# Penn State

## COVID-19 Modeling

There has been quite a bit of debate about the “dire” predictions that COVID-19 models have made and are making for infections and, especially, deaths, and how those predictions are being used to scare people.  I can say with a great deal of certainty that scientists making these models and doing the simulations are not intentionally trying to scare anyone.  (The only “scientists” I am skeptical of are the ones trying to sell books or market themselves for something.  The “Plandemic” woman is in this category.  She’s been peddling false hope to people with chronic illnesses for a long time.)  On the other hand, in the hands of the media and politicians the predictions can be used in many different ways.  I think many of the early models used a few different scenarios:  we do nothing, we socially distance and/or shutdown, we discover a vaccine, etc.  If you want to scare people, the predictions from the models in which we do nothing can certainly be used, and I believe that if we had done nothing we would be in a very serious situation.

I’ve spent most of the last 30 years developing and analyzing models, mostly trying to predict how physical systems will respond.  Physical system models are not hard to develop if you understand the physical laws that govern them (and the mathematics needed to study them).  There have been very few advances in modeling physical systems at scales visible to humans in nearly a century.  That is why physicists rightly say that most of what engineers do is classical physics.  One nice thing about physical systems is they are not alive to change their behaviors to something not included in the model.  (Note, “smart” materials on which I did a lot of research are not actually smart. [1])  Another nice thing is you can do controlled experiments to validate your model.  Finally, you have a lifetime of experience and intuition to use to see if the results make physical sense.  However, I think the best results are the ones that do not initially make intuitive sense and require you to adjust your intuition.  See footnote [2] for a great example of this and footnote [3] for my experience trying to get engineering students to use their intuition and common sense.

The basic model for disease spread is what’s called the SIR (susceptible/infected/recovered) model; there are many variations and extensions of this.  There are also many good explanations of this model online so I won’t go into details about it here.  I would recommend watching the YouTube video I’ve embedded at the end.  One thing to know about these models is that they are statistical and have many parameters that people can “tweak” and many “features” that can be added.  Being statistical, they will only give you an “average” sense of what might happen.  Likewise, you can adjust the parameters to get almost any prediction.  This is where so-called fitting comes in.  Scientists will tweak the parameters until they fit known cases and hope those parameters will predict what will happen in the future.  When scientists share these models they usually provide the parameters they’ve used and what “ingredients” have been included.  Although some people want to keep their models proprietary, and I would be skeptical of them.  The problem here is that by the time the predictions hit the media and politicians all those details have been stripped away to make it more digestible for the general public.

Statistical models have been used in physics for over a century, and from basically the time we realized matter was made of atoms but we could still measure properties of matter without having to keep track of every atom.  For example, the temperature of something basically measures on average the energy contained in the atoms/molecules comprising the material.  We don’t need to track every atom to get this average.  Likewise, the pressure from the air you feel is the forces of all the molecules in the air hitting you.  If the wind hits you from one side you notice a net force acting to push you in the direction the wind is blowing.  This is simply because more molecules are hitting you on one side than the other creating a net force that wants to move you.  Again, we do not need to keep track of every molecule/atom to determine what this force is.

Statistical models in physics (a subject called statistical mechanics) work extremely well and are used extensively.  Like SIR models statistical mechanics models can be more or less complicated by adding or removing ingredients.  For example, the “ideal gas law” that relates pressure, temperature, and volume was known long before we understood anything about atoms, and we now know that it can be completely derived by averaging the motion of atoms and molecules modeled as balls bouncing around.  However, there are cases when the ideal gas law doesn’t work well.  For example if the gas is made from molecules you can include the rotation of the molecule as an ingredient.  It turns out that under “normal” conditions this ingredient isn’t needed, but under extreme conditions it helps explain why the ideal gas law fails.  The other time statistical models don’t work well is when you don’t have enough particles (i.e. atoms or molecules) to average over.  If you only have, say, one thousand atoms bouncing around in a box, statistical averaging starts to not work so well.  Fortunately, with modern computing power, we can model billions of atoms moving around using molecular dynamic simulations.

