近年来国外的超光速实验

近10年来,多国科学家进行了微波及光脉冲的超光速传播实验,其中不少实验是利用所谓量子隧穿效应而实现超光速的,而意大利科学家则在微波和开放自由空间条件下在短距离上完成了超光速实验.2001年8月,J.Webb等人报告了对精细结构常数α的变化的研究结果,该研究是根据对类星体的观测,所分析的光是宇宙早期时天体发出的光;分析发现那时的α较小(故c较大)等等.笔者对超光速实验作了较详尽报道.还讨论了关于超光速相速实验方面的一些新情况.

Faster-than-light (Superluminal)Experimental Resarches in Last Decade

In last decade, faster-than-light (superluminal) propagation of microwaves or light pulses has been studied experimentally in several countries. Many of the attempts to send pulses faster than the speed of light involved a phonomenon called quantum tunneling,but the Italian scientists made measurements of pulse delay in microwave band in open free space on short distances. And then,in Aug. 2001 J. Webb et. al. describe the results of a search for time variation of the fine structure constant (a) in the spectra of distant quasars,each sample yields a smaller a (then a larger c) in the past of the universe, etc. In this paper,We give a bird-eye view of the experimental situation on faster-than-light (superluminal) subject in detail. Finally,the new experiments to superluminal phase velocity recently are described.