青蛙悬浮——一个令人惊奇和充满遐思却只需经典物理知识的实验

Frog levitation: an astonishing and intriguing experiment but only requiring the knowledge of classical physics

利用力学平衡和电磁学方面的知识,系统讨论了电荷、电偶极子、电介质、磁偶极子和顺磁介质不能实现悬浮,而抗磁质介质能够实现稳定悬浮的原因.介绍了盖姆青蛙悬浮实验技术上的细节以及背后简单的物理知识.对青蛙磁悬浮的探讨,不但能引发学生对其应用前景一系列的遐想,也能加深对静电学与磁学知识的理解.

By using the basic knowledge of mechanics and electromagnetism,we discuss the reasons why a charged particle,electrical dipole,dielectric,magnetic dipole,or paramagnetic material can not be suspended stably in a field and why a diamagnetic material can.Further,we introduce the details of the frog levitation experiment,which has been carried out by Geim,and its background physics.The explorations of such problem will not only intrigue students regarding to its perspective applications but also deepen their understanding to electrostatics and magnetism.