从前有只鸟停留在鲁国都城郊外,鲁君很喜爱它,用牛羊猪三牲俱备的规格来款待它,还奏起韶乐,要使它快乐,鸟儿却黯然神伤,头晕目眩,不敢吃东西,这是用别人供养自己的方法来养鸟。真正养鸟的方法,应该是让它栖息在深林,飞翔在江湖之上,让它吃鳅鱼,自由自在地漫步在山野,那么一块平地就够了。
在量子力学的领域里,观察者和被观察者密不可分,这对我们关于现实的经典观念提出了挑战。
The alternation of motion is ever proportional to the motive force impressed; and is made in the direction of the right line in which that force is impressed.