The word quantum
refers to discreetness. In Newtonian physics, all
quantities are allowed to be continuous. For instance,
particles can have any momentum, light can have any
frequency. A quanta is a discreet packet of energy,
charge, or any other quantity. For instance, one might
say that electric charge is quantized in units of In the next few pages, we will discuss the fact that all exchanges of energy come in discreet amounts. For instance, when light is absorbed by some material, the energy of the material does not rise continuously, but in discreet jumps. One says that the material has absorbed a light quanta. We will also learn that energy levels (orbits) of an electron in an atom do not have a continuous range of possible energies, but instead that only discreet orbits are possible. This rather bizarre behavior will be linked to the concept of wave-particle duality. We will see that particles can be discribed by wave functions that describe the probability of finding the particle. But, we will also see that these particles interact at specific points, like particles. A new fundamental
constant must be introduced to account for all these new
phenomena, .hThe constant will be
used to relate wave-like quantities to particle-like
quantities. For instance, a particle's energy of
its wave function, and a particle's momentum f is related to the wavelength p
l of its wave function.Quantum physics is necessary to explain properties of solids, atoms, nuclei and light. Aside from providing the basis for our understanding of natural phenomenon, quantum principles represent a fundamental change in how humans view nature. To many philosophers the probabilistic interpretation of quantum mechanics is very uncomfortable to accept, as it affects all aspects of determinism. The development of quantum physics in this century represents the greatest success of both mankind's science and mankind's philosophy. |