classical physics

Examples of classical physics in the following topics:

• Introduction: Physics and Matter

  • Physics is a natural science that involves the study of matter and its motion through space and time, along with related concepts such as energy and force .
  • Many concepts integral to the study of classical physics involve theories and laws that explain matter and its motion.
  • In fact, almost everything around you can be described quite accurately by the laws of physics.
  • Consider a smart phone; physics describes how electricity interacts with the various circuits inside the device.
  • Andersen explains the importance of physics as a science.

• Particle-Wave Duality

  • Wave–particle duality postulates that all physical entities exhibit both wave and particle properties.
  • Wave–particle duality postulates that all physical entities exhibit both wave and particle properties.
  • From a classical physics point of view, particles and waves are distinct concepts.
  • Photoelectric effect: Classical wave theory of light also fails to explain photoelectric effect.
  • Because of its counter-intuitive aspect, the meaning of the particle-wave duality is still a point of debate in quantum physics.

• The Bohr Model of the Atom

  • Bohr suggested that electrons in hydrogen could have certain classical motions only when restricted by a quantum rule.
  • From their sizes to their spectra, much was known about atoms, but little had been explained in terms of the laws of physics.
  • He suggested that electrons could only have certain classical motions:
  • In these orbits, the electron's acceleration does not result in radiation and energy loss as required by classical electrodynamics.
  • His many contributions to the development of atomic physics and quantum mechanics; his personal influence on many students and colleagues; and his personal integrity, especially in the face of Nazi oppression, earned him a prominent place in history.

• Further Reading

• Further Reading

• Further Reading

• Bibliography

  • Lectures on Physics.
  • Classical electromagnetic radiation.

• Atomic Structure

  • So far we have used classical and semi-classical approaches to understand how radiation interacts with matter.
  • We have generally treat the electrons (the lightest charged particle so the biggest emitter) classically and the radiation either classically or as coming in quanta (i.e. semi-classically).
  • We can imagine the operator $H$ as a matrix that multiplies the state vector $\psi$, so this equation is an eigenvalue equation with $E$ as the eigenvalue and $\psi$ as an eigenvector (or eigenfunction) of the matrix (or operator) $H$.The Hamiltonian classically is the sum of the kinetic energy and the potential energy of the particles.

• Further Reading

• Oscillator Strengths

  • A classical harmonic oscillator driven by electromagnetic radiation has a cross-section to absorb radiation of
  • We can write the Einstein coefficients in term of this classical one
  • $\displaystyle f_{if} = \frac{B_{if}}{B_{if}^\mbox{classical}} = \frac{2 m }{3 \hbar^2 g_i e^2} \left ( E_f - E_i \right ) \sum |{\bf d}_{if}|^2$