Deflategate Science Simplified

[raduray]

It kill me that most of the talking heads are not really addressing the science heads on. If the ball deflation is explained by the temperature drop, then the texts, phone calls, etc all become irrelevant. So, I've tried to simplify how the perfect gas law applies to this.

Perfect gas law says that absolute ball pressure is directly proportional to absolute temperature assuming ball volume is constant. If absolute temperature were to increase 50%, absolute ball pressure would go up by 50%.

Absolute ball pressure is measured ball pressure plus ambient atmospheric pressure.
Absolute temperature is measured temperature converted to Degrees Kelvin.

Locker room temperature of 72 Deg F converts to 295 Deg K
Playing field temperature of 45 Deg F converts to 280 Deg K, a 5% drop.

Now, given that ball pressure is directly proportional to temperature, let’s apply the 5% drop to the pressure. Remember that the measured ball pressure was 12.5 psi.

Ambient air pressure at sea level is 14.7 psi.
Absolute ball pressure measured in 72 Deg F locker room is 12.5 psi + 14.7 psi = 27.2 psi
Apply 5% drop to that and you get 25.8 psi at 45 Deg F.
Subtract the ambient air pressure (14.7) and you get 11.1 psi.

NOT THAT COMPLICATED!

Now, if you consider the ball got wet, it gets a bit more complicated. The wet ball would soften the leather, allowing it to expand a bit, thus increasing its volume, resulting in a somewhat even lower air pressure in game conditions.

Reference:

PV=nRT
P=Absolute Pressure (air gauge pressure plus ambient pressure)
V=Volume (volume of a dry football is constant across range of temperature)
n=number of molecules of air in the football (constant across the range of temperature)
R=Gas Constant. It's a constant, like pi.
T=Temperature in Deg K.

P=(nr/V)T
nr/V = K (constant)
P=KT
P directly proportional to T

EDIT 8/4/15
I've been called out because the temperature values I used above were not the ones reported in the Wells Report. That's a valid observation; the numbers I chose were to illustrate a point. So I recalculated using the Wells Report data: Locker Room Temp 71-74, Field Temp 48-50. I calculated the four permutations using the min and max for each reported range with the starting ball pressure set to 12.5 psi.

Locker Room-Field-Ball Pressure
71-----------48-----------11.32
74-----------50-----------11.28
71-----------50----------- 11.42
74---------- 48------------11.17
Calculated Average------11.30
Wells Report Average---11.49 (Logo), 11.11 (Non Logo)

Note that the Wells Report is based on several unsupported assumptions: the field temperature was not recorded, the initial ball pressures were not recorded, the locker room temperature was not recorded, which gauge was used was not recorded. It all makes for bogus science, recognized even by the NFL given their new ball handling procedures released just recently.

My point, though, is that even the bogus Wells numbers are consistent with the Natural Gas Law.

 

[chasa]

It kill me that most of the talking heads are not really addressing the science heads on. If the ball deflation is explained by the temperature drop, then the texts, phone calls, etc all become irrelevant. So, I've tried to simplify how the perfect gas law applies to this.

Perfect gas law says that absolute ball pressure is directly proportional to absolute temperature assuming ball volume is constant. If absolute temperature were to increase 50%, absolute ball pressure would go up by 50%.

Absolute ball pressure is measure ball pressure plus ambient atmospheric pressure.
Absolute temperature is measured temperature converted to Degrees Kelvin.

Locker room temperature of 72 Deg F converts to 295 Deg K
Playing field temperature of 45 Deg F converts to 280 Deg K, a 5% drop.

Now, given that ball pressure is directly proportional to temperature, let’s apply the 5% drop to the pressure.

Ambient air pressure at sea level is 14.7 psi.
Absolute ball pressure measured in 72 Deg F locker room is 12.5 psi + 14.7 psi = 27.2 psi
Apply 5% drop to that and you get 25.8 psi at 45 Deg F.
Subtract the ambient air pressure (14.7) and you get 11.1 psi.

NOT THAT COMPLICATED!

Now, if you consider the ball got wet, it gets a bit more complicated. The wet ball would soften the leather, allowing it to expand a bit, thus increasing its volume, resulting in a somewhat even lower air pressure in game conditions.

Reference:

PV=nRT
P=Absolute Pressure (air gauge pressure plus ambient pressure)
V=Volume (volume of a dry football is constant across range of temperature)
n=number of molecules of air in the football (constant across the range of temperature)
R=Gas Constant. It's a constant, like pi.
T=Temperature in Deg K.

P=(nr/V)T
nr/V = K (constant)
P=KT
P directly proportional to T

 

[hambone1818]

All due respect--and I appreciate the effort--but it is too complicated for most people. There's a reason politicians have slogans like 'Forward', that they speak in easily digested sound bites. There's a reason (beyond straight bias) that people have latched on to the 'deflator' text message.

If the average IQ is 100 (and in this country, that's a dubious claim) that means 50% of people are below 100. PV=nRT is orders of magnitude away from 'not complicated' for the majority of football fans, if we're being completely honest. And that said, the vast majority of these dumb fans, by extension, also hate the Patriots. They don't want to hear that the science exonerates the Patriots, so they say 'I don't care about that science stuff, what about the texts?'

After the AEI report Felger read a snippet regarding the calculations used. It was noticeably complicated, because it dealt with both the Patriots and Colts footballs and a comparison of both measurements. Why did he read it? Because he wanted to highlight how over-the-top complex the calculations are. "What the hell is this? I don't understand any of this crap, who cares about Ppatriots and Pcolts???" He was gloating about his relative stupidity! That's where we are, a Boston radio host gloating about his lack of intelligence as a way to shame the nerds who have data that largely exonerates the Patriots!

