Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site watmath.UUCP Path: utzoo!watmath!csc From: csc@watmath.UUCP (Computer Sci Club) Newsgroups: net.physics Subject: Re: No pencil/no paper problem. Message-ID: <6875@watmath.UUCP> Date: Sat, 11-Feb-84 18:47:57 EST Article-I.D.: watmath.6875 Posted: Sat Feb 11 18:47:57 1984 Date-Received: Sun, 12-Feb-84 03:53:56 EST References: <165@hou2g.UUCP> Organization: U of Waterloo, Ontario Lines: 23 The Zeeman effect does not create new states, it changes the energy levels of existing states in such a way that states that before had the same energy level now have different energy levels. One of the quantum numbers that determines the state of an electron is the spin. It can have one of two values +1/2 or -1/2. Now for every combination of quantum numbers other than spin, there exists two STATES, one corresponding to each value of the spin quantum number. In the absence of an external field an electron in either of the states would have the same energy, reffered to as (twofold) degeneracy. This leads to the erroneous impression that two fermions can occupy any energy level. In fact only one electron can occupy each state. The number of electrons that can occupy a single energy level depends on the energy level of the states, which depend on many things, including external fields. In the presence of an external magnetic field two states which differ only in the spin quantum number no longer have the same energy level associated with them. (One gets slightly higher, the other slightly lower) However as no new states are created, if the lower energy states were full before the field was applied they will be full after the field is applied and electrons will not cascade down. William Hughes