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#DeflateGate, a Super Bowl STEM Lesson

#DeflateGate, a Super Bowl STEM Lesson

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Deflated football

Making science fun is one of the biggest challenges for those who teach STEM, but sometimes the news provides a gift. And, the most recent offering is the headline called Deflate-Gate.  In case you’ve been in a deep slumber for the past few days, there is evidence that the footballs in a key game were underinflated, which would be helpful for players since a softer ball is easier to grip and catch. And, the public is captivated and wants to know if this under-inflation was intentional or not. 

Buried in that news report is a STEM lesson that is often found in a chemistry class on the Ideal Gas Law, which states that pressure and temperature are linked.  As the temperature increases, so does the pressure; as the temperature decreases, so does the pressure.

One culprit for the lower pressure in the footballs could be the weather, particularly colder temperatures. This idea can be introduced by placing an inflated balloon into a freezer for a bit. When the balloon is taken out some time later, it will be underinflated. As the balloon warms up, it will go back to the original shape.  This is the Ideal Gas Law in action. The experiment shows that temperature and pressure are linked. As the temperature went down, so did the pressure in the balloon.  

Well, we can apply this to Deflate Gate and look at the pressure of the football at two different instances: when the ball was inflated and when the ball was used in the game. And, the expression below would do the trick:

P1/ T1 =  P2/T2

In it, P1 is the pressure before the game (which should be between 12.5 and 13.5 psi), T1 is room temperature (70 ºF); T2 is the temperature outside during the game (say 49° F). Then, solve for P2, the pressure of the ball during the game.

(Remember:  Convert to metric when doing the math and them back and then back to units we know.)

Here is a YouTube video that spells this out: http://youtu.be/5bvYVFs3DQM

Have students make a calculation; have them speculate of how to account for the lost pressure. Engage them.

Even better. Get a football and a pressure gauge and test the football’s pressure at room temperature and then again after being in the freezer.  See if there is a difference. Test a hypothesis.  You will be a STEM rock star if you do.

Making science fun is challenging, but when we get a gift from the news we should use it and the NFL has provided a huge one.  Your students will never think that the Ideal Gas Law is boring again.

(Disclaimers: When it comes to the NFL debacle, we don’t know anything about the history of the ball, so this blog is just for educational purposes. This exercise is not intended to find a team at fault. And, while I wrote a book on football, called Newton’s Football, I do not benefit from the NFL’s outcome nor have any direct interests. My goal is to make science come alive! Ramirez Out.)


This post was created by a member of Edutopia's community. If you have your own #eduawesome tips, strategies, and ideas for improving education, share them with us.

Comments (12) Sign in or register to comment Follow Subscribe to comments via RSS

Elana Leoni's picture
Elana Leoni
Director of Social Media Strategy and Marketing @Edutopia, edcamp organizer

The real question is....can someone deflate 12 balls in 90 seconds....

Hillary Hill's picture
Hillary Hill
Social Media Marketing Associate at Edutopia

This is such a great way to turn a cultural event into a chance to learn! As a Boston-native and Patriots fan, I genuinely hope that Mother Nature was responsible for this...

Dan Boyn's picture

SCIENCE, DEFLATEGATE AND THE NATIONAL FOOTBALL LEAGUE

DeflateGate has erupted onto the National stage, and seems poised to stay there through Superbowl Sunday and beyond. It has been a fascinating, tortured soap opera that has vexed most of us and brought out the worst in some of us.

The DeflateGate "scandal" rages on because so many remain mystified by the inexplicable deflation of footballs in cold, wet games even though the science needed to dispel this mystery is not hard to grasp. In fact, the ideal gas law was formulated way back in 1834, and is taught in high school physics class.

INTRODUCTION

To determine if the New England Patriots have violated NFL rules about ball inflation, the main question is, "Was the drop in ball pressure due to natural causes or tampering?" As Coach Belichick explained last Saturday, the best way to truly answer this question is to do an experiment. Before such an experiment, a scientist will need to form a testable hypothesis, a prediction, based on the facts of the situation and what is known about natural laws. In this case, the relevant physical law is the Ideal Gas Law (Pressure x Volume = n x R x Temperature) combined with the fact that friction generates heat.

