Monday, August 13, 2007

Something I Thought I'd Share

Like most Americans, I'm comfortable with measuring temperatures in Fahrenheit and must less so in Celsius (or Centigrade if you prefer). If someone tells me it's 22 F I can translate that into "cold", 85 F as "warm" and 110 F as "crap it's hot". If I encounter a Celsuis temperature I'm much less certain, what's 28 C? Now my cell phone is equipped with a unit converter, but I'm not going to whip that out every time I need to do a conversion (I'm nerdy, but not THAT nerdy). I know the formula, multiply the Celsius temperature by nine-fifths and add 32, but multiplying by nine-fifths in your head is hard.

Well, here I offer to my readers (both of them) an easy method to convert Celsius to Farenheit in your head. I don't pretend it's original, the math works so I can hardly be the discoverer of it, but I've never seen it anyplace else before. You can use it with precise numbers to get a precise conversion, or you can use close-enough numbers to get an idea of what kind of temperature we're talking about.

Here goes: Take your Celsius temperture, double it, subtract ten percent, and add 32. Each of these steps is easy to do in your head especially if you're doing a close-enough conversion.

Let's do an example, 28 C. Doubling 28 gives us 56. Ten percent of 56 is 5.6, subtract that from 56 and you get 50.4, add 32 and you get 82.4. That's a precise conversion, exactly what you'd get using the usual formula (in fact you ARE using the usual formula, just doing so in a way that's easy to do in your head). Suppose you don't need an exact number, your British friend just told you it's 28 C today. Call it 30 C (close enough), double it to 60, subtract 6 (ten percent of 60) to get 54, add 32 and you get 86 and bear in mind that you're a little high (because you rounded your original number up). So you know it was pretty warm, but not extremely hot.

I told you I'm a nerd.

Wednesday, August 01, 2007

Junk Science

Each morning I pick up a free newspaper on the way to work, it gives me something to do on the subway. Yesterday’s newspaper contained an article stating that the number of tropical storms and hurricanes has been increasing, and that this increase is due to “human induced climate warming”, also known as “global warming”. It should come as no surprise that I consider the “science” of global warming to be sloppy at best and intentionally dishonest at worst, but let’s take a closer look.

The study in question gave a chart showing average yearly number of tropical storms and hurricanes for three time periods. First, from 1905 thru 1930 there were an average of 6 tropical cyclones and 4 hurricanes per year. From 1931 thru 1994 there were an average of 10 and 5, and from 1995 thru 2005 there were an average of 15 and 8 respectively. On the face of it one might be tempted to say something really is happening, that the number of storms has been increasing for the last hundred years.

Do you see anything wrong with those numbers? Before 1930 (the earliest timeframe reported) the most common method of identifying a storm was for a ship in the ocean to see it or get caught in it. Ship owners don’t like their vessels to get caught in hurricanes because they don’t make any money from cargo that’s at the bottom of the Atlantic Ocean. Shipping lanes, therefore, tend to avoid those areas where large-scale storms are more likely to form. For the first twenty-five years of the study (and the entire first data-point) the primary method for identifying storms intentionally avoiding being in a position to report the storm. Up until the 1960’s (half-way thru the second time period reported) storm identification still relied on ships and airplanes were also added to the mix. Airplanes also try to avoid large storms for the same reasons ships do, so while more storms could be identified and reported the means of identification still avoided the areas where they were most likely to have something to report. Only in the 1960’s did we begin to put weather satellites into orbit, and newer satellites have gotten more sophisticated and provide greater coverage. From 1995 thru 2005 (comprising only ten percent of the total time period reported on) we can now see a hurricane form anywhere in the world, for the first time we can be sure of a full and accurate count of the number of storms that form.

The scientific principle known as “Occam’s Razor” states that given two possible explanations the simpler one is likely to be the correct one. Apply that principle and ask yourself which is more likely given the information I provide above: are there really more hurricanes and tropical cyclones each year, or have there always been about the same number of storms but we’re now in a position to identify them all?