The conceit of the new Disney/Pixar cartoon epic, Up, is that an old guy's house gets attached to a bunch of helium balloons which lift it up out of the city and on a wonderful adventure.

That got Wired Science thinking: Could that actually work? And if so, how many balloons would you need?

We called Wolfe House Movers, which specializes in moving old structures and had Kendal Siegrist, a manager, take a look at the images from the movie to see how much the house might weigh.

"A building like that, you'd figure right around 100,000 pounds," Siegrist said.

Then we did some calculations. Air weighs about 0.078 pounds per cubic foot; helium weighs just 0.011 pounds per cubic foot. A helium balloon experiences a buoyant upward force that is equal to the air it displaces minus its own weight, or 0.067 pounds per cubic foot of helium balloon.

One more simple calculation — 100,000 pounds divided by 0.067 pounds per cubic foot — and you've got that it would take 1,492,537 cubic feet of helium to lift the house. Of course, you'd need some more balloons to keep getting it higher, but that's our minimum.

Now, let's assume you've got a bunch of spherical balloons three feet in diameter. They've got a volume in 14.1 cubic feet, so you'd need 105,854 of them filled with helium to lift the house. Eyeballing the cluster of balloons above the house in Up, let's say on average, it's 40 balloons across and deep and 70 balloons tall. Do the math and there could be 112,000 balloons in there.

"That's a great idea," Siegrist said, laughing. "I'd love to do that with the balloons."

Cluster Ballooning fans actually do this sort of thing, but with people in harnesses, not enormous houses, and they generally use a lot less balloons. They tend to use bigger balloons, say, six feet in diameter. You'd only need 13,208 of those.

But even if you could get the balloons and one hell of a strong cable, could a house be pulled from the top like that?

"If you go try picking it up, depending on what you're doing, you can," Siegrist said, "but for the most part, you want the house to bear the weight on its foundation."

The way real, professional house movers like to do it is to get into the house's basement and lift from below.

"The theory of our business is to replace the foundation with steel beams and then the steel beams can be transported wherever you need to, with the house just getting a free ride," he said.

See Also:

Images: 1. Disney/Pixar. 2. Clusterballoon.org

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