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.
Where is origin of idea that particles are waves or have a wave-like nature?
Louis-Victor de Broglie formulated the de Broglie hypothesis, claiming that all matter, not just light, has a wave-like nature: lambda = h/p
This is a generalization of Einstein's equation above, since the momentum of a photon is given by p=E/c and the wavelength by lambda=c/f ,where c is the speed of light in vacuum. De Broglie's formula was confirmed three years later for electrons (which differ from photons in having a rest mass)
with the observation of electron diffraction in two independent experiments.
At the University of Aberdeen, George Paget Thomson passed a beam of electrons through a thin metal film and observed the predicted interference patterns. At Bell Labs Clinton Joseph Davisson and Lester Halbert Germer
guided their beam through a crystalline grid. De Broglie was awarded the Nobel Prize for Physics in 1929 for his hypothesis. Thomson and Davisson shared the Nobel Prize for Physics in 1937 for their experimental work.
It is important highlight the fact, that verification were done for De Broglie's formula, not for claiming that all matter has a wave-like nature. And this root of problems. This assumption, automatically accepted by many physicist create confusing situation in QM interpretation of wave function.
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.
Where is origin of idea that particles are waves or have a wave-like nature?
Louis-Victor de Broglie formulated the de Broglie hypothesis, claiming that all matter, not just light, has a wave-like nature: lambda = h/p
This is a generalization of Einstein's equation above, since the momentum of a photon is given by p=E/c and the wavelength by lambda=c/f ,where c is the speed of light in vacuum. De Broglie's formula was confirmed three years later for electrons (which differ from photons in having a rest mass)
with the observation of electron diffraction in two independent experiments.
At the University of Aberdeen, George Paget Thomson passed a beam of electrons through a thin metal film and observed the predicted interference patterns. At Bell Labs Clinton Joseph Davisson and Lester Halbert Germer
guided their beam through a crystalline grid. De Broglie was awarded the Nobel Prize for Physics in 1929 for his hypothesis. Thomson and Davisson shared the Nobel Prize for Physics in 1937 for their experimental work.
It is important highlight the fact, that verification were done for De Broglie's formula, not for claiming that all matter has a wave-like nature. And this root of problems. This assumption, automatically accepted by many physicist create confusing situation in QM interpretation of wave function.
Early stage supposing that wave function is wave of matter. This was rejected with experimental result, when detector detect always whole particle only independetly from wave intensity. Second reason is dispersion of wave's packets.
Historicaly, De Broglie believed that wave function represent pilot wave which navigating particle. This idea don't fit with Occam's razor very well, because this require invloving of new phenomenon with unknown nature.
For practical use QM is still best Kopenhagen's intepretation wave function as wave of probability. This intepretaion bearing good explanation for practical use, but have a lot of strange and still not explained or implicit mysteries like
collaps of wave function, presence of measurement, quantum decoherence, Aspen's experiments, quantum Zeno effect (It describes the situation in which an unstable particle, if observed continuously, will never decay.
This occurs because every measurement causes the wavefunction to "collapse" to a pure eigenstate of the measurement basis.
In the context of this effect, an "observation" can simply be the absorption of a particle, with no observer in any conventional sense.), etc.
Source of pictures:
http://www.livescience.com/24509-light-wave-particle-duality-experiment.html
http://www.wikipedia.com
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