The Invasion of the Periodic Table by Physics

2013 ◽  
Author(s):  
Eric Scerri
Keyword(s):  
Twentieth Century ◽  
Brownian Motion ◽  
Periodic System ◽  
Periodic Table ◽  
X Rays ◽  
Cavendish Laboratory ◽  
Experimental Support ◽  
Experimental Physicist ◽  
Scientific Life

Although John Dalton had reintroduced the notion of atoms to science, many debates followed among chemists, most of whom refused to accept that atoms existed literally. One of these skeptical chemists was Mendeleev, but as we saw in the previous chapter this does not seem to have prevented him from publishing the most successful periodic system of all those proposed at the time. Following the work of physicists like Einstein and Perrin, the atom’s reality became more and more firmly established starting at the turn of the twentieth century. Einstein’s 1905 paper on Brownian motion, using statistical methods, provided conclusive theoretical justification for the existence of atoms but lacked experimental support. The latter was soon provided by the French experimental physicist Jean Perrin. This work led in turn to many lines of research aimed at exploring the structure of the atom, and many developments that were to have a big influence on attempts to understand the periodic system theoretically. In this chapter we consider some of this atomic research as well as several other key discoveries in twentieth-century physics that contributed to what might be called the invasion of the periodic table by physics. The discovery of the electron, the first hint that the atom had a substructure, came in 1897 at the hands of the legendary J. J. Thomson, working at the Cavendish laboratory in Cambridge. A little earlier, in 1895, Wilhelm Conrad Röntgen had discovered X-rays in Würzburg, Germany. These new rays would soon be put to very good use by Henry Moseley, a young physicist working first in Manchester and, for the remainder of his short scientific life, in Oxford. Just a year after Röntgen had described his X-rays, Henri Becquerel in Paris discovered the enormously important phenomenon of radioactivity, whereby certain atoms break up spontaneously while emitting a number of different, new kinds of rays. The term “radioactivity” was actually coined by the Polish-born Marie Slodowska (later Curie).

Twentieth Century and Beyond

2017 ◽  
Author(s):  
Don S. Lemons
Keyword(s):  
Twentieth Century ◽  
General Relativity ◽  
Brownian Motion ◽  
Atomic Nucleus ◽  
Hydrogen Atom ◽  
Early Universe ◽  
Higgs Field ◽  
Photoelectric Effect ◽  
X Rays ◽  
Matter Waves

During this period the diagrams that convey the ideas of physics become more symbolic and less representational. Rutherford’s discovery of the atomic nucleus (1910), Niels Bohr’s model of the Hydrogen atom (1913), matter waves (1924), and the transition from an early universe with no Higgs field to a universe with a Higgs field (2012) are examples of this point. The photoelectric effect (1905), Brownian motion (1905), X-rays and crystals (1912), general relativity (1915), the expanding universe (1927-1929), and the global greenhouse effect (1988) remain accessible with a simple representational sketch.

The Electron and Chemical Periodicity

2019 ◽  
Author(s):  
Eric Scerri
Keyword(s):  
Twentieth Century ◽  
Periodic System ◽  
Atomic Structure ◽  
Periodic Table ◽  
Free Particle ◽  
History Of Physics ◽  
History Of ◽  
Lothar Meyer ◽  
Deep Interest

J.J. Thomson’s discovery of the electron is one of the most celebrated events in the history of physics. What is not so well known is that Thomson had a deep interest in chemistry, which, among other things, motivated him to put forward the first explanation for the periodic table of elements in terms of electrons. Today, it is still generally believed that the electron holds the key to explaining the existence of the periodic table and the form it takes. This explanation has undergone a number of subtle changes. The extent to which the modern explanation is purely deductive or whether it is semiempirical is examined in this chapter. While Dmitri Mendeleev had remained strongly opposed to any attempts to reduce, or explain, the periodic table in terms of atomic structure, Julius Lothar Meyer was not so averse to reduction of the periodic system. The latter strongly believed in the existence of primary matter and also supported William Prout’s hypothesis. Lothar Meyer did not hesitate to draw curves through the numerical properties of atoms, whereas Mendeleev believed this to be a mistake, since it conflicted with his own belief in the individuality of the elements. This is how matters stood before the discovery of the electron, three years prior to the turn of the twentieth century. The atom’s existence was still very much a matter of dispute, and its substructure had not yet been discovered. There appeared to be no way of explaining the periodic system theoretically. Johnston Stoney first proposed the existence and name for the electron in 1891, although he did not believe that it existed as a free particle. Several researchers discovered the physical electron, including Emil Wiechert in Königsberg, who was the first to publish his findings. Because these early researchers did not seriously follow up on their results, it was left to the British physicist Thomson to capitalize upon and establish the initial observations.

