# Ernst Abbe

Ernst Abbe
( heliogravure after Emil Tesch)
Else Abbe

Ernst Karl Abbe (born January 23, 1840 in Eisenach , Sachsen-Weimar-Eisenach ; † January 14, 1905 in Jena , Sachsen-Weimar-Eisenach; [ ˈabə ], also Ernst Carl Abbe ) was a German physicist , statistician , optician , Industrial and social reformer . Together with Carl Zeiß and Otto Schott, he laid the foundations for modern optics and developed many optical instruments. Since 1899 he was the sole owner of theCarl Zeiss company and was instrumental in founding the company Jenaer Glaswerk Schott & Gen (today Schott AG ).

## Life

Ernst Abbe grew up in Eisenach in simple circumstances. His father Georg Adam Abbe was a foreman in a spinning mill. After attending primary school from 1846 to 1850, thanks to the private support of his father's employer ( Julius von Eichel-Streiber )  , he was able to attend the first-class Realschule - later the Realgymnasium - in Eisenach, which has been Ernst-Abbe's since 1922 for all subsequent historical epochs. Means high school . He graduated from the Realgymnasium in 1857 with the "certificate of maturity" and mostly good grades.

His natural scientific talent, which was already recognizable at the time, combined with a strong will, prompted his father to enable him to study mathematics, physics, astronomy and philosophy in Jena (1857–1859) and in Göttingen (1859–1861) despite his modest financial means . where Ernst Abbe himself earned part of his living as a private teacher. In addition, his father's employer family supported him during his studies in 1858 and 1859. His academic teachers included the mathematician Bernhard Riemann and the physicist Wilhelm Eduard Weber . His doctorate in Göttingen took place on March 23, 1861 on the subject of empirical justification of the principle of equivalence between heat and mechanical work .

He then became an assistant at the Göttingen observatory before he took a brief job (1861–1862) at the Physikalischer Verein in Frankfurt am Main and soon afterwards - on August 8, 1863 - in Jena with the subject of the lawfulness of the distribution of errors series of observations habilitated . He then taught mathematical physics there as a private lecturer . In 1870 Abbe was appointed associate professor (since 1891 released from teaching duties again). In 1873 he was elected a member of the Leopoldina Scholars' Academy . Abbe became director of the Jena observatory in 1878. In 1889 he was elected a corresponding member of the Bavarian Academy of Sciences . Since 1896 he was a corresponding member of the Prussian Academy of Sciences . He was also a member of the Royal Saxon Society of Sciences and the Astronomical Society .

Ernst Abbe married Else Snell in 1871, the daughter of the mathematician and physicist Karl Snell , one of Abbe's teachers . The two daughters Margarete (1872) and Paula (1874) emerged from this marriage . The grave of Abbe and his wife is in the north cemetery of Jena.

## Act

Large microscope from Carl Zeiss (1879) with optics based on calculations by Ernst Abbe

The offer from the university mechanic Carl Zeiss gave his professional life a decisive turnaround in 1866: Abbe, who was particularly interested in the development and improvement of scientific instruments, was to put his microscope production on a solid scientific basis. The trusting cooperation between Abbe and Zeiss could not be shaken by an initial setback: The first microscope built according to Abbe's calculations showed a drop in performance compared to the products of the older production. This fact challenged the physicist Ernst Abbe and led to his theory of image formation in the microscope and to a calculation of the maximum achievable microscopic resolution (see below). This insight was considered so important by Zeiss that he decided to take Abbe into the company as a partner on July 22, 1876 (valid from May 15, 1875). International recognition came on May 1, 1878, through honorary membership in the Royal Microscopical Society in London.

An important prerequisite for the consistently good quality of the optical instruments and their constant improvement lay in the mastery of the production of the various types of glass with reproducible properties and especially in the development of new optical glasses . Abbe was able to persuade Otto Schott from Witten an der Ruhr to build a manufacturing facility in Jena. Carl Zeiss was involved in it together with his son Roderich and Ernst Abbe ("Glastechnisches Laboratorium Schott & Genossen", 1884; later renamed "Jenaer Glaswerke Schott & Gen.", today Schott AG ). The Prussian government granted financial support.

