Atomic Precession modified 20120101
Faraday's Disk Generator
Faraday's disk generator and motor demonstrate the key components of forces, tangent velocity, magnetic field and current or moving charge all being perpendicular in three direction. Torques are also perpendicular in these three directions as in Euler's equations.
Larmor precession - Click figure to animate!
When Larmor precession occurs in an MRI, tissues absorb energy from the resonant radio wave which forces them into a high energy state, spin red up where the magnetic fields repell each other. As the tissues return to a lower energy state, spin red down where the magnetic fields attract each other, they radiate the energy as radio waves which form the image. Dr. Hornak has a great MRI site which suggested this graphic. When the energy of a photon matches the energy difference between the two spin states of an electron, proton or atom an absorption of energy may occur. Likewise, when the spin state goes from a higher to a lower energy a photon is emitted, again with this same energy. The energy is absorbed or emitted to make a transition between the spin up and spin down states or a spin flip. One can also see a spin flip as a rotation or a precession. See forces due to moving charge.
I recognize my son's profile in his MRI
This is an everyday example of precesssion so precession is real. The energy in an MRI is at Planck's frequency and at the gyromagnetic ratio. We can see that it is very closely related to the classical Faraday disk generator above. This is similar to the emitted and absorbed photon in the Bohr atom. For hydrogen the
gyromagnetic ratio = 42.58 MHz/T, megahertz per Tesla
energy = h*frequency, Planck's law
frequency = gyromagnetic ratio*B, resonance frequency
energy = h*gyromagnetic ratio*B, substituted for frequency
Precession
Why are atoms spheres? Dipoles, rotation, torque and precession.
Gyroscopes precess when subject to torques. Rings and rotating dipoles can be gyroscopes. A twirling baton is seen airborne and rotating.
Precession in atoms is a part of our everyday world. It is seen in microwave ovens and medical scanners.
The electron and proton orbital rings must precess like gyroscopes into spheres for us to see them as spherical atoms on scanning tunneling electron microscope pictures.
Slightly elliptical orbital rings precess into ellipsoids with oppositely charged ends which stick together like the atoms do in these same pictures.
Precession in electron and proton binary atoms or dipoles - Click figure to animate!
When you apply a tilting torque to a gyroscope, like pushing down on the N - in the figure, it precesses in a direction perpendicular to both the axis of the tilting torque and perpendicular to the axis of rotation.
We are looking down on the axis of rotation. Electrons orbit around the red and pink ellipse. Dipoles rotate into ellipses. When they are in the presence of a charge they experience a tilting torque around the short axis of the ellipse which tries to align the north and south poles of the ellipse with the charge like a compass aligns with a magnet. This tilting torque which is perpendicular to the long dipole axis of the ellipse and perpendicular to the axis of rotation produces a rolling precession around the long north-south axis of the ellipse. The ellipse rolls around its longest axis. The atoms precess like beads rolling on a string. A polarized elliptical ring precesses into a rolling polarized ellipsoid in the presence of a charge. We see them as polarized atoms. The atom which is a bipolar ellipsoid, prolate spheroid and dipole, aligns with charges. The opposite charges on each end of the atoms attract each other so the atoms stack in rows and columns.
The poloidal magnetic field is parallel to the axis of rotation of the electron and proton rings. The axis of rotation and the magnetic field rotates with the precession and is blurred by the precession, to a blinking north-south-north-south. This is like Larmor precession. This is similar to the description of helical electromagnetic waves. They can be described by Euler's equations.
Two ways of shaping orbiting charges into spheres - Click figure to enlarge!
In the left figure - the north and south poles are where the spirals start and stop. The polar angle only goes from zero to pi, we have not shown the return path from pi to two times pi. The equatoral angle makes many loops of two times pi. This is slightly like the way charges oscillate in magnetic bottles in the Van Allen belt. The charges loop around and reverse direction at each end of their spiral path between the poles.
In the right figure - The north and south poles are where the blue and red are concentrated, where the orbital planes intersect. The charges orbit in a slightly twisted plane which includes the polar axis, as they orbit they precess around the polar axis, just like a gyroscope, as we have seen in the previous animation. As the orbital plane precesses around the polar axis, it carries with it the magnetic field like Larmor precession.
