Baron
Baron is a rank of nobility or title of honour, often hereditary, in various European countries, either current or historical. The female equivalent is baroness. Typically, the title denotes an aristocrat who ranks higher than a lord or kn ...
Loránd Eötvös de Vásárosnamény (or Loránd Eötvös, , '' hu, vásárosnaményi báró Eötvös Loránd Ágoston''; 27 July 1848 – 8 April 1919), also called Baron Roland von Eötvös in English literature, was a Hungarian
physicist
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe.
Physicists generally are interested in the root or ultimate cau ...
. He is remembered today largely for his work on
gravitation
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stron ...
and
surface tension
Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) t ...
, and the invention of the
torsion pendulum
A torsion spring is a spring that works by twisting its end along its axis; that is, a flexible elastic object that stores mechanical energy when it is twisted. When it is twisted, it exerts a torque in the opposite direction, proportional ...
.
In addition to
Eötvös Loránd University
Eötvös Loránd University ( hu, Eötvös Loránd Tudományegyetem, ELTE) is a Hungarian public research university based in Budapest. Founded in 1635, ELTE is one of the largest and most prestigious public higher education institutions in Hung ...
and the
Eötvös Loránd Institute of Geophysics in Hungary,
the
Eötvös crater on the Moon,
the asteroid
12301 Eötvös and the mineral
lorándite
also bear his name, as well as peak (Cime Eotvos) in the
Dolomites
The Dolomites ( it, Dolomiti ; Ladin: ''Dolomites''; german: Dolomiten ; vec, Dołomiti : fur, Dolomitis), also known as the Dolomite Mountains, Dolomite Alps or Dolomitic Alps, are a mountain range located in northeastern Italy. They form pa ...
.
Life
Born in 1848, the year of the
Hungarian revolution, Eötvös was the son of the
Baron
Baron is a rank of nobility or title of honour, often hereditary, in various European countries, either current or historical. The female equivalent is baroness. Typically, the title denotes an aristocrat who ranks higher than a lord or kn ...
József Eötvös de Vásárosnamény (1813–1871), a well-known poet, writer, and liberal politician, who was cabinet minister at the time, and played an important part in 19th century Hungarian intellectual and political life. His mother was the
Hungarian noble lady Agnes Rosty de Barkócz (1825–1913), member of the illustrious noble family
Rosty de Barkócz that originally hailed from the
Vas county, and through this, he descended from the ancient medieval Hungarian noble
Perneszy family
The Perneszy de Osztopán family was an important and prestigious Hungarian noble family which gave many relevant personalities. Its members were high members of the nobility of the Kingdom of Hungary since the 13th century.
History History of ...
, which died out in the 18th century. Loránd's uncle was
Pál Rosty de Barkócz
Pál Rosty de Barkócz (pronunciation: pa:l 'rɔʃti 'bɒrkɔ:ʦ 29 November 1830 – 7 December 1874) was a Hungarian nobleman, photographer, and explorer.
Life
Born in Pest in the former Kingdom of Hungary. Pál István Ferenc, was a mem ...
(1830–1874) was a
Hungarian nobleman, photographer,
explorer
Exploration refers to the historical practice of discovering remote lands. It is studied by geographers and historians.
Two major eras of exploration occurred in human history: one of convergence, and one of divergence. The first, covering most ...
, who visited
Texas
Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
,
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe, New Mexico, Santa Fe
, LargestCity = Albuquerque, New Mexico, Albuquerque
, LargestMetro = Albuquerque metropolitan area, Tiguex
, Offi ...
, Mexico, Cuba and Venezuela between 1857 and 1859.
Loránd Eötvös first studied law, but soon switched to physics and went abroad to study in
Heidelberg
Heidelberg (; Palatine German: ') is a city in the German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914, of which roughly a quarter consisted of students ...
and
Königsberg
Königsberg (, ) was the historic Prussian city that is now Kaliningrad, Russia. Königsberg was founded in 1255 on the site of the ancient Old Prussian settlement ''Twangste'' by the Teutonic Knights during the Northern Crusades, and was ...
. After earning his doctorate, he became a university professor in
Budapest
Budapest (, ; ) is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second-largest city on the Danube river; the city has an estimated population o ...
and played a leading part in Hungarian science for almost half a century. He gained international recognition first by his innovative work on
capillarity, then by his refined experimental methods and extensive field studies in gravity.
