View source for Ernst Abbe

{{short description|German physicist, entrepreneur, and social reformer (1840–1905)}}
{{Use dmy dates|date=January 2023}}
{{Infobox scientist
| honorific_suffix = [[HonFRMS]]
| image = Ernst Abbe (HeidICON 29803) (cropped).jpg
| caption = 
| birth_date = {{birth date|1840|1|23|df=y}} 
| birth_place = [[Eisenach]], [[Saxe-Weimar-Eisenach]]
| death_date = {{death date and age|1905|1|14|1840|1|23|df=y}}
| death_place = [[Jena]], [[German Empire]]
| nationality = German 
| field = [[Physics]]<br />[[Optical engineering]]
| work_institution = [[University of Jena]]
| alma_mater  = {{ubl|[[University of Göttingen]]|[[University of Jena]]}}
| doctoral_advisor = {{ubl|[[Wilhelm Eduard Weber]]|[[Karl Snell]]}}
| doctoral_students = [[Heinrich Friedrich Weber]]
| notable_students  = [[Gottlob Frege]]
| known_for  = {{ubl|[[Abbe refractometer]]|[[Abbe number]]}}
| prizes =
| religion  =  
| footnotes = 
}}

'''Ernst Karl Abbe''' {{post-nominals|list=[[HonFRMS]]}} (23 January 1840 – 14 January 1905)  was a German businessman, optical engineer, physicist, and social reformer. Together with [[Otto Schott]] and [[Carl Zeiss]], he developed numerous optical instruments. He was also a co-owner of [[Carl Zeiss AG]], a German manufacturer of scientific microscopes, astronomical telescopes, planetariums, and other advanced optical systems.

== Personal life ==
[[File:Else Abbe.png|thumb|left|Else Snell]]
Abbe was born 23 January 1840 in [[Eisenach]], [[Saxe-Weimar-Eisenach]],<ref name="NDB">{{harvnb|Blasius|1953|pp=2–3}}</ref> to Georg Adam Abbe and Elisabeth Christina Barchfeldt.<ref name=wws>{{harvnb|Debus|Calinger|Collins|Kennedy|1968|p=2}}</ref> He came from a humble home – his father was a foreman in a spinnery. Supported by his father's employer, Abbe was able to attend secondary school and to obtain the general qualification for university entrance with fairly good grades, at the Eisenach Gymnasium, which he graduated from in 1857.<ref name=gu>{{harvnb|Günther|1970|p=6}}</ref> By the time he left school, his scientific talent and his strong will had already become obvious. Thus, in spite of the family's strained financial situation, his father decided to support Abbe's studies at the Universities of [[University of Jena|Jena]] (1857–1859) and [[University of Göttingen|Göttingen]] (1859–1861).<ref name="NDB"/> During his time as a student, Abbe gave private lessons to improve his income. His father's employer continued to fund him. Abbe was awarded his [[Doctor of Philosophy|PhD]] in Göttingen on 23 March 1861.<ref name=gu/> While at school, he was influenced by [[Bernhard Riemann]] and [[Wilhelm Eduard Weber]], who also happened to be one of the [[Göttingen Seven]].<ref name=gu2>{{harvnb|Günther|1970|p=7}}</ref> This was followed by two short assignments at the Göttingen [[observatory]] and at Physikalischer Verein in [[Frankfurt am Main|Frankfurt]] (an association of citizens interested in physics and chemistry that was founded by [[Johann Wolfgang von Goethe]] in 1824 and still exists today).<ref name=gu2/> On 8 August 1863 he qualified as a university lecturer at the University of Jena. In 1870, he accepted a contract as an associate [[professor]] of experimental [[physics]], [[mechanics]] and [[mathematics]] in Jena.<ref name="NDB"/><ref name=EB>{{harvnb|Hoiberg|2010|p=11}}</ref> In 1871, he married Else Snell, daughter of the mathematician and physicist Karl Snell, one of Abbe's teachers,{{refn|group=nb|Some sources give his wife's name as Elisabeth.<ref name=wws/>}} with whom he had two daughters.<ref name=wws/> He attained full professor status by 1879.<ref name=wws/> He became director of the [[Jena Observatory|Jena astronomical and meteorological observatory]] in 1878.<ref name=EB/>{{refn|group=nb|The dates of his job appointments at the University of Jena, including his appointment as director of the Jena Observatory has some uncertainty, as sources give different dates, as following. 1870: assistant lecturer on mechanics and experimental physics; 1873: associate professor; 1877: director of the Jena Observatory meteorological and astronomy departments.<ref name=wws/>}} In 1889, he became a member of the [[Bavarian Academy of Sciences and Humanities]]. He also was a member of the Saxon Academy of Sciences. He was relieved of his teaching duties at the University of Jena in 1891. Abbe died 14 January 1905 in Jena.<ref name="NDB"/> He was an atheist.<ref>Joseph McCabe (1945). A Biographical Dictionary of Ancient, Medieval, and Modern Freethinkers. Haldeman-Julius Publications. Retrieved 7 April 2013. He was not only a distinguished German physicist and one of the most famous inventors on the staff at the Zeiss optical works at Jena but a notable social reformer, By a generous scheme of profit-sharing he virtually handed over the great Zeiss enterprise to the workers. Abbe was an intimate friend of Haeckel and shared his atheism (or Monism). Leonard Abbot says in his life of Ferrer that Abbe had "just the same ideas and aims as Ferrer."</ref>

