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How to reduce the amount of air in a football without letting any air out
Watts Up with That? ^ | January 28, 2015 | By Alec Rawls

Posted on 01/28/2015 1:26:13 PM PST by Brad from Tennessee

Just fill the ball with warm humid indoor air, then when it temperature-equalizes with the 25°F cooler outdoor air on your AFC Championship playing field some of the water vapor in the ball will condense into water, leaving less air in the ball, solving the great mystery: how did the footballs used by the Championship winning New England Patriots show 12.5 psi of inflation pressure in the official pre-game check but only 10.5 psi when checked at halftime?

There is also a decrease in pressure due to the cooling of the molecules that remain gaseous. Those air molecules are not zipping around as fast as they were so they exert less outward pressure on the ball. But according to the ideal gas law, if there were no reduction in the number of gas molecules in the balls it would have taken a large drop in temperature, about 40°F, to cause the observed drop in air pressure. So says Boston College professor Martin Schmaltz:

"In order for a ball to register a 10.5 PSI in a 50 degree environment [the temperature on the field at halftime] but register a 12.5 PSI in the testing environment, the ball would have to have been inflated, stored, and/or tested in a 91 degree environment."

(Excerpt) Read more at wattsupwiththat.com ...


TOPICS: Science; Sports
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To: cdcdawg

“I still can’t see how a deflated ball is easier to throw. Catch, maybe, but not throw.”

A ball at low pressure is easier to grip. The weather was cold and wet.

I used to be a running back and I felt the optimum inflation pressure would let me touch my middle finger with my thumb. Or, left up to me, they’d just put handles on the ball.


41 posted on 01/28/2015 3:26:06 PM PST by DugwayDuke
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To: Brad from Tennessee

It would take only a couple seconds per ball, with a $2.99 bleeder, to drop the psi from 12 to 10. Take the balls into the private room, insert the bleeder, count one-Mississippi-two-Mississippi, then remove. You could deflate 12 footballs in less than one minute.


42 posted on 01/28/2015 5:14:15 PM PST by tom h
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To: Brad from Tennessee

We worked this out for a deflation from 13 psig at an unknown temperature to 10 psig at 20 degrees F. Assuming volume is constant... I believe the answer was to inflate the balls at 97 degrees F.


43 posted on 01/28/2015 5:44:30 PM PST by Rodamala
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To: The Cajun
Leonard and Penny Makeout

44 posted on 01/29/2015 2:23:52 PM PST by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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To: Steely Tom

Oh, it very much could make a big difference.

Now, is it worth digging through boxes for some college texts? Naah.


45 posted on 01/29/2015 2:26:35 PM PST by FreedomPoster (Islam delenda est)
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To: timestax
28-0

What pathetic whining.

You must be a lot of fun to watch a game with.......

46 posted on 01/29/2015 2:29:09 PM PST by Lakeshark
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To: FreedomPoster
Oh, it very much could make a big difference.

Now, is it worth digging through boxes for some college texts? Naah.

That's fine.

47 posted on 01/29/2015 3:04:29 PM PST by Steely Tom (Vote GOP for A Slower Handbasket)
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To: toast

The Colts balls don’t act as controls, since you dont know the starting conditions, or the specifics of when they were checked. Lots of rumor and assumption, and the reports only say that the Colts balls were checked at some point in time… Not necessarily even more than once.

That said, a drop of *temperature alone* in the footballs from 75°F two 50°F would give them a change of -1.27 PSI.

If the balls were at 75°F to begin with, and anywhere within the one PSI wide guidelines, by half time they would have been out of spec. Add to that the effect of having been wet, and you’ve got another half PSI or so loss of pressure.

These values have been confirmed experimentally many times in the last week.

The Colts balls may have simply not been measured with any significant precision, the information we received may be wrong, or the Colts balls were simply inflated outdoors or after having been outdoors for a length of time and were never at room temperature at all. Being kept in the hold of the bus and then topped off just before submission would account for it even if they had been properly measured.


48 posted on 01/29/2015 8:32:59 PM PST by lepton ("It is useless to attempt to reason a man out of a thing he was never reasoned into"--Jonathan Swift)
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To: cincinnati65

Pumps could ad a little, probably very little if the balls were anywhere near end pressure level.

This could do a lot more:
http://espn.go.com/video/clip?id=12221498

Note the dirth of measuring gauges, and the method of approving the balls.

This is what the Patriots claim they determined added about a PSI temporarily. The pumping probably added significantly less than just holding the balls in human hands.


49 posted on 01/29/2015 8:39:59 PM PST by lepton ("It is useless to attempt to reason a man out of a thing he was never reasoned into"--Jonathan Swift)
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To: Brad from Tennessee

Flubber Gas or have Moochelle Obama sit on one?


50 posted on 01/29/2015 8:57:21 PM PST by Kickass Conservative (If you think the Mulatto Marxist is bad, just wait until the Menopausal Marxist shows up.)
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To: lepton

Jan 30
“No knowledge of past in-game testing.
Asked if the NFL has tested the air pressure in footballs during a game in the past, and how important that is as a frame of reference in the ongoing investigation, Goodell said he didn’t know the answer and that attorney Ted Wells will look into that as part of the investigation. From our viewpoint, this answer warrants scrutiny based on the magnitude of the NFL’s investigation and the media firestorm it has created. How could Goodell not know? “


51 posted on 01/31/2015 10:11:59 AM PST by lepton ("It is useless to attempt to reason a man out of a thing he was never reasoned into"--Jonathan Swift)
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To: timestax
 photo 811715c7-4566-409d-bde5-bb070f38c199_zpsiw8ieuw6.jpg

52 posted on 02/06/2015 11:29:45 AM PST by timestax (American Media = Domestic Enemy)
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