February 1930 Radio-Craft[Table of Contents]
People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Radio-Craft was published from 1929 through 1953. All copyrights are hereby acknowledged. See all articles from Radio-Craft.
Fifth in the "Men Who Have Made Radio" series, Heinrich Hertz is honored here for giving mankind what author Hugo Gernsback appropriately termed "a sixth sense." Having earned his doctorate with a thesis on "the distribution of electricity over the surface of moving conductors," Hertz proved through his experiments the existence of electromagnetic waves - the aforementioned sixth sense. During his short 37 years on Earth, Heinrich Hertz accomplished an impressive amount of fundamental research and discovery. He was remembered fondly as a kind man who placed advancing the frontiers of science ahead of fighting for credit and spotlight attention.
The Fifth of a Series
On New Year's Day, 1894, a world troubled by wars, social and financial conflicts, with its attention concentrated upon the ambitions of empires, gave little heed to the deathbed of a young man of science whose brilliance of intellect was well matched by his devotion to the advancement of knowledge, and his nobility of spirit. A few scientists knew - but none fully realized at the time - that his genius had given to mankind what is virtually a sixth sense.
Heinrich Rudolph Hertz, born at Hamburg, Germany, on February 2, 1857, pursued as a youth his technical studies, with the purpose of becoming an engineer. The fascinating nature of scientific research, particularly in the field of electricity, where the misty outlines of new worlds were looming on the horizon, inclined him toward a career of discovery. "I would rather," he wrote to his parents in October, 1877, "be a great scientific investigator than a great engineer; but would rather be a second-rate engineer than a second-rate investigator." During the remainder of his short span of life, his ambition was rewarded.
In the following year, his investigations into the subject of "electric inertia," as certain phenomena were then described, won for him a prize, which he elected to receive in the form of a gold medal from the scientific society propounding the theme for investigation. In 1879, as an assistant at the Berlin Physical Institute, Hertz's ability attracted the interest of the great physicist Helmholtz, who urged him to study the interrelation of magnetism and electrical charges. His doctor's degree was awarded for a thesis on "the distribution of electricity over the surface of moving conductors."
Appointed professor of physics at the Karlsruhe Polytechnic High School (a term implying, in Germany, an educational institution of collegiate qualifications), Hertz carried out there, under great handicaps from the limited size of his laboratory and the deficiencies of his equipment, the experiments which were to rank him among the immortals of science.
As a physicist, however, his work was not restricted narrowly to the field which is forever associated with his name. We find among his earlier published papers an inquiry into "the contact of elastic solids," brought up by the practical problem of surveying the earth's surface; others on the evaporation of liquids, and the design of a new hygrometer - which occasioned a dutiful letter to his parents, suggesting that the device be employed in their home for the regulation of its humidity to a healthful degree; a study in 1883 of the cathode ray, which he determined to be "a phenomenon accompanying the discharges and having nothing to do directly with the path of the current"; and in the same year, the invention of the hot-wire ammeter for high-frequency current.
In 1883, Helmholtz proposed to his young friend an inquiry into the electromagnetic theory of Clerk Maxwell. The fruits of this study, four years later, carried to the world the proof of the existence of radio. In 1887, working under many difficulties, Hertz proved, with his simple apparatus, that electromagnetic radiation, in wavelengths from three meters down, can be created, and that it follows the law already recognized in the behavior of the immensely shorter waves of light.
"All propagation of electrical disturbances," he announced, "takes place through non-conductors; and conductors oppose this propagation which, in the case of rapid alternations, is insuperable." In the same year Hertz, examining into spark-gap discharges (the rather crude means by which he was able to detect the presence of radio waves by the currents which they set up in a resonant circuit) found that the existence of one spark affected the length of another; and finally trailed down the reason to the presence of ultra-violet light - which we now know to cause ionization, and consequently greater conductivity, of the air.
