Wednesday, January 28, 2015

Deflategate - the Patriots did not cheat

Interesting science experiment:
An experiment performed by a team at Carnegie Mellon provides empirical support for the Patriots’ claim to have done nothing unusual. The Carnegie experimentalists inflated a batch of footballs to 12.5 psi at a room temperature of 75°F, then let the balls equalize to a new ambient temperature of 50°F, resulting in an average pressure drop of 1.8 psi. (They also wet the leather balls to simulate the rainy conditions of the game, surmising that this might allow stretching that would reduce air pressure in the ball, but this seems likely to be a minor factor.)
It seems that the cooler temperature on the field caused some of the water vapor in the ball to condense, reducing the pressure.  This implies that what happened at the Patriots-Colts game happens all the time - any maybe even more for very cold stadiums like Green Bay.  I'd guess that in sub freezing temperatures players fingers start to lose some feeling and so the situation isn't as noticeable.

10 comments:

B said...

They knew. They didn't care. Those men all handle footballs all the time. They knew they were (ahem) soft.

But I sincerely doubt that the underinflated footballs made a difference in the game. There was a clear winner.

Tony Tsquared said...

Any kid that has an understanding of high school physics knows about temperature differential and Boyle's Law. It is the dumbing down of America that has made this a viable story.

And these people vote...

KurtP said...

Except that the temps didn't seem to affect the Colts balls the same way...in the same conditions.

R.K. Brumbelow said...

Scandal is presumed in all things, but I would be remiss if I did not suggest that there are 2 possible ways my brain could go:

First: Did they check to see how humidity in the contained air affected the pressure loss, because if you wanted softer balls a spray bottle near the air intake could be 'helpful'

Second: It is interesting that people think the only way to win hands down is to cheat, ergo if someone won, they thus must have cheated.

Russell Widhalm said...

Then why didn't the Colts' balls react in the same way?

And here's some food for thought:

Fumble-proof Patriots

ASM826 said...

I blame George Bush. You know it's true, you denier.

2cents said...

Let the guy from Maine who played football in December in the backyard all the time explain exactly what happened. When we were playing in the cold, the ball would start to get mushy. So we rubbed the Hell out it until the friction caused the ball to heat back up and regain pressure. This is something every kid from Maine (I am not sure about you people who grew up down south) knew. Belichick emphasized how they prepped the balls in his press conf, saying they rubbed vigorously to get the tack right ("it isn't fine china"). So the Pats rubbed the hell out of the balls as part of their pregame prep. Then gave them to the refs, who set them at 12.5 psi in a warm room. If they waited a few hours, the rubbing energy would dissipate and the psi would come down. If, as it sounds, they set the pressure quickly after getting the balls, it would come down AFTER they set the pressure. Then bring the same balls outside, and the pressure drops some more. BTW, the drop would be fairly uniform which explains how the Pats balls all ended up around the same psi.

So I get asked: what about the Colts balls being higher psi? Simple, they rubbed the balls down hours earlier, or even the day before in Indianapolis for all I know. That spike and then drop in pressure had already occurred before they gave theirs to the refs. The Pats had two pressure drops starting at the lowest allowable start point: (1) dissipation of the rubbing energy and (2) from the cold rain/temp. The Colts had only the latter, and probably started at a higher psi because that is what Luck likes. Bingo, explains the drop and the differential, and it is all very much within the letter and spirit of the NFL rules. A couple of more facts: the Pats are the best franchise in football over the past decade and a half, Tom Brady is a rich guy married to a supermodel who makes more than him and all y’all haters are jealous, which explains this ridiculousness a lot more than science does. Just sayin.

Borepatch said...

Russell, I have no idea why the Colt's balls didn't react the same way. Maybe they were filled in a colder room.

But the point is that an experiment shows this as expected behavior under reasonable circumstances. If you follow the link in the post there's a Youtube video of the experiment.

Some folks will want to hate them on the Patriots, but Science® says that they should hate for a different reason. ;-)

2cents said...

Borepatch, I have no doubt the Colt's footballs DID react the same way. However, I doubt they were rubbed down immediately before filling, plus they were probably filled to the higher end of the range.

Tam said...

Goddammit, they should keep the temperature and barometric pressure equal on both sides of the field! Or at least share their atmospheric force field technology with NASA!