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Maks fon LauePhysicist
Date of Birth: 09.09.1879
Country:  Germany |
Content:
- Max Theodor Felix von Laue
- University Studies and Academic Career
- Collaboration with Planck and the Diffraction of X-rays
- Nobel Prize-Winning Discovery
- Revolutionary Implications
- Subsequent Research and Anti-Nazi Stance
- Later Years and Legacy
Max Theodor Felix von Laue
Childhood and EducationMax Theodor Felix von Laue was born on October 9, 1879, in Pfaffendorf, Germany, to Julius von Laue, a civil servant in the military justice system, and Minna Zerrenner. The family received a hereditary nobility in 1913 when Laue's father was ennobled. Due to his father's profession, the family moved frequently, requiring Laue to attend several schools, but he primarily received his secondary education at the Protestant Gymnasium in Strasbourg. At the age of twelve, Laue developed an interest in physics, encouraged by his mother, who allowed him to attend "Urania," a Berlin society that promoted science.
University Studies and Academic Career
After graduating from gymnasium in 1898, Laue began studying physics, chemistry, and mathematics at the University of Strasbourg, while also completing his compulsory one-year military service. At the university, Ferdinand Braun's lectures sparked his interest in physics. Laue also studied at the universities of Göttingen, Munich, and Berlin. In 1903, he earned his doctorate with distinction from the University of Berlin under the supervision of Max Planck, with a dissertation on the theory of light interference in parallel plates. While working on his dissertation, Laue first became interested in physical optics.
Collaboration with Planck and the Diffraction of X-rays
He spent the following two years at the University of Göttingen before qualifying to teach physics in secondary schools. From 1905 to 1909, he served as Planck's assistant at the Institute of Theoretical Physics in Berlin. During this period, he attempted to apply the concept of entropy to radiation fields and explore the thermodynamic meaning of light wave coherence. Their collaboration turned into a lifelong friendship. After serving as a private lecturer at the University of Berlin from 1906 to 1909, Laue joined the physics department at the University of Munich under Arnold Sommerfeld.
In Munich, Laue lectured on optics and thermodynamics and published his first comprehensive monograph in 1911, dedicated to Albert Einstein's then-controversial theory of relativity. The following year, Laue was appointed to the Chair of Theoretical Physics at the University of Zurich, where he stayed for two years before moving to the University of Frankfurt. He spent a significant portion of World War I at the University of Würzburg under Wilhelm Wien, where he researched electron tubes used in telephone and wireless communication. In 1917, Laue was named deputy director of the Kaiser Wilhelm Institute for Physics in Berlin, where Einstein was director.
Nobel Prize-Winning Discovery
While continuing his primarily administrative duties at the institute, Laue accepted an offer in 1919 to become a professor of physics at the University of Berlin, a position he held until 1943. Soon after moving to Zurich, Laue became intrigued by a problem that had remained unsolved since Wilhelm Röntgen's discovery of X-rays in 1895: were these rays a form of electromagnetic radiation with extremely short wavelengths? At the time, Laue was working on a chapter on wave optics for the multi-volume "Encyclopedia of Mathematical Sciences." He needed to mathematically express the action of a diffraction grating on light waves.
Inspired by this work, Laue proposed that if X-rays were indeed electromagnetic waves, a crystal would act as a three-dimensional diffraction grating. X-rays scattered on individual atoms within the crystal would emerge in various directions, creating a diffraction pattern consisting of bright spots (where waves arrive in phase and reinforce each other) and dark areas (where waves interfere destructively). He suggested an experiment to prove or disprove his hypothesis.
In April 1912, Walter Friedrich and Paul Knipping, colleagues at the University of Munich, successfully passed a narrow beam of X-rays through a copper sulfate crystal and captured the scattered radiation on a photographic plate. Their first success was a diffraction pattern of dark spots, observed after developing the plate (dark spots on a negative correspond to greater exposure). These diffraction patterns, now known as Laue patterns, even when the incident X-rays consisted of a mixture of different wavelengths, only radiation of the same wavelength arrived at the dark spots, further confirming that electromagnetic wave interference was being observed.
