A Focus of Discoveries

The following sections are included:

• Preamble

• Preface

• Contents

During the last decades of the 19th century in Germany, industry experienced a marked expansion, to a large extent due to the rapid advances achieved in science and technology. In particular knowledge in the natural sciences saw an impressive growth, which resulted in the generation of a series of new German industries based on high technology. As examples we mention the production of metals and steel, railroad construction and ship-building, cryo-technology, vehicles driven by explosive motors, electrical engineering, optics, mechanical engineering, chemistry, and eventually aviation.

Prior to the foundation of the Physikalisch–Technische Reichsanstalt in the year 1887, several memoranda had been written pointing out the urgent need of the establishment of a research institute financed by the state. The tasks of such a state-operated facility were mainly experimental studies of problems resulting from the rapid industrial development of the time. This became quite clear, for example, in connection with the physical properties of glasses, as well as those of metals and alloys. The precision instruments for surveying provided important motivating material. Good control of the properties of glasses played an important role, for example, in the case of thermometric glass tubes, water-levels made of glass, and the instruments for astronomy continuously demanding higher quality.

Administratively the new Reichsanstalt (Imperial Institute) was under the control of the Ministry of the Interior. However, essentially this control extended only as far as the budget. A much more important role was given to the board, which supervised all activities. It consisted of 24 experts in the field of physics and the precision technique. The board was to meet annually and to evaluate the activities of the previous year and the plans for the next year.

Already soon after the foundation of the Physical–Technical Institute in Berlin it became obvious that it represented a much admired model. World-wide the Reichsanstalt was the first research center supported by the state, the members of which were completely free of any teaching duties in contrast to scientists at the universities and technical colleges. The developments at the Reichsanstalt in Berlin were noted with great interest, particularly abroad. Its leading role as a model can be clearly recognized, for example, in the case of the foundation of the National Physical Laboratory (NPL) in England and of the National Bureau of Standards (NBS) in the USA.

In the years after 1870 the beginning of electric illumination within and also outside of buildings was one of the main reasons for the rapid growth of the electric industry. At the time the development of the technique for the generation, transmission, and utilization of electric energy gained extreme importance.

Already shortly after its foundation the properties of materials at high and at low temperatures represented an important subject for the Reichsanstalt. At the time steam engines were replaced more and more by internal-combustion engines. Therefore, the quantitative investigation of the behavior of gases up to high temperatures and pressures became highly important. In this context there existed a strong interest in experimental data on the specific heat of gases and particularly in the details of the combustion process. During the years 1902 and 1903 at the board meetings of the Reichsanstalt these subjects were discussed extensively. In particular, it was Carl von Linde, a member of the board from 1895 until 1921, who emphasized the great technical–scientific relevance of these questions at the time. In this matter he was supported by Wilhelm Conrad Röntgen, also a board member from 1897 until 1920.

The chemical laboratory was already established in 1887, the year of the foundation of the Reichsanstalt. Franz Mylius, aged 33 years at the time, was charged with the management of this laboratory. He was to occupy this position until his retirement in 1919. In the beginning there were no intentions of developing an ambitious new chemical research program. Instead, the chemical activities were supposed to support the other sections of the PTR. So for a long time the investigations concentrated on the resistance of many types of glasses to chemical substances, a subject playing an important role for many laboratory instruments. At the time Otto Schott represented a key figure in the rapid development of the German optical industry (Optische Werkstätte Carl Zeiss & Co. in Jena) and of the German glass industry. Around 1890 the Glaswerke Schott & Söhne in Jena produced more than eighty different types of glasses. In the case of the PTR, another research area dealt with the purification of metals. For example, there was a need for highly pure antimony, because its melting point served as a fixed point of the temperature scale.

As in the case of the discovery of X-rays, the discovery of radiation caused by natural radioactivity was also the result of pure chance. At the end of the year 1895 Wilhelm Conrad Röntgen had discovered the radiation (named after him in some countries) quite unexpectedly when he performed experiments with gas discharge tubes in Wurzburg. By means of these experiments he wanted to obtain new insight into the electric conductance in gases. On the evening of November 8, 1895 in a completely darkened room, he observed that a piece of paper coated with barium platinocyanide placed on the table next to the discharge tube, which was enclosed within a black carton, lighted up brightly (fluoresced) during each discharge. The effect could not have been caused by the passage of visible light, since the shielding of the tube was impenetrable to light. Röntgen had discovered “a new kind of radiation”, as he formulated it in the title of his corresponding publication.

