John Bartlit: Curiosity is an eagle-eyed scout

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A  mighty whirlwind who shed Dorothy and Toto from Kansas to a colorful land far away. Adventures in Oz led Dorothy to see the truth back home more clearly than she had before.   

Mars teaches as smartly as Oz.     

This spring, I heard a popular talk in town on “Exploring Mars with Curiosity and Its Laser,” by Dr. Roger Weins, the project leader for the ChemCam laser that zaps red rocks on Mars to learn about them. 

We saw how the one-ton rover Curiosity is commanded to rove on its six wheels over the red landscape. The fastest it can move is less than 0.1 mph. 

We learned about the 10 instruments on board the rover for probing the Martian environment. The environment has countless parameters we want to know.

Work time on Mars is scarce and costly. The working life of Curiosity’s instruments is limited to two years or possibly as long as five or eight years.
The problem is clear. How should the instruments be designed and utilized so their work time on Mars produces the most data of the most value? 

The answer comes from a systems approach. Each instrument has one of three broad functions, which work together as an efficient overall system.
Some instruments are designed and used to make many good readings quickly. Other instruments are used to get better data, which takes longer to do. 

A few instruments acquire the most accurate information, which takes the most time.
The large range of fast, good data shows where better data would answer a key question. 

Only the most crucial data are measured to the best accuracy and precision, which takes the most time. 

Picture the system as a “funnel” of knowledge. The first level gathers initial data of wide scope. The second level of data takes a narrower look where more accuracy helps. The third level has the tightest focus and the best accuracy. 

The solution used on Mars to get the most value from time and money would do the same for regulatory resources on Earth.  

Companies now spend substantial time and money routinely acquiring the best quality data on emissions from exhaust stacks, even when the findings say emissions are always far below any permitted limit. 

These unproductive data could be replaced with a wider variety of good, fast, cheaper stack testing coupled with fewer of the slow, high-cost tests where having the best accuracy has little use. Systems thinking would produce more new knowledge of more value, at less cost. 

Indeed, the Mars plan makes even more sense on Earth, because of the tools we have for setting legal pollution limits. Limits of pollution are decided by the current laws of courts and laws of science.

The science used is epidemiology, which is the study of the effects on health that given levels of each pollutant have on populations.

The complexities met include the great variety of pollutants, the variety of populations, the throngs of health factors in people, and the endless combinations possible. Complete answers cannot keep up with new questions. 

Science deals with these obstacles by estimating uncertainties and adding margins of safety. 

In this way, a legal limit is drawn using current science. As with all science, new data will show new ways to learn more as time goes on.

The law treats every line drawn as an exact line between fine and foul. In epidemiology, no line drawn is this exact. 

This fact of science is a strong reason not to waste time and money just to know whether a plant’s emissions are half the legal limit or one-third of it. A fraction of the resources could be better used inventing efficient systems for inspecting. 

Exotic lands can give a strangely clear view of workaday things near us.