[jsyedidia]

"They had the deflated footballs for a reason.": It's called the ideal gas law. http://nesn.com/2015/01/boston-college-professor-weather-had... If you're concerned that the chairman of BC's physics department didn't do his calculations correctly, I also have a Ph.D. in physics and corroborated them. Make sure you use both absolute pressure and absolute temperature if you want to do the computations yourself; it's really quite simple.

By the way, about why the Colts balls didn't deflate: the BC professor says they may have over-inflated them, but I think a simpler explanation is that if the Colts prepared their balls outdoors and they equilibrated to outdoors temperatures before giving them to the refs, you would not expect them to deflate. Watch Belichick's press conference today, with an understanding of the ideal gas law, and the fact that working in a ball will also increase the temperature of the gas inside it, and it becomes obvious that if they followed the legal procedure Belichick claimed they followed, the Patriots did not cheat, unless you think having your footballs obey the ideal gas law is cheating.

[pdabbadabba]

I don't understand this as a defense. Either a) they inflated them under (roughly) the same conditions as the Colts and the disparity in the pressures of the teams' balls is due to the fact that they were intentionally underinflated originally, or b) they were, as you say, inflated to the correct pressure under different conditions and drifted away from the regulation pressure due to a change in temperature. Either way, the balls were underinflated at game time. Scenario a is worse, of course, but even in scenario b, you have to wonder why they didn't correct the pressure. (Quarterbacks are surely able to detect the lower pressure, and pretty much everyone -- particularly professional QBs, I would think -- is aware that pressure drops with the temperature).

And in any case, at best this is a possible explanation for the underinflation. There is no evidence that the explanation you give is true, or even likely, since it rests on totally unsupported assumptions about the conditions under which the teams inflated their balls.

[jsyedidia]

The reason that they didn't correct the pressure at game-time is that after the Patriots give the balls to the referees 2 hours and 15 minutes before game time, they are not allowed to touch them, and the refs do not have the procedure of re-checking them and correcting them. I imagine that there might be a rules or procedure change so that they do, and as early as the Super Bowl.

The "evidence" for my explanation is the ideal gas law and what Belichick said his team did in his press conference today. If the Patriots followed that procedure, which there is no reason to believe they didn't, and which is legal, one expects from the ideal gas law that their balls would seem under-inflated at half-time. It's basic physics and easy to understand theoretically and reproduce experimentally.

My speculation for what the Colts did rests on the reports that their balls did not deflate. For that to hold, given the laws of physics, something like the balls equilibrating to the outdoors temperatures before giving them to the refs must have happened.

[Anechoic]

you have to wonder why they didn't correct the pressure.

AFAIK, teams are not allowed to reinstall balls during the game, refs can, but they obviously didn't detect it until they measured the pressure at halftime.

Quarterbacks are surely able to detect the lower pressure

Everyone seems to be taking this as a given when it's not at all. There are qb's who can detect it, and others who can't.

[ragtimepiano]

Centers also handle the ball on every offensive play. Most centers are intelligent and kinesthetic players who would be as sensitive as the QB to the feeling of the ball. Someone needs to tough-talk the Pats center about this.

[fecak]

>"if the colts prepared their balls outdoors..." >"they may have over-inflated them..."

You are certainly speculating quite a bit here, no? As opposed to assuming the Pats under inflated their balls, intentionally or unintentionally, you are speculating that the Colts over inflated theirs and/or inflated them in a different environment?

[Anechoic]

You are certainly speculating quite a bit here, no?

Speculation is all there is at this point. All we know is that the Pats balls were under the NFL regs when measured at halftime and the Colts balls were not. We have no detailed information about the pre-game ball preparation steps for either team, no information about the Colts pressure preference (Belichick stated today that the Pats aim for a target pressure of 12.5 psi), etc.

And yes, the Colts could very well have overinflated their footballs, just as Aaron Rodgers claims to do with his game balls.

[jsyedidia]

No the BC professor speculated that they over-inflated them. I speculated that they prepared the balls outdoors. The reason for the speculation is that I know the ideal gas law holds. Therefore, if the Colts balls did not deflate when they took them to a colder temperature, there must be an explanation. I think the likeliest explanation is that the gas inside the balls had already equilibrated to an outdoors temperature.

Many people are speculating that the Patriots cheated on no grounds except that the balls deflated when taken outdoors, which is exactly what you expect from the laws of physics.

[Hasu]

It's not like this is the first time it's ever been cold outside. The New England Patriots play a lot of football, yes? They often do so during the winter months, no?

It's exactly what you'd expect from the laws of physics, which is precisely why even if the situation you suggest is the case, the Patriots still knew that the balls would deflate due to the aforementioned extremely predictable laws of physics, and they still cheated.

If they didn't know, then incompetence is no excuse. They cheated because they didn't know about the ideal gas law? They still cheated.

[jsyedidia]

Maybe they didn't know about the ideal gas law. It seems like very few other people do. Maybe they did know about the ideal gas law and took advantage of it. In any case, they followed all the rules "to the letter", at least if you believe they did what they said they did. Most people say that when you follow all the rules, you are not "cheating".

[fecak]

No, people are speculating the Pats cheated under the assumption that both teams inflated their balls to a similar psi, under the same inflation conditions, and for some reason the Pats balls (at a home game) reacted differently to the same weather conditions.

[jsyedidia]

Let's take it as a given that the Patriots balls deflated and the Colts balls didn't (we don't actually know that for certain, but I think it's reasonable to assume it's true). We know that if the Patriots prepared their balls indoors and worked on them up until the moment they gave them to the refs as they claimed they did and as is legal, the ideal gas law predicts a deflation of the Patriots' balls approximately equal to what is being rumored.

So the thing making people speculate the Patriots cheated is that the Colts' balls didn't deflate, combined with a lack of understanding of the ideal gas law, or a refusal to take it into account.

I take it as a given that the ideal gas law holds. That means that for the Colts' balls not to deflate when going from indoors to outdoors they must have prepared them differently than the Patriots. A simple explanation is that the gas inside their balls had already equilibrated to the outdoors temperatures before the balls were given to the refs (e.g. the Colts threw them around outside). It is speculation, but it seems to me more reasonable than the assumption that the Patriots' and Colts' balls both managed to evade the workings of the ideal gas law, and the Patriots' balls deflated because the Patriots cheated.

[Anechoic]

under the assumption that both teams inflated their balls to a similar psi, under the same inflation conditions

There are zero reasons to believe those assumptions are true.

or some reason the Pats balls (at a home game) reacted differently to the same weather conditions

All we know is that the Pats balls were under the limit and the Colts balls met the limit. To my knowledge, there has been nothing released/leaked about any decrease in pressure in the Colts balls, just that they were within the rules.

The Pats may or may not have done something untoward, but the only reason so many people seem to think it's a slam dunk is that they're misinterpreting the information that's out there.

[ragtimepiano]

Whether the Colts inflated their balls outdoors can be easily checked and would be a major news story. No story has appeared.