Above all, don’t lie to yourself. The man who lies to himself and listens to his own lie comes to a point that he cannot distinguish the truth within him, or around him, and so loses all respect for himself and for others. And having no respect he ceases to love.
― Fyodor Dostoyevsky
Over the past handful of years the capacity to maintain professional success and personal integrity has become increasingly strained. Simultaneously the whole concept of integrity within the public life has similarly become strained. I’ve been startled by the striking symmetry between my private, professional and public life as the incredible
and terrifying shit show of the 2016 American Presidential election. It all seems to be coming together in a massive orgy of angst, lack of honesty and fundamental integrity across the full spectrum of life. As an active adult within this society I feel the forces tugging away at me, and I want to recoil from the carnage I see. A lot of days it seems safer to simply stay at home and hunker down and let this storm pass. It seems to be present at every level of life involving what is open and obvious to what is private and hidden.
How do we deal with all of the conflict, tension and danger when the rules of the game seem to have been thrown out? Is this confluence of effects common to everyone helping to explain the World, or is it personal? I think it’s worth pondering the breadth and scope of the challenges as we head forward toward a hopefully more optimistic future and 2017.
I’ve highlighted the concept of integrity as the focal point and the thing at more imminent risk. This is an expansion of my previous discussion of peer review that revolves around the same axis. It gets to the ability to care with some depth about the work I do, and whether that concern is actually appreciated. What does personal integrity mean to me? Like most things it is complex and combines multiple aspects of the content of my daily life. The greatest element of personal angst deals with the truth and any willingness for truths to be articulated openly. Research and progress depends upon good ideas being applied to areas of opportunity. Another less charitable way of saying
the same thing is that progress depends on finding important, valuable problems and driving solutions. A second piece of integrity is hard work, persistence, and focus on the important valuable problems linked to great National or World concerns. Lastly, a powerful aspect of integrity is commitment to self. This includes a focus on self-improvement, and commitment to a full and well-rounded life. Every single bit of this is in rather precarious and constant tension, which is fine. What isn’t fine is the intrusion of outright bullshit into the mix undermining integrity at every turn.
When people don’t express themselves, they die one piece at a time.
― Laurie Halse Anderson
The core of the issue attacking integrity is the power and prevalence of bullshit in professional and public life. At a professional level bullshit has become the prevalent means of communication of results. Why create real work when fake work can be spun into results of equal and greater value. In fact bullshit is better because it can be whatever it needs to be for success. People continually produce results of m
inimal value that get marketed as breakthroughs. The lack of integrity at the level of leadership simply takes this bullshit and passes it along. Eventually the bullshit gets to people who are incapable of recognizing the difference. Ultimately, the result of the acceptance of bullshit produces a lowering of standards, and undermines the reality of progress. Bullshit is the death of integrity in the professional world.
There exists an appalling symmetry within the broadest public sphere. We are witnessing a political movement of disturbing power founded on bullshit. We see outright lies produced every day and never actively challenged. This bullshit may actually elect a completely unqualified and dangerous person President of the United States. Why work with facts or truth when bullshit is so incredibly effective? When we look more deeply at this problem we start to see that our political dysfunction is built upon a virtual mountain of bullshit. We see reality television, Facebook, Fox News, CNN, online dating, and a host of other modern things all-operating
within a vibrant and growing bullshit economy. Taken in this broad context, the dominance of bullshit in my professional life and the potential election of Donald Trump are closely connected.
A big part of the acceptance of bullshit as the medium of universal discourse is related to fear. Increasingly our professional and public lives are ruled by irrational fears. Fear of failure professionally is rampant. Fear of terrorism is also rampant. Fear of immigrants is yet another common fear tied to terrorism, racism and economic stress. Fear is a powerful emotion that overrules most rational responses to problems. It leads to people shrinking away from the sort of professional risk that research depends upon. Fear is also one of the most powerful tools of political despots. In each of these cases bullshit can be used to either quell or amplify fears. In the technical World bullshit can produce seeming success without regard to actual technical accomplishment. The acceptance of bullshit in place of actual results quells the risk of failure. In the political World bullshit can produce fear where little or none is warranted. We are seeing trillions of dollars and millions of votes being gener
ated by fear mongering bullshit. Even worse it has paved the way for greater purveyors of bullshit like Trump. We may well see bullshit providing the vehicle to elect an unqualified con man as the President.