One reason statistical models and molecular dynamic simulation work so well is that atoms do not have free will, i.e. under the same situation they will all act the same.  People on the other hand are very different.  It’s this behavior and the feedback causing that behavior that makes modeling populations so hard.  If you have millions of people you can try to estimate how the average person will behave and include that in a statistical model.  Most of the variations of the SIR are doing just that, but modeling behavior even on average is very difficult.  While we could theoretically model every person in the United States acting in an average way, we know this would provide the same results as the statistical model.  We could include some randomness in the every-person model, but again with enough people you’re still going to get the average result.  What an every-person model may help predict is how a very non-uniform population density plays a role.  However, SIR models can be adjusted for this too.

To help explain the SIR model, the creator of the two videos below basically does molecular dynamics simulations with people replacing the atoms and behaving in different random ways.  Note the Twitter screenshot he includes around the 2:14 mark with someone responding to him, “Im not a gas in a box :'(”  Because he is only using around one thousand people walking basically randomly he makes many runs and averages the results.  To try to model the variation in people’s behavior he uses various percentages and looks at how these percentages change the results.  For example, he varies the percentage of people infected that get quarantined or the percentage of people traveling from one community to another.

When you’re modeling things with algorithms instead of equations you can play around with all kinds of probable behaviors and actions.  Things can get extremely complicated and often you have no idea what the result might be.  There is actually a scientific/mathematical buzzword for this called “emergent behavior.”  According to Wikipedia, “emergence occurs when an entity is observed to have properties its parts do not have on their own.”  You can think of your body as the emergence of all the individual cells doing their own thing.  Scientists and mathematicians are enamored with emergent behavior because you often see very interesting and realistic behaviors emerge from very simple models of how the parts interact.

While I am certainly biased, I believe the scientific community is doing a great job simply trying to keep people informed.  Unfortunately, their messages can get distorted and used politically.  Plus, scientists usually avoid words like “never” and “always” so when someone asks them if it’s possible 10 million people will die, they’ll simply answer, “Yes.  It’s possible.”

Footnotes

[1]  Playing with a dielectric elastomer “smart” material water balloon in the lab of my former student Nakhiah Goulbourne at the University of Michigan during the summer of 2010.  What makes this material “smart” is a crazy-stupid 5,000V being applied across the membrane, although there is very little current so not much power.

Wrinkled mylar balloon.

[2] A great example of needing to adjust your intuition based on strange results from a model is a model/simulation I worked on with Elaine Serina when we were graduate students.  Elaine wanted to understand how forces on your fingertip get transferred to tension in the skin and stresses on the bone as part of a larger study on carpal tunnel syndrome.  As a simple first step, we decided to model the fingertip as an ellipsoid (think of a plain M&M) inflated by water and then compressed between two plates.  We wanted the initial inflation because there is usually tension in your skin (unless you’ve been soaking in water and are all “pruney”).  However, when Elaine took the equations I derived and wrote code to solve them she kept getting strange results that we were both convinced couldn’t be correct.  The simulations were showing that when you inflated the skin membrane you would get compressive stresses.  Our intuition said, “You can’t inflate something and get compression.”  We spent at least a month trying to figure out what was wrong with the model and/or the code to no avail.  After a meeting with our thesis adviser in which he concurred with our intuition that something must be wrong, we were walking back to our lab through the student union and noticed the inflated mylar balloons.  One of us (likely me because I was the one studying wrinkling caused by membrane compression) realized that all the mylar balloons were wrinkled around the edges, just where our model was predicting compressive stresses.  The only way you get wrinkles is when you have compressive stresses.  Thus, we realized our intuition was wrong!  As you inflate a mylar balloon the edges want to pull in towards the center.  This creates the compression.  If you have a rubber balloon of this shape, adding more pressure will eventually cause the wrinkles to disappear.  However, because mylar is so stiff you can’t pressurize it enough to remove the wrinkles without it rupturing.

[3] I was always a bit disheartened with how many mechanical engineering students did not seem to have this intuition when they got to the junior-level class I regularly taught.  To address this, part of every homework problem was a statement about why they felt their answer was correct or incorrect.  Early in the semester I would get answers like, “Because I followed all the steps and checked the math.”  I was constantly shocked at how many mechanical engineering students did not come into the class with the skill of looking at the result they got and evaluating if it made physical sense.  Every semester I talked a lot about “sanity checks.”  Plus, I wanted to know if they suspected their answer was not correct, as it’s much better in the real world to know a result is likely not correct than to think it is.

