The Experience: Mimicking the concept of a slinky on a roller coaster

The Trick: Building a giant spring, a spring, a marvelous thing!

Image: DisneySure, Epcot may have the reputation as Disney’s park for infotainment, but the most scientific ride at Walt Disney World is Slinky Dog Dash. It’s a brilliant demonstration of high-level physics concepts like kinetic energy, gravity, and the impact of momentum. In this way, it mirrors the Slinky itself.

Here’s a quick history lesson for you. A retired Navy Engineer, Richard James, noticed a problem while he worked at the Philadelphia Naval Shipyard toward the end of World War II. Sailors passed along stories of their instruments struggling in the face of stormy weather. James deduced that the addition of a spring to these instruments would keep them stable in such scenarios.

The inventor imagined many practical military applications wherein the springs would prevent objects from falling at unwelcome moments. The Navy was nonplussed. They quickly passed on the idea. Thankfully, James' wife, Betty, envisioned a different usage. She thought these small springs could become educational but entertaining toys. She coined the name, Slinky, and the two of them sold the famous department store, Gimbels, on the idea. The rest is toy history.

Image: DisneyWhen Imagineers learned that they would build a roller coaster based on the concept, they delighted in the possibilities. They wanted to display the scientific aspects of the slinky during the brief roller coaster ride. Even though Slinky Dog Dash is only two minutes long, it does a remarkable job of highlighting the main scientific applications of the Slinky.

Some of the physics principles at play are the Law of Conservation, potential and kinetic energy, gravity, and Newton’s First Law of Motion. Don’t worry. This isn’t an exam, and you won’t be tested later. All you need to understand is the basic stuff to appreciate Slinky Dog Dash.

An object motion stays in motion. That’s the Newtonian aspect. The Law of Conservation states that energy can’t be created, but it also can’t be destroyed. That’s where potential and kinetic energy come into play. Something possesses energy whether it’s stationary or in motion. The only question is whether it’s static, which is potential energy, or kinetic energy.

Image: DisneyWith a slinky, the object in question has a set amount of potential energy right up until you push it down the stairs Mexican Telenova style. Then, its energy transfers into the kinetic type. That object stays in motion thanks to another law of physics, gravity. That’s what pulls it down the stairs. And that’s how a slinky works.

Imagineers wanted to recreate the concept of the slinky with their roller coaster, and they did it by building a ride cart that mimics the design of the Slinky Dog from Toy Story. To craft this effect, they made coaster carts that bend and turn individually. This design simulates the slinky motion while demonstrating the Law of Conservation. It has that energy, whether it's moving or not, but the slinky design is the demonstration of what this science looks like during a real-world application.

The Experience: A pregnant pause that ramps up the enthusiasm

The Trick: Bringing a full motion coaster to a full-stop

Image: DisneySlinky Dog Dash’s coaster cart has potential energy that becomes kinetic once it gets revved up. But the genius part is neither the look nor the style of the roller coaster. It’s the trick that occurs in the middle.

Disney stops the ride for a few seconds, ostensibly to enhance excitement for the concluding track elements. In actuality, it's another smart display of potential and kinetic energy. The object in motion feels the push of gravity against it and comes to a full stop. Then, after a delicious pause, it explodes into action once again.

The mechanics aren't complicated. We're talking about a simple braking system, the standard coaster acceleration mechanisms, and a countdown clock to heighten anticipation. It’s the execution as well as the thought behind it that elevates the experience.

Image: DisneyFor starters, Disney had never constructed a roller coaster with a full-stop in the middle before. Those are actually quite rare in the theme park industry. The engineering isn't hard, of course. You just locate the hardware customarily found at the start of the ride to the spot where you want to stop the coaster. Obviously, you need to install some breaks, too. This leads to the unique construction aspect that Slinky Dog Dash has elements from the start and end of a typical roller coaster squarely in its middle section. Weird, huh?

The thought behind this oddity is twofold. On the one hand, it ably demonstrates the high-level physics concepts on display with a slinky. It celebrates the brilliance of one of the most popular toys of the 20th century. On the other hand, it’s just plain fun, which is the whole point of a Disney ride, right? Slinky Dog Dash is highbrow under the hood, but it’s something that a five-year-old will adore, too. Disney Imagineers snuck a massive amount of edutainment into a child-friendly roller coaster ride.