Here are two major paths to take in life, follow and be rewarded by the power structure, or confront power with the reality of their failing. So I’m confronted with guidance “don’t be a troublemaker” versus show integrity “speak truth to power”. Which is it? Which of these paths do our institutions support today? That’s easy. Be quiet and go quietly through life, and don’t make waves. Better yet, join the bullshit economy and contribute to its vibrant growth as our greatest export.
If you can’t speak truths and provide honest assessments in today’s World, or call out lies in public, can you have personal integrity? When actual bullshit has become the path to professional success, how does one come back? How much of yourself gets left behind in the process? And how does one keep ones self from being a mere shadow of one’s true self? I’ve been struggling with these questions at work with ever-greater regularity. My personal devotion to progress and research is continually undermined by bullshit replacing progress. Today it is easier to make shit up and pass it off as being completely equivalent to the result of honest good work. Moreover bullshit doesn’t have the downside of potentially not working, its “success” is virtually guaranteed. Just tell the people above you in the food chain what they want to hear, you’ll be rewarded in spades! Th
e beauty of it is the made up shit can conform to whatever narrative you desire, and completely fit whatever your message is. In such a world real problems can simply be ignored when the path to progress is problematic for those in power.
These same issues happen to energize a political dialog that becomes a shouting match. There is no truth and the whole thing degenerates into a shouting match. Beyond the shouting match you get the ability to ignore real problems that are inconvenient. A perfect example is climate change. For many traditional businesses climate change is really an inconvenient truth. When bullshit rules, it can be publically ignored without real risk to political success. We are seeing this play out right in front of all of us. We are in danger of losing all connection to facts, truth and science as guiding forces for determining optimal solutions to our very real problems. The road to this end is paved by allowing bullshit to be viewed as equivalent to solid facts.
Is there a path forward? Perhaps things simply need to devolve into the natural outcome from the current path. Nothing short of catastrophe will stop this orgy of bullshit choking public life. One might hope that we have the collective wisdom to avoid a calamity, one might hope.
One of the greatest regrets in life is being what others would want you to be, rather than being yourself.
― Shannon L. Alder
n the early days of computational science we were just happy to get things to work for simple physics in one spatial dimension. Over time, our grasp on more difficult coupled multi-dimensional physics became ever more bold and expansive. The quickest route to this goal was the use of operator splitting where the simple operators, single physics and one-dimensional were composed into complex operators. Most of our complex multiphysics codes operate in this operator split manner. Research into doing better almost always entails doing away with this composition of operators, or operator splitting and doing everything fully coupled. It is assumed that this is always superior. Reality is more difficult than this proposition, and most of the time the fully coupled or unsplit approach is actually worse with lower accuracy and greater expense with little identifiable benefits. So the question is should we keep trying to do this?
solution involves a precise dynamic balance. This is when you have the situation of equal and opposite terms in the equations that produce solutions in near equilibrium. This produces critical points where solution make complete turns in outcomes based on the very detailed nature of the solution. These situations also produce substantial changes in the effective time scales of the solution. When very fast phenomena combine in this balanced form, the result is a slow time scale. It is most acute in the form of the steady-state solution where such balances are the full essence of the physical solution. This is where operator splitting is problematic and should be avoided.
ods is their disadvantage for the fundamental approximations. When operators are discretized separately quite efficient and optimized approaches can be applied. For example if solving a hyperbolic equation it can be very effective and efficient to produce an extremely high-order approximation to the equations. For the fully coupled (unsplit) case such approximations are quite expensive, difficult and complex to produce. If the solution you are really interested in is first-order accurate, the benefit of the fully coupled case is mostly lost. This is with the distinct exception of small part of the solution domain where the dynamic balance is present and the benefits of coupling are undeniable.
method should be adaptive and locally tailored to the nature of the solution. One size fits all is almost never the right answer (to anything). Unfortunately this whole line of attack is not favored by anyone these days, we seem to be stuck in the worst of both worlds where codes used for solving real problems are operator split, and research is focused on coupling without regard for the demands of reality. We need to break out of this stagnation! This is ironic because stagnation is one of the things that coupled methods excel at!
