title: 求助，这段英文如何翻译！23Thatmethodinvolves 
desc: That method involves searching for cetial objects, called “standard candles”, whose intrinsic brightness is known. The distance to such an object can be worked out by comparing its apparent brightness with its known, absolute brightness. The recession speed, meanwhile, revealThat method involves searching for cetial objects, called “standard candles”, whose intrinsic brightness is known. The distance to such an object can be worked out by comparing its apparent brightness with its known, absolute brightness. The recession speed, meanwhile, reveals itself through the so-called “redshift”. Light from a receding object appears to be of longer wavelength (i.e., redder) than it does from a stationary object, for the same reason (the Doppler effect) that the pitch of an ambulance siren drops when it moves away from you. The redder the light, the faster an object is receding.
answer: 这种方法的具体做法是找到被称为“标准烛光”的天体，这一类天体的固定亮度是已知的。通过比较表观亮度和已知的绝对亮度，即可得出该天体和我们的距离。天体的退行速度可通过所谓的“红移”法测出。退行的天体发出的光线波长比静止天体发出的光线更长（意味着光线更偏红）。这和一辆救护车远去时，它的笛声音高越来越低是一个道理（多普勒效应）。光线越红，说明天体退行的速度越快。