Joined: April 2007
The Wikipedia link that K.E. provided is a good one to show you shouldn't be too hard on yourself for being confused on the issue. It isn't an easy question to answer.
Here is a Wikipedia link discussing Wave/Particle duality.
Wave–particle duality is deeply embedded into the foundations of quantum mechanics, so well that modern practitioners rarely discuss it as such. In the formalism of the theory, all the information about a particle is encoded in its wave function, a complex function roughly analogous to the height of a wave at each point in space. This function evolves according to a differential equation (generically called the Schrödinger equation), and this equation gives rise to wave-like phenomena such as interference and diffraction.
The particle-like behavior is most evident due to phenomena associated with measurement in quantum mechanics. Upon measuring the location of the particle, the wave-function will randomly "collapse" to a sharply peaked function at some location, with the likelihood of any particular location equal to the squared amplitude of the wave-function there. The measurement will return a well-defined position, a property traditionally associated with particles.
Although this picture is somewhat simplified (to the non-relativistic case), it is adequate to capture the essence of current thinking on the phenomena historically called "wave–particle duality". (See also: Mathematical formulation of quantum mechanics.)
At least one physicist considers the “wave-duality” a misnomer, as L. Ballentine, Quantum Mechanics, A Modern Development, p.4, explains:
When first discovered, particle diffraction was a source of great puzzlement. Are “particles” really “waves? in the early experiments, the diffraction patterns were detected holistically by means of a photographic plate, which could not detect individual particles. As a result, the notion grew that particle and wave properties were mutually incompatible, or complementary, in the sense that different measurement apparatuses would be required to observe them. That idea, however, was only an unfortunate generalization from a technological limitation. Today it is possible to detect the arrival of individual electrons, and to see the diffraction pattern emerge as a statistical pattern made up of many small spots (Tonomura) et al, 1989. Evidently, quantum particles are indeed particles, but whose behaviour is very different from classical physics would have us to expect.”
At least one scientist proposes that the duality can be replaced by a "wave-only" view. Carver Mead's Collective Electrodynamics: Quantum Foundations of Electromagnetism (2000) analyzes the behavior of electrons and photons purely in terms of electronic wave functions, and attributes the apparent particle-like behavior to quantization effects and eigenstates. According to reviewer David Haddon:
Mead has cut the Gordian knot of quantum complementarity. He claims that atoms, with their neutrons, protons, and electrons, are not particles at all but pure waves of matter. Mead cites as the gross evidence of the exclusively wave nature of both light and matter the discovery between 1933 and 1996 of ten examples of pure wave phenomena, including the ubiquitous laser of CD players, the self-propagating electrical currents of superconductors, and the Bose–Einstein condensate of atoms.
And while K.E. may consider it just more "psuedoscience", here are some interesting experimental results (Ashfer Experiment).
Afshar claims that his experiment invalidates the complementarity principle and has far-reaching implications for the understanding of quantum mechanics, challenging the Copenhagen interpretation. According to John G. Cramer, Afshar's results support Cramer's own transactional interpretation of quantum mechanics and challenges the many-worlds interpretation of quantum mechanics.
So what is this "transactional interpretation"?
More from Wikipedia...
Suppose a particle (such as a photon) emitted from a source could interact with one of two detectors. According to TIQM, the source emits a usual (retarded) wave forward in time, the "offer wave", and when this wave reaches the detectors, each one replies with an advanced wave, the "confirmation wave", that travels backwards in time, back to the source. The phases of offer and confirmation waves are correlated in such a way that these waves interfere positively to form a wave of the full amplitude in the space-time region between emitting and detection events, and they interfere negatively and cancel out elsewhere in space-time (i.e., before the emitting point and after the absorption point). The size of the interaction between the offer wave and a detector's confirmation wave determines the probability with which the particle will strike that detector rather than the other one. In this interpretation, the collapse of the wavefunction does not happen at any specific point in time, but is "atemporal" and occurs along the whole transaction, the region of space-time where offer and confirmation waves interact. The waves are seen as physically real, rather than a mere mathematical device to record the observer's knowledge as in some other interpretations of quantum mechanics.
John Cramer has argued that the transactional interpretation is consistent with the outcome of the Afshar experiment, while the Copenhagen interpretation and the many-worlds interpretation are not.
Sound familiar? It sounds like a different way of describing Penrose's OR interpretation.
I consider Penrose's OR to be a Copenhagen derivative, but that is just a label.
Labels aren't important, ideas are.