From Robert Stovoid
I liked the Feedback quote about hot air balloons from the “department of unusual units” (7 February). Right next to it in my Â鶹´«Ã½ newsletter was the following, also quoted on page 25 of the same issue: “Capacious crystal breaks roominess record: each gram of the new material has an internal surface area equivalent to 17 tennis courts.”
I for one welcome this comparison as I would like to see the old SI unit of area, which is of course the football pitch, replaced. Soccer pitches and American football pitches have different areas. Adopting the tennis court as the new SI unit will doubtless boost transatlantic co-operation between scientists.
Brighton, UK
