Comparing Temperatures

Sam Byford, writing for The Verge, “Tests Show New iPad Runs Up to 18 Percent Hotter Than iPad 2”:

Dutch website has taken an infrared camera to the new iPad and revealed that it runs at up to 33.6 degrees Celsius (92.5 Fahrenheit) when running the GLBenchmark — that’s an 18.7 percent increase on the iPad 2, which reached 28.3 degrees Celsius (82.9 Fahrenheit).

As Alex Dedalus points out on Twitter, to say this is a crap headline is give crap headlines a bad name. Celsius and Fahrenheit are relative temperature scales, not absolute, so you can’t do percentage-based comparisons. Think about it: 33.6 / 28.3 gives you an “18.7 percent” increase, but if you do the math with the same temperatures in Fahrenheit, you get 92.5 / 82.9 = “11.6 percent” increase. If you really want to do a percentage based comparison, you need to convert to an absolute temperature scale like Kelvin, which shows you that it’s actually a 1.8 percent increase in temperature (306.75 / 301.45). This is middle school science.

That doesn’t make for a good Verge headline though, and neither would “5.3 degrees” (Celsius), so I suggest going with Fahrenheit — “Tests Show New iPad Runs Up to 10 Degrees Hotter Than iPad 2” — to maximize the sensational impact while still being technically true.

Tuesday, 20 March 2012