Posted on 01/24/2015 4:07:43 PM PST by Steelfish
Deflate-gate: Patriots Coach Says 'Climatic Conditions' May Have Under-Inflated Balls Jan 24, 2015 By DEAN SCHABNER More From Dean »
New England Patriots coach Bill Belichick today said "climatic conditions" may have been to blame for the footballs that were under-inflated Sunday for the AFC Championship game, and said the team had not tried to tamper with them.
He said the team "followed the rules to the letter," denying any intentional wrongdoing by the Patriots.
"At no time was there any intent whatsoever to try to compromise the integrity of the game or to gain an advantage," Belichick said.
(Excerpt) Read more at abcnews.go.com ...
Yup. Add to all that: being wet.
Yup. If the Colts grabbed the bag of balls from the hold of the bus, and either topped them off or submitted them for the refs to adjust...trivial loss of pressure.
I was a science major and flunked nothing...a football CANNOT lose 2# of air pressure when going from a 70 degree room to an 50 degree field..PERIOD..
The Patriots footballs were a full 2# underinflated
...and a 10PSI ball is still hard. 8 is a fully inflated basketball.
Basic gas laws.
Volume remains constant.
No. It’s been besmirched by bad math and faulty assumptions.
Every attempt to replicate the effects experimentally shows the football defaulting at least 1.4 PSI, if quick cooled, and around 1.8 PSI if the leather is given time to absorb the water and stretch a bit.There are now dozens of videos. The quick cool understate the loss of pressure, but have the advantage of having the whole effect in a three minute video without time compression.
It’s been going on for more than a century. It’s always been accepted as a part of cold weather games.
Volume remains constant.
4/3 PI times the radii in each axis.
“Volume remains constant.”
You are confused...
Lets suppose the ambient temperature is 250 degrees. The ball is filled with 50% water vapor and 50% air. With the absolute (gauge) pressure at 12.5 PSI.
You now reduce the temperature to 150 degrees... The water vapor now condenses to liquid H2O. What’s the pressure in the ball?
Got it? It’s close to 6.5 PSI... Of course the volume remains more or less constant, but the pressure doesn’t. It conforms to Dalton’s law of partial pressures.
Btw, those are GAS laws.
If you want to play with phase changes, of course the rules are different.
And where are you going to fill the ball with 50% water vapor?
“Btw, those are GAS laws.”
You need to review Dalton’s law of partial pressures. It states that in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases.
http://en.wikipedia.org/wiki/Dalton%27s_law
The air in the football of course would normally be a mixture of different gases. Our atmosphere is mostly nitrogen and oxygen with a small percentage of other gasses like CO2 and argon for instance.
Each component gas expands or contracts differently with temperature. So we need to know what the gasses are in the football to determine the pressure at any given temperature.
If the balls,for instance, were filled with mostly CO2, the pressure could indeed change by the pressure difference that was measured in the balls in question. Also any water vapor in the ball would turn to liquid if the temperature was below the dew point.
Since we don’t know at this point what gasses were in the balls in question, and until we do, it’s impossible to say if it could be temperature related.
The volume of the bladder in the ball has nothing to do with it. You can measure the same pressure changes with temperature in a CO2 cylinder or a propane tank.
The rules apparently do not say where, when, how, with what, at what temperature, etc. that a ball must be inflated.
It only says they must be between 12.5 and 13.5 psi.
Does anyone know (including link) if each team inflates their own balls or if referees inflate the balls and then give them to the team?
If NE inflates theirs to 12.5 and Indy inflates theirs to 13.5, they would both be legal, but NE’s would be underinflated once they hit the outdoors and got to air temperature.
Also, Aaron Rodgers says that the officials will deflate footballs. See here: http://www.nydailynews.com/sports/football/aaron-rodgers-calls-refs-deflating-balls-major-problem-article-1.2086653
If you can't verify that phenomenon, I suggest a different climate for a day or two or a change of equipment.
As for gas pressures in a fixed volume (which the leather encased bladder in the ball is, for all practical purposes) temperature is the primary factor in determining pressure within the ball given a fixed amount of air inside.
If you don't believe that, try putting the recommended pressure in your car tires in a 90 degree garage, then park it outside in -30 weather. Then check the pressure after it has cooled off. It isn't the volume in the system, nor water vapor which should not have been present in significant amounts, it is the thermal expansion or contraction of the gasses involved. This isn't a steam engine, it's a football.
Try this law instead: Boyle's Law
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“Or, better yet: Ideal Gas Law”
The Ideal Gas Law dos not apply because none of the gasses that we are discussing are ideal gases. Oxygen comes the closest, nitrogen is far away from it. CO2 is even further away.
An “Ideal Gas” in this context would be one who’s vapor pressure would reach zero when the temperature was absolute zero. That would make the pressure for delta T linear.
And no gas, in that context, is an Ideal Gas.
I have my chem eng degree and pro license and experience in various industries working on the situation. So far it appears that there is much to do about what and how natural conditions and causes could affect a manufactured object that is about to be tossed about and kicked about. It would be very difficult to strictly apply the ideal/perfect gas law(s) to a football. A person might throw in some of the fudge factors developed over years of research but it seems to me that trying to make a court like case for use of an inflatable ball that has been subjected to specified reasonable conditions is a bit too much.
Do you have inside information that alerted you that the Pats absolutely deflated those balls? Is there no other alternative to that narrative? I absolutely believe Belichick and Brady stating that they had nothing to do with the balls being deflated. There have been quite a few demonstrations on balls deflating due to atmospheric conditions.
This is so frustrating to hear people state for fact that they know that the Patriots did this and there is no other way it happened. Are we all guilty until proven innocent all of a sudden? They are given the name of cheaters over one incident of which all other teams were doing at the same time. Thing was they weren’t caught doing it. In fact it wasn’t even outlawed until the 2006 season. The Pats were caught in 2007 taping what 80,000 people could see on TV. And that was their only infraction - but now they are cheaters! Just ridiculous!
They don’t deserve this! Let the NFL determine what happened and then you can state for fact what actually happened. Until then - you know nothing!
Oh and sorry for going off on you (really) - I am a die hard Pats fan and I am just sticking by my boys!
“It would be very difficult to strictly apply the ideal/perfect gas law(s) to a football.”
That was my my position as well, that ideal gas law wasn’t applicable because we were not dealing with an ideal gas.That’s what I was trying to tell Smokin’ Joe.
Dalton’s law of partial pressures could play apart, if we knew what gas(s) were actually in the football. Topping them off with CO2 for instance, could very well make them loose 2 pounds of pressure at 45 degrees. And it could have been done quite innocently.
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