== Life work ==
[[File:Microscope Zeiss 1879.jpg|thumb|upright|Microscope by Carl Zeiss (1879) with optics by Abbe]]
[[File:Ernst-Abbe-Denkmal Jena Fürstengraben - 20140802 125709.jpg|thumb|upright|The resolution limit formula engraved in an Ernst Abbe memorial in Jena, Germany]]
[[File:Stamps of Germany (BRD) 1968, MiNr 548.jpg|thumb|upright|German stamp of 1968]]
[[File:Abbe-Grab kl.jpg|thumb|upright|Ernst Abbe, relief at his grave]]In 1866, he became a research director at the [[Carl Zeiss AG|Zeiss Optical Works]], and in 1868 he invented the [[Apochromat|apochromatic lens]], a microscope lens which eliminates both the primary and secondary color distortion.<ref name=EB/> By 1870, Abbe invented the [[Abbe condenser]], used for microscope illumination.<ref name =EB/> In 1871, he designed the first [[refractometer]], which he described in a booklet published in 1874.<ref name=wws/><ref>{{harvnb|Abbe|1874}}</ref>  He developed the laws of image of non-luminous objects by 1872.<ref name=wws/> Zeiss Optical Works began selling his improved microscopes in 1872, including models with homogenous immersion objective by 1877 and his apochromatic objective microscopes in 1886.<ref name=pf>{{harvnb|Pfeiffer|1991|p=445}}</ref> He created the [[Abbe number]], a measure of any [[Transparency (optics)|transparent]] material's variation of [[refractive index]] with [[wavelength]] and Abbe's criterion, which tests the hypothesis, that a systematic trend exists in a set of observations (in terms of resolving power this criterion stipulates that an angular separation cannot be less than the ratio of the wavelength to the aperture diameter, see [[angular resolution]]).<ref>{{harvnb|Joint Committee of Civil Engineers|American Congress on Surveying and Mapping|American Society for Photogrammetry and Remote Sensing|1994}}</ref> Already a professor in [[Jena]], he was hired by [[Carl Zeiss]] to improve the manufacturing process of optical instruments, which back then was largely based on trial and error.

Abbe was the first to define the term [[numerical aperture]],<ref name="NA Est">{{harvnb|Abbe|1881}}</ref> as the sine of the half angle multiplied by the refractive index of the medium filling the space between the cover glass and front lens.

Abbe is credited by many for discovering the resolution limit of the microscope, and the formula (published in 1873)

{{NumBlk|::|<math>d = \frac{\lambda}{2 NA}</math>|{{EquationRef|Eq. 1}}}}

although in a publication in 1874,<ref>{{harvnb|Helmholtz|Fripp|1876}}</ref> [[Helmholtz]] states this formula was first derived by [[Joseph Louis Lagrange]], who had died 61 years prior. Helmholtz was so impressed as to offer Abbe  a professorship at the [[University of Berlin]], which he declined because of his ties to Zeiss.<ref name=gu2/> Abbe was in the camp of the wide aperturists, arguing that microscopic resolution is ultimately limited by the aperture of the optics, but also argued that depending on application there are other parameters that should be weighted over the aperture in the design of objectives. In Abbe's 1874 paper, titled "A Contribution to the Theory of the Microscope and the nature of Microscopic Vision",<ref>{{harvnb|Abbe|1876}}</ref> Abbe states that the resolution of a microscope is inversely dependent on its aperture, but without proposing a formula for the resolution limit of a microscope.

In 1876, Abbe was offered a partnership by Zeiss and began to share in the considerable profits.<ref name=gu2/> Although the first theoretical derivations of {{EquationNote|Eq. 1}} were published by others, it is fair to say that Abbe was the first to reach this conclusion experimentally. In 1878, he built the first homogenous immersion system for the microscope.<ref name=wws/> The objectives that the Abbe Zeiss collaboration were producing were of ideal ray geometry, allowing Abbe to find that the aperture sets the upper limit of microscopic resolution, not the curvature and placement of the lenses. Abbe's first publication of {{EquationNote|Eq. 1}} occurred in 1882.<ref>{{harvnb|Abbe|1883}}</ref> In this publication, Abbe states that both his theoretical and experimental investigations confirmed {{EquationNote|Eq. 1}}. Abbe's contemporary Henry Edward Fripp, English translator of Abbe's and Helmholtz's papers, puts their contributions on equal footing. He also perfected the [[Interference (wave propagation)|interference method]] by [[Fizeau]], in 1884.<ref name=wws/> Abbe, Zeiss, Zeiss' son, [[Roderich Zeiss]], and [[Otto Schott]] formed, in 1884, the [[Schott AG|Jenaer Glaswerk Schott & Genossen]]. This company, which in time would in essence merge with Zeiss Optical Works, was responsible for research and production of 44 initial types of optical glass.<ref name=pf/> Working with [[telescope]]s, he built an image reversal system in 1895.<ref name=wws/>