Already during his studies Ernst Abbe successfully worked on a publicly advertised price task from thermodynamics (Jena 1858) and his first biographer Felix Auerbach reported on another price task that was solved in mechanics . These successes already made him known in university circles. His actual publication activity began with the dissertation, empirical justification of the principle of equivalence between heat and mechanical work (Göttingen 1861), followed by a proposal for a modified arrangement of the meridian instruments (1862), which resulted from the brief activity for the Göttingen University Observatory emerged , then the habilitation thesis on the regularity in the distribution of errors in observation series (Jena 1863). Because of his practical work for Carl Zeiss, most of the contributions on the principles of optical imaging and the associated instruments remained either torso - such as the treatise "On Determining the Light Intensity of Optical Instruments etc." (1871) - or unwritten - such as the basic theory of the microscope, of which only brief references in remote journals came about (1873). Therefore, unlike his colleagues, many of the results of the researcher Abbe can only be dated imprecisely. Abbe's contributions to optics include

Ernst Abbe Monument in Jena with the formula in the upper area, erected in 1977
• the refined theory of image errors that can be used in optical calculations (which practically goes beyond Seidel's eikonal);
• the Abbe sine condition of the map;
• the resolution limit after Abbe a microscope to . Here d is the line spacing of an illuminated optical grating, the light wavelength , n the refractive index of the medium between the object and the lens (this can be air, but also a liquid) and half the opening angle of the lens (found around 1870, published in 1873) . In contrast to Helmholtz , Abbe does not start from self-luminous objects, but from coherently illuminated objects. According to Abbe, structures can still be resolved if in the microscope of the diffraction image of the structure, in addition to the 0th order (main maximum), the first secondary maximum also contributes to the formation of the image. For self-luminous objects there is a different mathematical relationship (see resolution (microscopy) ).${\ displaystyle d = {\ frac {\ lambda} {2n \ sin \ alpha}}}$${\ displaystyle \ lambda}$${\ displaystyle \ alpha}$
• the theory of the resolution limit (published in 1873);
• the theory of image formation in the microscope, taking into account the diffraction of light (lecture 1887/88);
• the investigation of the position and size of the apertures .

In addition to the improvement of the "old" objectives, the creation of "homogeneous immersion systems " (1878) and the increase in image fineness through the " apochromats " (1886) produced according to Abbe's calculations should be mentioned among the decisive advances in microscope technology Fluorspar as an optical material as well as through targeted glass-technical research in cooperation with Schott . Of the many new optical devices ascribed to him, the Abbe condenser (lighting apparatus for microscopes, 1869) and the Abbe refractometer (since 1869) are of particular importance.

## Abbe's socio-political work and the establishment of the Carl Zeiss Foundation

The position as co-owner of the Carl Zeiss company not only made Abbe wealthy. At the same time, it sharpened his view of the imbalance that prevailed at the time between employer and employee, especially since he himself had experienced this relationship first hand in his youth. After the death of Carl Zeiss, 24 years his senior (on December 3, 1888), the idea of ​​a foundation took on a solid form, after numerous negotiations with the Grand Ducal State Ministry in Weimar and the university town of Jena. The certificate of the Carl Zeiss Foundation is dated May 19, 1889. The foundation (as a legal person) was initially to be his sole heir in the event of Ernst Abbe's death, subject to certain conditions. In December 1889 Abbe was able to get the founder's son (Roderich Zeiss) to leave the management of the company and only remain a silent partner . The final step took place on May 17 and 18, 1891. After Roderich Zeiss received a severance payment, all shares in the Carl Zeiss company and those shares that Abbe and Zeiss held in Schott & Gen. owned over to the foundation. Abbe was entrusted with the management of the company together with Siegfried Czapski and Otto Schott.

The final determination of the foundation statute and its publication for the workforce did not come about until August 26, 1896.

Abbe's social and political commitment in the last years of his active life (1894–1903) was considerable. He donated the Jena Reading Hall and the Volkshaus as places of party political as well as intellectual-literary life and campaigned with word and deed for higher education and training for the working class. Abbe's practical-political engagement found expression in his socio-political writings, contained in the collected treatises. The measures and suggestions he introduced were always based on a meticulous analysis of the actual conditions, whether it was about the introduction of the eight-hour day at Carl Zeiss or the legality of the ban on assembly in the Grand Duchy of Weimar. Although Abbe was a member of the Liberal People's Party , he campaigned for the Social Democrats .

In 1890 he founded the Jenaer Volksblatt with political friends . This should break the monopoly of the conservative Jenaische Zeitung and be obliged to provide information from all political directions. The sheet was published by Bernhard Vopelius until 1941 with the subtitle "Founded by Professor Ernst Abbe".

