He was born in Menominee, Michigan, to Knud Nielsen and Maren Sorensen, immigrant parents who had moved to the United States from Denmark.
[1] His college education was attained at the University of Michigan, where he earned a Ph.D.
He then spent a year at the Bohr's Institute in Copenhagen as a Scandinavian-American Fellow.
Much of his work at OSU involved the infrared spectra of molecules; particularly with regard to their vibrational-rotational energies.
He performed pioneering design work with high-resolution spectrographs, and made major theoretical contributions on molecular spectra.