In order to produce high quality objectives, Abbe made significant contributions to the diagnosis and correction of [[optical aberration]]s, both [[spherical aberration]] and [[coma aberration]], which is required for an objective to reach the resolution limit of {{EquationNote|Eq. 1}}. In addition to spherical aberration, Abbe discovered that the rays in optical systems must have constant angular magnification over their angular distribution to produce a diffraction limited spot, a principle known as the [[Abbe sine condition]].<ref name="NA Est"/> So monumental and advanced were Abbe's calculations and achievements that [[Frits Zernike]] based his [[Phase contrast microscopy|phase contrast]] work on them, for which he was awarded the [[Nobel Prize]] in 1953, and [[Hans Busch (physicist)|Hans Busch]] used them to work on the development of the [[electron microscope]].<ref name=gu2/>

During his association with [[Carl Zeiss]]' [[microscope]] works, not only was he at the forefront of the field of optics but also labor reform. He founded the [[Social Democratic Party of Germany|social democratic]] Jenaische Zeitung (newspaper) in 1890<ref>{{Cite book|last=Walter|first=Rolf|url=https://books.google.com/books?id=fqPstAEACAAJ|title=Carl Zeiss: Zeiss 1905–1945|date=1996|publisher=Böhlau Verlag|isbn=978-3-412-11096-3|pages=25|language=de}}</ref> and in 1900, introduced the [[Eight hour day|eight-hour workday]], in remembrance of the 14-hour workday of his own father.<ref name=pf/> In addition, he created a pension fund and a discharge compensation fund.<ref name=wws/> In 1889, Ernst Abbe set up and endowed the [[Carl Zeiss Foundation]] for research in science.<ref name=wws/> The aim of the foundation was "to secure the economic, scientific, and technological future and in this way to improve the job security of their employees."<ref name=pf/> He made it a point that the success of an employee was based solely on their ability and performance, not on their origin, religion, or political views.<ref name=pf/> In 1896, he reorganized the Zeiss optical works into a cooperative with profit-sharing.<ref name=EB/> His social views were so respected as to be used by the [[Prussia]]n state as a model and idealized by [[Alfred Weber]] in the 1947 book ''Schriften der Heidelberger Aktionsgruppe zur Demokratie und Zum Freien Sozialismus'' (''Writings of the Heidelberg Action Group on Democracy and Free Socialism'').<ref>{{harvnb|Günther|1970|p=9}}</ref>

The crater [[Abbe (crater)|Abbe]] on the [[Moon]] was named in his honour.<ref>{{Gazetteer of Planetary Nomenclature |id=9 |name=Abbe}}</ref>

