Anders Jonas Ångström was a famous Swedish physicist who discovered the spectrum of aurora borealis, also known as northern lights.
Google Doodle put up an illustration on August 13 in celebration of Angstrom’s birthday.
He was born in Logdo in Sweden in 1814.
He died in Uppsala in Sweden in 1874.
According to the Encyclopedia Britannica, Angstrom’s most important work concerned heat conduction and spectroscopy.
“He devised a method of measuring thermal conductivity, showing it to be proportional to electrical conductivity. In 1853 he pointed out that the electric spark yields two superposed spectra, one from the metal of the electrode and the other from the gas through which it passes. From Euler’s resonance theory Ångström deduced a principle of spectrum analysis: that an incandescent gas emits rays of the same refrangibility as those it can absorb,” it said.
Angstrom also published a map of the normal solar spectrum, which long remained authoritative.
And he was the first to examine the spectrum of the aurora borealis, which is best known for producing the hazy green glow in the northern regions of the world on some nights.
Angstrom detected and measured the characteristic bright line in its yellow-green region, but he was mistaken in supposing that this same line is also to be seen in the zodiacal light.
(Kungl. Biblioteket, Stockholm)