Hertz scientist biography books

The vacancy at Bonn came about because Rudolf Clausius had died in August When Hertz moved to Bonn in the spring of not only did he move into Clausius 's chair but he also moved into his house. He undertook more research into Maxwell 's theories, publishing two theoretical papers in He searched for a mechanical basis for electrodynamics starting from Maxwell 's equations.

As he wrote in the Introduction to Electric waves an English translation of some of his papers published in :- Maxwell's theory is Maxwell 's system of equations. Hertz was a fervent believer in the aether and during this work proposed identifying electromagnetic fields in free space with polarization of the aether. McCormmach writes [ 1 ] :- Hertz brought an unparalleled clarity to Maxwell 's theory, organising its concepts and its formalism so that others were able quickly to go beyond him.

Even before moving to Bonn, Hertz suffered the first signs of his serious health problems. He had already complained of toothache and had major dental treatment. In he had all his teeth removed in an attempt to cure the persistent condition. However, by early the problem returned, this time in his throat and nose. The pain became to intense that he could no longer work.

He was given hay fever treatment and went to health clinics to try to find a cure. Nothing was successful, and this was not too surprising since the condition was caused by a malignant bone condition. Bravely he began teaching again in the spring of , undergoing several operations which at least provided a short spell of respite but one consequence of the illness was that he now suffered from depression.

He gave his final lecture on 7 December. He died less than a month later. In mechanics Hertz followed Kirchhoff and considered only length, time and mass as the fundamental entities, force being a derived concept. The hypothesis was that in addition to perceptible masses the universe contained hidden, moving masses bound to one another by rigid constraints.

In [ 19 ] he talks about Hertz's approach to mechanics having three novelties: 1 a philosophical introduction, 2 an account of mechanics that does not introduce force as a basic concept, and 3 a geometric form. See also Barker [ 6 ]. Hamilton [ 15 ] and Kjaergaard [ 17 ] where Hertz's philosophy is discussed. Another interesting approach to the same question is by Wilson in [ 27 ].

He writes:- During the past decade and a half, several scholars have tried to gain a better understanding of Wittgenstein 's early thought by examining the philosophical aspects of his scientific education. In addition to Hertz, but to a much lesser extent, they have also discussed the role played by Ludwig Boltzmann's philosophical writings in Wittgenstein 's intellectual development.

While analysing and stressing the importance of Hertz's influence on Wittgenstein , however, they have misconstrued the chronological and substantive relationship between Hertz's philosophy and the philosophical writings and ideas of Boltzmann. This, in turn, has significantly affected the current understanding of the genesis and development of Wittgenstein 's early thought.

After Hertz died, one of his friends gave this eulogy:- He was a noble man, who had the singular good fortune to find many admirers, but none to hate or envy him; those who came into personal contact with him were struck by his modesty and charmed by his amiability. He was a true friend to his friends, a respected teacher to his students, who had begun to gather around him in large numbers, some of the coming from great distances; and to his family a loving husband and father.

References show. Biography in Encyclopaedia Britannica. G Gerc, The principles of mechanics, explained in a new connection Russian Klassiki nauki. P Barker, Hertz and Wittgenstein, Stud. Exact Sci. O Darrigol, The electrodynamics of moving bodies from Faraday to Hertz, Centaurus 36 , - S D'Agostino, Hertz's researches and their place in nineteenth century theoretical physics, Centaurus 36 1 , 46 - K Hamilton, Darstellungen in 'The principles of mechanics' and the 'Tractatus': the representation of objects in relation in Hertz and Wittgenstein, Perspect.

Heinrich Hertz's image of mass in his 'Prinzipien der Mechanik', Arch. Roumaine Sci. T E Phipps, Hertz's contribution to electromagnetic theory, Rev. J Tougas, Hertz und Wittgenstein. Zum historischen Hintergrund des 'Tractatus', Conceptus 29 75 , - With no formal training in electricity and magnetism when he joined the Electric Telegraph Company, he learned by doing.

When the British government put all telegraphy under the control of the Post Office, Preece was named its Chief Electrician. Born in and, like many of his contemporaries, convinced that experience rather than theory was the key to teasing out the technological opportunities in nature, he dismissed the younger Maxwellians as upstarts who had little respect for the empirical knowledge acquired by their elders.

The scientific and technical arguments between Preece and the Maxwellians were often acrimonious. The Maxwellians themselves had been unsuccessful in their search for empirical evidence. When he published his electromagnetic wave work in , Hertz was instantly acknowledged as a leading physicist of the day. Offers poured in, and by he had moved to the University of Bonn.