Today’s title is a conclusion that comes from my recent assessments and experiences at work. It has completely thrown me off stride as I struggle to come to terms with the evidence in front of me. The obvious and reasonable conclusions from the consideration of recent experiential evidence directly conflicts with most of my most deeply held values. As a result I find myself in a deep quandary about how to proceed with work. Somehow my performance is perceived to be better when I don’t care much about my work. One reasonable conclusion is that when I have little concern about outcomes of the work, I don’t show my displeasure when those outcomes are poor.
nal integrity is important to pay attention to. Hard work, personal excellence and a devotion to progress has been the path to my success professionally. The only thing that the current environment seems to favor is hard work (and even that’s questionable). The issues causing tension are related to technical and scientific quality, or work that denotes any commitment to technical excellence. It’s everything I’ve written about recently, success with high performance computing, progress in computational science, and integrity in peer review. Attention to any and all of these topics is a source of tension that seems to be completely unwelcome. We seem to be managed to mostly pay attention to nothing but the very narrow and well-defined boundaries of work. Any thinking or work “outside the box” seems to invite ire, punishment and unhappiness. Basically, the evidence seems to indicate that my performance is perceived to be much better if I “stay in the box”. In other words I am managed to be predictable and well defined in my actions, don’t provide any surprises.
The only way I can “stay in the box” is to turn my back on the same values that brought me success. Most of my professional success is based on doing “out of the box” thinking working to provide real progress on important issues. Recently it’s been pretty clear that this isn’t appreciated any more. To stop thinking out of the box I need to stop giving a shit. Every time I seem to care more deeply about work and do something extra not only is it not appreciated; it gets me into trouble. Just do the minimum seems to be the real directive, and extra effort is not welcome seem to be the modern mantra. Do exactly what you’re told to do, no more and no less. This is the path to success.
done the experiment and the evidence was absolutely clear. When I don’t care, don’t give a shit and have different priorities than work, I get awesome performance reviews. When I do give a shit, it creates problems. A big part of the problem is the whole “in the box” and “out of the box” issue. We are managed to provide predictable results and avoid surprises. It is all part of the low risk mindset that permeates the current World, and the workplace as well. Honesty and progress is a source of tension (i.e., risk) and as such it makes waves, and if you make waves you create problems. Management doesn’t like tension, waves or anything that isn’t completely predictable. Don’t cause trouble or make problems, just do stuff that makes us look good. The best way to provide this sort of outcome is just come to work and do what you’re expected to do, no more, no less. Don’t be creative and let someone else tell you what is important. In other words, don’t give a shit, or better yet don’t give fuck either.
The news is full of stories and outrage at Hillary Clinton’s e-mail scandal. I don’t feel that anyone has remotely the right perspective on how this happened, and why it makes perfect sense in the current system. It epitomizes a system that is prone to complete breakdown because of the deep neglect of information systems both unclassified and classified within the federal system. We just don’t pay IT professionals enough to get good service. The issue also gets to the heart of the overall treatment of classified information by the United States that is completely out of control. The tendency to classify things is completely running amok far beyond anything that is in the actual best interests of society. To
compound things, further it highlights the utter and complete disparity in how laws and rules do not apply to the rich and powerful. All of this explains what happened, and why; yet it doesn’t make what she did right or justified. Instead it points out why this sort of thing is both inevitable and much more widespread (i.e., John Deutch, Condoleezza Rich, Colin Powell,
and what is surely a much longer list of violations of the same thing Clinton did).