The house where Ernst Abbe lived and where he died in Jena
Grave of Ernst Abbe in the north cemetery (Jena)

On September 24, 1903, the workforce received notification of Abbe's resignation from management. She honored him in an unusual way at the beginning of October with a torchlight procession through Jena's streets. The Berliner Tageblatt reported on this on October 3, 1903 and quoted the title of the song at the end: “How could I forget yours”. After leaving the management, Abbe's health deteriorated noticeably. He died on January 14, 1905 in Jena, where the population took an overwhelming share of the funeral services for him. The Berliner Tageblatt of January 18, 1905 dedicated an extensive obituary to him on the front page. At the memorial meeting of the German Physical Society on March 3, 1905, Siegfried Czapski, his long-time employee and successor as the Foundation's representative in the management, said, among other things: “This man, who politically showed himself to be a radical, was an opposition man to the government one of the warmest patriots whose Germany could boast, admittedly not a patriot of big words, but a patriot of action ... ”- He later continued:“ One of the main motives of Ernst Abbe was the following consideration: the advancing expansion of industry and thus the group of people employed in it is unstoppable - so it must be ensured in good time that these people remain or become full members of the bourgeoisie and do not sink to the level of helotism , semi-slavery '. "

Abbe is buried next to his wife in Jena North Cemetery. The Art Nouveau tomb is decorated with a portrait medallion made by Adolf von Hildebrand .

The foundation's commitment to the workforce created a labor peace that was probably unique in the socio-politically turbulent years of the German Empire . Admittedly, precise knowledge of the foundation in the period before the First World War hardly got beyond Jena and the relevant specialist groups, while the optical products of the Carl Zeiss company set standards worldwide. The foundation statute has been changed several times. A completely revised statute was last published in 2004. (See also Carl Zeiss Foundation )

## Awards, honors

Ernst Abbe, relief on his gravestone
Postage stamp 1956

"We microscopists feel obliged above all to Ernst Abbe , whose restless efforts are mainly due to the perfection of our instruments."

- Eduard Strasburger : Botanical internship, 1884

Abbe's profound impact in the fields of device construction and optics led to his name being associated with various terms from this field of work. The best known is the Abbe number . But the Abbe invariant , the Abbe sine condition , the Abbe refractometer , the Abbe comparator principle or the Abbe method also bear his name.

The Ernst Abbe University of Applied Sciences in Jena was named after him. In his honor there is a teaching building for mathematics and physics in Jena Abbeanum . A square, a street, the city library and the football stadium in Jena and streets in many other German cities are also named after him. There are Ernst Abbe grammar schools in Jena , Eisenach , Oberkochen and Berlin-Neukölln . The Ernst Abbe School (school for the visually impaired) in Stuttgart-Zuffenhausen was also named after him in 1991. For some time now, the Technical University of Ilmenau has had the Ernst Abbe Center for Research and Transfer, a research and teaching building that includes the University Language Center and the Institute for Digital Media Technology.

Abbe's work can be viewed in the Optical Museum in Jena . The Ernst Abbe monument is located on Carl-Zeiß-Platz in Jena .

Abbe was depicted in 1956 on the special stamp 110 years Carl Zeiss-Werke Jena of the GDR Deutsche Post .

In 1968 his name was mentioned on a postage stamp of the Deutsche Bundespost with the motif 100 years of scientific microscope construction .

In 1992 the Ernst Abbe Foundation was established, which took over the non-industrial assets of the former Jena Carl Zeiss Foundation .

The asteroid (5224) Abbe and the lunar crater Abbe were named after him.

2018 was in Langel (Cologne-Merkenich) the Ernst Abbe street named after him.

There is also a Abbestrasse in 10587 Berlin. Abbestraßen and Ernst Abbe Streets can also be found in numerous other cities.

## Fonts

• Collected Treatises. G. Fischer, Jena 1904-1940;
• Volume 1: Treatises on the theory of the microscope. 1904;
• Volume 2: Scientific papers from various fields, patent specifications, memorial speeches. 1906;
• Volume 3: Social Policy Writings. 1906;
• Volume 4: Unpublished publications with scientific and technical content. Half 1: The creation of the Schott & Gen. glass factory. According to simultaneous documents from official and personal possessions between March 1882 and January 1885. 1928;
• Volume 5: Development and nature of the Carl-Zeiß-Stiftung based on letters and documents from the time it was founded. 1940.
• The correspondence between Otto Schott and Ernst Abbe about optical glass. 1879–1881 (= publications of the Thuringian Historical Commission. Volume 2, ZDB -ID 999738-6 ). Edited by Herbert Kühnert. G. Fischer, Jena 1946.
• Letters to his youth and college friends Carl Martin and Harald Schütz. 1858-1865. Edited and edited by Volker Wahl and Joachim Wittig with the assistance of Bolko Schweinitz and Annette Vogt . Akademie-Verlag, Berlin 1986, ISBN 3-05-000040-6 .

