Most educated people don’t know who invented the telescope. I interviewed numerous engineering, medical and business graduates between the ages of 25 and 80. Some had no idea. Many replied that the inventor was Galileo Galilei. The answer is wrong as demonstrated 84 years ago by the experimental physicist Prof. Domenico Argentieri, who was among other things director of Salmoiraghi. (1)
It was Leonardo da Vinci in 1492 who invented and built the first telescope. Leonardo had deduced (by analogy with the waves produced by the fall of an object on a calm and undisturbed horizontal surface of water) that sounds and lights are also transmitted by waves. These do not involve horizontal motion, but a transverse tremor – that is, perpendicular to the horizontal surface.
Leonardo also built flat convex lenses (to correct presbyopia “of the sixties”); in 1492 he built a first telescope without an eyepiece. He perfected it and in 1508 mounted a plano-convex lens (objective) in a tube at the other end of which (at a distance of 72 millimeters) he had aligned a diverging biconcave lens (ocular) with a diameter of 46 millimeters and a thickness at the edges of 4 millimeters. It magnified by about 40%, then improved up to a few times.
The description of the structure of the telescope and of the tools with which he grinded and rectified the lenses, is reported – accompanied by excellent drawings – in the Codex Atlanticus (2) (now in the Ambrosiana Library) and in Leonardo’s manuscripts A, E, F preserved at the Academy of France.
The latter had been lost and Félix Ravaisson Mollien (1813-1900) found them in 1889, who, however, was unable to interpret them correctly. Ravaisson Mollien was inspector of French libraries – in 1870 he was appointed curator of the classical section of the Louvre by Napoleon III. A scholar and philosopher, he is known for his essay on habit, which he called an important factor in understanding mana nature – also relevant to discussions of moral issues. Ravaisson had considerable influence on French culture; according to some, in particular on Proust, Bergson, Merleau-Ponty, Derrida and Deleuze (the latter two well-known exponents of the so-called new French philosophy, analyzed in its transparent nullity by Alan Sokal and Jean Bricmont) and also on Heidegger.
Leonardo da Vinci’s drawings Collected by Pompeo Leoni
Sheet 53 (verso) of manuscript F (written in 1508) shows the design of the telescope with two lenses, but Ravaisson misinterpreted it as relating to two separate lenses to be used outdoors and the other “in the studio”.
The priority of Leonardo’s invention was demonstrated by D. Argentieri in the works cited. A copy of Leonardo’s telescope, bearing the inscription “Year 1590” was brought to Holland. It inspired perhaps the optician Hans Lipperhey who presented his telescope which he had made before the one Galileo showed in 1609.
It does not seem that the aforementioned copy could have been inspired by the parabolic mirror and glasses made in Naples in 1580 by Giambattista Della Porta, who invented the camera obscura, refuted astrology, was accused of witchcraft, founded physiognomy, wrote “De telescope ”and other treatises on surprising natural phenomena, refraction, the elastic force of steam as well as numerous comedies. He was in correspondence with Galileo and claimed to have invented the telescope himself while admitting that he had not made significant astronomical observations. Curiously, his priority was accepted by Kepler, who in 1610 had an interesting correspondence with Galileo.
In the three years spent in Rome (1513-1515) Leonardo studied the geometry of large concave parabolic mirrors to replace the lenses to obtain excellent magnifications. He built them in bronze and two centuries before Newton found that adding arsenic to the alloy as well as making the bronze more brittle greatly increased its hardness. The material, thus made compact and fine-grained, was much more suitable for being sanded like glass with good optical properties.
In the Codex Atlanticus (Folio 396 straight and verso) Leonardo reported the drawing of his 12 meter long machine to grind parabolic mirrors with a focal distance of 6 meters which is represented in the following figure.
Leonardo: 12 m long machine for grinding parabolic mirrors with a focal length of 6m (Codex Atlanticus Sheet 396)
These machines have not come down to us, nor parts of them – as is the case with many other machines designed by Leonardo, of which wooden models have been reconstructed in modern times. Leonardo secretly built several examples with the help of two German craftsmen known as Mastro Giorgio and Mastro Giovanni degli Specchi. The latter collaborated in the construction of the aforementioned large concave parabolic mirror with which Leonardo was able to see considerable enlargements of the moon he wrote about and perhaps also the 4 satellites of Jupiter – a century before Galileo.
On folio 247 of the Codex Atlanticus, Leonardo tells how Giovanni degli Specchi wanted to build a copy of the large parabolic mirror that he wanted to take with him to Germany. Leonardo did not allow him to build it and wrote that he only gave him partial drawings of each of the component parts with an indication of the width, length, height and shape of each.
If Leonardo had seen the four satellites of Jupiter (which Galileo called “Medicei” a century later), he would have kept the secret so as not to be persecuted by the Inquisition which could have burned him despite the protection of popes and cardinals, his merits hagiographic (paintings and frescoes of Christ, saints and martyrs.) and numerous formal Catholic invocations in his writings.
Argentieri’s reconstruction of the data on the Leonardo telescope did not convince everyone (see the Journal of Astronomy, N ° 45, 4 December 2019) Some astronomers denied that Leonardo had ever built telescopes. Among these: Pio Emanuelli and Vasco Ronchi, who had a long and fiery controversy with Argentieri, who concludes his violent criticisms of Ronchi (in the third book cited above in the note [1]) by copying the following vulgar reflection by Leonardo himself (Codex Trivulziano, Sheet 14):
“Demetrius used to say that he is not different from the words and voice of the ignorant imperis that it is from soni and noises caused by the belly full of superfluous wind. And this not without reason he said: because he did not consider it to be different from which side we sent the voice out or from the lower part or from the mouth because both were of equal value and substance. “
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[1] Argentieri, D. – Leonardo’s Optics, pp. 405-435- Proceedings of the Leonardesca Exhibition in Milan 1939
Argentieri, D. – Leonardo’s optics, Typographic Study of the Civil Engineers, 1939
Argentieri, D. – Discovery of the curvatures of the lenses of the telescope by Vinci, ed. Macciachini, Milan 1939
[2] there are 399 sheets (65 x 47.5 cm – format used for atlases, hence the name) of writings, notes and drawings bound with a title in gold
