UP

Nick and I are avid fans of Disney Pixar. And any movie that make you cry within the first 4 minutes - without the characters even talking - is incredible. We saw this movie when it first came out in the theaters and again last night. Here is our conversation during the scene where you first see the balloons and the house begins to float away.

N: I don't get it

B: What?

N: How does the house not fly away

B: What do you mean?

N: If the balloons are tied to the house, the house should still float away.

B: They're tied to the backyard, probably by a tarp or something.

N: That's my little engineer.

So could the house in UP actually fly? I was going to try and do the math myself....but someone else already did it. So I'll just recap. Their explanation is here.

1. House weighs ~100,000lbs

2. Air weighs 0.078 lbs/cuft and helium weighs 0.011 lbs/cuft. This means that a cubic foot of helium fwill have an upward force of 0.078lbs but a downward force of 0.011lbs - net 0.068 in the UP direction. (This is the same way things float or sink in water.....both air and water are fluids).

3. So we have a net 0.068lbs/cuft in the UP direction. If the house weighs 100,000lbs, that means you'll need 100,000lbs/0.068lbs/cuft = 1,470,588cuft of helium for the house to hover. You'll need more if you want the house to float.

4. Let's say all the balloons are 1.5ft, spherical balloons - ~1.8 cuft. (4/3*pi*r^3...and yes, I had that one memorized for some odd reason)

5. So you'd need 832,182 balloons. Let's call it an even million to make it float.

6. The website thinks it it technically possible, I just don't think Mr. Fredrickson (the guy from the movie) could inflate a million balloons in 1 night.

7. NOW - let's say the he was more efficient and used balloons that were 3ft in diameter. This would be 14.1cuft or 104,022 balloons. And we'll say 120,000 for good measure. That could be done....I guess. 10,000/hr for 12 hrs. Still seems impossible, but he was pretty determined.

Say you wanted to make yourself fly - because duh, we've all thought about it at one time or another. 150lb person would require 85 1.5ft diameter spherical balloons - say 100 to float away. That seems very possible....and didn't some guy tie a bunch to his chair, float away, die and then land a Darwin Awards? SO yeah, definitely feasible.