科學圖說

螢軌與車軌(Firefly and Headlight Trails)

人的眼睛，無法看見經過一段時間累加的軌跡，但相機可以經過長時間拍攝，捕捉一段時間內發生的畫面。夜間肉眼看見螢火蟲一閃一閃發光，但只能看到一個光點，透過攝影捕捉，就能看到一條光軌。路過的車燈也因為長時間曝光，出現一道車軌的光影。

It is not possible for the unaided human eye to see a light trail. However, through time-lapse photography, such trails can be captured. At night, the light pattern produced by fireflies flashes, but we can only see single light points. Through a camera, firefly light trails can be observed. However, car headlights appeared as another light trail under time exposure.