'Fundamental Substance' enigma

[RascalPuff]

The Fundamental Substance (aka 'FS')

'Fundament' (from fundus, the bottom).
'Fundamental' - of or forming a foundation or basis; basic; essential.

'Substance' (substantia), essence, material (from substare - to be present, exist).

To exist is to occupy three or more dimensions of space, possess positive inertia - a tendency for a defined moving entity to remain in uniform motion until acted upon or otherwise encountering an outside force, and, negative inertia - a tendency to oppose a resistance to force(s) acting upon it.

Particle: (See above, and, 'in physics, the minute part or portion of matter, the aggregation of which parts constitutes the whole mass; a piece of matter so small as to be considered without magnitude, though having - negative and positive - inertia and the force of attraction'.) A surfaceless charge of electricity emanating/projecting an electromagnetic field, the density of which increases as its center-source is approached.

('There is no space empty of field'. - Einstein)

Field: In physics, a space in which magnetic or electrical forces are active.

Substance (continued): The real or essential part of anything; essence; reality; matter.
In philosophy, the essence or substratum which underlies and is capable of having attributes or causing phenomena, but which in spite of changes in outward manifestation remains the same; that which really is or exists, as distinguished from its qualities, attributes, and the phenomena by which it is perceived.
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George Paget Thompson (1892-1975). Like his father (J.J. Thompson), G.P. Thompson attended Trinity College, Cambridge University, and did some postgraduate work at the Cavendish. He held positions at Cambridge, Aberdeen University, and Imperial College, London. G.P. Thompson performed experiments on electron scattering through celluloids that revealed diffraction effects characteristic of wave phenomena. For this work he shared (with C.J. Davisson) the 1937 Nobel prize in physics.

*It has been quipped that J.J. Thompson got the Nobel prize for discovering that electrons are particles, and G.P. Thompson (J.J. Thompson's son) got it for discovering that they aren't.

AIP Emilio Segrè Visual Archives, E. Scott Barr Collection

The Enigma:
* They were both right. Hence, the since coined phrase, 'wavicles'. - RP

J.J. Thompson:

Electron As A Particle

In 1899, Thomson set out to resolve the doubt concerning the significance of the e/m values of the "corpuscles" by determining directly their charge as well as the charge to mass ratio. Unfortunately, this could not be done with the cathode-ray particles, and so he turned to another source. It was well-known towards the end of the 19th century that ultra-violet light falling on certain metals, particularly zinc, was associated with the emission of negatively charged particles, a phenomena known as the photoelectric effect. Thomson determined the en ratio for these particles by means of electric and magnetic fields and found it to be virtually the same as for the cathode ray corpuscles. Charged particles emitted by an incandescent filament, i.e. by the thermionic effect, also had a similar e/m value. His estimate of the electronic charge of the photoelectric particles turned out to be similar to the unit electronic charge. In view of the consistency of the e/m for the negatively charged particles produced in different ways, it was reasonable to conclude that the particles were identical.

In the words of Thomson: "The experiments just described, taken in conjunction with previous ones .... on cathode rays, show that in gases at low pressures negative electrification, though it may be produced by very different means, is made up of units each having a charge of electricity of a definite size; the magnitude of this negative charge is .... equal to the positive charge carried by the hydrogen atom (ion) in the electrolysis of solutions".

Because the charge on the particles present in the cathode rays, and associated with the thermionic and photoelectric effect, was identical with the elementary electric charge, the name electron originally intended by G. Johnstone Stoney for magnitude of the charge, soon became associated with the actual particles themselves.


G.P. Thompson:

Electron As A Wave

The diffraction and interference properties of radiation necessitate a wave structure, but photoelectric phenomena and the Compton effect imply that radiation consists of particles rather than waves. In Compton effect, an instant X-ray is scattered by a free electron just like in a collision between two rigid spheres. In other words, radiation may be regarded as exhibiting a dual wave - particle behaviour; some of the properties of the radiation may be wave properties where as others are particle properties. By means of Planck's Quantum Theory equation and the mass energy relationship of Einstein, Prince Louis-Victor Pierre Raymond de Broglie (1892-1987) deduced that a particle mass m moving with a velocity v should be associated with waves of length l (lambda), given by

l = h / mv

where h is the Planck's constant. It was calculated that with a moderately high velocity such as could be obtained by passage of an electron through a potential of about 100 to 1000 volts, the de Broglie waves should have a wavelength of the order of 10-8 cms. If this were the case, then crystals should be capable of producing diffraction effects with electrons.

The first definite proof that electrons can be diffracted and consequently exhibit wave, as well as the familiar particle, properties was obtained in the Bell Telephone Laboratories in New York by C.J. Davisson and L.H. Germer in 1927. By studying the reflection and scattering by a nickel crystal, of a beam of electrons, given a specific velocity by passage through a known potential difference, it was found that the electrons behaved like waves rather than particles. Using electrons which had been accelerated by a potential of 54 volts, the experimental results were found to be equivalent to those expected from radiation of wavelength 1.65 Å, in remarkably good agreement with the value of 1.67 Å calculated by means of the de Broglie equation.

Further, evidence for the existence of electron waves was obtained independently in 1927, by George Paget Thompson (1892-1975), son of J.J. Thompson. He passed a stream of fast moving electrons through a very thin sheet of metal and then allowed the resulting beam to fall on a photographic plate. Upon development, the plate showed a diffraction pattern consisting of a series of concentric circles, just as might have been produced by X-rays, indicating that the electrons were manifesting wave properties.

Best regards,
- RP (aka Kai)