Revolutionary Implications
Thrilled by the confirmation of his hypothesis, Laue overcame the remaining theoretical challenges. He found that describing the diffraction on a two-dimensional grating required repeating the calculations performed for a one-dimensional grating several times. His derived equations allowed for the determination of the real positions of atoms in crystals and the wavelength of X-rays by comparing experimentally observed Laue patterns to the equations. Thus, Laue opened up a transformative area of study (X-ray crystallography), using X-rays to determine the structure of crystals and, in crystals of known structure, the wavelength of X-rays. The analysis of X-rays emitted by atoms (X-ray spectroscopy) became crucial for understanding atomic structure.
Einstein called Laue's discovery "one of the most beautiful in physics." For "his discovery of the diffraction of X-rays by crystals," Laue was awarded the 1914 Nobel Prize in Physics. Presenting the laureate, H.D. Granqvist of the Royal Swedish Academy of Sciences stated, "As a result of Laue's discovery, it has been irrefutably established that X-rays are light waves of very short wavelength. Furthermore, it has led to the most important discoveries in the field of crystallography... Laue's discovery," Granqvist continued, "makes it possible to determine the position of atoms in crystals and to obtain extensive useful information."
Subsequent Research and Anti-Nazi Stance
Laue's work laid the foundation for numerous discoveries, including William L. Bragg's methods of X-ray crystallography, Dorothy C. Hodgkin's determination of the molecular structure of penicillin, and John C. Kendrew and Max Perutz's work on amino acids. It also contributed to the development of spectroscopy and solid-state physics. Refining his theory of X-ray interference, Laue investigated the interaction between atoms in a crystal and incident electromagnetic radiation. Toward the end of his life, he approached the theory of diffraction from an entirely new perspective, considering the energy flow instead of the traditional wave amplitudes.
In the 1930s, Laue collaborated with Walter Meissner in research that led to the discovery of the Meissner effect, which describes how a superconductor expels a magnetic field. At a physics conference held at the University of Würzburg in 1933, Laue publicly condemned the new Nazi government of Adolf Hitler for ousting Albert Einstein as director of the Kaiser Wilhelm Institute for Physics in Berlin. He likened the persecution of Einstein to the persecution of Galileo Galilei in the 17th century. Laue not only defended Einstein's theory of relativity from attacks by Nazi-sympathizing scientists such as Philipp Lenard and Johannes Stark but also actively opposed Stark's admission to the Prussian Academy of Sciences and the German Research Association.
Despite his vocal anti-Nazi stance, Laue was allowed to teach and conduct scientific research throughout World War II. After Berlin became a target of relentless bombing in 1944, Laue relocated the Kaiser Wilhelm Institute for Physics to Hechingen, Württemberg. The following year, he was arrested by the Allies and sent to England with other German scientists. Laue was permitted to return to Germany in 1946. Upon his return, he became acting director of the Max Planck Institute (the former Kaiser Wilhelm Institute) and a professor of physics at the University of Göttingen. In these positions, as well as a consultant to the Physikalisch-Technische Bundesanstalt in Berlin, Laue played a leading role in the resurgence of science in postwar Germany.
Later Years and Legacy
From 1951 until his retirement seven years later, Laue served as director of the Fritz Haber Institute for Physical Chemistry in Berlin. In 1910, Laue married Magdalene Degan, with whom he had a son and a daughter. Laue enjoyed sailing, mountaineering, classical music, and, notably, fast driving in cars and motorcycles. On April 8, 1960, while on his way to a meeting in Wannsee, he collided with a motorcyclist and was trapped in his overturned car. After recovering from his injuries, Laue passed away. He was buried in Göttingen, where Max Planck, Walther Nernst, and other prominent German scientists rest.
In addition to the Nobel Prize, Laue received many other honors, including the Max Planck Medal of the German Physical Society (1932) and the Grand Cross of the Order of Merit of the Federal Republic of Germany (1953). He held honorary doctorates from the universities of Bonn, Stuttgart, Munich, Berlin, Manchester, and Chicago, and was a member of numerous scientific societies, including the American, German, and French Physical Societies, as well as the Vienna Academy of Sciences. In 1948, Laue was elected honorary president of the International Union of Crystallographers, and in 1953, he was made an officer in the Order of the Legion of Honour.
