Anders Jonas Ångström (; ; 13 August 1814 – 21 June 1874) was a Swedish
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 ...
and one of the founders of the science of
spectroscopy
Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum.
Spectro ...
.
[P.Murdin (2000): "Angstrom" chapter in ''Encyclopedia of Astronomy and Astrophysics''. ]
Ångström is also well known for his studies of
astrophysics
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the ...
,
heat transfer
Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems. Heat transfer is classified into various mechanisms, such as thermal conduction, ...
,
terrestrial magnetism
The ''Journal of Geophysical Research'' is a peer-reviewed scientific journal. It is the flagship journal of the American Geophysical Union. It contains original research on the physical, chemical, and biological processes that contribute to the u ...
, and the
aurora borealis
An aurora ( aurorae or auroras),
also commonly known as the northern lights (aurora borealis) or southern lights (aurora australis), is a natural light display in Earth's sky, predominantly observed in high-latitude regions (around the Arc ...
. In 1852, Ångström formulated in ''Optiska undersökningar'' (Optical investigations),
[ Note: Although Ångström submitted his paper to the Swedish Royal Academy of Science on 16 February 1853, it was published in the volume for Academy's proceedings of 1852.
German translation: . English translation: ] a law of absorption, later modified somewhat and known as
Kirchhoff's law of thermal radiation
In heat transfer, Kirchhoff's law of thermal radiation refers to wavelength-specific radiative emission and absorption by a material body in thermodynamic equilibrium, including radiative exchange equilibrium. It is a special case of Onsage ...
.
Biography
Anders Jonas Ångström was born in
Medelpad
Medelpad ( or ) is a historical province or ''landskap'' in the north of Sweden. It borders Hälsingland, Härjedalen, Jämtland, Ångermanland and the Gulf of Bothnia.
The province is a part of Norrland and as such considered to be Northe ...
to Johan Ångström, and schooled in
Härnösand
Härnösand () is a Urban areas in Sweden, locality and the seat of Härnösand Municipality in Västernorrland County, Sweden with 25,012 inhabitants in 2023. It is called "the gate to the High Coast" because of the world heritage landscape just ...
. He moved to
Uppsala
Uppsala ( ; ; archaically spelled ''Upsala'') is the capital of Uppsala County and the List of urban areas in Sweden by population, fourth-largest city in Sweden, after Stockholm, Gothenburg, and Malmö. It had 177,074 inhabitants in 2019.
Loc ...
in 1833 and was educated at
Uppsala University
Uppsala University (UU) () is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in operation.
Initially fou ...
, where in 1839 he became
docent
The term "docent" is derived from the Latin word , which is the third-person plural present active indicative of ('to teach, to lecture'). Becoming a docent is often referred to as habilitation or doctor of science and is an academic qualifi ...
in physics. In 1842, he went to the
Stockholm Observatory to gain experience in practical astronomical work, and the following year he was appointed keeper of the
Uppsala Astronomical Observatory.
Intrigued by
terrestrial magnetism
The ''Journal of Geophysical Research'' is a peer-reviewed scientific journal. It is the flagship journal of the American Geophysical Union. It contains original research on the physical, chemical, and biological processes that contribute to the u ...
he recorded observations of fluctuations in magnetic intensity in various parts of Sweden, and was charged by the Stockholm Academy of Sciences with the task, not completed until shortly before his death, of working out the magnetic data obtained by on her voyage around the world in 1851 to 1853.
In 1858, he succeeded Adolph Ferdinand Svanberg in the chair of physics at Uppsala. His most important work was concerned with
heat
In thermodynamics, heat is energy in transfer between a thermodynamic system and its surroundings by such mechanisms as thermal conduction, electromagnetic radiation, and friction, which are microscopic in nature, involving sub-atomic, ato ...
conduction and
spectroscopy
Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum.
Spectro ...
. In his
optical
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultravio ...
researches, ''Optiska Undersökningar'', presented to the
Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences () is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for promoting nat ...
in 1853, he not only pointed out that the electric spark yields two superposed spectra, one from the metal of the electrode and the other from the gas in which it passes, but deduced from
Leonhard Euler
Leonhard Euler ( ; ; ; 15 April 170718 September 1783) was a Swiss polymath who was active as a mathematician, physicist, astronomer, logician, geographer, and engineer. He founded the studies of graph theory and topology and made influential ...
's theory of resonance that an incandescent gas emits luminous rays of the same refrangibility as those it can absorb.
This statement, as Sir
Edward Sabine
Sir Edward Sabine (; 14 October 1788 – 26 June 1883) was an Irish physicist, geodesist,astronomer, geophysicist, ornithologist, polar explorer, soldier, and the 30th president of the Royal Society.
He led the effort to establish a system o ...
remarked when awarding him the
Rumford medal of the
Royal Society
The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
in 1872, contains a fundamental principle of
spectrum analysis, and though overlooked for a number of years it entitles him to rank as one of the founders of spectroscopy.
From 1861 onward, he paid special attention to the solar spectrum. His combination of the
spectroscope
An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify mate ...
with photography for the study of the
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Sola ...
resulted in proving that the
Sun
The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...
's atmosphere contains
hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
, among other elements (1862), and in 1868 he published his great map of the normal
solar spectrum
Sunlight is the portion of the electromagnetic radiation which is emitted by the Sun (i.e. solar radiation) and received by the Earth, in particular the visible light perceptible to the human eye as well as invisible infrared (typically perc ...
in ''Recherches sur le spectre solaire'', including detailed measurements of more than 1000
spectral line
A spectral line is a weaker or stronger region in an otherwise uniform and continuous spectrum. It may result from emission (electromagnetic radiation), emission or absorption (electromagnetic radiation), absorption of light in a narrow frequency ...
s, which long remained authoritative in questions of wavelength, although his measurements were inexact by one part in 7000 or 8000, owing to the metre he used as a standard being slightly too short.

He was the first, in 1867, to examine the spectrum of the
aurora borealis
An aurora ( aurorae or auroras),
also commonly known as the northern lights (aurora borealis) or southern lights (aurora australis), is a natural light display in Earth's sky, predominantly observed in high-latitude regions (around the Arc ...
, and detected and measured the characteristic bright line in its yellow-green region; but he was mistaken in supposing that this same line, which is often called by his name, is also to be seen in the
zodiacal light
The zodiacal light (also called false dawn when seen before sunrise) is a faint glow of diffuse sunlight scattered by interplanetary dust. Brighter around the Sun, it appears in a particularly dark night sky to extend from the Sun's direct ...
.
He was elected a member of a number of learned societies, including the
Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences () is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for promoting nat ...
in 1850, the
Royal Society
The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
in 1870 and the
Institut de France
The ; ) is a French learned society, grouping five , including the . It was established in 1795 at the direction of the National Convention. Located on the Quai de Conti in the 6th arrondissement of Paris, the institute manages approximately ...
in 1873. He died in Uppsala on 21 June 1874.
In 1845, Ångström married Augusta Bedoire (1820–1906).
She was the daughter of Jean Henric Bedoire and Catharina Henrietta Littorin and belonged to the
Bedoire family, a Stockholm merchant family of
Huguenot
The Huguenots ( , ; ) are a Religious denomination, religious group of French people, French Protestants who held to the Reformed (Calvinist) tradition of Protestantism. The term, which may be derived from the name of a Swiss political leader, ...
origin.
His son,
Knut
Knut ( Norwegian and Swedish), Knud ( Danish), or Knútur ( Icelandic) is a Scandinavian and German first name, of which the anglicised form is Canute. In Germany both "Knut" and "Knud" are used. In Spanish and Portuguese Canuto is used which ...
(1857–1910), was also a physicist.
Honours
The
Ångström
The angstrom (; ) is a unit of length equal to m; that is, one ten-billionth of a metre, a hundred-millionth of a centimetre, 0.1 nanometre, or 100 picometres. The unit is named after the Swedish physicist Anders Jonas Ångström (1814–18 ...
unit (1 Ã… = 10
−10 m) in which the
wavelength
In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats.
In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...
s of light and interatomic spacings in condensed matter are sometimes measured is named after him.
The unit is also used in
crystallography
Crystallography is the branch of science devoted to the study of molecular and crystalline structure and properties. The word ''crystallography'' is derived from the Ancient Greek word (; "clear ice, rock-crystal"), and (; "to write"). In J ...
as well as spectroscopy.
The crater
Ångström
The angstrom (; ) is a unit of length equal to m; that is, one ten-billionth of a metre, a hundred-millionth of a centimetre, 0.1 nanometre, or 100 picometres. The unit is named after the Swedish physicist Anders Jonas Ångström (1814–18 ...
on the
Moon
The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...
is named in his honour.
One of the main building complexes of
Uppsala University
Uppsala University (UU) () is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in operation.
Initially fou ...
, the Ångström Laboratory, is named in his honour. This building houses various departments including the Department of Physics and Astronomy, Department of Mathematics, Department of Engineering Sciences, Institute of Space Physics, and the Department of Chemistry.
Death
Anders Ångström died in June 1874 from
meningitis
Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, intense headache, vomiting and neck stiffness and occasion ...
, shortly before his sixtieth birthday.
See also
*
Johann Balmer
*
Gustav Kirchhoff
Gustav Robert Kirchhoff (; 12 March 1824 – 17 October 1887) was a German chemist, mathematician, physicist, and spectroscopist who contributed to the fundamental understanding of electrical circuits, spectroscopy and the emission of black-body ...
*
Theodore Lyman
*
Friedrich Paschen
Louis Carl Heinrich Friedrich Paschen (22 January 1865 – 25 February 1947) 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 ...
*
Janne Rydberg
*
Spectrum analysis
References
Further reading
*
External links
*
{{DEFAULTSORT:Angstrom, Anders Jonas
1814 births
1874 deaths
Foreign members of the Royal Society
Members of the French Academy of Sciences
Members of the Royal Swedish Academy of Sciences
People from Timrå Municipality
19th-century Swedish astronomers
19th-century Swedish physicists
Uppsala University alumni
Spectroscopists
Burials at Uppsala old cemetery
Members of the Royal Society of Sciences in Uppsala