Parentless since 1813, Mädler was forced to give private lessons to earn a living and was only able to study mathematics and astronomy at university from 1818, and then only on the side. Together with the Berlin banker Wilhelm Beer, who had a private observatory built near his villa in 1829, he carried out observations of the moon and Mars, of which they produced the first accurate maps. From 1830-36, he made drawings of the moon’s surface over 600 nights and became world-famous for this outstanding achievement. His lunar maps subsequently became a standard work. He received a doctorate and was appointed professor of astronomy in 1837. In 1840, he succeeded Georg W. Struve as head of the observatory in Dorpat (now Tartu in Estonia) at the instigation of C.F. Gauss, where he carried out observations of double stars. In addition to his scientific work, Mädler was also active in publishing and was the first to coin the name “photography”. In 1858, he submitted a proposal for a calendar reform, which was never implemented.
He retired in 1865, was elevated to the Russian nobility and returned to Germany. Here he became historically active and devoted himself to his work “History of Celestial Science”. His work “Der Wunderbau des Weltalls oder populäre Astronomie” from 1842 was continued by others.
Johann Heinrich von Mädler and Christian Doppler
Mädler was the leader of the opponents among the astronomers who accepted Doppler’s conclusions that the astronomical velocities of the stars were great enough to be expressed in visible color, and was also their most prominent representative. He used every opportunity to refute Doppler’s views.
Mädler published a review in No. 51 of the Stuttgarter Morgenblatt in 1843, which Doppler came across by chance. This review was so devastating for him that he wrote a sharp reply, which he also wanted to publish in the Stuttgarter Morgenblatt. However, he was supposedly denied this because of the length of the article, but in reality – according to Doppler – because of his anti-critical remarks. He published his reply in 1844 in the fiction magazine “Österreichische Blätter für Literatur und Kunst” (No. 15), from which we learn the following:
I can hardly describe the mixture of astonishment and indignation that came over me as I read through that essay. – Mr. Mädler finds a treatise that promises to deal with double stars, and this is enough for him to consider himself a preferably competent judge of its entire content. But anyone who judges books and treatises by their titles and people by their clothes is acting prematurely, for there is often something quite different behind both than one might at first suspect. Mr. Mädler had a very similar experience with my treatise.
Doppler had come to the conclusion that a speed of 33 miles per second towards or away from the observer was necessary to produce a perceptible color change. Mädler denies that speeds of more than 10, let alone 33 miles per second can occur at all with celestial bodies; according to Doppler, however, the latter is necessary to explain color changes in stars. For him, the Doppler principle thus remained a disproved hypothesis for the rest of his life. Doppler replies:
If Mr. Recensent now claims that no celestial body, or at least no so-called fixed star, can or may move at a speed of more than 10 miles per second, this does not mean much according to the above, or rather it only wants to say as much as: “I, Dr. Mädler in Dorpat, believe that this is so”, and I simply counter such an extravagant assumption with the well-balanced prevailing view of almost all other astronomers.
Mädler’s voice was not the only critical one. Renowned astronomers of the 19th century were so preoccupied with conventional research that they continued to view the new research method, the rise of astrophysics, which had emerged through the combination of telescope, spectroscope and photography, with skepticism for a long time.
Inspired by the discovery of spectral analysis in 1860 by Gustav R. Kirchhoff and Robert W. Bunsen, Ernst Mach wrote in his introduction to the 1873 reprint of his work on the Doppler principle that he, Mach, 1860, was the first to point out the possibility of measuring line shifts in stellar spectra. The relevant section reads:
In the determination of color, which will be made for the purpose of calculation, one cannot rely on the naked eye, but one should proceed casually as follows: “The image of the star is divided by the prism into a spectrum, in which two different lines are now shown, one originating from our atmosphere, the other from the star; the latter must now change their position when the star changes color, and from this change the velocity of the star is determined”.
Mädler replied to Mach in his book “Geschichte der Himmelskunde”:
…and if Dr. Mach in Vienna has made the attempt to revive Doppler’s hypothesis, which has already been decisively refuted, and even sees in it a means of determining the proper motion of the solar system in terms of quantity and direction, it must be replied: that everything we can deduce about the fixed star motions does not give us the slightest hope of ever seeing such an expectation realized…”.
On February 21, 1861, when Mach had already confirmed Doppler’s principle experimentally and theoretically, Mädler, who had become a corresponding member of the Imperial Academy of Sciences in Vienna in 1848, spoke at the Academy’s invitation in the place where Petzval had already raised his voice against Doppler:
The Doppler formulas developed by Mr. Mach may be tested practically by other means: astronomy cannot provide a test object for this (Sitzber. d. K. Akademie d. Wiss. Wien, 1861, p. 289)
The combination of the Doppler principle with the spectroscopy of starlight, with photometry and photography – as Doppler had repeatedly pointed out – was the beginning of a development which in the 20th century brought a deep penetration into the nature of cosmic processes and which is still ongoing today.
Dr. Peter Maria Schuster, 2017