## literature

• Astronomical Society: Portrait Gallery of the Astronomical Society. Tullberg, Stockholm 1904, p. 7 digitized
• Felix Auerbach : Ernst Abbe - his life, his work, his personality. Academ. Publishing company, Leipzig 1918.
• Sebastian Demel, Peter Steinbach: "No boons - better law". Ernst Abbe as a scientist, entrepreneur and founder . In: Yearbook on Liberalism Research 26 (2014), pp. 271–293.
• Bernd Dörband, Henriette Müller: Ernst Abbe, the unknown genius. Searching for traces in Jena, Eisenach, Göttingen and Frankfurt am Main . Bussert and Stadeler, Jena 2005, ISBN 3-932906-67-5 .
• C. Freitag, Helmut Rechenberg : Ernst Abbe - a physicist and entrepreneur as a social reformer. On the 150th birthday of Ernst Abbe, who founded the Carl Zeiss Foundation 100 years ago . In: Physikalische Blätter , 46, 1990, No. 1., pp. 8-11.
• N. Günther: Abbe, Ernst . In: Charles Coulston Gillispie (Ed.): Dictionary of Scientific Biography . tape 1 : Pierre Abailard - LS Berg . Charles Scribner's Sons, New York 1970, p. 6-9 .
• Theodor HeussAbbe, Ernst Carl. In: New German Biography (NDB). Volume 1, Duncker & Humblot, Berlin 1953, ISBN 3-428-00182-6 , pp. 2-4 ( digitized version ).
• Kerstin Gerth, Wolfgang Wimmer: Ernst Abbe. Scientists, entrepreneurs, social reformers. Jena 2005. (English, German)
• Norbert Günther: Ernst Abbe, creator of the Zeiss Foundation. Scientific publishing company, Stuttgart 1951.
• Klaus Hentschel : Abbe, Ernst Karl. In: Werner E. Gerabek , Bernhard D. Haage, Gundolf Keil , Wolfgang Wegner (eds.): Enzyklopädie Medizingeschichte. De Gruyter, Berlin / New York 2005, ISBN 3-11-015714-4 , p. 1 f.
• Antje Klemm, Nikolaus Knoepffler (ed.): Ernst Abbe as an entrepreneur and social reformer - a contribution to business ethics. Herbert Utz Verlag, Munich 2007, ISBN 978-3-8316-0705-1 . ( PDF ).
• Moritz von Rohr : Ernst Abbe. Verlag G. Fischer, Jena 1940. Verlag G. Fischer, Jena 1946.
• Rüdiger Stolz, Joachim Wittig (eds.): Carl Zeiss and Ernst Abbe. Life, work and meaning. Jena 1993.
• Matthias Steinbach : economists, philanthropists, humanitarian. Professor Socialism in the Academic Province , Berlin 2008.
• Harald Volkmann: Carl Zeiss and Ernst Abbe, their life and their work. Deutsches Museum - treatises and reports; R. Oldenbourg Verlag, Munich; VDI-Verlag, Düsseldorf; 1966, issue 2.
• Wolfgang Zinth, Ursula Zinth: Optics, light rays - waves - photons . 3. Edition. Oldenbourg Verlag, Munich 2011, ISBN 978-3-486-70534-8 , pp. 202-207.

## Movies

Wikisource: Ernst Abbe  - Sources and full texts
Commons : Ernst Abbe  - album with pictures, videos and audio files

Databases

photos

## Individual evidence

1. Ernst Abbe . Springer-Verlag, Frankfurt 2013, lecturer in Frankfurt am Main, p. 31 ( limited preview in Google Book search).
2. Member entry by Ernst Abbe at the German Academy of Natural Scientists Leopoldina , accessed on November 21, 2015.
3. Member entry by Ernst Abbe (with picture) at the Bavarian Academy of Sciences , accessed on February 3, 2016.
4. Ernst Karl Abbe. Corresponding member. In: Berlin-Brandenburg Academy of Sciences (members of the previous academies ).
5. Chronology. In: Association for the preservation of Abbe'schen Gedankenguts eV
6. Guy Cox: Optical Imaging Techniques in Cell Biology . CRC Press, Taylor & Francis Group, Boca Raton, Florida 2012, ISBN 978-1-4398-4825-8 , pp. 15 .
7. ^ Matthias Steinbach : Economists, Philanthropists, Humanitarian. Professor Socialism in the Academic Province , Berlin 2008, pp. 294–317.
8. ^ Berliner Tageblatt , October 3, 1903, evening edition.
9. Berliner Tageblatt , January 18, 1905, morning edition.
10. Photo: The grave of Ernst Abbe. In: knerger.de .
11. ^ Eduard Strasburger : Botanical Practical Course , Foreword to the 1st Edition. Gustav Fischer Verlag, 1884.
12. Central name archive. (pdf, 361 kB) In: Official Gazette of the City of Cologne. July 25, 2018, pp. 304/308 , accessed July 26, 2018 .