## Thoughts on the NCAA punishment

If you read any of my previous posts, you might guess that I’m not a huge fan of the NCAA penalties placed on Penn State.  As someone that teaches vibrations regularly it’s interesting to watch the pendulum swing back and forth, never seeming to reach an equilibrium.  In this case, the NCAA wanted to flex its muscle to show the world that it has more power than it actually does.  People (not me) had been saying that penalties it has handed out in the past are too weak, so it needed to stand up and grab some headlines by overreaching its bounds.  What happened at Penn State had nothing to do with exploiting the student-athletes the NCAA is there to protect.  It has now deemed itself a watchdog for anything remotely related to collegiate athletics.

Regarding the specific penalties, the only one I have a real problem with is the fine.  Sixty million dollars is a lot of money.  While I’m glad it will be put to good use, I wonder if it will come only from the athletic department.  I sure hope so because it’s now going to be even harder to argue against state budget cuts that are always proposed.  Tuition was already going to increase because of this indirect loss of state funds.

Another thing I keep reading about is the need to change the culture and the organizational structure that led to this situation.  The thing is the organizational structure is not what caused the problem.  PSU has much the same organization structure as any other university.  It’s not like back in the day at Auburn where the football coach (Dye) was also the athletic director.  It’s also not like a former coach or player (here here NU, UM, et al.) is the athletic director.  People seem to have the impression that PSU’s organizational structure somehow gave Paterno, et al. too much power.  While I agree entirely Paterno had too much power, it was not the organizational structure that gave it to him.

That brings me to the culture.  The football culture here is as distorted and twists as it is at most major universities.  It does not seem any worse than it was a UM; although it is certainly worse than it was at Cal (Berkeley).  I would think it’s actually not as bad as many other schools (Texas, TAMU, UF, FSU, Auburn, Alabama, LSU, Notre Dame, Nebraska, Oklahoma, USC, Miami, et al.).  These schools seem to have cultural issues at least as serious as PSU.  Ultimately, it seems to me to be more a cultural issue of our society.

So why did this tragedy happen at PSU and not someplace else?  Mostly it was just bad luck and could have happened at any number of schools.  We brought someone (Sandusky) on campus (as a student-athlete) that happened to be a very clever sociopath.  Unfortunately he was also a good player and coach, and smart enough to not get caught during his early years.  (Note, I’m assuming he did not become a pedophile in his later years and had been abusing children for much longer than we know.)  The other piece in the puzzle was that we hired a coach that would turn into an arrogant old man that had nothing else to do besides coach football and, thus, wouldn’t retire.  I also believe Paterno truly felt that he was the only person good enough to coach the PSU football team.

The problem was he was just hear for so long (current students may have grown up with their parents and grandparents idolizing him) that he slowly turned into a dictator.  Unfortunately there was never really any good reason to get rid of him (until the end).  Sure he had some losing seasons but then you’re basically firing someone for not winning games.  PSU alumni and administrators thought he had sacrificed too much for the university to fire him for not winning.  It’s really hard to fire a legend unless they do something bad.  Unfortunately, very few people knew about the bad things he did until the end.  He did do a lot for the university by living a very modest life, earning a modest (relative to other coaches) salary, and donating much of his endorsement income back to the university.  However, I will stick by my early Facebook comments that in the end he will have cost the university more than he gave it.  His “I’m a simple man trying to teach young athletes to be good people.” was probably true to start.  However, as the years wore on, I think that was more of a front to continue to garner alumni support.  I read someone suggesting we have term limits on football coaches.  That’ll never happen but you have to be mindful that at some (tipping) point a coach has too much power.

The thing that people outside PSU don’t seem to see is that the culture changed the minute Paterno was fired and this new culture was cemented when he died.  The NCAA punishments are not going to change the culture.  In fact, I worry that they’ll make it worse.  There will be even more of an ‘us against them’ attitude that will insulate the university from the world. Maybe forcing the football team to be terrible will help change the culture of the blindly devoted PSU alumni that are the ones that really enabled this mess.  Unfortunately, its hard to punish such a large group of people, most of whom had nothing explicitly to contribute to the situation.  What I would like to see is the university try to pay this fine by using a true supply and demand system for ticket prices.  The alumni are still likely going to fill the stadium–for most of them it’s a tradition that won’t end because the team stinks–so let the ticket prices climb until profit is maximized.  Then the people that truly enabled this situation will be penalized.