Check out this informative video which also explains the science behind the pressure-drop: https://www.youtube.com/watch?v=hf8oQ4rhR-A

THE FOUR PHYSICAL PHASES OF DEFLATEGATE

Knowing the conditions at the AFC Championship game and how the Patriot's footballs were treated, it's not hard to anticipate the result based on the four different physical phases the balls went through. The logical prediction is that ball pressure would drop significantly below the NFL minimum 12.5 psi. In fact, this is a certainty:

1) Rubbing Phase - Before the AFC Championship game, the balls were in the locker room, where the air temperature was likely 70-75 degrees. The balls were then rubbed vigorously for a substantial preparation period. The rubbing created heat from friction. The heat increased the air Temperature in the footballs above the indoor temperature. The warm air couldn't expand the footballs by much, so the Pressure would increase.

2) Cooling Phase A - The warmed footballs were given to referee Walt Anderson, who was asked to set the pressure at 12.5 psi. The balls stayed in the official's locker room for over 2 hours and gradually cooled back to the indoor temperature. This initial drop in Temperature would result in a corresponding drop in Pressure (approx 1 psi per Coach Belichick).

3) Cooling Phase B - 10 minutes before kickoff, the balls were taken by NFL staff to the sideline. The temperature was approximately 50 degrees, but would have been lower on surfaces exposed to rain and wind-chill. Over the course of the first half, Brady's wet balls would have cooled to below 50 degrees. This second drop in ball Temperature would result in a further drop in ball Pressure (psi).

4) Stretching Phase - In addition, the leather of a wet football stretches, increasing the Volume inside it. Increased ball Volume would cause a third drop in ball Pressure (psi). Did you see the condition of the balls? Several pictures show them dripping wet and soaked through in the hands of the players and referees. The leather would have stretched - how much would have to be determined by experiment.

Taken together, these physical and climate factors would definitely drop the pressure in the footballs to substantially below the 12.5 psi set, per NFL protocol, by officials 2 hours pregame. This is not a possibility, it is a certainty.

Just like when you hold a solid object in your hand then let it go, it will fall according to physical laws (gravity), so it is that whenever a referee in their locker room inflates a warmed ball to the lower limit of 12.5 psi, then takes it out into cold, wet, windy weather, that ball will be underinflated 100% of the time. There is no question that this has happened countless times in late season, cold weather games throughout the history of the National Football League. Asterisks all around for everybody, especially the Packers!

THE UNFINISHED PHASE, THE NEXT STEP

Aside from the certainty of cold weather pressure drop, the real question we are left with is, "How much does it drop?" This will be answered not by rifling through the team's email, text messages and surveillance video, but rather by an experiment. Hence Coach Belichick's usual common sense in taking the opportunity to do just this before the team left Foxborough. Until someone else performs and documents the definitive experiment (several amateur scientists have posted attempts on YouTube), we should all take him at his word that ball pressure would have dropped enough, without any tampering, to account for what was observed by the referees during the recent AFC championship game.

THE BUREAUCRATIC PHASE, CATCH-22

It should be pointed out that an NFL football team could have avoided football deflation below the league minimum 12.5 psi in very cold weather by checking the ball pressure on the sideline during the game and pumping more air into them (increasing the "n" in the Ideal Gas Law). The League has unwittingly created an untenable situation for cold weather games where a team will either be guilty violating NFL rules against tampering with the balls if it reinflates them, or guilty of using underinflated balls if it leaves them alone.

THE PSYCHOLOGICAL PHASE, THE BLIND LEADING THE BLIND

During this fascinating, frustrating, all-consuming week of DeflateGate, some might wonder how could so many intelligent, highly paid NFL executives and officials have established such a flawed rule, a rule that appears ignorant of the fact that cold weather drops ball Pressure. Sadly, most journalists and commentators also lack this knowledge and have plunged ahead recklessly with false accusations and little curiosity about the basic facts of the matter. They think that for the ball pressure to drop significantly, someone must have tampered with them and let some air out. They just know it. Emboldened by ignorance and sinister suspicion, they have proclaimed "the Patriots are cheaters!" Why have so many been so blind to their ignorance?

The answers to this questions come from the other important scientific field at play in DeflateGate: Cognitive and Social Psychology. Discussion of this is complex and goes way beyond the issue of football pressure, but is extremely relevant to the media and society at large. If you are interested, please look up "Cognitive Bias" and "The Dunning-Kruger effect: Why The Incompetent Don't Know They're Incompetent".

The science of cognitive bias is necessary to help us to understand how overconfident NFL officials established unworkable inflation rules. It also helps us to better understand why so many pundits have failed to appreciate the reasons for football deflation in a cold wet game yet have gone on to lob accusations of ball tampering with great confidence and righteous indignation (and a few tears).

