Stupid size comparisons

Today’s Guardian contains this spectacular piece of idiocy. Speaking of a chunk of ice that fell off a glacier and caused a huge wave, they said:

The chunk of ice [was] estimated to be the size of four football pitches

First, a minor quibble. Not all football pitches are the same size. Four football pitches could be anything between 20,000 and 52,000 square yards. (Thats 16,000-43,000 m^2). That’s a pretty big margin of error, even for an estimate.

Second, much more major gripe. Chunks of ice are 3-dimensional. What does comparing it to an area, a 2-dimensional thing, even mean? Does that mean the area of glacier that was lost, as seen from above? If so, how thick was the ice below it? That makes a huge difference to how much stuff we are talking about.

Now, even if the ice were only a centimetre thick and we take the lower estimate for the area, that’s still 160,000 kg of ice. Which sounds a lot, but is an order of magnitude less than the weight of water in an olympic sized swimming pool (2.5m kg).

I bet there are whole websites dedicated to this kind of stupid size comparison thing. It sometimes comes up in New Scientist’s Feedback column…

This post brought to you by pedantry, my boundless capacity for procrastination and WolframAlpha.