If a light illuminates a certain space, its intensity at twice the distance is not twice as feeble, but two times two, equal four times, as feeble.
如果一个光源照亮某一个地方，这个地方距离光源越远，光照强度会越弱，但是光照强度并不是与光源距离等比例地减弱，就是说，距离延长两倍，光照强度并不是减弱两倍，而是减弱两倍的两倍，等于减弱四倍；
If a light illuminates a certain space, its intensity at twice the distance is not twice as feeble, but two times two, equal four times, as feeble.
如果一个光源照亮某一个地方，这个地方距离光源越远，光照强度会越弱，但是光照强度并不是与光源距离等比例地减弱，就是说，距离延长两倍，光照强度并不是减弱两倍，而是减弱两倍的两倍，等于减弱四倍；
应用推荐