## What’s a fair punishment?

As I have read more and more speculation about what punishment the NCAA will hand down to PSU, I have started to think what might be fair and what might fit with all of what has been leaked.

One suggestion I have always liked is for the athletic department to essentially be run as a non-profit and donate all proceeds to a charity (likely for abused children).  The problem with that idea is that a non-profit (and least a fake one like this would be) can always make sure to spend all the revenue so there appears to be no profit.  I.e. the athletic department could just make sure it spends everything it earns so there’s nothing left for charity.

Another thing that I’ve read about is the NCAA taking over the athletic department.  At first this seemed quite strange but it fits with the idea of running things as a non-profit.  With the NCAA overseeing things, the athletic department could not spend frivolously to burn all the revenue.  If this were the reason for the NCAA taking over (or having oversight) then I think it’s not a bad idea.

The last piece to the puzzle is the fine the NCAA appears to be planning to levy.  I’ve read that it’s somewhere between $30 and$60 million.  That seems pretty excessive to pay all at once.  If this were taken from the athletic department over a year or two it would devastate non-revenue sports, not the football program.  Like they do at almost all large universities, football and basketball pay the way for almost all other sports.  Thus, forcing the athletic department to run at a loss would be punishing a lot of ‘real’ student-athletes.

Finally, the last I heard the athletic department has an income of roughly $15 million most years. (I’m not exactly sure what they do with that money but it’s separate from the academic budget.) Thus, say the NCAA forces PSU to run the athletic department as a non-profit for four years. If income stays as it is, that would make for a$60 million fine.  If income drops as one might expect, the number might be closer to \$30 million.

By simply taking the income the athletic department might have made, the NCAA will avoid punishing other athletic programs.  Some athletic department projects might be put on hold (hopefully the new ice rink is already paid for), but cutting back on the lavishness of the facilities for the football team will probably be a good thing.

## Butt out NCAA

If the ‘credible sources’ are correct the NCAA will be announcing ‘severe and unprecedented’ penalties to Penn State athletics tomorrow.   While I have long thought the football culture around here needed to change and think that the past leadership should be criminally charged, when I hear about the NCAA wanting to impose sanctions to punish the university it always seems wrong.  I have thought a lot about why it ‘feels’ wrong and have gone back and forth between thinking my gut feeling was correct.  I like to trust my instincts but I had a hard time developing a rational argument for why I feel this way.

At first I was thinking the NCAA was overstepping its bounds because this is more of a failure of leadership than a failure to abide by NCAA policy.  I will be very interested in what infractions are cited in support of the penalties and if Penn State has the guts to appeal.  The problem to me is that I don’t really like this argument.  While the problem was indeed more a problem of leadership it was enabled by the athletic department and a lack of control from our leadership.  Thus, in that regard I feel the NCAA should be involved.

However, even after dismissing this argument, I still just felt like the NCAA should butt out of this.  Today I think I finally figured out why I feel this way.  Hopefully I can articulate my feelings in this post.

First, I have never been a fan of the NCAA or how college athletics seems to overshadow academics at some of the nation’s best universities.  The entire system needs to be blown up.  And in some regards I feel shutting down PSU football for a year might actually be a good thing in the long term.   However, the real problem I have with the NCAA getting involved is the stated mission of the NCAA.  According to their web site:

Founded more than one hundred years ago as a way to protect student-athletes, the NCAA continues to implement that principle with increased emphasis on both athletics and academic excellence.

Besides wondering if the NCAA really has the interest of student-athletes in mind, they are supposed to be protecting them from abuse by universities.  Again, while they seem to be more about enabling universities to abuse student-athletes than anything else, there were no abuses of NCAA athletes in this situation.  The NCAA is not here to protect coaches or children, or to punish coaches or universities that do not protect children.  The judicial system does that.  Hopefully, the judicial system will continue to punish the people that committed these crimes.

In my mind, the real problem with the NCAA getting involved is that in many ways they are acting like the PSU leadership, overstepping their bounds to preserve public perception.  They seem to be all too willing to continue to enhance the public perception that they are an organization that oversees entire universities not just the athletic programs at universities.