One thing I've learned over the years is not to argue with rocket scientists.
Here's a synopsis from the Mythbusters Web Site.
Helium Football/Catching a Bullet
Written by Doolley012
Monday, 20 March 2006
Air Date: February 1, 2006
Helium Football/Catching a Bullet
The Myth: A football filled with helium will fly farther than one equally pressurized with air.
The Possible Source: A kicker who played for the Oakland Raiders from 1973 to 1986, Ray Guy, had an astonishing kick, which made the ball seem to stay in the air for exceptionally long amounts of time. This period in the air was dubbed hang time. Reportedly, during a game in the 70's, one had such a spectacular hang time that the ball was immediately collected and tested for the presence of helium. It came up negative.
Debrah Nolan [Statistician] provides Adam and Jamie with expert analysis of the data collected during their experiments.
"I put everything on my head." - Adam
"Well, yeah, but we would, you know, aspire to not be idiots." - Jamie
The Action/Results: To begin, Adam and Jamie travel to San Francisco City College where they meet with football coach John Balano and kicker Tim Sonnenburg. After getting some pointers on proper kicking techniques (and humorously attempting) the two agree that the college kicker would be the best choice for sending the ball downfield. Ten trials are performed, five with helium and five with air. The data collected shows the balls filled with helium went an average of 3 yards farther than the ones filled with air. Unfortunately, there were too many outliers in the data set, and so Adam and Jamie, unsatisfied with the method, contemplate how to achieve more accurate results.
The next experiment is simply to determine how large a difference of weight is given between the two footballs. After emptying the ball and refilling it with the standard 13psi of air, they find the ball has gained 3.2 grams in weight. The ball is once again flattened, filled with helium and weighed. Surprisingly, it is almost 7 grams lighter than the ball filled with air - even lighter than the football without anything in it. Following this, the two pressurize a football using Grant's bottle rocket rig until a satisfying explosion occurs.
To eliminate human and atmospheric variables, Adam and Jamie set up a kicking machine in an indoor hangar at Moffet Field. Jamie sets up a bungee cord to trigger the firing mechanism to further avoid human error. Jamie then proceeds to fire twenty air filled balls through the hangar, followed by twenty helium balls while Adam marks and records their distance. In the end, the Mythbusters have 60 data points and take the records to statistician Debrah Nolan. She finds that the air filled balls actually had a one-inch advantage, but declares the data inconclusive.
The two finally decide to test the transfer of energy from a kick to the ball. By modifying the A-frame shock rig used in the catching a bullet myth, Adam and Jamie can give a determined amount of force to the ball from a pendulum-like motion. After "kicking" the balls with a hammer and viewing the resultant high-speed film, they find
that both the air-filled and helium-filled balls had the same speed. The helium balls did not have the advantage.
The final conclusion was that because the helium balls were lighter, they were more susceptible to drag when flying through the air. The very thing that should've made them fly farther, was, in fact, causing the balls to move a slightly shorter distance.
Alan Lichtenstein, MD
Mens et manus
He who laughs last...Thinks slowest.