 

16. SPIELBERG ADDED AN OFFSCREEN IMPROV MOMENT.

The scene where Brody’s son Sean mimics his father’s movements at the dinner table was based on a real thing that happened between Scheider and child actor Jay Mello in between takes. Spielberg loved the off-the-cuff moment so much that he re-staged it and put it in the movie.

Another iconic moment was also a spontaneous one: Brody’s famous “You’re gonna need a bigger boat” line was entirely improvised by Scheider on the day of shooting.

17.  ROBERT SHAW PUT HIS OWN SPIN ON THE INDIANAPOLIS SPEECH.


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Quint’s U.S.S. Indianapolis speech wasn’t in the novel, and the backstory of Quint being a sailor on the ship first appeared in an uncredited rewrite of the script by playwright Howard Sackler. Later, writer-director (and Spielberg’s friend) John Milius expanded the characteristic into a multi-page monologue, which was then whittled down and spruced up by actor Robert Shaw (himself a playwright) on the day of shooting.

18. SOME REAL SHARK FOOTAGE WAS USED.

Zanuck demanded that real shark footage be used in the movie, and Spielberg used it sparingly. He hired experts Ron and Valerie Taylor to shoot underwater footage of 14-foot sharks off the coast of Australia. For scale, they hired a little person actor named Carl Rizzo to appear as Hooper in a mini shark cage in hopes that they could create the illusion of a shark attacking the character. After trying to get the right shot for about a week, the sharks would only swim around the cage. Then, during a take when Rizzo wasn’t in the cage, a shark became entangled in the cage’s bridle, causing it to thrash and roll around. This footage was included in the final film.

19. DESPITE ALL THE BLOODY SHARK ATTACKS, THE MOVIE IS RATED PG.

Jaws was initially rated R by the MPAA. But after some of the more gruesome frames of the shot showing the severed leg of the man attacked by the shark in the estuary were trimmed down, the film was given a PG-rating (the PG-13-rating wasn’t created until after Spielberg’s own film, Indiana Jones and the Temple of Doom, caused the MPAA to change the system in 1984). The poster for the film still reads that the movie “MAY BE TOO INTENSE FOR YOUNGER CHILDREN.”

20. SPIELBERG DIDN’T DIRECT SOME OF THE FINAL SCENES.

Spielberg didn’t direct the shot of the shark exploding. In fact, he had already returned to Los Angeles to begin post-production on the film after the film’s grueling shooting schedule and left the shot up to the production’s second unit.

21. THE POSTER IMAGE CAME ABOUT BY CHANCE.

The film’s iconic poster image was designed by artist Roger Kastel for the paperback edition of Benchley’s book. Kastel modeled the image of the massive shark emerging from the bottom of the frame after a great white shark diorama at the American Museum of Natural History. The female swimmer at the top was actually a model that Kastel was sketching at his studio for an ad in Good Housekeeping. He asked her to stay an extra half-hour and had her pose for the image by standing on a stool and pretending to swim.

22. JAWS WAS HUGE.

Jaws was the first movie released in more than 400 theaters in the United States, and the first movie to gross over $100 million at the box office. It was the highest grossing movie of all time until Star Wars was released two years later.

23. SPIELBERG INCLUDED A NOD TO HIS PREVIOUS MOVIE.

The faint roaring sound that is heard after the shark is blown up was also used by Spielberg in Duel, when that film’s villainous truck falls off a cliff.

24. IT ORIGINALLY ENDED JUST LIKE MOBY DICK.

The original ending in the script had the shark dying of harpoon injuries inflicted by Quint and Brody à la Moby Dick, but Spielberg thought the movie needed a crowd-pleasing finale and came up with the exploding tank as seen in the final film. The dialogue and foreshadowing of the tank were then dropped in as they shot the movie.

25. THE MAIN THEME MUSIC IS EASY TO PLAY

The sole music notes played for composer John Williams’ Jaws theme are E and F. Jaws marked the second time Williams worked with Spielberg after his film The Sugarland Express, and Williams has since composed the music for every Spielberg movie since with the exception of 1985's The Color Purple and 2015's Bridge of Spies.

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The Fascinating Reason Why There Are No Mosquitoes at Disney World
Jacqueline Nell/Disneyland Resort, Getty Images
Jacqueline Nell/Disneyland Resort, Getty Images

There are no mosquitoes in The Most Magical Place on Earth. That's right, Disney World is so dedicated to making sure you have the time of your life that they've made the bugs practically disappear. How do they pull that off? No, the answer isn't magic. Vlogger Rob Plays delved into the answer in a video spotted by Neatorama.

It would be a feat to get rid of pesky mosquitoes anywhere, but Disney World is in Florida, a.k.a. swamp territory, where insects are more abundant than other places. Bugs are annoying, but they're also dangerous if they're carrying diseases like Zika, and Disney has a responsibility to protect its guests. In short, Disney gets rid of the pests by employing a comprehensive program that includes spraying insecticides and maintaining natural predators, and they do all of this with a level of vigilance that's fearsome to behold.

The park has something called the Mosquito Surveillance Program to manage it all. There are carbon dioxide traps everywhere, and once they catch bugs, the team at Disney freezes and analyzes the population to determine how best to eradicate them. Interestingly enough, they also employ the use of chickens. These sentinel chickens, as they're called, live in coops all over Disney World. While these feathered employees are going about their daily life, their blood is being monitored for mosquito-borne diseases like West Nile virus. Lucky for the chickens, they don't get sick from the virus—but if they do pick it up, the Disney team knows where in the park they got it from so they can deliver a swift blow to the mosquitoes in that area.

You may also notice that the video is populated by clips of the Seven Dwarfs spraying insecticides. If you're wondering how you missed a lengthy sequence in which Happy, Grumpy, and co. did battle with the local insect population in 1937's Snow White and the Seven Dwarfs, you didn't. The clips come from a separate propaganda film that Disney made during World War II called The Winged Scourge, all about the dangers of malaria and the insects that carry it. The disease caused major casualties for the Allies while fighting in the Pacific Ocean theater of World War II.

Next time you're visiting Disney World, be sure to appreciate the relatively insect-free utopia before returning to the real world.

[h/t Neatorama]

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