==Bibliography==
Abbe was a pioneer in optics, lens design, and microscopy, and an authority of his time. He left us with numerous publications of his findings, inventions, and discoveries. Below is a list of publications he authored including many links to the scanned Google Books pages.
{{div col|colwidth=30em}}
* {{Cite journal | last = Abbe | first = Ernst | volume = 9 | pages = 469–480 | title = Über einen neuen Beleuchtungsapparat am Mikroskop | journal = Archiv für mikroskopische Anatomie | year = 1873 | url = https://books.google.com/books?id=LMkVAAAAYAAJ&q=abbe&pg=PA469 | doi=10.1007/bf02956177 | trans-title = About a New Illumination Apparatus to the Microscope | publisher = Verlag von Max Cohen & Sohn | location = Bonn, Germany | s2cid = 119495892 | language = de | ref=none | url-access = subscription }}
* {{Cite journal | last = Abbe | first = Ernst | doi = 10.1007/BF02956173 | issn = 0176-7364 | volume = 9 | issue = 1 | pages = 413–468 | title = Beiträge zur Theorie des Mikroskops und der mikroskopischen Wahrnehmung | journal = Archiv für Mikroskopische Anatomie | access-date = 27 August 2010| year = 1873| url = https://books.google.com/books?id=LMkVAAAAYAAJ&q=Abbe%20Archiv%20f%C3%BCr%20Mikroskopische%20Anatomie%201873&pg=PA413 | trans-title = Contributions to the Theory of the Microscope and of Microscopic Perception | author-mask = 2 | ref=none | publisher = Verlag von Max Cohen & Sohn | location = Bonn, Germany | s2cid = 135526560 | language = de }}
* {{Cite journal | last = Abbe | first = Ernst | volume = 8 | pages = 96–174 | title = Neue Apparate zur Bestimmung des Brechungs und Zerstreuungsvermögens fester und flüssiger Körper | journal = Jenaische Zeitschrift für Naturwissenschaft | year = 1874 | url = https://books.google.com/books?id=87UUAAAAYAAJ&q=Jenaische%20Zeitschrift%20f%C3%BCr%20Naturwissenschaft%20Volume%208&pg=PA96 | trans-title = New Equipment for Determining the Refraction and Dispersion Property of Solids and Liquids | location = Jena, Germany | language = de | publisher = Mauke's Verlag | author-mask = 2 |ref=none }}
* {{Cite journal | last = Abbe | first = Ernst | volume = 13 | issue = 2 | pages = 77–82 | title = A New Illuminating Apparatus for the Microscope | journal = The Monthly Microscopical Journal | year = 1875 | url = https://books.google.com/books?id=sOEUAAAAYAAJ&q=A%20new%20illuminating%20apparatus%20for%20the%20microscope%201875%20abbe&pg=PA77 | doi=10.1111/j.1365-2818.1875.tb00845.x | publisher = Robert Hardwicke | location = London, UK |ref=none | author-mask = 2 | url-access = subscription }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Lawson | editor-first = Henry | volume = 1 | pages = 200–261 | title = A Contribution to the Theory of the Microscope and the Nature of Microscopic Vision | journal = Proceedings of the Bristol Naturalists' Society | year = 1876 | url = https://books.google.com/books?id=TC8UAAAAYAAJ&q=Bristol%20Naturalists%20Society%201875&pg=PA200 | publisher = Williams & Northgate | location = London, UK | translator = Fripp, H. E. | author-mask = 2 |ref=none }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Lawson | editor-first = Henry | volume = 14 | issue = 4 | pages = 191–201 | title = Extracts from Dr. H. E. Fripp's Translation of Professor Abbe's Paper on the Microscope | journal = The Monthly Microscopical Journal | year = 1875 | url = https://books.google.com/books?id=UTA4AAAAMAAJ&q=On%20the%20microscope%20abbe%201875%20monthly&pg=PA191 | publisher = Williams & Northgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2| doi = 10.1111/j.1365-2818.1875.tb00067.x | url-access = subscription }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Lawson | editor-first = Henry | volume = 14 | pages = 245–254 | title = Extracts from Dr. H. E. Fripp's Translation of Professor Abbe's Paper on the Microscope (Cont.) | journal = The Monthly Microscopical Journal | year = 1875 | url = https://books.google.com/books?id=UTA4AAAAMAAJ&q=On%20the%20microscope%20abbe%201875%20monthly&pg=PA245 | publisher = Williams & Northgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2| doi = 10.1111/j.1365-2818.1875.tb00076.x | url-access = subscription }}
* {{Cite journal | last = Abbe | first = Ernst | pages = 11–17 | title = Über mikrometrische Messung mittelst optischer Bilder | journal = Jenaische Zeitschrift für Naturwissenschaft  | year = 1878 | url = https://books.google.com/books?id=nbcUAAAAYAAJ&q=ueber%20mikrometrische%20messung%20mittelst%20optischer%20bilder&pg=PR11 | trans-title = About Micrometric Measurement by Means of Optical Images | publisher = Verlag Von Gustav Fischer | location = Jena, Germany | language = de | author-mask = 2 |ref=none }}
* {{Cite journal | last = Abbe | first = Ernst | pages = 98–105 | title = Über Blutkörper-Zählung | journal = Jenaische Zeitschrift für Naturwissenschaft | year = 1878 | url = https://books.google.com/books?id=nbcUAAAAYAAJ&q=Uber%20Blutkoerper%20Zahlung&pg=PR98 | trans-title = About Counting Blood Cells | publisher = Verlag Von Gustav Fischer | location = Jena, Germany | language = de | author-mask = 2 |ref=none }}
* {{Cite journal | last = Abbe | first = Ernst | pages = 129–142 | title = Über die Bedingungen des Aplanatismus der Linsensysteme | journal = Jenaische Zeitschrift für Naturwissenschaft  | year = 1878 | url = https://books.google.com/books?id=nbcUAAAAYAAJ&q=Ueber%20die%20Bedingungen%20des%20Aplanatis&pg=PA129 | trans-title = The Conditions Under Which Aplanatism of the Lens Systems | publisher = Verlag Von Gustav Fischer | location = Jena, Germany | language = de | author-mask = 2 |ref=none }}
* {{Cite journal | last = Abbe | first = Ernst | pages = 71–109 | title = Über die Grenzen der geometrischen Optik | journal = Jenaische Zeitschrift für Naturwissenschaft   | year = 1878 | url = https://books.google.com/books?id=nbcUAAAAYAAJ&q=Ueber%20die%20Grenzen%20der%20geometrischen%20Optik&pg=RA1-PA71 | trans-title = Beyond the Limits of Geometric Optics | publisher = Verlag Von Gustav Fischer | location = Jena, Germany | language = de | author-mask = 2 |ref=none }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 2 | issue = 3 | pages = 256–265 | title = On Stephenson's System of Homogeneous Immersion for Microscope Objectives | journal = Journal of the Royal Microscopical Society | date = 11 June 1879 | url = https://books.google.com/books?id=d_MVAAAAYAAJ&q=Stephenson's%20System%20abbe&pg=PA256 | doi=10.1111/j.1365-2818.1879.tb01651.x | publisher = Williams & Norgate | location = London, UK | author-mask = 2|ref=none | url-access = subscription }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 2 | issue = 7 | pages = 812–824 | title = On New Methods for Improving Spherical Correction applied to the Construction of Wide-angled Object-glasses | journal = Journal of the Royal Microscopical Society | year = 1879 | url = https://books.google.com/books?id=d_MVAAAAYAAJ&q=Stephenson's%20System%20abbe&pg=PA812 | doi=10.1111/j.1365-2818.1879.tb01548.x | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2| url-access = subscription }}
* {{Cite journal | last = Abbe | first = Ernst | pages = 57–66 | title = Über die Bestimmung von Zeit und Polhöhe aus Beobachtungen in Höhenparallen | journal = Jenaische Zeitschrift für Naturwissenschaft | date = 2 May 1879 | url = https://books.google.com/books?id=nbcUAAAAYAAJ&q=Uber%20die%20Bestimmung%20von%20Zeit%20and%20Abbe&pg=PA57 | trans-title = The Determination of Time and Latitude Observations Made in Höhenparallen | publisher = Verlag Von Gustav Fischer | location = Jena, Germany | language = de | author-mask = 2 |ref=none }}
* {{Cite journal | last = Abbe | first = Ernst | pages = 35–44 | title = Über die Bestimmung der Brechungs-Verhältnisse fester Körper mittelst des Refractometers | journal = Jenaische Zeitschrift für Naturwissenschaft | date = 21 February 1879 | url = https://books.google.com/books?id=nbcUAAAAYAAJ&q=Uber%20die%20Bestimmung%20von%20Zeit%20and%20Abbe&pg=PA35 | trans-title = The Determination of the Refractive Ratios of Solids by Means of Refractometers | publisher = Verlag Von Gustav Fischer | location = Jena, Germany | language = de | author-mask = 2 |ref=none }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 3 | pages = 509–515 | title = Conditions on Aplanatism of Systems of Lenses | journal = Journal of the Royal Microscopical Society | year = 1880 | url = https://books.google.com/books?id=xe4BAAAAYAAJ&q=Conditions%20of%20microsteroscopic%20vision%201%20Abbe&pg=PA831 | publisher = Williams & Norgate | location = London, UK | author-mask = 2 |ref=none }}{{failed verification|date=May 2015}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 3 | pages = 20–31 | title = Some Remarks on the Apertometer | journal = Journal of the Royal Microscopical Society | year = 1880 | url = https://books.google.com/books?id=YOAUAAAAYAAJ&q=Some%20remarks%20on%20the%20apertometer%20abbe%20v%203&pg=PA20 | doi=10.1111/j.1365-2818.1880.tb05648.x | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2| url-access = subscription }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 1 | pages = 831 | title = Conditions of Aplanatism for Wide-angled Pencils | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1880 | url = https://books.google.com/books?id=mXBJAAAAYAAJ&q=Microscopy%20Society%20Journal%201880%20Abbe%20509&pg=PA509 | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 1 | pages = 526 | title = The Essence of Homogeneous Immersion | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1881 | url = https://books.google.com/books?id=xe4BAAAAYAAJ&q=Conditions%20of%20microsteroscopic%20vision%201%20Abbe&pg=PA526 | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 1 | pages = 690–692 | title = Illumination for Binocular Microscopes with High Powers | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1881 | url = https://books.google.com/books?id=xe4BAAAAYAAJ&q=Conditions%20of%20microsteroscopic%20vision%201%20Abbe&pg=PA690 | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 1 | pages = 831–832 | title = Penetrating Power of Objectives | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1881 | url = https://books.google.com/books?id=xe4BAAAAYAAJ&q=Conditions%20of%20microsteroscopic%20vision%201%20Abbe&pg=PA831 | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | volume = 17 | pages = 197–224 | title = Beschreibung eines neuen stereoskopischen Oculars | journal = Repertorium für Experimental-Physik für Physikalische Technik | year = 1881 | url = https://books.google.com/books?id=1UzPAAAAMAAJ&q=Beschreibung%20eines%20neuen%20stereo%20a%20197&pg=PA197 | trans-title = Description of a New Stereoscopic Eye-piece | language = de | publisher = Druck und Verlag Von R. Oldenbourg | location = Munich, Germany | author-mask = 2 |ref=none }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 1 | pages = 131–134 | title = Origin of Homogeneous Immersion | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1881 | url = https://books.google.com/books?id=xe4BAAAAYAAJ&q=Journal%20of%20the%20Royal%20Microscopical%20Society%20Abbe%20On%20the%20Function%20of%20Aperture&pg=PA131 | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 1 | pages = 680–689 | title = Conditions of Microstereoscopic Vision – "Penetration" | series = 2 | year = 1881 | url = https://books.google.com/books?id=xe4BAAAAYAAJ&q=Conditions%20of%20microsteroscopic%20vision%201%20Abbe&pg=PA680 | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 1 | issue = 3 | pages = 388–423 | title = On the Estimation of Aperture in the Microscope | journal = Journal of the Royal Microscopical Society | year = 1881 | url = https://books.google.com/books?id=xe4BAAAAYAAJ&q=Conditions%20of%20microsteroscopic%20vision%201%20Abbe&pg=PA388 | doi=10.1111/j.1365-2818.1881.tb05909.x | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2| doi-access = free }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 1 | issue = 2 | pages = 203–211 | title = On the Conditions of Orthoscopic and Pseudoscopic Effects in the Binocular Microscope | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1881 | url = https://books.google.com/books?id=xe4BAAAAYAAJ&q=Conditions%20of%20microsteroscopic%20vision%201%20Abbe&pg=PA203 | doi=10.1111/j.1365-2818.1881.tb05902.x | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 1 | pages = 298–299 | title = Abbe's Stereoscopic Eye-piece | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1881 | url = https://books.google.com/books?id=xe4BAAAAYAAJ&q=Conditions%20of%20microsteroscopic%20vision%201%20Abbe&pg=PA298 | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 2 | pages = 693–696 | title = Miniatured Images | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1882 | url = https://books.google.com/books?id=Oks4AAAAMAAJ&q=Miniature%20images%202%201882%20Journal%20Abbe&pg=PA693 | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 2 | issue = 3 | pages = 300–309 | title = The Relation of Aperture and Power in the Microscope | journal = Journal of the Royal Microscopical Society | year = 1882 | url = https://books.google.com/books?id=KPQVAAAAYAAJ&q=Journal%20of%20Microscopy%201881%20%22The%20Relation%20of%20Aperture%20and%20Power%20in%20the%20Microscope%22&pg=PA300 | doi=10.1111/j.1365-2818.1882.tb00190.x | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 2 | issue = 1 | pages = 460–473 | title = The Relation of Aperture and Power in the Microscope (continued) | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1882 | url = https://books.google.com/books?id=4r4EAAAAQAAJ&q=Journal%20of%20the%20Royal%20Microscopical%20Society%20%201881&pg=PA460 | doi=10.1111/j.1365-2818.1882.tb04805.x | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2| url-access = subscription }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 3 | issue = 1 | pages = 790–812 | title = The Relation of Aperture and Power in the Microscope (continued) | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1883 | url = https://books.google.com/books?id=aHhJAAAAYAAJ&q=The%20Relation%20of%20Aperture%20and%20Power%20in%20the%20Microscope%20abbe&pg=PA790 | doi=10.1111/j.1365-2818.1883.tb05956.x | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2| url-access = subscription }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 4 | issue = 1 | pages = 348–351 | title = Note on the Proper Definition of the Amplifying Power of a Lens or Lens-System | journal = Journal of the Royal Microscopical Society | year = 1884 | url = https://books.google.com/books?id=th4AAAAAMAAJ| doi=10.1111/j.1365-2818.1884.tb01110.x | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2}}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 4 | issue = 1 | pages = 20–27 | title = On the Mode of Vision with Objectives of Wide Aperture | journal = Journal of the Royal Microscopical Society | year = 1884 | url = https://books.google.com/books?id=th4AAAAAMAAJ&q=Journal%20of%20the%20Royal%20Microscopical%20society%201884&pg=PA20 | doi=10.1111/j.1365-2818.1884.tb02005.x | publisher = Williams & Norgate | location = London, UK | author-mask = 2 | ref=none | editor-mask = 2| url-access = subscription }}
* {{Cite journal | last = Abbe | first = Ernst | volume = 2 | pages = 107–108 | title = The new microscope | journal = S Ber Jena Ges Med | year = 1886 | author-mask = 2 |ref=none }}{{Full citation needed|date=May 2015}}
* {{Cite book | last = Abbe | first = Ernst | title = Über Verbesserungen des Mikroscope mit Hilfe neuer Arten optischen Glases | year = 1886 | trans-title = About Enhancements of the Microscope Using New Types of Optical Glass | language = de | url = https://books.google.com/books?id=6vMYAAAAYAAJ&q=%C3%9Cber+Verbesserungen+des+Mikroscope+mit+Hilfe+neuer+Arten+optischen+Glases&pg=PT4 | author-mask = 2 |ref=none }}
* {{Cite journal | last = Abbe | first = Ernst | volume = 10 | pages = 446–447 | title = Messapparate für Physiker | journal = Zeitschrift für Instrumentenkunde | year = 1890 | language = de | trans-title = Measuring Equipment for Physicists | author-mask = 2 |ref=none }}
* {{Cite book | last = Abbe | first = Ernst | publisher = Google Patents | title = Double Prism for Totally-Reflecting Refractometers | year = 1895 | author-mask = 2 |ref=none }}
* {{Cite book | last = Abbe | first = Ernst | publisher = Vopelius | title = Motive und Erläuterungen zum Entwurf eines Statuts der Carl Zeiss-Stiftung | year = 1895 | trans-title = Motives and Explanations on the Draft Statute of the Carl Zeiss Foundation | language = de | author-mask = 2 |ref=none }}
* {{Cite journal | last1 = Abbe | first1 = Ernst | last2 = Rudolph | first2 = P. | volume = 99722 | title = Anamorphotisches Linsensystem | journal = German Pat | year = 1897 | trans-title = Anamorphic Lens System | language = de | author-mask = 2 |ref=none }}
* {{cite book | last = Abbe | first = Ernst | title = Gesammelte Abhandlungen | language = de | trans-title = Collected Essay | year = 1904 | lccn = 94235187 | others = 5 volumes, released from 1904 until 1940 | publisher = Hildesheim | location = New York, NY | author-mask = 2 |ref=none }}
* {{Cite book | last1 = Abbe | first1 = Ernst | last2 = Lummer | first2 = Otto | last3 = Reiche | first3 = Fritz | publisher = F. Vieweg und Sohn | location = Braunschweig, Germany | title = Die Lehre von der Bildentstehung im Mikroskop | year = 1910 | trans-title = The Theory of Image Formation in the Microscope | language = de | lccn = 10017693 | author-mask = 2 |ref=none }}
* {{Cite book | last = Abbe | first = Ernst | publisher = Gustav Fischer | location = Jena, Germany | title = Sozialpolitische Schriften | year = 1921 | language = de | trans-title = Socio-political Writings | lccn = 49036118 | author-mask = 2 |ref=none }}
{{div col end}}
<!-- Holding off on these as these are not written as a bibliography would indicate. I am not sure the best way to add them in.
 * {{Citation | last = Abbe | first = Ernst | title = Telescope | location = Jena, Germany | accessdate = 27 August 2010| date = 22 June 1897| url = http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=0584976.PN.&OS=PN/0584976&RS=PN/0584976}}