The Nucleus and the Periodic Table: Radioactivity, Atomic Number, and Isotopy

2019 ◽  
Author(s):  
Eric Scerri
Keyword(s):  
Nineteenth Century ◽  
Twentieth Century ◽  
Nuclear Structure ◽  
Atomic Number ◽  
Alpha Particle ◽  
Periodic Table ◽  
Radioactive Decay ◽  
X Rays ◽  
Harsh Criticism ◽  
Influence Attempts

Theories of the atom were reintroduced into science by John Dalton and were taken up and debated by chemists in the nineteenth century. As noted in preceding chapters, atomic weights and equivalent weights were determined and began to influence attempts to classify the elements. Many physicists were at first reluctant to accept the notion of atoms, with the tragic exception of Ludwig Boltzmann, who came under such harsh criticism for his support of atomism that he eventually took his own life. But around the turn of the twentieth century, the tide began to turn, and physicists not only adopted the atom but transformed the whole of science by performing numerous experiments aimed at probing its structure. Their work had a profound influence on chemistry and, more specifically for our interests here, the explanation and presentation of the periodic table. Beginning with J.J. Thomson’s discovery of the electron in 1897, developments came quickly. In 1911, Ernest Rutherford proposed the nuclear structure of the atom, and by 1920 he had named the proton and the neutron. All of this work was made possible by the discovery of X-rays in 1895, which allowed physicists to probe the atom, and by the discovery of radioactivity in 1896. The phenomenon of radioactivity destroyed the ancient concept of the immutability of the atom once and for all and demonstrated that one element could be transformed into another, thus in a sense achieving the goal that the alchemists had sought in vain. The discovery of radioactivity led to the eventual realization that the atom, which took its name from the idea that it was indivisible, could in fact be subdivided into more basic particles: the proton, neutron, and electron. Rutherford was the first to try to “split the atom,” something he achieved by using one of the newly discovered products of radioactive decay, the alpha particle.

Understanding the Properties of “Numbers”

2014 ◽  
Author(s):  
Victor J. Katz ◽  
Karen Hunger Parshall
Keyword(s):  
Twentieth Century ◽  
Algebraic Systems ◽  
Modern Algebra ◽  
The Creation ◽  
Eighteenth And Nineteenth Centuries ◽  
The Way

This chapter looks at how mathematicians sought to understand the properties of “numbers” and in doing so pave the way for modern algebra. As mathematicians in the eighteenth and nineteenth centuries struggled to understand what Fermat's alleged proof of his so-called “last theorem” might have been, they, as well as others motivated by issues other than Fermat's work, eventually came to extend the notion of “number.” And, they did this in much the same spirit that Évariste Galois had extended that of “domain of rationality” or field, that is, through the creation and analysis of whole new types of algebraic systems. This freedom to create and explore new systems—and new algebraic constructs like the determinants and matrices that were encountered in the previous chapter—became one of the hallmarks of the modern algebra that developed into the twentieth century.

The Implied Masturbator Speaks

2021 ◽  
pp. 89-122
Author(s):  
Y. Yvon Wang
Keyword(s):  
Twentieth Century ◽  
Mass Media ◽  
Late Qing ◽  
Early Twentieth Century ◽  
Open Discussion ◽  
Cultural World ◽  
Ideological Change ◽  
Better Than ◽  
Print Market

This chapter builds on the material and technological transformations described in the previous chapter to discuss changing ideas about sexual representations. The chapter begins to directly talk about the desires of the implied masturbator. From the late Qing into the early twentieth century, mass media conquered the Chinese cultural world. Ambitious intellectuals at the turn of the twentieth century increasingly put their ideas onto a print market that was more open than ever before. The chapter analyses how literary professionalization remained a deviation from the orthodox path of officialdom. It also elaborates the five aspects of ideological change around sex and sexual representations at the turn of the twentieth century. Many of these ideological transformations were led by political and cultural reformers, including proponents of a “New Culture.” These self-declared iconoclasts argued for revising the boundaries of legitimacy around desire itself. Ultimately, the chapter introduces the downfall of Zhang Jingsheng, a leading member of the New Culture group. The chapter addresses how Zhang's open discussion of his personal desires made him vulnerable to becoming seen as no better than an implied masturbator.

