**Józeph Petzval** was a Hungarian mathematician who invented the Laplace transform independently of Laplace.

- This town was in Hungary when Petzval was born there but it is now in Slovakia.
- Let us note at this stage that Otto Petzval also became a professor of mathematics and published Elementary mathematics (Hungarian) (1856) and Higher mathematics (Hungarian) (1867).
- In 1826 Petzval entered the Institutum Geometricum of the University of Pest (today the Eötvös Loránd University) to study philosophy and mathematics.
- After graduating from the University with an engineering degree in 1828, Petzval was appointed to the city of Pest as an expert in flood prevention and drainage.
- Petzval taught mechanics and mathematics at the University of Pest from 1832 and he became a professor in Higher Mathematics at the University of Pest in 1835.
- Petzval worked for much of his life on the Laplace transform.
- But for a student of Petzval we might today call the Laplace transform the Petzval transform.
- Petzval fell out with this student who then accused Petzval of plagiarising Laplace's work.
- Today Petzval is best remembered for his work on optical lenses and lens aberration done in the early 1840's (Petzval curvature is named after him) which allowed the construction of modern cameras.
- Petzval produced an achromatic portrait lens that was vastly superior to the simple meniscus lens then in use.
- This Petzval highly luminous early form of photo lens was used by the enterprising Viennese optician Voigtländer, who launched its mass production and won a silver medal at the World's Exhibition Fair in Paris.
- Petzval also perfected the telescope and designed the opera glasses.
- This description actually hides a lot of the difficulties that Petzval encountered.
- The portrait lens he designed was a great improvement on previous lenses and Petzval had completed the calculations by May 1840.
- Voigtländer made a fortune but Petzval had not taken out patents and received no royalties.
- Voigtländer again used Petzval's designs to market his own cameras, further increasing the enmity between the two men.
- Although Petzval is now recognised for his remarkable work on optics, he was so disillusioned by how things turned out that he gave up all his work on optics and even stopped lecturing on the subject.
- Petzval seems to have been entirely in the right over his arguments with Voigtländer but, unfortunately, he also had an argument with Christian Doppler where he was totally incorrect.
- First Petzval considered photography as an art form for portraits and landscapes, not as a tool in scientific research.
- Christian Doppler was elected to the Academy in 1848 and Petzval in 1851.
- Petzval objected to this proposal and it was not taken further.
- Soon Petzval launched another attack on Doppler, attacking the Doppler principle which relates the frequency of a source to its velocity relative to an observer.
- Petzval's attack came at the meeting of the Austrian Academy of Sciences on 15 January 1852 where he presented his paper Über die Unzukömmlichkeiten gewisser populärer Anschaungsweisen in der Undulationstheorie und ihre Unfähigkeit des Princip der Erhaltung der Schwingungsdauer zu ersetzen Ⓣ(On the unsuitability of certain popular ways of looking at the undulation theory and their inability to replace the principle of maintenance of the wavelength).
- the full member, Professor Petzval held a lecture 'On the unsuitability of certain popular ways of looking at the undulation theory and their inability to replace the principle of maintenance of the wavelength'.
- In fact, Petzval's protracted and hard attacks, which came to a head during the meeting of the Austrian Academy of Sciences under the presidency of Andreas von Baumgartner on 21 May 1852, were eventually shown to be the best mathematical proof of Doppler's theory.
- A third meeting of the Academy on 21 October 1852 again saw Petzval attack Doppler but by this time Doppler was too ill to defend himself and had travelled south hoping to restore his health.
- The result of all this was that the Academy supported Petzval belief that Doppler's theory was incorrect despite the fact that it had been verified experimentally many times since it was first proposed.
- In 1877, on reaching the age of 70, Petzval retired from his professorship at the University of Vienna.
- In 1905 the mayor of Vienna recalled that Petzval had been a great man and a great scholar who brought glory to the city of Vienna and glory to the University of Vienna.
- However, he said that although Petzval had lived in Vienna for 54 years he had remained faithful to his native country, he remained Hungarian.
- Petzval won many distinctions for his work.

Born 6 January 1807, Spisská Belá, Hungary (now in Slovakia). Died 17 September 1891, Vienna, Austria.

View full biography at MacTutor

Origin Slovakia

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive