Person: Doppler, Christian Andreas
Christian Doppler was an Austrian mathematician who is best known for the Doppler effect in wave theory.
Mathematical Profile (Excerpt):
- Doppler attended primary school in Salzburg and then attended secondary school in Linz.
- His parents were unsure of his academic potential and consulted the professor of mathematics at the Salzburg Lyceum who recommended that Doppler should study mathematics at the Vienna Polytechnic Institute.
- The Polytechnic Institute had only been founded in 1815, so it was still a new establishment when Doppler began his studies there in 1822.
- At the end of his studies at the University of Vienna in 1829, Doppler was appointed as assistant to the professor of higher mathematics and mechanics at the University, Professor A Burg.
- This assistantship was only a temporary post and Doppler, rather older than most others, began to seek a permanent post at the age of 30.
- Doppler submitted himself to a number of these competitions, both for school and university places.
- While this was going on Doppler had to earn his living and he spent 18 months as a bookkeeper at a cotton spinning factory.
- This was a period of sadness and great difficulty for Doppler and it is not surprising that he decided to give up the unequal struggle and emigrate to America.
- It had taken a long time for the process of appointing to reach its conclusion and Doppler took up his post in March 1835, almost exactly two years after entering the competition.
- Doppler was ambitious and teaching elementary mathematics at the Technical School was not greatly to his liking.
- Doppler did get another chance of a post at the Polytechnic, however, and at the end of 1837 the professorship in practical geometry and elementary mathematics became vacant.
- Doppler assumed the duties of the post but things were not that straightforward.
- Doppler did not have to take part in the competition but was hurt by the fact that it was held at all.
- Doppler did not have an easy time teaching at the Polytechnic.
- For example, in January and February 1843 Doppler had to examine 256 students in 17 days, both in writing and orally, in arithmetic and algebra.
- In July 1847 Doppler orally examined 526 students in mathematics and 289 in geodesy.
- By 1844 Doppler's health, always less than good, failed under the strain.
- many people who can save Doppler for science and not let him die under the yoke.
- The situation was made worse by Doppler's students complaining that he was too harsh in his examining.
- Doppler was investigated and reprimanded while the students were allowed to retake their examinations.
- Doppler considered himself totally innocent and demanded that the reprimand be withdrawn.
- Eventually the reprimand was reluctantly withdrawn by the end of 1844 but Doppler was not well enough to return to his duties until 1846.
- With such a difficult time in Prague, it is no surprise that Doppler wanted to move and he was offered the professorship of mathematics, physics and mechanics at the Academy of Mines and Forests in Banska Stiavnica.
- Doppler had reached the high point of his career.
- What qualities had carried Doppler through the struggles of his early experiences to this important position?
- However, despite this Doppler did have genius within him.
- Bolzano reviewed the first paper which Doppler submitted to the Royal Bohemian Society of Sciences in 1837.
- After recommending Doppler's paper on applied analysis for publication, Bolzano commented about Doppler himself.
- So Bolzano, himself a great mathematical innovator, could see the genius in Doppler.
- did not have much understanding of Doppler's originality or of his intuitive ways of thinking.
- However two years before Bolzano wrote this, Doppler had presented his most famous brilliant idea to the Royal Bohemian Society.
- On the 25 May 1842 Doppler presented the paper On the coloured light of the double stars and certain other stars of the heavens.
- The paper presented for the first time the Doppler principle which relates the frequency of a source to its velocity relative to an observer.
- Doppler derived the principle in a few lines treating both light and sound as longitudinal waves in the ether and matter, respectively.
- Doppler was incorrect regarding light being a longitudinal wave.
- Fresnel had already published his theory that light was a transverse wave but, although Doppler had read Fresnel's work, he did not accept it.
- However the error does not really affect the result of Doppler's principle.
- Doppler also was wrong when he tried to illustrate his theory with an application to the colours of double stars.
- Although Doppler was correct in saying that his principle would change the colours of double stars, depending on which star was approaching or receding from the Earth, the effect is too small to be significant.
- In 1846 Doppler published a better version of his principle where he considered both the motion of the source and the motion of the observer.
- Not everyone of course was immedately convinced by Doppler's theory.
- No other work by Doppler came anywhere close in matching the importance of his publications on the Doppler principle.
- However one can often see the germ of some important future discovery there, even though the idea as presented by Doppler is basically incorrect.
- Doppler had some difficulty becoming a member of the Royal Bohemian Society despite very strong support from Bolzano and his good relations with the Society.
- In 1837, when he reviewed the first paper that Doppler submitted to the Society, Bolzano requested in his report that Doppler be elected to the Society.
- This was not acted on but, in the following year, Doppler was proposed again and not elected in a ballot.
- On 28 June 1840 Doppler was eleced an associate member of the Royal Bohemian Society after a close ballot of 7 for and 5 against.
- Other honours which came Doppler's way in 1848 were election to ordinary membership of the Imperial Academy of Sciences in Vienna and an honorary doctorate from the University of Prague.
- Doppler's time as the first Director of the Institute of Physics at Vienna University was a short one.
Born 29 November 1803, Salzburg, Austria. Died 17 March 1853, Venice (now Italy).
View full biography at MacTutor
Tags relevant for this person:
Astronomy, Origin Austria, Physics
Adapted from other CC BY-SA 4.0 Sources:
- O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive