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Biography of Anders Jonas Angstrom

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August 13, 1814 June 21, 1874

Who is Anders Jonas Angstrom?


The Swedish physicist Anders Jonas Angstrom was born in Lögdö, Sweden, on 13 August 1814. Today he is remembered as one of the founders of the science of spectroscopy.

In just 29 1843 he was appointed Director of the Astronomical Observatory of Uppsala city; in 1858, always in the same city he became Professor of physics.

Studies


Anders Jonas Angstrom is famous in the field of science for his work on magnetism, optics and heat, but above all to study the phenomenon of Aurora Borealis.

The Sun and hydrogen


Angstrom in 1862 proved that the Sun's atmosphere contains hydrogen: to do this, he used a combination of the spectroscope with photography.

He published his research on the solar spectrum in Recherches sur le spectre solaire (1868), which includes detailed measurements of more than 1000 spectral lines.

Spectral analysis


In a paper presented at the Academy of Stockholm 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's theory of resonance that an incandescent gas emits luminous rays of the same refractive capacity than it can absorb.

This statement contains a fundamental principle of spectrum analysis: although for several years his studies were neglected, today science is unanimous in indent Angstrom among the founders of spectroscopy.

For these studies received a Rumford Medal in 1872, by the Royal Society.

The Aurora Borealis


He was the first to examine the spectrum of the aurora borealis (in 1867): ne identified, measured, the characteristic bright line in its yellow-green region.

The unit of measure that bears his name

In recognition of his contributions to spectroscopy the unit of measurement of wavelengths of rows is defined: Ångströms (1 Å = 0.1 nm).

This unit is used in crystallography as well as spectroscopy.

Anders Jonas Angstrom died shortly before reaching 60 years of age, in Uppsala, June 21, 1874.

Scientific inheritance transmitted to son

His son, Knut Ångström (1857-1910), he was known for his research at Uppsala University on solar radiation, the radiation of heat from the Sun and its absorption by the Earth's atmosphere.

For his research, Knut devised various delicate methods and instruments, including electric compensation pyrheliometer, invented in 1893, and an apparatus for obtaining a photographic representation of the infrared spectrum, in 1895.

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