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Article: Ask the experts.(particle spin)
- Article from:
- The Science Teacher
- Article date:
- December 1, 2005
CopyrightCOPYRIGHT 2005 National Science Teachers Association. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Q What does "spin" refer to in particle physics? Why is this concept necessary?
Danny, Student
Scottsburg High School
Scottsburg, Indiana
A To answer this question, let's start with some classical mechanic concepts. Angular momentum is the rotational analog of (linear) momentum. An everyday object that is spinning has angular momentum. If we attach electric charge to that spinning object, the circulating charge acts like a loop of current, and produces a magnetic dipole--a tiny electromagnet.
Because an electron has angular momentum and a magnetic dipole, it is natural to talk of its spin. Natural, but somewhat misleading, ...