NFL wants to investigate cheating by weighing ball

[DetlefK]

http://deadspin.com/report-patriots-under-nfl-investigation-for-deflating-1680358128

The New England Patriots are charged with deflating footballs to make them easier to catch in rough weather. The NFL is investigating and confiscated a ball. They want to investigate this by weighing the ball...

1 mol of air weighs about 16 gramm.
1 mol of Ideal Gas has a volume of 22.4 liters.
1 football has a volume of about 1 liter. => 1 football contains about 1/20th of a mol of gas. => 1 football contains approx. a gram of air.

And they want to find out whether a few milligram of air are missing by weighing the ball.



My suggestion would be to let the ball in question and a standard-ball drop and compare how they bounce...

[Daemonaquila]

1. The stupid burns.

Not that it matters, because BOTH teams get the same advantage, but this level of "scandal" and "investigation" over a game is bizarre.

[trotsky]

2. Yes but if one team practiced and prepared with underinflated balls,

and the other did not, there could be something to it. I don't see that it would be the difference in a 45-7 drubbing but Belicheat is always looking for an edge, whether bending rules or outright breaking them.

[brett_jv]

10. Each team brings their own 12 footballs to the game to be used when they're on offense ...

And they're left in the charge of those balls after an inspection/pressure check before teh game.

So, the possibility of 'cheating' by one team via manipulation of pressure of their own footballs is definitely a real one.

I'm very keen to know though whether the discrepancies could possibly be accounted for via PSI measurements being taken at different ambient temperatures.

The Pats reaction to their inevitable fine and perhaps loss of draft picks ... will perhaps be the most telling ... if they're innocent, they'll probably complain ... if guilty, they'll likely quietly suck it up ...

[TheCowsCameHome]

3. Not only that, but the Pats ordered those heavy downpours

to fall only on the Colts.

I tell ya, it's an outrage!!!!!!!!!!!!

[Igel]

4. Gonna weight that in a vacuum?

Or take into account buoyancy effects?

How about adjust for the fact that the interior of the ball isn't at standard pressure?

And let's not forget humidity. Humid air is less dense.

Easier to just test the internal pressure directly--not by a ball drop but using a little device that the ball sits in. (Although then we'd have to make sure that the temperature didn't change during the game, whether ambient temperature or through body heat or even from continued not-quite-adiabatic compression.)

Probably get a larger effect from tweaking the ball's coefficient of friction by scuffing it.

And you'd certainly get a larger effect from sweating on it. Or letting it dry out in the hot sun.

They're not concerned about mass, about friction. They're concerned about some sort of coefficient of deformation. Pressure is just a proxy for that.


(Now my head hurts.

[Fluothane]

6. Gas Laws

I pretty much agree with you in that Charles Law explains most of this. If volume is constant, temperature varies directly with pressure. It was pretty cold yesterday and the temperature dropped throughout the event. If the balls were filled in a warm room and subjected to lower temperatures, the ball would weigh the same but might appear more "deflated".

Another explanation might be that the Patriots are a superior team and embarrassed the Colts in an AFC championship. And.... "The players gonna hate, hate hate" (Swift, 2014)!

[grasswire]

5. USC was fined in 2012 for intentionally deflating game balls.

USC has been fined and reprimanded by the Pac-12 after it was discovered that one of the Trojans' student managers had intentionally deflated game balls during the first half of Saturday's loss to Oregon.

"Game officials discovered and re-inflated three of the balls before the game and two others at halftime. All balls were regulation in the second half," read a statement from US

....snip

Quite simply, and as you might think, a slightly deflated football is easier to grip. As a result, a football that's easier to grip is easier to throw, catch and hold. A football that's easier to throw, catch and hold is often a football that ends up getting spiked in the end zone.

Another thing to consider is the fact that college teams use their own football, meaning that in Saturday night's game, Oregon had its own set of footballs on offense and USC its own set. So, theoretically, a team could deflate its own footballs very slightly and not worry about the opposing offense catching on when it had possession.

http://www.usatoday.com/story/gameon/2012/11/08/usc-fined-deflated-game-balls/1691303/

[Ptah]

7. NFL rules stipulate that footballs must be inflated between 12.5 and 13.5 pounds

Any kitchen scale could be used to weigh it.

[xocet]

8. What exactly are your units? n/t

[Ptah]

9. About thirty posts per chuckle. n/t