London: Taylor and Francis, 1904. 1st Edition. FIRST EDITION OF J. J. THOMSON'S 'PLUM PUDDING MODEL': "THE MOST WIDELY ACCEPTED THEORY OF ATOMIC STRUCTURE UP TO ABOUT 1913" (Peacock, The Quantum Revolution, 34). In the search for an atomic model, a number of physicists "proposed atomic models with a central positive core and electrons either orbiting around it like planets around the sun or like the rings of Saturn. But none of these models could explain either the stability of the atom or the observed rules of the spectral lines" (ibid). The physicist J. J. Thomson "imagined that the electrons were embedded like plums throughout a pudding of uniform positive charge, with the number of electrons equal to the atomic number of the atom, so that the overall charge would add up to zero.
At this point there was no clear evidence that positive charge comes in discrete corpuscles. Thomson imagined the electrons to be swarming around in shells or rings in such a way that their electrostatic repulsions balanced, and he was encouraged by the fact that with some mathematical fudging he could get the structure of the shells to suggest the layout of the periodic table of the elements. The model was quite unable to predict the frequencies of observed spectral lines... But Thomson's model did at least give some account of the stability of the atom, and in the period of about 1904-1909, with still no direct evidence for the existence of a central positive core, the Thomson model seemed like the best bet" (ibid). The Plum Pudding Model was abandoned with the later discovery of the atomic nucleus. J. J. Thomson win the 1906 Nobel Prize in Physics.
ALSO INCLUDED: FIRST EDITION OF THE BRACE EXPERIMENT, "THE FIRST OPTICAL EXPERIMENT MEASURING THE RELATIVE MOTION OF EARTH AND THE LUMINIFEROUS AETHER WHICH WERE SUFFICIENTLY PRECISE TO DETECT MAGNITUDES OF SECOND ORDER TO V/C" (Wikipedia). Brace's results were negative, "which was of gret importance for the development of the Lorentz transformation and consequently of the theory of relativity" (ibid). The American physicist and specialist in optics "examined the question [of] whether the Earth's motion may cause a body to become doubly refracting," something which as first sight might be expected (PRNAAS, 1904, 6, 809). Item #358
CONDITION & DETAILS: London: Taylor and Francis. Entire volume. Ex-libris and bearing occasional light stamp within. New end papers. No marks at the spine whatsoever. Octavo (8.5 x 5.5 inches; 213 x 138mm). [viii], 720, . 27 plates. Handsomely rebound in three quarter calf over gilt-ruled maroon paper boards. Four gilt-ruled raised bands at the spine. Gilt devices in the spine compartments. Gilt-lettered red and black spine labels. Tightly and very solidly bound. An occasional spot within, quite minor. Very good condition in every way.