have before me a copy of Nelson & Williams's 1200 page book Infectious
Disease Epidemiology: Theory and Practice, which has a big chapter on the SIR
(susceptible–infected–recovered) model. Mathematical models, they say
repeatedly, are only toys to aid in understanding:
Mathematical models are supposed to aid in the educational process and not simply be “black boxes” that produce answers. For conceptual understanding, a limited number of assumptions are an advantage. [p. 207]
In an SIR model, there is no provision for the tendency of viruses to mutate so as not to kill their host. Nor do models account for human behavior. Yet we're still seeing epidemiologists predicting cycles of disease and death that repeat seasonally ad infinitum. We will, they say, have to hunker down in isolation for years—until the next deadly virus comes flying from somewhere like a bat out of hell.
Even in particle physics, where the human element is totally removed, no one trusts computer models. Physicists don't even trust the mathematics the models are based on until it's verified experimentally. If there is one thing scientists agree on, it's that it's impossible to obtain new knowledge from a computer model. Anthony Fauci knew this: in his 2750-page book Harrison's Principles of Internal Medicine, there is not a single computer model. He'd be guilty of malpractice to use one.
Epidemiologic models are no more science than are the models in economics or climate studies. They provide hypotheses, and they're useful to test whether our assumptions can account for the observed facts, but they can never provide new facts.
The dilemma that modelers face is not that computer models are always wrong, though we all know Ferguson's model was spectacularly wrong in the COVID-19 case; it's that models are effectively partial differential equations, which (if you had introductory calculus) assume everything but what we're interested in remains constant. Sadly, that doesn't happen.
Economics has its homo economicus who always spends his money wisely, and epidemiology has its virus epidemiologicus, which is an imaginary virus that never mutates, infects people just as well in the summer when it's humid as in the winter when it's not, and has a fixed basic reproduction number that never changes. The population is composed of interacting groups of varying density, but they never change their behavior. This gives epidemiology an aura of being mathematically provable and therefore authoritative.
And that is just what political activists want. If they can convince the public that their apocalyptic predictions are backed by scientific evidence, they can use the news media to stampede people into doing what they want. Of late people have taken to using the expression “The Science” as a way of clubbing their opponents over the head. If “The Science” says something, it is true, and you are a Covidiot or a virus denier or a climate denier or some other kind of denier if you question it.
Well, people crave power, and they will lie and misrepresent science to acquire it. We give climate activists like Greta Thunberg a break because she's young and cute and she missed a lot of school. But no one should consider her or anyone else as a source of authority just because they claim “The Science” backs them up. Science is but a tool and the knowledge it produces is a fickle friend.
Science today has many problems. I'm old enough to remember when scientists worked by thinking about problems, deciding on a hypothesis, and then doing experiments. That has changed. Nowadays the first step is to look on the government's web page and read the program announcements. You choose what your next project will be on the likelihood of spinning your existing project into something the government wants.
These days the job of an academic scientist is to discover what the customer—the US government—wants. Our job is to bring in grants, preferably R01s, that pay for our salary, our assistants' salary, and the salaries of all the bureaucrats and diversity manglers at the university. Having a grant is now essential: it's nearly impossible to get an academic position without one. We are no longer seekers of truth; we are seekers of government money.
The NIH's Center for Scientific Review doesn't have a suggestion box, and they discourage researchers from contacting them for any reason. The purpose is to avoid grant-seekers from trying to manipulate the system. But it also means that we're often herded into asking the wrong questions using the wrong techniques. That might explain the lack of progress on so many diseases.
Another rule we all abide by is never to criticize a fellow scientist. Doing so would not only invite retribution, it would turn science into a mirror image of Twitter. So for decades we had to bite our tongues while people nattered on about how eating a single egg could kill you because it contained cholesterol. The Science was settled, bloodied tongues notwithstanding, until one day it wasn't. Silence among scientists does not signify agreement, nor does the number of papers on a topic mean it's not a dead end. Often quite the opposite.
Even if science were done properly, it isn't some infallible Oracle of Delphi that gives us the truth. It is not a source of authority. It's a way of asking questions. We do that by holding innocent little molecules down and torturing them to give up their secrets one at a time. When scientists depart from that, either by asking the questions the funding agencies are willing to pay for or by avoiding empirical measurements altogether, they can still produce answers. Those answers may be opinions or computer fantasies. They might even be true. But they won't be science.
may 10 2020, 12:03 pm