Last week I had to take some new training at work. It was utter torture. The DoE managed to find the worst person possible to train me, and managed to further drain them of all personality then treated him with sedatives. I already take a massive amount of training, most of which utterly and completely useless. The training is largely compliance based, and generically a waste of time. Still by the already appalling standards, the new training was horrible. It is the Hillary-induced E-mail classification training where I now have the authority to mark my classified E-mails as an “E-mail derivative classifier”. We are constantly taking reactive action via training that only undermines the viability and productivity of my workplace. Like most my training, this current training is completely useless, and only serves the “cover your ass” purpose that most training serves. Taken as a whole our environment is corrosive and undermines any and all motivation to give a single fuck about work.
professionals work on old hardware with software restrictions that serve outlandish and obscene security regulations that in many cases are actually counter-productive. So, if Hillary were interested in getting anything done she would be quite compelled to leave the federal network for greener, more productive pastures.
ything is not my or anyone’s actual productivity, but rather the protection of information, or at least the appearance of protection. Our approach to everything is administrative compliance with directives. Actual performance on anything is completely secondary to the appearance of performance. The result of this pathetic approach to providing the taxpayer with benefit for money expended is a dysfunctional system that provides little in return. It is primed for mistakes and outright systematic failures. Nothing stresses the system more than a high-ranking person hell-bent on doing their job. The sort of people who ascend to high positions like Hillary Clinton find the sort of compliance demanded by the system awful (because it is), and have the power to ignore it.
Of course I’ve seen this abuse of power live and in the flesh. Take the former Los Alamos Lab Director, Admiral Pete Nanos who famously shut the Lab down an denounced the staff as “Butthead Cowboys!” He blurted out classified information in an unclassified meeting in front of hundreds if not thousands of people. If he had taken his training, and been compliant he should have known better. Instead of being issued a security infraction like any of the butthead cowboys in attendance would have gotten, he got a pass. The powers that be simply declassified the material and let him slide by. Why? Power comes with privileges. When you’re in a position of power you find the rules are different. This is a maxim repeated over and over in our World. Some of this looks like white privilege, or rich white privilege where you can get away with smoking pot, or raping unconscious girls with no penalty, or lightened penalties. If you’re not white or not rich you pay a much stiffer penalty including prison time.

complete and utter bullshit. People who have highlighted huge systematic abuses of power involving murder and vast violation of constitutional law are thrown to the proverbial wolves. There is no protection, it is viewed as treason and these people are treated as harshly as possible (Snowden, Assange, and Manning come to mind). As I’ve noted above people in positions of authority can violate the law with utter impunity. At the same time classification is completely out of control. More and mo
re is being classified with less and less control. Such classification often only serves to hide information and serve the needs of the status quo power structure.
I’ll just say up front that my contention is that there is precious little excellence to be found today in many fields. Modeling & simulation is no different. I will also contend that excellence is relatively easy to obtain, or at the very least a key change in mindset will move us in that direction. This change in mindset is relatively small, but essential. It deals with the general setting of satisfaction with the current state and whether restlessness exists that ends up allowing progress to be sought. Too often there seems to be an innate satisfaction with too much of the “ecosystem” for modeling & simulation, and not enough agitation for progress. We should continually seek the opportunity and need for progress in the full spectrum of work. Our obsession with planning, and micromanagement of research ends up choking the success from everything it touches by short-circuiting the entire natural process of progress, discovery and serendipity.
n my view the desire for continual progress is the essence of excellence. When I see the broad field of modeling & simulation the need for progress seems pervasive and deep. When I hear our leaders talk such needs are muted and progress seems to only depend on a few simple areas of focus. Such a focus is always warranted if there is an opportunity to be taken advantage of. Instead we seem to be in an age where the technological opportunity being sought is arrayed against progress, computer hardware. In the process of trying to force progress where it is less available the true engines of progress are being shut down. This represents mismanagement of epic proportions and needs to be met with calls for sanity and intelligence in our future.
