Football bags

Does anyone know for certainty whether the Pats football bags are insulated or are they just duffle bags or mesh bags? Any pics? My friends are now coming at me with that angle...ie. "aren't the bags insulated and zipped up?" Who's got the answer?

Why would they be insulated? this isnt domino's.

Funny...that's exactly what I said!

A canvas bag in and of it's self will provide insulation. It's simple physics Try sleeping in a rain storm at 45 degrees and let me know if you would prefer a bag for shelter.

The bag IIRC shown during the stupid deflategate was not canvas, but a more insulated vinyl type like certain bat bags are made of.

Oh my aching head

That may be why some balls only went down a few ticks while others were down 1 psi. The ones that were used more on a wet rainy day cooled to ambient temperature or close to it.

Balls that stayed dry cooled less.

Just a reminder of the math involved. If the balls were inflated at "exactly" 12.5 PSI at 72°F, it would take about a 2°F drop to pull the pressure down 0.1 PSI, and about 10°F to pull it down 0.5 PSI.

ctpatsfan, correct, with a little embellishment. The THEORETICAL pressure lapse rate between 75 & 50 °F is 0.051 psi/°F. I went a step further & measured it experimentally and came up with a value of 0.06 psi/°F.

There are some clowns out there (for example, THREE PhDs on The Weather Channel) who claim 0.02 psi/°F (or equivalently, 0.2 psi/10°F). These idiots have made the mistake of using gauge pressure and/or °F in the calculations instead of absolute pressure & temperature.

Surprisingly, astronomer Neil deGrasse Tyson made this same mistake, but corrected it when his error was pointed out to him. (Only to go on to make a 2nd mistake.?!) Bill Nye, the "Science Guy", completely screwed the pooch. But he never, as far as I can tell, did ANY calculations at all. He just announced that the Pats had to have cheated. What a buffoon.

The insulation in the bag is irrelevant. It's not comparable to a person being in a bag. With a person, there is a bunch of metabolism trying to warm up the air inside the bag. This will work, and keep a person much warmer when protected by a bag. With the footballs, there is nothing adding heat to the inside of the bag. No heater, no metabolism. The air in the bags will drop to ambient air temp.

The rain water plays an interesting role. Since it fell from altitude, it is likely colder than the 48°F - 50°F reported near the end of the 1st half, which is a "dry bulb" temp (i.e., "thermometer under an umbrella"). But the water's primary role is as a superb heat conductor / heat sink. A couple hundred times more effective than air conduction. This would have brought the temp of the air inside the ball down much faster than bringing them inside & drying them off would have brought the temp back up to room temp.

In the experiments that I ran, after dropping them to 50°F with a cold bath & cold air, the pressure inside the balls was STILL significantly low three full hours after I dried them off & sat them in a 71°F room. The moisture in the leather of the ball, the dependence on pure conduction and the lack of convection keeps the temp of the air inside the ball low for a long time. And that temperature is all that matters to the internal pressure.

It should also be noted that having cold air on the "measured" (i.e., "inside the ball") side of the pressure gauge's bellows & warm air on the "atmospheric reference" side WILL produce a gauge pressure reading that is too low. The assumption in the gauge's calibration is that the temp of the air on both sides is the same.

The size of this error depends on the details of the gauge's design. It'd have to be determined experimentally.

How much possesion did the colts have. There balls may have stayed in the bag longer without exposure. That would account for not a drastic temp change. And if there balls were indeed at the higher end of psi it would easily explain theirs staying within range.