While there, he turned his attention back to mechanics, attempting to do for that field what Maxwell had done for electromagnetism : reduce it to a simple set of equations based, in this case, on only mass, time and length. In , he was diagnosed with first a head cold and then an allergy. His body was invaded by stubborn infections, and his condition progressively deteriorated.

For nearly two years, he suffered through debilitating poor health. His spirits must have been very low, yet he always remained a playful father. Fearing that the end was near, he was determined to finish his treatise on mechanics. He faced death with courage, humility and a sense of duty. Three weeks before his death on 1 January , he wrote to his parents:.

I did not desire or choose this fate, but since it has overtaken me, I must be content; and if the choice had been left to me, perhaps I should have chosen it myself. In a fitting end to his peripatetic life, he was returned to Hamburg for burial. At least intellectually, he continued to be a moving target. His approach did not find widespread acceptance among physicists, who would soon focus their attention on quantum mechanics and relativity, but it was embraced by philosophers of science — in particular by Ludwig Wittgenstein, who had a background in engineering.

Despite the climate of anti-Semitism, German scientists refused to go along with this plan. For his role in setting the stage for the world-changing technologies that would emerge from the electromagnetic field concept, Hertz has also been recognized by the IEEE, which created the Heinrich Hertz Medal in It honors outstanding achievement in the field of radio waves.

Mathilde Hertz and Charles Susskind eds. And Science Museum of London, In the autumn of , after Hertz received his professorship at Karlsruhe, he was experimenting with a pair of Riess spirals when he noticed that discharging a Leyden jar into one of these coils produced a spark in the other coil. With an idea on how to build an apparatus, Hertz now had a way to proceed with the "Berlin Prize" problem of on proving Maxwell's theory although the actual prize had expired uncollected in The antenna was excited by pulses of high voltage of about 30 kilovolts applied between the two sides from a Ruhmkorff coil.

He received the waves with a resonant single- loop antenna with a micrometer spark gap between the ends. This experiment produced and received what are now called radio waves in the very high frequency range.

Hertz scientist biography books

Between and Hertz conducted a series of experiments that would prove the effects he was observing were results of Maxwell's predicted electromagnetic waves. Starting in November with his paper "On Electromagnetic Effects Produced by Electrical Disturbances in Insulators", Hertz sent a series of papers to Helmholtz at the Berlin Academy, including papers in that showed transverse free space electromagnetic waves traveling at a finite speed over a distance.

Hertz had positioned the oscillator about 12 meters from a zinc reflecting plate to produce standing waves. Each wave was about 4 meters long. Hertz measured Maxwell's waves and demonstrated that the velocity of these waves was equal to the velocity of light. The electric field intensity , polarization and reflection of the waves were also measured by Hertz.

These experiments established that light and these waves were both a form of electromagnetic radiation obeying the Maxwell equations. Hertz did not realize the practical importance of his radio wave experiments. It's of no use whatsoever But they are there. Asked about the applications of his discoveries, Hertz replied, [ 24 ] [ 27 ]. Hertz's proof of the existence of airborne electromagnetic waves led to an explosion of experimentation with this new form of electromagnetic radiation, which was called "Hertzian waves" until around when the term " radio waves " became current.

Within 6 years Guglielmo Marconi began developing a radio wave based wireless telegraphy system, [ 28 ] leading to the wide use of radio communication. In , he tried to prove that the cathode rays are electrically neutral and got what he interpreted as a confident absence of deflection in electrostatic field. However, as J. Thomson explained in , Hertz placed the deflecting electrodes in a highly-conductive area of the tube, resulting in a strong screening effect close to their surface.

Nine years later Hertz began experimenting and demonstrated that cathode rays could penetrate very thin metal foil such as aluminium. Philipp Lenard , a student of Heinrich Hertz, further researched this " ray effect ". He developed a version of the cathode tube and studied the penetration by X-rays of various materials. However, Lenard did not realize that he was producing X-rays.

Hermann von Helmholtz formulated mathematical equations for X-rays. It was formed on the basis of the electromagnetic theory of light Wiedmann's Annalen , Vol. However, he did not work with actual X-rays. Hertz helped establish the photoelectric effect which was later explained by Albert Einstein when he noticed that a charged object loses its charge more readily when illuminated by ultraviolet radiation UV.

In , he made observations of the photoelectric effect and of the production and reception of electromagnetic EM waves, published in the journal Annalen der Physik. His receiver consisted of a coil with a spark gap , whereby a spark would be seen upon detection of EM waves. He placed the apparatus in a darkened box to see the spark better.

He observed that the maximum spark length was reduced when in the box. A glass panel placed between the source of EM waves and the receiver absorbed UV that assisted the electrons in jumping across the gap. When removed, the spark length would increase. He observed no decrease in spark length when he substituted quartz for glass, as quartz does not absorb UV radiation.

Hertz concluded his months of investigation and reported the results obtained. He did not further pursue investigation of this effect, nor did he make any attempt at explaining how the observed phenomenon was brought about. In and , Hertz published two articles [ 32 ] [ 33 ] [ 34 ] on what was to become known as the field of contact mechanics , which proved to be an important basis for later theories in the field.

Joseph Valentin Boussinesq published some critically important observations on Hertz's work, nevertheless establishing this work on contact mechanics to be of immense importance. His work basically summarises how two axi-symmetric objects placed in contact will behave under loading , he obtained results based upon the classical theory of elasticity and continuum mechanics.

The most significant flaw of his theory was the neglect of any nature of adhesion between the two solids, which proves to be important as the materials composing the solids start to assume high elasticity. It was natural to neglect adhesion at the time, however, as there were no experimental methods of testing for it. To develop his theory Hertz used his observation of elliptical Newton's rings formed upon placing a glass sphere upon a lens as the basis of assuming that the pressure exerted by the sphere follows an elliptical distribution.

He used the formation of Newton's rings again while validating his theory with experiments in calculating the displacement which the sphere has into the lens. Kenneth L. Johnson , K. Kendall and A. Roberts JKR used this theory as a basis while calculating the theoretical displacement or indentation depth in the presence of adhesion in Similar to this theory, however using different assumptions, B.

Derjaguin , V. Muller and Y. Toporov published another theory in , which came to be known as the DMT theory in the research community, which also recovered Hertz's formulations under the assumption of zero adhesion. This DMT theory proved to be premature and needed several revisions before it came to be accepted as another material contact theory in addition to the JKR theory.

Both the DMT and the JKR theories form the basis of contact mechanics upon which all transition contact models are based and used in material parameter prediction in nanoindentation and atomic force microscopy. These models are central to the field of tribology and he was named as one of the 23 "Men of Tribology" by Duncan Dowson. Hertz also described the " Hertzian cone ", a type of fracture mode in brittle solids caused by the transmission of stress waves.

Hertz always had a deep interest in meteorology , probably derived from his contacts with Wilhelm von Bezold who was his professor in a laboratory course at the Munich Polytechnic in the summer of As an assistant to Helmholtz in Berlin , he contributed a few minor articles in the field, including research on the evaporation of liquids, [ 39 ] a new kind of hygrometer , and a graphical means of determining the properties of moist air when subjected to adiabatic changes.

In the introduction of his book Principles of Mechanics , Hertz discusses the different "pictures" used to represent physics in his time including the picture of Newtonian mechanics based on mass and forces , a second picture based on conservation of energy and Hamilton's principle and his own picture based uniquely on space, time, mass and the Hertz principle , comparing them in terms of 'permissibility', 'correctness' and 'appropriateness'.

Because Hertz's family converted from Judaism to Lutheranism two decades before his birth, his legacy ran afoul of the Nazi government in the s, a regime that classified people by "race" instead of religious affiliation. Hertz's name was removed from streets and institutions and there was even a movement to rename the frequency unit named in his honor hertz after Hermann von Helmholtz instead, keeping the symbol Hz unchanged.

His family was also persecuted for their non-Aryan status. Hertz's youngest daughter, Mathilde, lost a lectureship at Berlin University after the Nazis came to power and within a few years she, her sister, and their mother left Germany and settled in England. His daughter Mathilde Carmen Hertz was a well-known biologist and comparative psychologist.

The SI unit hertz Hz was established in his honor by the International Electrotechnical Commission in for frequency , an expression of the number of times that a repeated event occurs per second. In , in East Germany , a Heinrich Hertz memorial medal [ 48 ] was cast. The Submillimeter Radio Telescope at Mt. Graham, Arizona, constructed in is named after him.

A crater that lies on the far side of the Moon , just behind the eastern limb, is the Hertz crater , named in his honor. On his birthday in , Google honored Hertz with a Google doodle , inspired by his life's work, on its home page.