The way toward excellence, innovation and improvement is to figure out how to break what you have. Always push your code to its breaking point; always know what reasonable (or even unreasonable) problems you can’t successfully solve. Lack of success can be defined in multiple ways including complete failure of a code, lack of convergence, lack of quality, or lack of accuracy. Generally people test their code where it works and if they are good code developers they continue to test the code all the time to make sure it still works. If you want to get better you push at the places where the code doesn’t work, or doesn’t work well. You make the problems where it didn’t work part of the ones that do work. This is the simple and straightforward way to progress, and it is stunning how few efforts follow this simple, and obvious path. It is the golden path that we deny ourselves of today.
n the success of modeling & simulation to date. We are too satisfied that the state of the art is fine and good enough. We lack a general sense that improvements, and progress are always possible. Instead of a continual striving to improve, the approach of focused and planned breakthroughs has beset the field. We have a distinct management approach that provides distinctly oriented improvements while ignoring important swaths of the technical basis for modeling & simulation excellence. The result of this ignorance is an increasingly stagnant status quo that embraces “good enough” implicitly through a lack of support for “better”.
Modeling & simulation arose to utility in support of real things. It owes much of its prominence to the support of national defense during the cold war. Everything from fighter planes to nuclear weapons to bullets and bombs utilized modeling & simulation to strive toward the best possible weapon. Similarly modeling & simulation moved into the world of manufacturing aiding in the design and analysis of cars, planes and consumer products across the spectrum of the economy. The problem is that we have lost sight of the necessity of these real world products as the engine of improvement in modeling & simulation. Instead we have allowed computer hardware to become an end unto itself rather than simply a tool. Even in computing, hardware has little centrality to the field. In computing today, the “app” is king and the keys to the market hardware is simply a necessary detail.
To address the proverbial “elephant in the room” the national exascale program is neither a good goal, nor bold in any way. It is the actual antithesis of what we need for excellence. The entire program will only power the continued decline in achievement in the field. It is a big project that is being managed the same way bridges are built. Nothing of any excellence will come of it. It is not inspirational or aspirational either. It is stale. It is following the same path that we have been on for the past 20 years, improvement in modeling & simulation by hardware. We have tremendous places we might harness modeling & simulation to help produce and even enable great outcomes. None of these greater societal goods is in the frame with exascale. It is a program lacking a soul.
The title is a bit misleading so it could be concise. A more precise one would be “Progress is mostly incremental; then progress can be (often serendipitously) massive” Without accepting incremental progress as the usual, typical outcome, the massive leap forward is impossible. If incremental progress is not sought as the natural outcome of working with excellence, progress dies completely. The gist of my argument is that attitude and orientation is the key to making things better. Innovation and improvement are the result of having the right attitude and orientation rather than having a plan for it. You cannot schedule breakthroughs, but you can create an environment and work with an attitude that makes it possible, if not likely. The maddening thing about breakthroughs is their seemingly random nature, you cannot plan for them they just happen, and most of the time they don’t.
modern management seems to think that innovation is something to be managed for and everything can be planned. Like most things where you just try too damn hard, this management approach has exactly the opposite effect. We are actually unintentionally, but actively destroying the environment that allows progress, innovation and breakthroughs to happen. The fastidious planning does the same thing. It is a different thing than having a broad goal and charter that pushes toward a better tomorrow. Today we are expected to plan our research like we are building a goddamn bridge! It is not even remotely the same! The result is the opposite and we are getting less for every research dollar than ever before.
A large part of the problem with our environment is an obsession with measuring performance by the achievement of goals or milestones. Instead of working to create a super productive and empowering work place where people work exceptionally by intrinsic motivation, we simply set “lofty” goals and measure their achievement. The issue is the mindset implicit in the goal setting and measuring; this is the lack of trust in those doing the work. Instead of creating an environment and work processes that enable the best performance, we define everything in terms of milestones. These milestones and the attitudes that surround them sew the seeds of destruction, not because goals are wrong or bad, but because the behavior driven by achieving management goals is so corrosively destructive.
