Alfred Kleiner: The Physicist and Mentor to Albert Einstein
Alfred Kleiner (1849–1916) was a distinguished Swiss physicist and a central figure in the academic landscape of Zurich at the turn of the 20th century. While he made significant contributions to experimental physics and served in high-ranking administrative roles, he is perhaps best remembered today as the Doktorvater (doctoral advisor) to one of the most influential scientists in history: Albert Einstein.
Kleiner's career was defined by a commitment to the foundations of physics and a willingness to support unconventional thinkers during a period of rapid scientific evolution.
[ไม่มีภาพประกอบ]Key Facts
- Born: 24 April 1849 in Maschwanden, Zurich, Switzerland.
- Died: 3 July 1916 (aged 67).
- Primary Role: Professor of Experimental Physics at the University of Zurich.
- Notable Student: Served as the doctoral advisor for Albert Einstein.
- Academic Focus: Statistical physics and measuring instruments.
- Administrative Peak: Served as Rektor (Chancellor) of the University of Zurich from 1908 to 1910.
Academic Foundation and Career Progression
Alfred Kleiner pursued his higher education at the University of Zurich, where he earned his PhD in 1874. His doctoral thesis, titled Zur Theorie der intermittirenden Netzhautreizung (On the Theory of Intermittent Retinal Stimulation), was completed under the guidance of Johann Jakob Müller.
Kleiner's professional ascent within the Swiss academic system was steady and prestigious. He began as a Privatdozent (a private lecturer) in 1870 and later held a similar position at the Swiss Federal Institute of Technology (ETH), then known as the Polytechnikum, between 1875 and 1885. His trajectory at the University of Zurich saw him move from Associate Professor (1880) to Full Professor (1885), eventually reaching the position of Chancellor (Rektor) from 1908 to 1910, before becoming an Emeritus Professor in 1915.
Research on Gravitational Shielding
Beyond his teaching, Kleiner engaged in experimental research. In the early 1890s, alongside students Fritz Laager and Theodor Erismann, he investigated whether gravitational attraction could be influenced by shielding. Motivated by the work of Charles Burton Thwing and Louis Winslow Austin, the team conducted experiments that ultimately showed no effect greater than the margin of experimental error. These findings were published between 1904 and 1911.
The Relationship with Albert Einstein
The intersection of Alfred Kleiner's life and Albert Einstein's career occurred during a volatile period for the young physicist. Einstein had initially been advised by Heinrich F. Weber, but after a major falling out, Einstein transitioned to Kleiner's supervision in 1901. This shift coincided with Einstein changing his dissertation focus from thermoelectricity to molecular kinetics (the study of the motion of molecules).
At the time, ETH was not authorized to grant doctoral degrees, meaning students had to obtain them through the University of Zurich. As the holder of the university's only physics chair, Kleiner became the primary gateway for ETH physics students seeking doctorates.
Correspondence reveals that Kleiner and Einstein shared a productive intellectual rapport. In December 1901, Einstein wrote to Mileva Maric, noting that Kleiner had encouraged him to publish his ideas on the electromagnetic theory of light for moving bodies, praising Einstein's proposed experimental method as the simplest and most appropriate approach.
Einstein's path to the degree was not linear. He withdrew his first dissertation attempt in 1902 and briefly considered abandoning the doctorate entirely. However, by 1905, he submitted his final thesis, Eine neue Bestimmung der Moleküldimensionen (A New Determination of the Molecular Dimensions). Kleiner and mathematics professor Heinrich Burkhardt both provided highly positive reviews, with Kleiner noting the difficulty of the hydrodynamics involved.
In a lighter anecdote recorded by biographer Carl Seelig, Einstein recalled that Kleiner initially returned the dissertation for being too short; once Einstein added a single sentence, it was accepted.
[ไม่มีภาพประกอบ]Legacy and Professional Support
Kleiner's support for Einstein extended beyond the doctoral degree. After Einstein delivered a lecture on electrodynamics and relativity at the University of Zurich in 1909, Kleiner suggested he apply for a newly created professorship in theoretical physics. Thanks to Kleiner's recommendation, the Regierungsrat des Kantons Zürich appointed Einstein as an associate professor on 7 May 1909, with an annual salary of 4,500 Swiss Francs.
| Year/Period | Position/Milestone | Institution |
|---|---|---|
| 1874 | PhD Recipient | University of Zurich |
| 1870 | Privatdozent | University of Zurich |
| 1875–1885 | Privatdozent | ETH Zurich (Polytechnikum) |
| 1880 | Associate Professor | University of Zurich |
| 1885 | Full Professor | University of Zurich |
| 1908–1910 | Rektor (Chancellor) | University of Zurich |
| 1915 | Emeritus Professor | University of Zurich |
Frequently Asked Questions
Who was Alfred Kleiner?
Alfred Kleiner was a Swiss physicist and professor at the University of Zurich who specialized in experimental physics and statistical physics. He is most famous for being the doctoral advisor to Albert Einstein.
How did Alfred Kleiner help Albert Einstein?
Kleiner provided the academic supervision necessary for Einstein to earn his PhD in 1905, offered critical feedback on his early theories regarding the electrodynamics of moving bodies, and later recommended him for a professorship in theoretical physics at the University of Zurich.
What was the subject of Einstein's PhD thesis under Kleiner?
Einstein's 1905 dissertation was titled Eine neue Bestimmung der Moleküldimensionen (A New Determination of the Molecular Dimensions), focusing on the dimensions of molecules.
Did Alfred Kleiner conduct his own original research?
Yes. In the 1890s, Kleiner and his students investigated whether gravitational attraction could be shielded, though their experiments found no evidence of such an effect.
Why did Einstein switch from Heinrich F. Weber to Alfred Kleiner?
Einstein switched advisors after experiencing a major falling out with Weber, leading him to seek the guidance of Kleiner at the University of Zurich.