The Physics of Natural Football Deflation

well, it seems they were conjecturing, and not actually testing. i think the theory is correct, but the numbers aren't provable unless they did some testing that day. however, that may prove to be the undoing for the nfl, short of videotape of someone physically letting the air out.

 

If we had a survey, we could ask the following questions:

How do you think this happened (Pick one)
(1) Intentional Tampering after the referee check (eg; letting air out or ball switcheroo)
(2) Intentional Tampering before referee check by hot air or sauna moist air method
(3) Unintentional normal pressure variation just normal ideal gas law and lower temperatures
(4) Other more fancy tampering (Helium etc)

Note that some of my previosuly suggested causes seem to be ruled out as of today ( I had suggested using balls that leak slowly). Only Items 1 and 4 would seem to be against the rules.

 

This would much more fun if the cheating were revealed baseball style, like when the cork flys out of the broken bat.

 

..and the length of time between filling and the Refs test.

Meant to borrow a football today to do some tests

 

Well we don't have enough info, but here is what I hear:
(1) Brady was an activist on ball preparation, with P Manning getting a rule change to allow teams to provide balls
(2) Brady liked lower inflation pressure (per 2011 interview)
(3) The reason NFL checked the balls at half-time was apparently feedback before the game from other opponents
(4) The Patriot footballs flunked the the half time pressure check

So it would seem semi-obvious that the Patriots were probably doing anything they could think of, within the rules, to make sure the balls had the lowest possible pressure at game time. The NFL seems to have weak rules on ball inflation, so that possibly leaves a lot of room for chemistry and physics creativity (which is my interest in the story - Steelers are not in it this year so I got no skin in the game).

Ultimatelty I guess the Patriots were in some technical violation of the rules, since the balls tested low pressure at half-time. Apparently we do not know the half-time pressure readings for each ball so it's one thing if one ball was 2-psi low, another thing if all 11 were >2 psi low.

It also seems obvious NFL will change the ball prep rules as that is part of the problem.

 

bill speaks! he is claiming that they give the balls to the refs at 12.5 psi. the refs then test them and can adjust the pressure if they want to. he says the refs are in control of the balls until they are brought out onto the field.

extrapolating from that (me not bill) if the colts chose 13.5 psi, then the on field tests would have to be different.

 

...but we need to know the history of how they prep the balls.
12.5 psia from a hot compressor, or my latest thought, from the freezer like a cold gen2 bladder tank , may shift in pressure on the field. 70F to 50F does not really get to 2 psia under.

Any info from the Patriots is helpful, because it is testable in the lab, one way or the other. I've been listening closely to other quarterbacks, Aikman etc. to hear how they think it could happen. So far nobody seems to be thinking this is normal pressure variation under the normal situation.

 

he only said that the balls are inflated in the controlled condition of the locker room, and given to the ref's also in a controlled condition room. he did say that they did their own experiment, and the ball only dropped one psi after being outside for awhile.

kinda felt like he threw the ref's under the bus, which may not help him in the soup bowl.

 

Not sure I got this right....
I tried to see what Bill B. said....he seemed to say their prep "process" results in a ball that loses 1.5-psia on the field, of that 0.5 psia loss is just due to ambient temp. The other 1-psia loss I presume due to somehow manipulating the ball, he said not purposely to decrease pressure, but to increase grip of the football. But I am thinking conceivably there are ways to make volume smaller (heaviest guy sit on it) and then it may expand slightly slowly, giving more volume.

 

bill said, these tests and theories don't explain the final numbers at halftime, whatever they were, (2 psi below?) and he is eager to hear the leagues theory or evidence of what actually happened. to me it sounded like the ref's must have done something, which doesn't make sense, unless their pressure gauge was off, and thy didn't use the same one on the colt's balls.
if they only gave them the squeeze test, and the pats had them at 12.5, they should still be at 11.0 at the least during the game. unless, bill knows they only give them the squeeze test and set them to 12.0, which might result in 10.5, but brady likes 12.25, so that really doesn't make sense either.

 

that's the funny thing, i've never noticed the balls. where are they? what kind of container?

what were the colts balls at the 2 hour pre check? what were they at the half? where were their's?

what was the recheck temp? we'll never know the ground temp. it was a 6:30 game and had been rainy and warm all day.

so many questions, so few answers.

 

bill said they stayed within the rules. knowing him, that means he found a loophole.

 

I am parsing Coach Bill B. but I think he is saying some prelim. testing suggests their ball prep procedure may result in a ball that loses more pressure than just ambient temp would account for. They brought the balls back inside and warmed up the balls and there still down 1-psi from when they left the room. The teams have approval to break-in the new balls (except the kickers lost this priviledge due to the microwaves etc they were using). So I do not know but I think we are saying there could be methods of manipulating the balls that impact the pressure for a few hours.

 

They are probably already using broken-in balls so the "virgorous rubbing" is questionable need.