Eötvös is remembered today for his experimental work on
gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
, in particular his study of the equivalence of gravitational and inertial
mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different ele ...
(the so-called
weak equivalence principle
In the theory of general relativity, the equivalence principle is the equivalence of gravitational and inertial mass, and Albert Einstein's observation that the gravitational "force" as experienced locally while standing on a massive body (suc ...
) and his study of the
gravitational gradient on the Earth's surface. The weak equivalence principle plays a prominent role in
relativity theory
The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena ...
and the
Eötvös experiment
The Eötvös experiment was a famous physics experiment that measured the correlation between inertial mass and gravitational mass, demonstrating that the two were one and the same, something that had long been suspected but never demonstrated with ...
was cited by
Albert Einstein
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theor ...
in his 1916 paper ''The Foundation of the General Theory of Relativity''. Measurements of the gravitational gradient are important in applied
geophysics
Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' so ...
, such as the location of petroleum deposits. The
CGS unit for gravitational gradient is named the
eotvos in his honor.
From 1886 until his death, Loránd Eötvös researched and taught in the
University of Budapest
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, th ...
, which in 1950 was renamed after him ''(
Eötvös Loránd University
Eötvös Loránd University ( hu, Eötvös Loránd Tudományegyetem, ELTE) is a Hungarian public research university based in Budapest. Founded in 1635, ELTE is one of the largest and most prestigious public higher education institutions in Hung ...
)''.
Eötvös is buried in the
Kerepesi Cemetery
Kerepesi Cemetery (Hungarian: ''Kerepesi úti temető'' or ''Kerepesi temető'', official name: ''Fiumei úti nemzeti sírkert'', i.e. "Fiume Road National Graveyard") is the most famous cemetery in Budapest. It is one of the oldest cemeteries in ...
in Budapest, Hungary.
Torsion balance
A variation of the earlier invention, the
torsion balance, the
Eötvös pendulum, designed by Hungarian Baron Loránd Eötvös, is a sensitive instrument for measuring the density of underlying rock strata. The device measures not only the direction of force of gravity, but the change in the force of gravity's extent in the horizontal plane. It determines the distribution of masses in the Earth's crust. The Eötvös torsion balance, an important instrument of geodesy and geophysics throughout the whole world, studies the Earth's physical properties. It is used for mine exploration, and also in the search for minerals, such as oil, coal and ores. The Eötvös pendulum was never patented, but after the demonstration of its accuracy and numerous visits to Hungary from abroad, several instruments were exported worldwide, and the richest oilfields in the United States were discovered by using it. The Eötvös pendulum was used to prove the equivalence of the
inertial mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementa ...
and the
gravitational mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementa ...
accurately, as a response to the offer of a prize. This equivalence was used later by
Albert Einstein
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theor ...
in setting out the theory of
general relativity
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics ...
.
This is how Eötvös describes his balance:
One of Eötvös' assistants who later became a noted scientist was
Radó von Kövesligethy.
Honors
To honor Eötvös, a postage stamp was issued by Hungary on 1 July 1932. Another stamp was issued on 27 July 1948 to commemorate the centenary of the birth of the physicist.
Hungary issued a postage stamp on 31 January 1991.
[colnect.com/en/stamps/stamp/181792-Lóránd_Eötvös-People-Hungary]
See also
*
Eotvos, a unit of gravitational gradient
*
List of geophysicists
This is a list of geophysicists, people who made notable contributions to geophysics, whether or not geophysics was their primary field. These include historical figures who laid the foundations for the field of geophysics. More recently, some of ...
*
Lorándite, a mineral named after Loránd Eötvös
References
Further reading
*
External links
*
Eötvös and STEP''(biographical remarks and a summary of his research)''
Eötvös Loránd Virtual Museum
{{DEFAULTSORT:Eotvos, Lorand
1848 births
1919 deaths
Scientists from Budapest
19th-century Hungarian physicists
Eötvös Loránd University faculty
Fluid dynamicists
Education ministers of Hungary
Members of the Hungarian Academy of Sciences
Burials at Kerepesi Cemetery
Geophysicists