THE FINAL PHASE, A DEFINITIVE SOLUTION

While the science of human cognition and its limitations is probably powerless to eliminate the mass hysteria of DeflateGate, high school physics can help us to reliably keep NFL footballs properly inflated during games in any kind of weather. Like most scientific solutions, the fix for NFL ball pressure is simple, and elegant. Here it is:

1) Keep the current process of the teams giving their game balls to the officials 2-3 hours before kick-off. The officials have time to inspect the balls and allow time to correct any concerns.
2) At least 90 minutes before kick-off, the officials place the balls in breathable tamper proof bags or other containers, seal the containers with tamper-proof fasteners, and take them down to the field. This will allow the air inside the footballs to equilibrate to the climactic conditions (i.e. temperature) on the field.
3) The bags should be placed in plain sight of both teams, fans and officials in the center of the field. In any case, they must not be left near sideline heaters or cooling fans.
4) The outside of the containers should be reflective White in color. (If the containers were black or other dark color and left in the sun, they will heat up the balls and prevent equilibration.
5) Whether to keep the balls dry from any rain will have to be determined.
6) The officials will break open the tamper-proof seals 10-20 minutes before kickoff, remove the balls, and adjust air pressure to NFL specifications.
7) Officials should be allowed to check and readjust ball pressures at half-time or other times during the game.

Problem solved.

SUMMARY

DeflateGate is the unfortunate outcome of irrational rules for pregame football inflation that have been adopted by NFL executives, lawyers and business owners who clearly lacked common sense and a knowledge of basic high-school physics. Robert Kraft's indignation is certainly justified, but should be tempered by the realization that he joined so many others in implementing these rules. While apparently competent to manage business and legal matters, one wonders about the competency of NFL officials to handle all the other important matters facing the unprecedented sport of American football (like the epidemic of concussions and head injuries, for which there is also a simple scientific solution - see http://www.huffingtonpost.com/ainissa-g-ramirez-phd/footballs-paradigm-s... ).

DeflateGate is not about who said what to who, about whether a coach or player is popular or likeable, about whether anyone should have felt a drop in football pressure by squeezing the ball, or about whether deflation makes it easier or harder to hold, throw or catch a football. At least, this is not what it should be about. No, this controversy is simply about the pressure-drop in footballs during a cold, wet game. To determine whether or not pressure would have naturally dropped without tampering, the NFL needs a few scientists, not a team of lawyers on a witch hunt in need of a conspiracy. Most importantly, there is a simple, science-based process that NFL referees can easily follow to prevent similar problems in the future. It involves leaving the balls in sealed white bags at midfield for 90 minutes then adjusting ball pressure 15 minutes before kick-off.

Please consider these comments and feel free to publish, print, reproduce and pass on any portion of them.

REFERENCES

http://www.nfl.com/rulebook/ball

http://en.wikipedia.org/wiki/Ideal_gas_law

http://www.spring.org.uk/2012/06/the-dunning-kruger-effect-why-the-incom...

http://en.wikipedia.org/wiki/Dunning-Kruger_effect

http://www.psmag.com/health-and-behavior/confident-idiots-92793

Dan Boyn's picture

Thanks, Dr. Ramirez. I enjoyed your lesson. This is a great opportunity for students to learn science facts and science attitude, and to observe what happens in our country when decision-makers make rules without knowing the science.

One small point about your explanation of the Ideal Gas Law, temperature must be in degrees Kelvin.

Keep up the good work, especially your understanding of the science of football head injuries, and what needs to be done about it. The main scientific principle involved in this issue comes from Biology, and involves the essential role of pain in maintaining behaviors that protect our tissues. Inevitably, tissues become damaged when pain sensation in blocked (from a helmet, from a drug or from nerve damage). Pain sensation is (almost always) a precious gift. The failure to appreciate this by the NFL and the medical community has caused much unnecessary suffering and disability.

Bert Berla's picture

There's more here, too.

It'd be super cool to extend this to use more of the ideal gas law and measure the change in displacement (volume) of a football when cold vs. warm. The structure of the football might make this difference smaller than that predicted by the ideal gas law, but you could show that the ideal gas law works nicely for just a balloon. And while the displacement would change when you weighted the ball to hold it under the water, it won't when you let the ball float, because that displacement is a function of weight only.

Liz McLaughlin Woodard's picture

I am planning on doing this lesson with my students. Does anyone have a middle school-friendly article that students could read as well? THanks!

Alex Shevrin's picture
Alex Shevrin
Teacher/leader & techie at independent, alternative, therapeutic high school

Liz, I don't specifically have an article but there is a great website called http://gokicker.com/ that has lots of news and articles that are easy to read and aligned with teenage interests, depending which end of middle school you're in.

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