The ideal gas law only works in degrees Kelvin. This has significant deflategate implications.
The ideal gas law is essentially a proportional relationship. If we assume volume to be constant, a change in temperature should produce a proportional corresponding change in pressure. If we are to measure in degrees Fahrenheit, a temperature drop from 70 degrees to 50 should result in a 28% drop in pressure. Using Celsius units, the temperature drop is 21 degrees to 10, which would result in more than a 50% decrease in pressure.
The problem is, Celsius and Fahrenheit scales are not linear. They both define zero at an arbitrary point at which there is still heat energy. The Kelvin scale defines zero as absolute zero. On this scale, the true temperature drop from pregame to halftime is about 294 degrees Kelvin to 283 degrees Kelvin. This should correspond to a pressure drop of only 3% - 4%.
This should make intuitive sense when you think about it. Tomorrow night's game is going to be played in near-zero or sub-zero temperatures. If a balmy 50 degree game caused balls to deflate so much, how flat would three balls be when the temperature is 50 degrees lower? Would the balls not be inverted if the temperature dips below zero, since this should hypothetically result in "negative pressure.
Unfortunately, the ideal gas law justifies the thinking that there was intent to deflate the footballs. That's just how the math works out.
Now, what the ideal gas law does not explain is this...both Clete Blakeman and Dyrol Prioleau took independent pressure measurements of the footballs during that game. For each of the 11 Patriots footballs measured, Blakeman's measure was significantly lower than Prioleau's. However for the (only) 4 Colts footballs measured, Blakeman found 3 of the balls to be more inflated than Prioleau.
So, how is it that Blakeman's measurements, compared with Prioleau's, were always lower when measuring Patriots balls, yet simultaneously higher when measuring Colts balls? I offer two simple measurements. Either (a), Blakeman is corrupt, or has it out for the Patriots organization, an easy emotional conclusion to reach given his history with this franchise, or (b), Blakeman is a freaking moron who does not know how to operate a pressure gauge.
There is no third explanation. The truth depends on your belief in Hanlon's Razor.