The following sections are included:

• Einstein’s Arrival in Berlin and the Prehistory

• The Einstein – de Haas Experiment 1915

• The Coincidence Experiment by Geiger and Bothe 1925

• December 1932 — a Depressing Epilogue

The following sections are included:

• The Two Sides of the Particle Concept

• Schrödinger’s Parable of Quantum Statistics

• Electric Quantum Units

The following sections are included:

• A Planck–Einstein Dispute

• Reality as the Maximum Information Available

• A Resumé

Metrology: Science of Measurement. — As briefly as the term may be defined in the “International Dictionary of the Metrology” (1993), its claim of validity is substantial and versatile. Metrology denotes the infrastructure of all methods serving the experimental investigation of nature and in the same way the construction and reliability of technical objects and procedures. This infrastructure is based on measures binding worldwide, and it includes theoretical as well as practical aspects of the measuring process, independent of the required accuracy and of the branch of natural science and technology from which they originated. Because of the agreement on and the worldwide distribution of standards, it also provides procedures for the comparison and calibration of measuring instruments. In other words: metrology guarantees the reliability of the scientific-technical structure of the world. In this way it generates an infrastructure, which is kept hidden behind the historic sequence of physical discoveries and technical inventions. Nevertheless, metrology develops in harmony with the advances of basic research. The roots of scientific metrology are to be found in 19th-century physics and in the technical-scientific upturn during the first 50 years of the activities of the PTR and of the other metrological state institutes at the turn to the 20th century. In the context of the history of the PTR, two important aspects of the infrastructure of measuring technique shall be illustrated here: (a) the coordination of the uniformity of physical measurements within the framework of the Meter Convention (1875), and (b) the importance gained by the recognition of the Principle of Relativity (1905) in the case of the universal definition of the standard of the physical quantity “length” and of the fundamental order of space and time within measuring technique.

The following sections are included:

• Hermann von Helmholtz: President 1888 – 1894

• Friedrich Kohlrausch: President 1895 – 1905

• Emil Warburg: President 1905 – 1922

• Walther Nernst: President 1922 – 1924

• Friedrich Paschen: President 1924 – 1933

The complete political turnabout happening in Germany in the early 1930s affected the PTR in a very special way. Here it meant the attempt to connect a centralism in the politics of science (principle of the leader) in the institution with an anti-semitic ideology in physics, which grew out of the strict rejection of modern physics, characterized as “Jewish”. Quantum theory and the Theory of Relativity were subjected to massive polemics partly sanctioned by the state. A narrowing of scientific perspective towards the established conservative positions of an ideology and the suppression of an uninhibited modern way of thinking were the consequences. In addition there were the effects of the law governing the reestablishment of professional civil service (Gesetz über die Wiederherstellung des Berufsbeamtentums) from April 7, 1933, which enforced the dismissal of those PTR members of Jewish origin. On the one hand, serious reservations and objections mainly directed against the concepts of the Theory of Relativity could be discussed within the standard scientific exchange of the PTR — in Chapter 9 we mentioned the position of Ernst Gehrke. However, on the other hand, the extreme positions of the protagonists of “German Physics”, Johannes Stark and Philipp Lenard, make it very difficult if not impossible for the generation of today to understand the causes of this depressing development and its historic consequences for German science. Certainly, one of the causes was the important new function given to the political parties after the end of the monarchy in 1918; the effect on the PTR was just the consequent application of this to the structure of a large scientific institution of the Reich. However, it appears very difficult to understand that this change was connected with people who themselves had made significant contributions to physics. At this point it is important to listen to a witness of great personal integrity and scientific competence, whose actions since the middle 1920s were closely connected with the PTR, and who had quite essentially affected the fate of the PTR/PTB, assisting in the rebuilding of metrology in the western part of Germany after the Second World War: Max von Laue.

The following sections are included:

• A Metamorphosis of Electrical Base Units

• Physical Implications

• Discoveries Paving the Way

• Conclusion

The following sections are included:

• Literature

• Name Index

• About the Authors