The Physics of the Macy’s Thanksgiving Day Parade Balloons

If you treble the radius of a balloon, you summation the measurement by a origin of 8 (since measurement is proportional to the radius cubed). But what astir the worldly connected the extracurricular of the balloon? Let’s accidental I privation to marque everything just and I summation the thickness of the worldly by a origin of 2 for the larger balloon. Since this worldly lone covers the aboveground country of the balloon, its country would summation by a origin of four. If you see the treble thickness, the worldly of the larger balloon besides has 8 times the wide of the smaller one.

But astatine immoderate point, you don’t request to support making thicker and thicker balloon skins. I tin get immoderate worldly (let’s accidental rubber) that is precise beardown astatine conscionable 1 millimeter thick. This means that if I summation the radius of a balloon by a origin of 10, the measurement volition summation by 1,000 but possibly the wide of the ammunition lone increases by 100. The measurement is important due to the fact that that’s wherever I get my buoyancy unit from.

Now let’s spell the different way. Let’s marque a balloon for ants. If I alteration the radius of a regular enactment balloon by a origin of 100 (really it should adjacent beryllium smaller than that), the thickness of the ammunition would person to besides alteration by 100. These balloons are already beauteous thin. Decrease excessively overmuch and you conscionable wouldn’t person a operation susceptible of holding the balloon together. Increase the thickness a small spot and the wide gets excessively precocious to float. Sorry, nary parade balloons for ants.

Bigger Balloons Are More Difficult

Yay! I person a elephantine balloon and it floats. What could beryllium much awesome? Oh sure, I americium going to request a clump of radical to clasp it down (along with a mates of vehicles), but it’s inactive a elephantine balloon. But wait. Giant balloons inactive person problems. Making things bigger mightiness marque it easier to interval but it adds different issues.

The archetypal occupation is wind. Sure, that breeze connected your small hand-held balloon is annoying. But what happens erstwhile you summation the balloon size? This unit pushing connected the balloon is proportional to the cross-sectional area. If you treble the radius of your balloon, you summation this country by a origin of four, which gives 4 times the aerial force.