Ernst Emil Alexander Back
Encyclopedia
Ernst Emil Alexander Back (October 21, 1881 – June 20, 1959) was a German physicist
, born in Freiburg
. He attended school in Strasbourg
until 1900, and from 1902 until 1906 studied law in Strasbourg
, Munich
, and Berlin. He then worked in the legal profession in Alsace-Lorraine
until 1909, afterwards taking leave to study physics in Tübingen
. He retired from the legal profession in 1912, and earned his Ph.D.
in 1913. His thesis, titled Zur Prestonschen Regel, was on the subject of what would later be called the Paschen-Back effect, and was named after Back and Friedrich Paschen
.
Between 1914 and 1918 he served with the German army
during World War I
. Following this conflict he became head of a Veifa-Werke laboratory in Frankfurt am Main
, a company that produced electrical and X-ray equipment. In 1920 he left to become an assistant at the Physics Institute in Tübingen
. He was promoted to professor in 1926 at Hohenheim University, and became a full professor in 1929. He remained at this post until 1936 when he returned to become a professor at Tübingen.
From 1926 to 1927 Samuel Abraham Goudsmit
worked with Back to make the first measurement of nuclear spin and its Zeeman effect
.
Back retired in 1948, and died in Munich
over a decade later. The crater Back
on the Moon
is named in his memory.
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
, born in Freiburg
Freiburg
Freiburg im Breisgau is a city in Baden-Württemberg, Germany. In the extreme south-west of the country, it straddles the Dreisam river, at the foot of the Schlossberg. Historically, the city has acted as the hub of the Breisgau region on the western edge of the Black Forest in the Upper Rhine Plain...
. He attended school in Strasbourg
Strasbourg
Strasbourg is the capital and principal city of the Alsace region in eastern France and is the official seat of the European Parliament. Located close to the border with Germany, it is the capital of the Bas-Rhin département. The city and the region of Alsace are historically German-speaking,...
until 1900, and from 1902 until 1906 studied law in Strasbourg
Strasbourg
Strasbourg is the capital and principal city of the Alsace region in eastern France and is the official seat of the European Parliament. Located close to the border with Germany, it is the capital of the Bas-Rhin département. The city and the region of Alsace are historically German-speaking,...
, Munich
Munich
Munich The city's motto is "" . Before 2006, it was "Weltstadt mit Herz" . Its native name, , is derived from the Old High German Munichen, meaning "by the monks' place". The city's name derives from the monks of the Benedictine order who founded the city; hence the monk depicted on the city's coat...
, and Berlin. He then worked in the legal profession in Alsace-Lorraine
Alsace-Lorraine
The Imperial Territory of Alsace-Lorraine was a territory created by the German Empire in 1871 after it annexed most of Alsace and the Moselle region of Lorraine following its victory in the Franco-Prussian War. The Alsatian part lay in the Rhine Valley on the west bank of the Rhine River and east...
until 1909, afterwards taking leave to study physics in Tübingen
Tübingen
Tübingen is a traditional university town in central Baden-Württemberg, Germany. It is situated south of the state capital, Stuttgart, on a ridge between the Neckar and Ammer rivers.-Geography:...
. He retired from the legal profession in 1912, and earned his Ph.D.
Ph.D.
A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...
in 1913. His thesis, titled Zur Prestonschen Regel, was on the subject of what would later be called the Paschen-Back effect, and was named after Back and Friedrich Paschen
Friedrich Paschen
Louis Karl Heinrich Friedrich Paschen , was a German physicist, known for his work on electrical discharges. He is also known for the Paschen series, a series of hydrogen spectral lines in the infrared region that he first observed in 1908...
.
Between 1914 and 1918 he served with the German army
German Army
The German Army is the land component of the armed forces of the Federal Republic of Germany. Following the disbanding of the Wehrmacht after World War II, it was re-established in 1955 as the Bundesheer, part of the newly formed West German Bundeswehr along with the Navy and the Air Force...
during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
. Following this conflict he became head of a Veifa-Werke laboratory in Frankfurt am Main
Frankfurt
Frankfurt am Main , commonly known simply as Frankfurt, is the largest city in the German state of Hesse and the fifth-largest city in Germany, with a 2010 population of 688,249. The urban area had an estimated population of 2,300,000 in 2010...
, a company that produced electrical and X-ray equipment. In 1920 he left to become an assistant at the Physics Institute in Tübingen
Tübingen
Tübingen is a traditional university town in central Baden-Württemberg, Germany. It is situated south of the state capital, Stuttgart, on a ridge between the Neckar and Ammer rivers.-Geography:...
. He was promoted to professor in 1926 at Hohenheim University, and became a full professor in 1929. He remained at this post until 1936 when he returned to become a professor at Tübingen.
From 1926 to 1927 Samuel Abraham Goudsmit
Samuel Abraham Goudsmit
Samuel Abraham Goudsmit was a Dutch-American physicist famous for jointly proposing the concept of electron spin with George Eugene Uhlenbeck in 1925.-Biography:...
worked with Back to make the first measurement of nuclear spin and its Zeeman effect
Zeeman effect
The Zeeman effect is the splitting of a spectral line into several components in the presence of a static magnetic field. It is analogous to the Stark effect, the splitting of a spectral line into several components in the presence of an electric field...
.
Back retired in 1948, and died in Munich
Munich
Munich The city's motto is "" . Before 2006, it was "Weltstadt mit Herz" . Its native name, , is derived from the Old High German Munichen, meaning "by the monks' place". The city's name derives from the monks of the Benedictine order who founded the city; hence the monk depicted on the city's coat...
over a decade later. The crater Back
Back (crater)
Back is a small lunar impact crater that is located near the eastern limb of the Moon. It lies on the northwest edge of the Mare Smythii, and the northeast rim is adjacent to the crater Schubert. To the west is Jenkins, and to the southwest is the Weierstrass–Van Vleck crater pair. The crater Back...
on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
is named in his memory.