From: utzoo!decvax!cca!KATZ@USC-ISIF@sri-unix Newsgroups: net.space Title: Re: SPACE Digest V2 #261 Article-I.D.: sri-unix.2442 Posted: Wed Aug 4 12:49:06 1982 Received: Thu Aug 5 04:42:51 1982 From: Alan R. KatzIT IS NOT TRUE that in a tunnel diode the electrons move from one place to another without occupying the intervening space. The electrons DO occupy the intervening space (their wave functions do). I have heard this in many science fiction stories (and pseudo-science books) and it shows a complete misunderstanding of quantum mechanics (although it sounds neat in an SF story). Classically, it would be impossible for an electron of a given energy to cross a certain barrier, however, quantum mechanically, there is a finite (but small) probability that the electron does cross it. Since there are many electrons, some of them do get through even though according to classical mechanics (which is wrong in this regime) they should not. The electrons that do get through had their wave function transmitted through the barrier (its like a similar effect with light waves). Alan -------