Astronomy and Spaceflight in Italian

The twenty-ninth entry is la radiazione di fondo cosmica, and the thing to look at is the last letter. English builds a term like this by stacking bare nouns in front of a head noun, « cosmic background radiation », and nothing in that string says whether « cosmic » belongs to « background » or to « radiation ». A reader who already knows the physics supplies the answer and never notices the gap. A reader who does not has to guess, and English offers no way of settling it. Italian cannot leave the question open. An adjective there carries gender and number, and it can agree with one noun only. Radiazione is feminine and fondo is masculine, so the -a of cosmica has fastened it to the radiation, while cosmico would have fastened it to the background and the phrase would say something else. The ending is not ornament. It is the bracket that English writes with nothing at all. The same test runs through the rest of this list: l’orbita terrestre bassa, il periodo orbitale, la sonda spaziale. Read the final vowel first, and the phrase sorts itself out before the meaning arrives.