November 16th, 2005
I just finished reading this Reuters story, “Rising Sea Levels Threaten New Jersey.” Nevermind the obvious question of whether we’d really be menaced by the disappearance of New Jersey. I would like to focus on details tangential to the main story, as is my custom.
Notice the next-to-last paragraph,
Worldwide, sea levels are expected to rise between 0.09 and 0.88 meter (0.29 and 2.88 feet) between 1990 and 2100, the report said, citing figures from the Intergovernmental Panel on Climate Change.
Do you see anything amiss? Many scientists and engineers in the audience have already leapt out of their seats. I will explain the problem anyway, for those of you trained in the humanities.
The issue is one of precision. Or rather, too much of it.
What most likely occurred is that the Journalism major who wrote this lifted the metric figures from the published paper. Writing for a U.S. audience, he obviously needed English equivalents.
If you plug 0.09 and 0.88 meters through a conversion calculator, you get 0.29527559055118110236220472440945 feet and 2.8871391076115485564304461942257 feet, respectively. The author made the rookie mistake of cutting these off at the same number of decimal places.
This author, like most reporters, does not understand significant figures. The trouble is that the metric numbers quoted give one and two significant digits, respectively. His converted numbers erroneously give two and three significant digits.
I have gone to the trouble of rewriting his paragraph for him.
Worldwide, sea levels are expected to rise between 0.09 and 0.88 meter (0.3 and 2.9 feet) between 1990 and 2100, the report said, citing figures from the Intergovernmental Panel on Climate Change.
You may think that this is a silly thing for me to be complaining about. Not so. Significant digits are one of the first lessons in every science class, from elementary school through the first few semesters of college. Anyone doing science reporting should at least be familiar with significant digits.
Given this, it is not difficult to understand why there is so much confused and idiotic coverage of the Dover Design trial (I am on board with refusing to call it “Intelligent”) and why it is reported at least once a year that the speed of light has been exceeded (Everyone say it together with me: “Phase velocity vs Group velocity”).