At the age of 17 Debye entered the Technical Institute of Aachen and earned his diploma in electrical engineering in 1905.
Debye followed Sommerfeld to the University of Munich and obtained his doctorate in physics by a mathematical analysis of the pressure of radiation on spheres of arbitrary electrical properties.
After receiving his Ph. D from the University of Munich, Debye taught there.
A fitting recognition of Debye's youthful excellence was his succession in 1911, at the age of 27, to Albert Einstein in the chair of theoretical physics at the University of Zurich.
While in Zurich he worked out, on the basis of Max Planck's and Einstein's ideas, the first complete theory of the specific heat of solids and the equally important theory of polar molecules.
X-ray Research In Göttingen, Debye started a most fruitful collaboration with P. Scherrer.
Their first paper, "X-ray Interference Patterns of Particles Oriented at Random" (1916), gave immediate evidence of the enormous potentialities of their powder method to explore the structure of crystals with very high symmetry.
It was in this connection that they formulated the important concept of "atomic form factor. " In 1923 he collaborated with E. Hückel to propose the Debye-Hückel theory, which advanced the quantitative understanding of electrolyte solutions.
Debye had already been for 2 years the director of the Physical Institute at the University of Leipzig when his classic monograph, Polar Molecules, was published in 1928.
Thus in 1934 he readily accepted the invitation of the University of Berlin to serve both as professor at the university and as director of the Kaiser Wilhelm Institute.
It was awarded to him "for his contributions to our knowledge of molecular structure through his investigations on dipole moments and on the diffraction of x-rays and electrons in gases. "
Shortly after World War II broke out, he was informed that he could no longer enter the laboratory of the Institute unless he assumed German citizenship.
As Debye refused, he was told to stay home and keep busy writing books.
He succeeded in making his way to Italy and from there to Cornell University, which invited him to give the Baker Lectures in 1940.
Debye made Cornell his permanent home.
In pure research he further investigated, in collaboration with his son, Peter P. Debye, the light-scattering properties of polymers, on which he based the now generally accepted absolute determination of their molecular weights.
Since 1913 he had been married to Mathilde Alberer, who shared his lively interest in gardening and fishing.