* {{Citation| last = Abbe| first = Ernst| author2 = Paul Rudoph| title = Photographic Objective| location = Jena| access-date = 27 August 2010| date = 26 August 1890| url = http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=0435271.PN.&OS=PN/0435271&RS=PN/0435271}}
* {{Cite journal | volume = 1 | last = Abbe | first = E. | title = Die optischen Hilfsmittel der Mikroskopie. Bericht über die wissenschaftlichen Apparate auf der Londoner internationalen Ausstellung (1876), Hrsg. Hoffmann, AW (1878), Braunschweig, 383 | journal = Abbe, E.(1904), Gesammelte Abhandlungen, Bd | year = 1876 }} -->

==See also==
{{div col|colwidth=30em}}
*[[Abbe condenser]]
*[[Diffraction-limited system#The Abbe diffraction limit for a microscope|Abbe diffraction limit]]
*[[Abbe error]]
*[[Eyepiece#Orthoscopic or "Abbe"|Abbe eyepiece]]
*[[Abbe number]]
*[[Abbe prism]]
*[[Abbe refractometer]]
*[[Abbe sine condition]]
*[[Abbe–Koenig prism]]
*[[Porro–Abbe prism|Abbe–Porro prism]]
*[[Aberration in optical systems]]
*[[Crown glass (optics)]]
*[[Dermatoscopy]]
*[[Diaphragm (optics)]]
*[[Calculation of glass properties]]
*[[Optical aberration]]
*[[Optical dilatometer]]
*[[German inventors and discoverers]]
{{div col end}}