So the difference is really simple and clear. You must be expanding the state of the art, or defining what it means to be world class. Simply being at the state of the art or world class is not enough. Progress depends on being committed and working actively at improving upon and defining state of the art and world-class work. Little improvements can lead to the massive breakthroughs everyone aspires toward, and really are the only way to get them. Generally all these things are serendipitous and depend entirely on a culture that creates positive change and prizes excellence. One never really knows where the tipping point is and getting to the breakthrough depends mostly on the faith that it is out there waiting to be discovered.
Computing the solution to flows containing shock waves used to be exceedingly difficult, and for a lot of reasons it is now modestly difficult. Solutions for many problems may now be considered routine, but numerous pathologies exist and the limit of what is possible still means research progress are vital. Unfortunately there seems to be little interest in making such progress from those funding research, it goes in the pile of solved problems. Worse yet, there a numerous preconceptions about results, and standard practices about how results are presented that contend to inhibit progress. Here, I will outline places where progress is needed and how people discuss research results in a way that furthers the inhibitions.
table. To do the best job means making some hard choices that often fly in the face of ideal circumstances. By making these hard choices you can produce far better methods for practical use. It often means sacrificing things that might be nice in an ideal linear world for the brutal reality of a nonlinear world. I would rather have something powerful and functional in reality than something of purely theoretical interest. The published literature seems to be opposed to this point-of-view with a focus on many issues of little practical importance.
upon this example. Worse yet, the difficulty of extending Lax’s work is monumental. Moving into high dimensions invariably leads to instability and flow that begins to become turbulent, and turbulence is poorly understood. Unfortunately we are a long way from recreating Lax’s legacy in other fields (see e.g.,
where it does not. Progress in turbulence is stagnant and clearly lacks key conceptual advances necessary to chart a more productive path. It is vital to do far more than simply turn codes loose on turbulent problems and let great solutions come out because they won’t. Nonetheless, it is the path we are on. When you add shocks and compressibility to the mix, everything gets so much worse. Even the most benign turbulence is poorly understood much less anything complicated. It is high time to inject some new ideas into the study rather than continue to hammer away at the failed old ones. In closing this vignette, I’ll offer up a different idea: perhaps the essence of turbulence is compressible and associated with shocks rather than being largely divorced from these physics. Instead of building on the basis of the decisively unphysical aspects of incompressibility, turbulence might be better built upon a physical foundation of compressible (thermodynamic) flows with dissipative discontinuities (shocks) that fundamental observations call for and current theories cannot explain.
Let’s get to one of the biggest issues that confounds the computation of shocked flows, accuracy, convergence and order-of-accuracy. For computing shock waves, the order of accuracy is limited to first-order for everything emanating from any discontinuity (Majda & Osher 1977). Further more nonlinear systems of equations will invariably and inevitably create discontinuities spontaneously (Lax 1973). In spite of these realities the accuracy of solutions with shocks still matters, yet no one ever measures it. The reasons why it matter are far more subtle and refined, and the impact of accuracy is less pervasive in its victory. When a flow is smooth enough to allow high-order convergence, the accuracy of the solution with high-order methods is unambiguously superior. With smooth solutions the highest order method is the most efficient if you are solving for equivalent accuracy. When convergence is limited to first-order the high-order methods effectively lower the constant in front of the error term, which is less efficient. One then has the situation where the gains with high-order must be balanced with the cost of achieving high-order. In very many cases this balance is not achieved.
se. Everyone knows that the order of accuracy cannot be maintained with a shock or discontinuity, and no one measures the solution accuracy or convergence. The problem is that these details still matter! You need convergent methods, and you have interest in the magnitude of the numerical error. Moreover there are still significant differences in these results on the basis of methodological differences. To up the ante, the methodological differences carry significant changes in the cost of solution. What one finds typically is a great deal of cost to achieve formal order of accuracy that provides very little benefit with shocked flows (see Greenough & Rider 2005, Rider, Greenough & Kamm 2007). This community in the open, or behind closed doors rarely confronts the implications of this reality. The result is a damper on all progress.
assessment of error and we ignore its utility perhaps only using it for plotting. What a massive waste! More importantly it masks problems that need attention.
