Physics Is On Patriots' Side, Really
The great “Deflategate" mystery – is actually, once and for all, no mystery. How did 11 of 12 game footballs, at the end of the AFC Championship Game between the New England Patriots and Indianapolis Colts show up with less pressure than the minimum permitted of games balls? Specifically, how did they end up below the 12.5 minimum pounds per square inch (or PSI) permitted by the NFL? The answer is not speculation, it is fact.
Patriots Coach Bill Belichick conducted a press conference on Thursday indicating he has no idea what happened. Shortly afterward, Patriots quarterback Tom Brady indicated he has no idea. Both seemed credible, and vexed. After all, this is a huge distraction. They have a game – oh yes, the Super Bowl, to play shortly. How can one explain the odd change in ball pressure by roughly 2 pounds per square inch by end of a cold, rainy game? The answer is not just theoretical physics, but an experiment that will prove it to anyone. You can test this one at home.
Forget the formula if you wish, but here it is: PV equals nRT, where “P” is pressure, “T” temperature, “V” is volume, “n” the quantity of gas inside a ball, or inside a tire for that matter, “R” a so-called constant that is like the ratio of two numbers to each other (it does not change). With this equation, one thing always happens: Falling temperature produces a marked, that is measurable, drop in pressure inside the ball (or tire). Now, forget the formula, unless you want to work the numbers out from known and assumed facts. Instead, use your own eyes.
Take a football and inflate at roughly 75 degrees – room temperature – to 12.5 PSI. A tire air gauge will help you. Be sure the skin of the ball is at 75 degrees also. This should be at or near the likely temperature at which the Patriot game balls were inflated (all inside, as usual). They were inflated at 4:25 p.m. on Jan. 18, 2014. Game time was 6:40 p.m. According to all public reports, they were brought outside prior to game time – but had been tested for pressure inside.
Now, keep your air gauge ready. Put the football either outside (if you are in New England) or in the freezer for a while. Wait until the thermometer drops to the temperature at end of the Patriots-Colts game, five hours later, which was in the upper 30s according to the National Weather Service. Now, watch this. Here is the big “Aha!” moment. You will measure the PSI in the ball YOU filled to a perfect 12.5 PSI. Assuming roughly unchanging barometric pressure (which may be unfair to the Patriots given the storm), and no change in your sea level or Foxborough’s, you will find that something has happened. As a change in temperature of nearly 40 degrees occurred, the PSI dropped markedly.
In a car tire, the change will be roughly one to two pounds’ drop for every ten degrees in drop in temperature. That would be between 4 and 8 pounds' drop for a car tire. For a football, based on these core assumptions, it could easily be 2 pounds. Would the ball feel different? Sure – it ought to. It likely often does when temperatures fall so markedly between indoor and outdoor measurements.
Does that warrant accusations and recriminations and defamation of a team or their coach or player? Hardly. The pressure MUST drop markedly under those circumstances. There is no choice – and the officials have never altered the balls in any game of which I am aware based on such a scenario. That is all part of the game.
So, why did 11 footballs have a PSI that fell that day, while a 12th did not? Answer: Very likely, one football was either brought to the field later, after the others – that would be decisive – or it was inflated later, while outside. Still not convinced? Talk with a mechanic.
The real mystery? Where did this non-issue come from? Who started the distracting rumor? Was Seattle behind the attack on Patriots concentration and integrity pre-Super Bowl? Permissible pre-game trash talk now includes defamation? Ad hominem attacks on a star coach and quarterback? This all makes modern politics look like a tame game. The amateur inquiry without reference to facts does not reflect well on the National Football League.
So, what should be done? First, the physics responsible should be openly discussed, empirically tested, end the attack. Second, the Patriots should consider a lawsuit, look for answers as to exactly where this rumor started – and why? Third, the NFL should immediately clear the Patriots of wrongdoing, and note that the league never regularly, methodically or consistently tests post-game balls. Finally, someone should point out that this red herring is about a grievance without a basis to grieve. Quarterbacks often like the harder balls better, softer less well.
In short, we now know the facts now. Get on with it. This is a great big media distraction, one without basis – implicitly created by someone to suggest wrongdoing of a team approaching the Super Bowl. Is that not the real issue worth an investigation? As for the balls, there is no there, there – only air there, and plenty of it.