==Notes==
{{reflist|group=nb}}

==References==
{{Reflist}}

===Sources===
* {{Cite journal | last = Abbe | first = Ernst | volume = 8 | pages = 96–174 | title = Neue Apparate zur Bestimmung des Brechungs und Zerstreuungsvermögens fester und flüssiger Körper | journal = Jenaische Zeitschrift für Naturwissenschaft | year = 1874 | url = https://books.google.com/books?id=87UUAAAAYAAJ&q=Jenaische%20Zeitschrift%20f%C3%BCr%20Naturwissenschaft%20Volume%208&pg=PA96 | trans-title = New Equipment for Determining the Refraction and Dispersion Property of Solids and Liquids | location = Jena, Germany | language = de | publisher = Mauke's Verlag }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Lawson | editor-first = Henry | volume = 1 | pages = 200–261 | title = A Contribution to the Theory of the Microscope and the Nature of Microscopic Vision | journal = Proceedings of the Bristol Naturalists' Society | year = 1876 | url = https://books.google.com/books?id=TC8UAAAAYAAJ&q=Bristol%20Naturalists%20Society%201875&pg=PA200 | publisher = Williams & Northgate | location = London, UK | translator = Fripp, H. E. }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 1 | issue = 3 | pages = 388–423 | title = On the Estimation of Aperture in the Microscope | journal = Journal of the Royal Microscopical Society | year = 1881 | url = https://books.google.com/books?id=xe4BAAAAYAAJ&q=Conditions%20of%20microsteroscopic%20vision%201%20Abbe&pg=PA388 | doi=10.1111/j.1365-2818.1881.tb05909.x | publisher = Williams & Norgate | location = London, UK | doi-access = free }}
* {{Cite journal | last = Abbe | first = Ernst | editor-last = Crisp | editor-first = Frank | volume = 3 | issue = 1 | pages = 790–812 | title = The Relation of Aperture and Power in the Microscope (continued) | journal = Journal of the Royal Microscopical Society | series = 2 | year = 1883 | url = https://books.google.com/books?id=aHhJAAAAYAAJ&q=The%20Relation%20of%20Aperture%20and%20Power%20in%20the%20Microscope%20abbe&pg=PA790 | doi=10.1111/j.1365-2818.1883.tb05956.x | publisher = Williams & Norgate | location = London, UK | url-access = subscription }}
* {{cite encyclopedia | last = Blasius | first = Ewald | year = 1953 | title = Abbe, Ernst Carl | encyclopedia = Neue Deutsche Biographie | language = de | location = Berlin, Germany | publisher = Duncker & Humblot | lccn = 54001573 }}
* {{cite encyclopedia | editor1-last = Debus | editor1-first = Allen G. | editor2-last = Calinger | editor2-first = Ronald S. | editor3-last = Collins | editor3-first = Edward J. | editor4-last = Kennedy | editor4-first = Stephen J. | encyclopedia = World Who's Who in Science: A Biographical Dictionary of Notable Scientists from Antiquity to the Present | publisher = A. N. Marquis Company | location = Chicago, IL | title = Abbe, Ernst Karl | isbn = 978-0-8379-1001-7 | lccn = 68056149 | year = 1968 | url-access = registration | url = https://archive.org/details/worldwhoswhoinsc0000unse }}
* {{cite encyclopedia | last = Günther | first = Norbert | editor-last = Gillispie | editor-first = Charles Coulston | title = Abbe, Ernst | encyclopedia = [[Dictionary of Scientific Biography]] | year = 1970 | location = New York, NY | publisher = Charles Scribner's Sons | volume = I: Pierre Abailard – L. S. Berg | pages = 6–9 | isbn = 978-0-684-10112-5 | lccn = 69018090 }}
* {{Cite journal | last1 = Helmholtz | first1 = Hermann | last2 = Fripp | first2 = Henry Edward | volume = 16 | pages = 15–39 | title = On the Limits of the Optical Capacity of the Microscope | journal = The Monthly Microscopical Journal | issue = 1 |date = July 1876 | doi = 10.1111/j.1365-2818.1876.tb05606.x | url = https://zenodo.org/record/1433195 }}
* {{cite encyclopedia | editor-last = Hoiberg | editor-first = Dale H. | encyclopedia = Encyclopædia Britannica | title = Abbe, Ernst | edition = 15th | year = 2010 | publisher = Encyclopædia Britannica, Inc. | volume = I: A-Ak – Bayes | location = Chicago, IL | isbn = 978-1-59339-837-8 | lccn = 2008934270 | url-access = registration | url = https://archive.org/details/newencyclopaedia2009ency }}
* {{cite book | author = Joint Committee of Civil Engineers | author2 = American Congress on Surveying and Mapping | author3 = American Society for Photogrammetry and Remote Sensing | name-list-style=amp| title = Glossary of the Mapping Sciences | year = 1994 | publisher = American Society of Civil Engineers | location = New York, NY | lccn = 94030078 | isbn = 978-0-7844-0050-0 }}
* {{cite encyclopedia | last = Pfeiffer | first = Wolfgang | editor-last1 = Hast | editor-first1 = Adele | editor-last2 = Pascal | editor-first2 = Diane B. | editor-last3 = Berney | editor-first3 = Kate | editor-last4 = Barbour | editor-first4 = Philippe A. | editor-last5 = Griffin | editor-first5 = Jessica | title = Carl-Zeiss-Stiftung | pages = 445–447 | encyclopedia = International Directory of Company Histories | volume = III: Health & Personal Care Products – Materaials | publisher = St James Press | location = Chicago, IL | year = 1991 | isbn = 978-1-55862-059-9 | lccn = 89190943 }}