From Brownian Motion to Bending Beams

2021 ◽  
pp. 84-98
Author(s):  
Robert W. Batterman
Keyword(s):  
Brownian Motion ◽  
Correlation Function ◽  
Correlation Functions ◽  
Materials Science ◽  
Prima Facie ◽  
Representative Volume ◽  
Representative Volume Elements ◽  
Hydrodynamic Correlation

This chapter argues that the hydrodynamic, correlation function methodology discussed in “fluid” contexts is really the same methodology employed in materials science to determine effective values for quantities like conductivity, elasticity, stiffness. Thus, Einstein’s arguments discussed in the previous chapter have a bearing on what prima facie appear to be completely different problems. The mesoscale approach using representative volume elements and correlation functions to describe the important features of those representative volume elements is presented in some detail.

scholarly journals A Review of Shaped Charge Variables for its Optimum Performance

2019 ◽  
Vol 9 (6) ◽  
pp. 4917-4924
Author(s):  
K. Naeem ◽  
A. Hussain ◽  
S. Abbas
Keyword(s):  
Twentieth Century ◽  
Powder Metallurgy ◽  
Diagnostic Techniques ◽  
Shaped Charge ◽  
X Rays ◽  
Detailed Review ◽  
Late Twentieth ◽  
Late Twentieth Century ◽  
Land Water ◽  
Explosive Detonation

Shaped charge is a device for focusing the chemical energy of explosives to a particular point or line for penetration or cutting purpose respectively. They are used for the penetration or cutting of various types of targets on land, water, underground, underwater, or air. Their shape is either conical or linear and consists of explosive, casing and liner. The liner is bent towards the central axis producing a thin hypervelocity jet by the energy released as a result of the explosive detonation. This jet is utilized against the target. Shaped charges can perforate or penetrate targets like aircrafts, ships, submarines, armored vehicles, battle tanks, and bunkers. This paper presents a detailed review of analytical works, computer simulations, and experimental results related to the liner. Among modern diagnostic techniques flash x-rays, radiography is most used in the experiments performed in the last 40 years. Powder metallurgy, which started in the late twentieth century raised the efficiency of shaped charges to new altitudes. The efficiency of the shaped charge depends on numerous factors such as explosive’s type, liner’s material, geometry and metallurgy, manufacturing technique, and casing thickness. Factors concerning the liner’s material, metallurgical advancements, and geometry are discussed chronologically and in detail.

A Brownian Model for Literary Crowds

2018 ◽  
Author(s):  
Rachel Crossland
Keyword(s):  
Twentieth Century ◽  
Brownian Motion ◽  
James Joyce ◽  
Joseph Conrad ◽  
Literary Texts ◽  
Molecular Physics ◽  
Early Twentieth Century ◽  
Brownian Model ◽  
Night And Day

Chapter 6 applies the ideas explored in Chapter 5 to a range of early twentieth-century literary texts, especially those by Woolf and Lawrence. The focus here is on crowd and city scenes, including the modernist figures of the flâneur and the passante. The chapter as a whole argues for the relevance of contemporary ideas on molecular physics, especially Brownian motion, to portrayals of individual characters in relation to crowds, drawing on a range of texts including Woolf’s Night and Day and Mrs Dalloway, Lawrence’s The Trespasser and The White Peacock, and texts by Joseph Conrad, James Joyce, and H. G. Wells. Together with Chapter 5, this chapter demonstrates how ideas, language, and imagery were shared across disciplines in the early twentieth century, and argues that considering different disciplines together can help us to recapture a sense of the ways in which particular issues were experienced at the time.

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