Intensely chivalrous, Hertz exemplified in his modest announcements to the scientific world the utmost desire that all of the theorists and discoverers who had preceded him should have their full share of credit toward the pyramid of achievement he had reared on the previous bases. He was in, truth, the very knight of science; self-effacing, seeking no personal distinction, but only to advance the progress of truth, and let the glory fall where it would. "I have carried out with the greatest possible care these experiments (by no means easy ones) although they were in opposition to my pre-conceived views"; he wrote, and accepted with generous approval, the results of better-equipped experimenters.
The conclusions of Hertz, derived from the study of what we would now class as ultra-short radiation, have never been carried out in practical exploitation to their full limit. After longer waves had been found, in practice, most suited to distant communication, radio practice has swung back, year by year, toward shorter wavelengths. The phenomenon of wave reflection has been employed in directional-beam transmission and reception; that of plane polarization has been experimentally utilized; but as yet the refraction of waves (demonstrated by Hertz with a large prism of pitch in his laboratory) has been put to no practical account. However, as work with ultra-short waves proceeds down to the lengths of less than a meter, we may expect to see radio projectors using lenses like those of a searchlight, and possibly receivers like telescopes.
"It is a fascinating idea, that the processes in air which we have been investigating represent to us on a million fold-larger scale the same processes which go on in the neighborhood of a Fresnel mirror, or between the glass plates used for exhibiting Newton's rings," wrote Hertz, describing some of the experiments which he has made classic. (They are described in the January issue of Radio-Craft, on page 312).
The experiments of Hertz lacked, undoubtedly, the publicity with which today's press would have greeted them; but, in the world of science, they gained for the modest professor immediate recognition, just as his fine personality commanded the esteem of all who met him.
Appointment to the chair of physics at the University of Bonn (where he was to end his days) was welcomed by him, for the added research facilities which were thus placed at his disposal. He there added nothing sensational to the knowledge of the great subject which he had so masterfully handled; but it may be noted that, in 1891, Hertz found that cathode rays pass through metal, thus anticipating the inquiries into the X-ray which have been of such scientific and medical value. His last work was a treatise on "The Principles of Mechanics." Hertz possessed the faculty, not always found among great scientists, of dealing with abstruse subjects in a popular manner; and his lecture to the Heidelberg Association for the Advancement of Science on his discoveries is a classic of this nature. Its closing words may appropriately be quoted here:
"We have found a starting point for further attempts, which is a stage higher than any used before. Here the path does not end abruptly in a rocky way; the first steps that we can see form a gentle ascent, and among the rocks there are tracks leading upward. There is no lack of eager and practiced explorers; how can we feel otherwise than hopeful of the success of future attempts?"
How well this prediction of Hertz is to be fulfilled, time is still telling. The young explorer in the untrodden ways of science was cut off in his prime; but the paths he indicated are thronged and frequented by those who reverence his name.
A graceful tribute is paid to the memory of Hertz by his countrymen, who place his name in the daily speech of radio beside those of his predecessors, Volta, Ohm, Ampere, Faraday and Henry. The "Hertz" - is the unit of frequency, a cycle of alternation per second; most used in its multiple, the "kilohertz" (kilocycle). The more general use of this term would be a well-deserved international tribute to a man who has merited much from the entire human race, who are his beneficiaries.
The rare autograph and photograph of Professor Hertz, which Radio-Craft has been privileged to reproduce, is from the large collection of Major William J. Hammer, of New York, a distinguished electrical engineer, and former vice-president of the A. 1. E. E. and the New York Electrical Society. Major Hammer, who was intimately associated with Edison during the development of the electric lamp and its commercial introduction, was in 1889 Edison's personal representative at the Paris exposition, and later accompanied Mr. and Mrs. Edison to the German Scientific congress at Heidelberg. At this time Major Hammer made many acquaintances among European scientists; and he later obtained from Dr. Hertz the original photograph, with the autograph, which remains among the most-prized of the treasures which he has assembled.
Posted October 12, 2015