布洛赫教授告诉过你如何在一滴水中探测到磁原子核的进动。尽管这样的实验在我们的实验室里已经司空见惯，但我还没有失去一种惊奇和喜悦的感觉，即这种微妙的运动应该存在于我们周围的所有普通事物中，只向寻找它的人展示它自己。我记得，就在七年前我们第一次实验的冬天，用新的眼睛观察雪。那里的雪覆盖着我的门前台阶——巨大的质子堆在地球磁场中静静地前进。把这个世界看作是一个丰富而奇怪的东西，这是许多发现的私人回报。但我担心这与我们作为物理学家必须问自己的一个严肃问题没有什么关系：我们能从这一切中学到关于物质结构的什么？

Professor Bloch has told you how one can detect the precession of the mag- netic nuclei in a drop of water. Commonplace as such experiments have become in our laboratories, I have not yet lost a feeling of wonder, and of delight, that this delicate motion should reside in all the ordinary things around us, revealing itself only to him who looks for it. I remember, in the winter of our first experiments, just seven years ago, looking on snow with new eyes. There the snow lay around my doorstep - great heaps of protons quietly precessing in the earth‘s magnetic field. To see the world for a moment as something rich and strange is the private reward of many a discovery. But I am afraid it has little bearing on the sober question we must, as physicists, ask ourselves: What can we learn from all this about the structure of matter?