【時文選讀】Just A Second 世界進步了「一秒」

    The flow of time is an enigma, but clock time is our own invention. When astronomer Christiaan Huygens invented the pendulum clock in the 17th century, a second became firmly established as 1/86,400 of a solar day. But the duration of Earth’s rotation varies by microseconds daily and a second gradually gets longer. That became a problem in the early 20th century, when experimental verification of quantum mechanics and the emergence of radio broadcasting required a steadier, more precise unit of time.

 

    人類無法解釋時間的流逝，但人類發明了時鐘來釐清時間。天文學家Christiaan Huygens在17世紀發明了擺鐘，此後一「秒」的時長被正式確定為一個太陽日的1/ 86400。但地球自轉的周期每天都在以微秒變化，一秒其實逐漸在拉長。這一現象在20世紀初期帶來了麻煩，彼時，驗證量子力學的實驗、播放無線廣播都需要一個更穩定而精準的計時單位。