As editor of Here's one shared by our senior staff reporter Frank Esposito, who is enjoying the beginning of a second week of sub-freezing temperatures in Akron, Ohio.
Frank points out that the wind-chill formula, "the weatherman's favorite alarmist statistic," has a plastics angle! More than 60 years ago, Antarctic explorers Paul Siple and Charles Passel left plastic bottles of water outside in the wind and observed the rate at which they froze. Their equation used wind speed and air temperature to describe the rate at which the bottles gave off heat, expressed in watts per square meter.
These days meteorologists use more complex formulas that, they believe, more accurately measure how wind speed and temperature feel to human skin.
Still, the lead story on Slate.com today explores the "gaudy negative numbers" that result from calculating wind chills, and suggests that we stop trying to perfect the equation.
The old system might have overstated the numbers when it said that 5 degrees could feel like minus 40. But after three decades of practice, we all got pretty good at translating from the outrageous numbers in the weather reports to our own experience. When the weather service recalibrated the system in 2001, we had to start all over and rebuild our frame of reference from scratch.Rather than trying to patch up wind chill's inconsistencies, we should just dump it altogether. The best algorithm we'll ever have for determining how cold it feels comes from our own experience.
I'm ready to chuck the equation, and the experience factor too, and spend the next couple of months in Florida. Can I get someone to shovel my sidewalk when I'm gone?
Comments (2)
What was the plastic? 60 years ago there were a few PE bottles made, no HDPE, probably very brittle in Antarctic temps. I wonder how they could tell when the inside was completely frozen.
Re windchill factor, the wind IS important in heat transfer from the bottle, and the commenter was just giving another example of how people resent numbers as they may challenge their personal reactions. For the rest of us who are still indoors when we hear the weather news, it gives us a standard to live (dress) by. That numerophobia has profound relevancy in daily life, including "environmentalists" who don't want to see evidence of plastics' environmental values.
Posted by allan griff | February 13, 2007 9:18 AM
Posted on February 13, 2007 09:18
Speaking of numerophobia, I have a blog that shows mold designers how to engineer better molds. The address is http://moldengineering.blogspot.com/
I do have software to sell, BUT the information on the blog is free. The above URL will take you there, if you are interested.
Posted by R. Huber | February 13, 2007 12:28 PM
Posted on February 13, 2007 12:28