In the end shocks are a well-trod field with a great deal of theoretical support for a host issues of broader application. If one is solving problems in any sort of real setting, the behavior of solutions is similar. In other words you cannot expect high-order accuracy almost every solution is converging at first-order (at best). By systematically ignoring this issue, we are hurting progress toward better, more effective solutions. What we see over and over again is utility with high-order methods, but only to a degree. Rarely does the fully rigorous achievement of high-order accuracy pay off with better accuracy per unit computational effort. On the other hand methods which are only first-order accurate formally are complete disasters and virtually useless practically. Is the sweet spot second-order accuracy? (Margolin and Rider 2002) Or just second-order accuracy for nonlinear parts of the solution with a limited degree of high-order as applied to the linear aspects of the solution? I think so.
When one is solving problems involving a flow of some sort, conservation principles are quite attractive since these principles follow nature’s “true” laws (true to the extent we know things are conserved!). With flows involving shocks and discontinuities, the conservation brings even greater benefits as the Lax-Wendroff theorem demonstrates (
variables don’t). The beauty of primitive variables is that they trivially generalize to multiple dimensions in ways that characteristic variables do not. The other advantages are equally clear specifically the ability to extend the physics of the problem in a natural and simple manner. This sort of extension usually causes the characteristic approach to either collapse or at least become increasingly unwieldy. A key aspect to keep in mind at all times is that one returns to the conservation variables for the final approximation and update of the equations. Keeping the conservation form for the accounting of the complete solution is essential.
The use of the “primitive variables” came from a number of different directions. Perhaps the earliest use of the term “primitive” came from meteorology in terms of the work of Bjerknes (1921) whose primitive equations formed the basis of early work in computing weather in an effort led by Jules Charney (1955). Another field to use this concept is the solution of incompressible flows. The primitive variables are the velocities and pressure, which is distinguished from the vorticity-streamfunction approach (Roache 1972). In two dimensions the vorticity-streamfunction solution is more efficient, but lacks simple connection to measurable quantities. The same sort of notion separates the conserved variables from the primitive variables in compressible flow. The use of primitive variables as an effective approach computationally may have begun in the computational physics work at Livermore in the 1970’s (see e.g., Debar). The connection of the primitive variables to classical analysis of compressible flows and simple physical interpretation also plays a role.
Now we can elucidate how to move between these two forms, and even use the primitive variables for the analysis of the conserved form directly. Using Huynh’s paper as a guide and repeating the main results one defines a matrix of partial derivatives of the conserved variables,
So before getting to all the things fucking everything up, let’s talk about why the job should be so incredibly fucking awesome. I get to be a scientist! I get to solve problems, and do math and work with incredible phenomena (some of which I’ve tattooed on my body). I get to invent things like new ways of solving problems. I get to learn and grow and develop new skills, hone old skills and work with a bunch of super smart people who love to share their wealth of knowledge. I get to write papers that other people read and build on, I get to read papers written by a bunch of people who are way smarter than me, and if I understand them I learn something. I get to speak at conferences (which can be in nice places to visit) and listen at them too on interesting topics, and get involved in deep debates over the boundaries of knowledge. I get to contribute to solving important problems for mankind, or my nation, or simply for the joy of solving them. I work with incredible technology that is literally at the very bleeding edge of what we know. I get to do all of this and provide a reasonably comfortable living for my loved ones.
art of these systematic control mechanisms at play is the growth of the management culture in all these institutions. Instead of valuing the top scientists and engineers who produce discovery, innovation and progress, we now value the management class above all else. The managers manage people, money and projects that have come to define everything. This is true at the Labs as it is at universities where the actual mission of both has been scarified to money and power. Neither the Labs nor Universities are producing what they were designed to create (weapons, students, knowledge,). Instead they have become money-laundering operations whose primary service is the careers of managers. All one has to do is see who are the headline grabbers from any of these places; it’s the managers (who by and large show no leadership). These managers are measured in dollars and people, not any actual achievements. All of this is enabled by control and control enables people to feel safe and in control. As long as reality doesn’t intrude we will go down this deep death spiral.