==Further reading==
* {{cite web|last=Sella |first=Andrea |title=Abbé's refractometer |series=Chemistry World |date=November 2008 |page=67 |url=http://www.rsc.org/chemistryworld/Issues/2008/November/AbbesRefractometer.asp |website=Royal Society of Chemistry |access-date=6 May 2015 |archive-date=24 September 2015 |archive-url=https://web.archive.org/web/20150924125635/http://www.rsc.org/chemistryworld/Issues/2008/November/AbbesRefractometer.asp |url-status=live  }}
* Volkmann, Harald. "Ernst Abbe and his work." ''Applied Optics'' 5.11 (1966): 1720–1731.

==External links==
{{Commons}}
*[https://diversedaily.com/ernst-karl-abbe-revolutionizing-optics-and-microscopy/ Abbe's contributions]
*{{cite web | author = Paselk, Richard A. | title = The Evolution of the Abbe Refractometer | url = https://www2.humboldt.edu/scimus/Essays/EvolAbbeRef/EvolAbbeRef.htm | access-date = 11 May 2008 | archive-date = 29 November 2021 | archive-url = https://web.archive.org/web/20211129150422/https://www2.humboldt.edu/scimus/Essays/EvolAbbeRef/EvolAbbeRef.htm | url-status = dead }}
*[http://www.atago.net/USA/mame.html Basic Principles of Refractometers (and Polarimeters) ]
*{{MacTutor Biography|id=Abbe}}
*{{MathGenealogy|id=52329}}
*[http://micro.magnet.fsu.edu/optics/timeline/people/abbe.html Molecular Expressions's biography]
* {{Gutenberg author |id=8866| name=Ernst Abbe}}
* {{Internet Archive author |sname=Ernst Karl Abbe}}
*[http://www.musoptin.com/abbe_ref_2028.html Abbe Refractometer] by Carl Zeiss made in 1904
* {{PM20|FID=pe/000012}}

{{Authority control}}

{{DEFAULTSORT:Abbe, Ernst}}

[[Category:1840 births]]
[[Category:1905 deaths]]
[[Category:19th-century German businesspeople]] 
[[Category:19th-century German inventors]]
[[Category:19th-century German physicists]]
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[[Category:Carl Zeiss AG people]]
[[Category:Fellows of the Royal Microscopical Society]]
[[Category:German atheists]]
[[Category:German manufacturing businesspeople]]
[[Category:German scientific instrument makers]]
[[Category:History of glass]]
[[Category:Glass engineering and science]]
[[Category:Glass physics]]
[[Category:Lens designers]]
[[Category:Members of the Göttingen Academy of Sciences and Humanities]]
[[Category:Members of the Prussian Academy of Sciences]]
[[Category:Microscopists]]
[[Category:Optical engineers]]
[[Category:People from Eisenach]]
[[Category:People from Saxe-Weimar-Eisenach]]
[[Category:University of Göttingen alumni]]
[[Category:University of Jena alumni]]