Analog SFF, November 2011 by Dell Magazine Authors

Author:Dell Magazine Authors
Language: eng
Format: mobi, epub
Tags: Science Fiction
Publisher: Dell Magazines

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Department: THE ALTERNATE VIEW: INTELLECTUAL PROXIES

by Jeffery D. Kooistra

I have been reading Meditations by Marcus Aurelius lately (a free edition I got on my beloved Kindle), the Roman emperor from 161-180 a.d. who very much earned the reputation of “philosopher king.” I stumbled across a passage that struck a chord within me because it so resonated with events in my life that happened a dozen years ago this month. I will quote the passage later, but first, some preliminary discussion.

A proxy is a substitute, a stand-in, something you use when the real thing isn't available. Not everything used as a substitute is a proxy, though. If you use an artificial sweetener in your coffee because the sugar bowl is empty, that is a substitute but not a proxy for sugar. But if you use tree ring measurements to figure out what global temperature trends were like hundreds of years ago, either before thermometers were invented or because no one recorded temperatures in the region of interest with a thermometer at the time, then the tree ring data is a proxy for thermometer temperature measurements.

Before you use a substitute for what you actually wish you could use, you have to figure out just how sufficient a substitute your proxy is. This is not going to be another column about climate change, but I do want to use tree rings as an example for just a few more sentences. When you measure tree rings and calculate your averages, ideally the rings would yield the same set of average temperatures that a thermometer would have given you. You couldn't hope to have the uncertainties in the measurements be as good, of course, but in the end it is hoped that the proxy will accurately reflect reality. For instance, if the tree ring data shows a quantitatively degree-resolvable increase in temperatures over a hundred-year-long period, you want that to reflect what thermometers would have shown.

Now, I brought up tree ring proxies because they are both easy to understand and easy to misuse. Indeed, when used in producing the “hockey stick” global warming graph, that particular set of data negatively correlated with the mid-twentieth century instrument record. This led to the use of the programming “trick” that became the “hide the decline” controversy of the Climategate e-mails. Nevertheless, there is a rational scientific basis behind trying to use tree ring data as a temperature proxy, and tree rings are an adequate proxy for determining qualitative climate variations over time. One can follow the argument for why such data should work, and then it's just a matter of demonstrating, via hard work, that it, in fact, does. Unfortunately, in the hockey-stick case, wishful thinking was substituted for hard work and the rest is history.

In ordinary life it is also necessary to use proxies, and I call them intellectual proxies if they're being used as a stand-in for our own knowledge and expertise. This usually means relying on experts of one kind or another, but

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