semiclassical approach

Examples of semiclassical approach in the following topics:

• Quantum-Mechanical View of Atoms

  • Bohr's model successfully explained spectroscopic data of hydrogen very well, but it adopted a semiclassical approach where electron was still considered a (classical) particle.

• The Bohr Model of the Atom

  • Therefore, his atomic model is called a semiclassical model.

• Energy, Mass, and Momentum of Photon

  • Max Planck explained black body radiation using semiclassical models, in which light is still described by Maxwell's equations, but the material objects that emit and absorb light, do so in amounts of energy that are quantized.

• Relativistic Energy and Mass

  • In special relativity, as the object approaches the speed of light, the object's energy and momentum increase without bound.
  • As the object approaches the speed of light, the object's energy and momentum increase without bound .
  • As the velocity increases toward the speed of light (c), the denominator of the right side approaches zero, and consequently approaches infinity.
  • The relativistic kinetic energy increases to infinity when an object approaches the speed of light, this indicates that no body with mass can reach the speed of light.

• A General Approach

  • Your approach to problem solving can involve several key steps.

• Relativistic Momentum

  • As one approaches the speed of light, however, relativistic momentum becomes infinite while Newtonian momentum continues to increases linearly.
  • This figure illustrates that relativistic momentum approaches infinity as the speed of light is approached.
  • Compare Newtonian and relativistic momenta for objects at speeds much less and approaching the speed of light

• Thermal Radiation

  • We know that as light travels through the material the intensity field should approach the source function but we also know that the light emerging from the window must have $I_\nu=B_\nu(T)$.
  • A thermal emitter has $S_\nu = B_\nu(T)$,$B_\nu(T)$ so the radiation field approaches $B_\nu(T)$ (blackbody radiation) only at large optical depth.

• Relativistic Kinetic Energy

  • The equation shows that the energy of an object approaches infinity as the velocity $v$ approaches the speed of light $c$.
  • Compare classical and relativistic kinetic energies for objects at speeds much less and approaching the speed of light

• The Third Law

  • In simple terms, the third law states that the entropy of a perfect crystal approaches zero as the absolute temperature approaches zero.

• Helical Motion

  • Charged particles approaching magnetic field lines may get trapped in spiral orbits about the lines rather than crossing them, as seen above.
  • Those particles that approach middle latitudes must cross magnetic field lines, and many are prevented from penetrating the atmosphere.