So thank you for trying to simplify, but it doesn't matter. Those who care about the Pats will try to understand the science and many will succeed and understand the issues with Exponents numbers. Those who don't care will dismiss the science entirely and focus on 'deflator'. It's easier, and it fits their narrative, period.

 

[signbabybrady]

Just think about how dumb the average person is and then realize half the population is dumber.

 

[turkeyneck]

Talking science to a sports "journalist" is like trying to explain chess to a cow. You are wasting your time. They don't get it. They can't get it. They don't want to get it. Talk science and all they hear is "Wuh...wuh...wuhh..." like the sound of the adults in a Charlie Brown cartoon.

 

[raduray]

Just think about how dumb the average person is and then realize half the population is dumber.

That's a mean reality.

 

[The Brandon Five]

Just think about how dumb the average person is and then realize half the population is dumber.

And if we are talking about Jets fans (i.e. the League Office), more than half!

 

[Palm Beach Pats Fan]

even less complicated
8 sentences to give clarity even to the most thick-headed:

1) When a football cools, its internal pressure drops.
2) When a football cools by about 24 degrees (72 degrees to 48 degrees at halftime) it drops by about 1.2 psi.
3) When a football is wet, its internal pressure likely drops a bit more.
4) The Patriots footballs dropped by about 1.0 psi, on average, from their pregame pressures (measured inside).
5) If you totally discount the refs memory over which gauge he used, you can claim that they dropped about 1.4 psi, on average.
6) There is some inherent error in reading these gauges: one person using the same gauge on the same ball got values differing by 0.4 psi (this was the tests on the intercepted ball).
7) Neither one one these halftime numbers for a psi drop (1.0, 1.4) is significantly different than what you'd expect them to be if nobody took any air out of them.
8) The 4 Colts footballs tested indeed dropped less in pressure, simply because of when they were tested, at the very end of halftime, after they sat in a warm room for probably at least 12 minutes.

 

[chasa]

the easiest thing to do really, is show people that water expands when its frozen. then explain to them that gasses do the opposite.

 

[Rob0729]

I thought the simplification of the science of the Wells Report:

The science doesn't prove human deflation of footballs = Make up the science

 

[Palm Beach Pats Fan]

simplest possible thing to do is ask"explain this"

 

[The Brandon Five]

the easiest thing to do really, is show people that water expands when its frozen. then explain to them that gasses do the opposite.

Water might not be the best example for a simple explanation. You might really lose them on this:

 

[JJC]

He was gloating about his relative stupidity!

That! You can't fix stupid.

This is the world we live in. A world that sees reason and science as magic. As Arthur C. Clarke famously said, (paraphrased) any science sufficiently advanced beyond your understanding appears to be magic. Welcome to the new Dark Ages.

Silver lining? Since you (we?) understand the magic, it is important that we use it to manipulate the ignorant through fear, intimidation, and greed - for their own good, of course. When reason is no longer effective at managing discourse and civility, what else do you have available? We are your new Druid overlords. Watch our magic. Fear our Gods.

How to Use It. First, claim the Power of Deflation is within your grasp. Demonstrate this by drinking half a bottle of Poland Springs water and putting it in the fridge. Tell the morons that Our God will deflate the bottle. Wait two hours and remove the bottle. Behold! The bottle has caved in. Remind the morons that Our God will do the same to his head and penis, unless he accepts Our God's judgement all matters. If challenged or confronted, Rochambeau the unbeliever. Behold the Power of Inflation instead, as his testes swell.

 

[moosekill]

Even simpler if you live somewhere that has winters and you liked to play basketball as a kid. If it was cold and you went outside to shoot baskets the ball would get flat after a while. And when you brought it back in if you set it near the heater it would magically get full again.

 

[MagicMarker]

There are two parts that are complicated for people to understand -- the ideal gas law, and the statistics. I read AEI's report and I took stats in college and I admit I had to read it several times to really understand it. If you didn't take a stats class terms like statistically significant, linear regression and r-squared don't mean anything. It's difficult to change minds when they don't understand what you're saying.

I thought that was a really good illustration of the ideal gas law, though.

 

[FourierSeries]

If the average IQ is 100 (and in this country, that's a dubious claim) that means 50% of people are below 100.

Actually, it doesn't mean that at all. It only means that 50% of people are below 100% if the population is normally distributed (which some studies show to not be the case.) It's the median that measures the exact middle of the distribution and cuts the data in half (for any distribution.)

But I digress.

 

[raduray]

Actually, it doesn't mean that at all. It only means that 50% of people are below 100% if the population is normally distributed (which some studies show to not be the case.) It's the median that measures the exact middle of the distribution and cuts the data in half (for any distribution.)

But I digress.

Google "IQ distribution curve" and you'll find that IQ tests are designed to result in a normal (bell) distribution curve. That is not to say that these tests give a true representation of intelligence.

 

[FourierSeries]

Google "IQ distribution curve" and you'll find that IQ tests are designed to result in a normal (bell) distribution curve. That is not to say that these tests give a true representation of intelligence.

Fair enough. I assume that intelligence itself tends to be approximately normal anyways.

 

[lurker1965]

... He was gloating about his relative stupidity! ...

If one is Moe Howard "Einstein" is an insult. Sad that we don't even get the smart Stooge. (That was Shemp or Curly who's hand flipping move could control Moe.)

 

[eom]

I might start a deflategate science simplified thread simplified thread