MadSci Network: Physics |
In the quantum mechanical harmonic oscillator, for which the classical analog is a point mass m attached to an ideal massless Hooke's Law spring with force constant k, the zero-point energy is 1/2 of Planck's reduced constant (h-bar) times the angular frequency of oscillation (omega) above the bottom of the parabolic potential well. Classically, omega is the square root of k/m. So as the mass increases in this model, the zero-point energy decreases. http://en.wikipedia.org/wiki/Zero-point_energy and http://en.wikipedia.org/wiki/Quantum_harmonic_oscillator For massless fields, like the electromagnetic field, there is a contribution to the vacuum energy of 1/2 h-bar omega for every photon frequency omega at each point in space. This leads to an infinite energy which is treated differently in quantum field theory and in general relativity, which are still not unified in physics. http://math.ucr.edu/home/baez/vacuum.html and http://en.wikipedia.org/wiki/Vacuum_catastrophe For massive fields, like the electron field, the quantum excitations are virtual particle-antiparticle pairs. The contribution to the vacuum energy is still infinite as in the case of massless fields. The difference is that the lowest energy excited mode of the vacuum is now twice the mass of the particle times the speed of light squared (when the virtual particle pair is created at rest) instead of an arbitrarily small frequency photon with energy close to zero. http://en.wikipedia.org/wiki/Virtual_particle --Randall J. Scalise http://www.physics.smu.edu/scalise
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