On May 29, 2009, Pixar did it again: “Up” debuted in theaters, became one of the best films of the year, and grossed over $700 million without breaking a sweat. Its story is fabulous, and the image of a house floating with balloons is etched into the minds of millions. Obviously, the developers of “Up” didn't hesitate to suspend physics to achieve their goal, but if we briefly move to the real world… how many balloons do you need to make the house from Up float?
The house from Up, or how to “kill physics” the right way
Exceptions. Tricks. “Suspension of disbelief” is the formal term. In the words of Aristotle himself, the audience ignores the unreality of fiction to experience “catharsis”. Cinema is full of examples, and honestly, many movies don't work without them. The ships of Star Wars and Star Trek have sound in space, action heroes cling to the roofs of cars as if glued, Indiana Jones survived a nuclear bomb in a refrigerator, and Up has a house floating with balloons.
One of the first things that Pete Docter (one of the creators of Up, and its director) had to solve was the calculation of how many balloons are actually needed for a house like Up's to float... and the original result came out to 26.5 million. The solution? They used around 10 thousand in the animation, and cheated. A later analysis published by the channel The Film Theorists raises the number even further, breaking through the ceiling of 31 million balloons. So... what alternatives do we have?
How many balloons do you need to make the house from Up float?
31 million balloons is an absurd quantity to reproduce. The people at Corridor Crew explain that the closest thing to that was the Balloonfest '86 that took place in Cleveland, with the release of a million and a half balloons... causing two deaths, two lawsuits, and millions of dollars in losses. 31 million balloons have the capacity to cover an entire city and block out the Sun, following the evolution of the wind. It's a “current” of balloons.
If we have to visualize a viable alternative, all arrows point to replacing party balloons with weather balloons... many of them. A weather balloon is so big that a human can stand inside it, but what do we fill it with? The video explains the virtues and problems of hydrogen (very light, extremely dangerous) and helium (much safer, but heavier, and there's less and less of it), however, it also explores the hypothesis of the “vacuum balloon”, made of exotic materials... and nothing inside. The concept is similar to the vacuum airship that Francesco Lana de Terzi imagined in the 17th century. If we imagine for a moment that such a super vacuum balloon exists, the house from Up would need one of 75 meters in diameter to float.
The project of Jonathan Trappe went around the world, but we must not forget that he stripped his “house” down to the absolute minimum. The house from Up with its Queen Anne style can weigh up to 260 tons, more than the Statue of Liberty. And so we return to weather balloons. If we consider that a balloon two meters in diameter can lift up to 3.6 kilograms (in addition to its own weight), and that its final capacity changes with weather conditions (they work better if the day is cold)... the calculations suggest between 72,000 and 80,000 weather balloons to make the house from Up float. Good luck...?
