Not Ideal
Over the last few months a remarkable thing has happened: there has been a confluence of physics and football that has been reported by many popular newspapers in the wake of Deflategate (a.k.a. the unusual drop in air pressure in footballs used by the New England Patriots in the AFC championship game against the Indianapolis Colts).
One New York Times article tried to explain how this could have happened using goofy and contrived photos of someone in a lab coat writing equations on a white board. This was meant to show how the ideal gas law could provide quasi-scientific evidence that the pressure drop in New England Patriot’s footballs could have occurred naturally, and could have happened without any deliberate deflation, even though the footballs from the opposing team remained at normal pressure. This situation reminds Chris of the time he compared the incredible mess on the desk of a fellow grad student to the entropy of an ideal gas. The associate director of our research institute was walking by at the time and said “Oh there’s nothing ideal about it!†The same can be said about the events related to Deflategate and in the news reporting on the subject. Perhaps the best possible outcome from this is to take advantage of a teaching moment.
There are two broad possibilities with regard to the pressure drop in the Patriot footballs: the pressure dropped because of natural conditions such as a change in temperature; the balls were deliberately deflated (most news stories have created confusion by using the term deflation to describe both of these possible mechanisms, when in fact the former is a pressure drop without deflation). To put this in perspective, the ideal gas law is not some exotic equation that is used exclusively by physicists with advanced degrees. It’s a fundamental equation that is taught in high school chemistry (PV=nRT), and it doesn’t take any advanced education to perform your own analysis of the ball pressure. In fact, the hardest part about using this equation is making sure the units are correct. A quick glance at Wikipedia lists the gas constant R using 27 different combinations of units. Note that the analysis shown in the New York Times article above uses Rankine for temperature, a unit of measure that is so obscure that modern spell checkers don’t even recognize it. As we have pointed out many times before in this blog, it would be much more sensible to use metric units, but it is likely that the NFL would perceive this as being un-American. It probably doesn’t help that the most widely used system of measurement in the world has a French name (Le Système International d’Unités, more commonly known as SI Units).
Of course this is all pure hooey. If a football can drop 2 psi when moved from a 70 degree locker room to a 50 degree playing field, then why is the run up to Super Bowl XLIX the first time we are observing it? And why doesn’t it happen often in places like Green Bay or Minneapolis where the temperature differences between inside and outside are much greater? This is reminiscent of the scene in My Cousin Vinnie when Vinnie Gambini (Joe Pesche) is questioning a self-respecting southerner who claims to have cooked non-instant grits in about 5 minutes. He exclaims “Perhaps the laws of physics cease to exist on your stove?!?” Indeed we might be left with a similar conclusion with regard to the Patriots. Probably the best possible outcome from all of this is that children who watch professional sports will take a greater interest in science. Stories like this also create the incorrect perception that you need an advanced degree in physics from Columbia to perform basic scientific analysis. In fact, you do not need an advanced degree in anything from anywhere. What you do need is common sense, a basic degree of confidence with algebra and the ability to be a keen observer. Using these criteria almost anyone who has taken high school chemistry should be able to perform an analysis using the ideal gas law. And anyone with a football, a pump and a pressure gauge should be able to reproduce what happened during the Patriots-Colts game. In other words, this phenomenon should be reproducible by any football player who is old enough to read. In the United States this should be tens of millions of people as a conservative estimate.
We have been waiting until the news stories about Deflategate die down before we post this blog entry, but it appears that this may never happen. At this point several people have confessed to deflating the balls including Matt Damon, Ben Affleck, Steven Tyler and many others. The NFL has decided that the balls were deliberately deflated and that Tom Brady knew about it. As a result he was suspended for several games, but this suspension was erased. There is almost certainly more to come.
Lastly, as DAVID WALDSTEIN at the New York Times recently pointed out, it is surprising that the NFL has decided to pay such close attention to ball pressure, while virtually ignoring issues like domestic violence, drug use and brain injury.
What percentage of Americans do you suppose (a) took high school chemistry, and (b) remember any of it, and (c) have a degree of confidence with algebra?