recognize is the relative simplicity of running mediocre operations without any drive for excellence. Its great work if you can get it! If your standards are complete shit, almost anything goes, and you avoid the need for conflict almost entirely. In fact the only source of conflict becomes the need to drive away any sense of excellence. Any hint of quality or excellence has the potential to overturn this entire operation and the sweet deal of running it. So any quality ideas are attacked and driven out as surely as the immune system attacks a virus. While this might be a tad hyperbolic, its not too far off at all, and the actual bull’s-eye for an ever growing swath of our modern world.
We see a large body of people in society who are completely governed by fear above all else. The fear is driving people to make horrendous and destructive decisions politically. The fear is driving the workplace into the same set of horrendous and destructive decisions. Its not clear whether we will turn away from this mass fear before things get even worse. I worry that both work and politics will be governed by these fears until it pushes us over the precipice to disaster. Put differently, the shit show we see in public through politics mirrors the private shit show in our workplaces. The shit is likely to get much worse before it gets better.
Stability is essential for computation to succeed. Better stability principles can pave the way for greater computational success. We are in dire need of new, expanded concepts for stability that provides paths forward toward uncharted vistas of simulation.
nstability at Los Alamos during World War 2. This method is still the gold standard for analysis today in spite of rather profound limitations and applicability. In the early 1950’s Lax came up with
the equivalence theorem (interestingly both Von Neumann and Lax worked with Robert Richtmyer,
methodology using Mathematica,
Hyperbolic PDEs have always been at the leading edge of computation because they are important to applications, difficult and this has attracted a lot of real unambiguous genius to solve it. I’ve mentioned a cadre of genius who blazed the trails 60 to 70 years ago (Von Neumann, Lax, Richtmyer
he desired outcome is to use the high-order solution as much as possible, but without inducing the dangerous oscillations. The key is to build upon the foundation of the very stable, but low accuracy, dissipative method. The theory that can be utilized makes the dissipative structure of the solution a nonlinear relationship. This produces a test of the local structure of the solution, which tells us when it is safe to be high-order, and when the solution is so discontinuous that the low order solution must be used. The result is a solution that is high-order as much as possible, and inherits the stability of the low-order solution gaining purchase on its essential properties (asymptotic dissipation and entropy-principles). These methods are so stable and powerful that one might utilize a completely unstable method as one of the options with very little negative consequence. This class of methods revolutionized computational fluid dynamics, and allowed the relative confidence in the use of methods to solve practical problems.
need is far less obvious than for hyperbolic PDEs. The truth is that we have made rather stunning progress in both areas and the breakthroughs have put forth the illusion that the methods today are good enough. We need to recognize that this is awesome for those who developed the status quo, but a very bad thing if there are other breakthroughs ripe for the taking. In my view we are at such a point and missing the opportunity to make the “good enough,” “great” or even “awesome”. Nonlinear stability is deeply associated with adaptivity and ultimately more optimal and appropriate approximations for the problem at hand.
Further extensions of nonlinear stability would be useful for parabolic PDEs. Generally parabolic equations are fantastically forgiving so doing anything more complicated is not prized unless it produces better accuracy at the same time. Accuracy is imminently achievable because parabolic equations generate smooth solutions. Nonetheless these accurate solutions can still produce unphysical effects that violate other principles. Positivity is rarely threatened although this would be a reasonable property to demand. It is more likely that the solutions will violate some sort of entropy inequality in a mild manner. Instead of producing something demonstrably unphysical, the solution would simply not have enough entropy generated to be physical. As such we can see solutions approaching the right solution, but in a sense from the wrong direction that threatens to produce non-physically admissible solutions. One potential way to think about is might be in an application of heat conductions. One can examine whether or not the flow of heat matches the proper direction of heat flow locally, and if a high-order approximation does not either choose another high-order approximation that does, or limit to a lower order method wit unambiguous satisfaction of the proper direction. The intrinsically unfatal impact of these flaws mean they are not really addressed.