dougettinger wrote:Art, you went to a lot of effort for this answer. It was much appreciated. However, it does cause some stupid questions. I never heard the term "anti-parallel". Is the meaning similar to the spin axes of the Sun and planet Uranus ? I know there is opposite spin: CW and CWW. What causes the switching of the hydrogen atoms from parallel to anti-parallel configuration?
Hi, Doug.
Mercury (Axial tilt ~ 2.11′ ) and the sun are in a parallel spin state.
Venus (Axial tilt ~ 177.3° ) and the sun are in an anti-parallel spin state.
<<The proton and electron of a hydrogen atom are both little spinning dipole magnets that interact with each other.
The excited higher energy state has the two spins going in the same direction (i.e., parallel).
The ground state energy state has the two spins going in the opposite direction (i.e., anti-parallel).
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An electron orbiting a proton with parallel spins (pictured)
has higher energy than if the spins were anti-parallel.
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Collisions with other hydrogen atoms and interaction with the cosmic microwave background are constantly mixing up these two neutral hydrogen atomic states such that there are roughly equal numbers of each state. However, every year one ten millionth of the excited parallel spin states will spontaneously decay to the ground anti-parallel thus radiating a 1420.4 MHz photon.>>
[quote="dougettinger"]Art, you went to a lot of effort for this answer. It was much appreciated. However, it does cause some stupid questions. I never heard the term "anti-parallel". Is the meaning similar to the spin axes of the Sun and planet Uranus ? I know there is opposite spin: CW and CWW. What causes the switching of the hydrogen atoms from parallel to anti-parallel configuration?[/quote]
Hi, Doug.
Mercury (Axial tilt ~ 2.11′ ) and the sun are in a parallel spin state.
Venus (Axial tilt ~ 177.3° ) and the sun are in an anti-parallel spin state.
<<The proton and electron of a hydrogen atom are both little spinning dipole magnets that interact with each other.
The excited higher energy state has the two spins going in the same direction (i.e., parallel).
The ground state energy state has the two spins going in the opposite direction (i.e., anti-parallel).
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[img]http://upload.wikimedia.org/wikipedia/en/thumb/3/31/HydrogenLineAntiParallel.png/300px-HydrogenLineAntiParallel.png[/img]
[b]An electron orbiting a proton with parallel spins (pictured)
has higher energy than if the spins were anti-parallel.[/b]
-----------------------------------------------------------------------------------
Collisions with other hydrogen atoms and interaction with the cosmic microwave background are constantly mixing up these two neutral hydrogen atomic states such that there are roughly equal numbers of each state. However, every year one ten millionth of the excited parallel spin states will spontaneously decay to the ground anti-parallel thus radiating a 1420.4 MHz photon.>>