Asked by: Sree Subject: Physics Question: Actually what is spin? How it is consider as 1/2 , 1 etc. What is its physical significance . --------------------------------------------------------------------- Visitor Ip: 115.69.128.208
spin is an intrinsic property like mass or charge .Intrinsic properties can be measured or experienced , its origion is mysterious . why an electron has got a mass or charge.these questions are still unanswerable.same is the case with spin .spin has nothing to do with spin about an axis .It is purely a quantum effect .But it produces same effect as when a body spins about its own axis ie spin angular momentum . Spin of the electron is selected to 1/2 to match with experimental observations like stern gerlach experiment. But it can be theoretically prooved using relativistic quantum mechanics. spin is related with the symmetry of the wavefunction. its physical significance is evident from magnetic effects.
spin is the intrinsic property of the elementary particle, or material or an object. it arises due to the quantum numbers. quantum NUMBERS occurs due to the schrodinger s wave eqation naturally
The astronomical analogy is the earth revolving around the sun in one year but simultaneously turning around its own axis within one day. The total angular momentum of the earth is the orbital angular momentum plus the "spin" of the earth. Similarly, the electron of the hydrogen atom has for l > 0 an orbital angular momentum l = rxp and in addition its spin s Einstein–de Haas Effect Einsteinproposed the following experiment in order to gain insight into the causes of magnetic properties of solids. It was actually performed some years later by the Dutch physicist Wander Johannes de Haas (1878–1960). An iron cylinder with mass m and radius R hangs on a thin wire in a vertical magnetic field B = {0, 0, B z}, produced by an electric current through a coil. The magnetic field was chosen sufficiently strong to saturate the magnetization
M= Nµ of the cylinder withN free electrons, each possessing the magnetic moment µ. In cases of saturation, all magnetic moments point in one direction opposite to that of the magnetic field. Since the free electrons in the conduction band of iron have no orbital angular momentum and therefore also no orbital magnetic moment (there is no force center to cause a circular motion of the electrons) the magnetic moment must have another reason. We will see that it is caused by the spins of the free electrons.
spin is an intrinsic property like mass or charge .Intrinsic
properties can be measured or experienced , its origion is
mysterious . why an electron has got a mass or charge.these questions
are still unanswerable.same is the case with spin .spin has nothing to
do with spin about an axis .It is purely a quantum effect .But it
produces same effect as when a body spins about its own axis ie spin
angular momentum . Spin of the electron is selected to 1/2 to match
with experimental observations like stern gerlach experiment. But it
can be theoretically prooved using relativistic quantum mechanics.
spin is related with the symmetry of the wavefunction. its physical
significance is evident from magnetic effects.