We say that "apples and oranges" can't be expressed as a ratio, and that's because mathematics is citrus-based and prejudiced against apples.  Note that "tangerine" and "tangent" share the same Latin source, "tangere" ("touching"); "satsumas" and "summations" are derived from the Latin "summa" ("highest"); "lemons" and "lemniscates" both come from the ancient Greek island of Lemnos.  It's worth pondering ("ponder" has the same Latin root as the Ponderosa lemon ["weigh"]) just how Ugli the citrus bias is, my little Clementine.