10.48255/1973-9494.JCSCH.21.2021.16
La stampa finale di “Albert Einstein Corrispondence avec Michele Besso 1903 – 1955” è stata pubblicata da Collection Savoir, Hermann, Parigi, su “Nine-Eleven” nel 2001. Dopo aver raccolto l’intera tiratura della corrispondenza Einstein/Besso, l’erede del Besso Estate, il Dott. Vittorio Besso, è stato invitato a partecipare al convegno scientifico LACONA V (LACONA è l’abbreviazione delle parole Lasers for Artworks Conservation, che è il nome del più importante convegno internazionale del settore) dove ha conosciuto la tecnica laser per il restauro dei dipinti. Successivamente, al suo ritorno nel suo studio oftalmologico a Imperia, in Italia, il Dr. Besso eseguì l’ablazione laser di pitture superficiali rivelando pentimenti dell’autografo del pittore su un dipinto della “Monna Lisa” nella collezione di famiglia di dipinti rinascimentali ereditati. Una fotografia IR della poco leggibile firma è stata quindi confrontata con autografi convalidati dell’assistente e compagno di Leonardo, Francesco Melzi, e risultata geometricamente incoerente con le firme convalidate. Gli istogrammi di ampiezza delle caratteristiche di questa “Monna Lisa” sono stati successivamente confrontati con ritratti originali convalidati comparabili di Melzi, rivelando “impronte digitali” in chiaroscuro. Qualsiasi potenziale attribuzione a Melzi sarebbe coerente con la storia della famiglia Besso come rivelata nei cinquantadue anni di corrispondenza Einstein/Besso riguardante sia l’arte che la scienza.
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1973-9494
15258
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Vadim Parfenov
https://creativecommons.org/licenses/by/3.0
Conservation Science in Cultural Heritage
histogram
Special relativity: Albert Einstein to Leonardo Da Vinci
Text.Serial.Journal
https://conservation-science.unibo.it/
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Articles
2022-08-02
2022-07-19
2022-08-02
2022-08-02
337-344
CSCH
Vadim Parfenov
2021
10.48255/1973-9494.JCSCH.21.2021.16
337
St. Petersburg Electrotechnical University, St. Petersburg, Russian Federation
1973-9494
histogram
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Special relativity: Albert Einstein to Leonardo Da Vinci
https://conservation-science.unibo.it/article/download/15258/14497
21
S    PECIAL RELATIVITY:
     ALBERT EINSTEIN TO LEONARDO DA VINCI

    John Asmus
    University of California San Diego, CA, USA

    Vadim Parfenov *   1




    St. Petersburg Electrotechnical University, St. Petersburg, Russian Federation

    Keywords: Mona Lisa, Leonardo Da Vinci, laser cleaning, painting, histogram

    DOI: 10.48255/1973-9494.JCSCH.21.2021.16



    1. Introduction

     Einstein’s musicianship is widely recognized (Figure 1), whereas the role of the engi-
neer, Michele Angelo Besso, in the “Theory of Special Relativity” is seldom appreciated
in spite of Einstein’s dedication at the close of his paper, which reads: “In conclusion I
wish to say that in working at the problem here dealt with I have had the loyal assistance
of my friend and colleague M. Besso, and that I am indebted to him for several valuable
suggestions”. For centuries the Besso family owned and operated an electrical-contract-
ing business in Milan. Furthermore, Albert Einstein and Francesco Melzi found periodic
employment in the Besso firms and also resided with the Besso family, as did Leonardo.
Upon the death of Leonardo, his protegee and heir, Melzi, returned to Milan and, pre-
sumably, lived with the Besso family for a time. Naturally, he would have had in his pos-
                                                   session both the inherited items from
                                                   Leonardo’s estate as well as his personal
                                                   belongings, including paintings he had
                                                   produced as an apprentice and student
                                                   under Leonardo’s inspiration and guid-
                                                   ance. It is clear from their more than fifty
                                                   years of correspondence (Collection
                                                   Savoir) that both Albert Einstein and Mi-
                                                   chele Besso were deeply interested in the
                                                   intersection of art and science and the
                                                   Besso family’s art collection. Thus, it is
                                                   more than plausible that the Besso family
                                                   would have come into possession of at
                                                   least a gift from Francesco Melzi, if not his
                                                   entire material legacy, including his own
                                                   paintings. As Leonardo’s visitors to Châ-
                                                   teau de Cloux in France on 10/10/1517,
Figure 1. Einstein was the most famous physicist   Cardinal Luigi of Aragon and Antonio de
of the 20th Century and an accomplished violinist. Beatis, wrote and spoke highly of a paint-



    * Corresponding author: restlaser@gmail.com
                                                                                                                                     ing now believed to be the Louvre “Mona
                                                                                                                                     Lisa,” there is little room for doubt that Melzi
                                                                                                                                     would have also executed a “Mona Lisa”
                                                                                                                                     study and copy as a Leonardo student,
                                                                                                                                     “family” member, and apprentice. The Bes-
                                                                                                                                     so family has assumed for several genera-
                                                                                                                                     tions that a “Mona Lisa” painting in their pos-
                                                                                                                                     session (Figure 2) is in fact such a painting,
                                                                                                                                     executed by Melzi.
                                                                                                                                         The current owner of the painting (Dr.
                                                                                                                                     Vittorio Besso, ophthalmologist) visually
                                                                                                                                     examined the painting a number of times
                                                                                                                                     and determined that there were signs of
                                                                                                                                     restoration and retouching. As a result of
                                                                                                                                     attending the international conference LA-
                                                                                                                                     CONA V (Lasers in Conservation of Art-
                                                                                                                                     works) in Paris in 2001, and excited by the
                                                                                   Figure 2. The “Mona Lisa” painting in the Bes-    efficiency of the laser cleaning technique
                                                                                   so`s family art collection, originally located in for removing dirt layers and overpainting,
                                                                                   their Milan residence for several generations.    Dr. Besso subsequently performed laser
                                                                                                                                     ablation of some overpainting, in his oph-
J. Asmus, V. Parfenov - Special relativity: Albert Einstein to Leonardo Da Vinci




                                                                                   thalmological studio in Imperia, which revealed pentimenti. He divested a small area of
                                                                                   heavy impasto with his ophthalmological Nd:YAG laser and revealed what appeared to
                                                                                   be faint hints of a signature. Then, infrared photographs were next taken of the la-
                                                                                   ser-divested surface in order to enhance the visibility of the pentimenti.


                                                                                       2. Experimental results

                                                                                       2.1. Infrared imaging of the signature pentimenti

                                                                                                                                                        The infrared photographs
                                                                                                                                                    of the Besso “Mona Lisa”
                                                                                                                                                    painting were taken by one of
                                                                                                                                                    the authors of the paper (John
                                                                                                                                                    Asmus) with a conventional
                                                                                                                                                    35 mm photo-camera loaded
                                                                                                                                                    with infrared-sensitive film and
                                                                                                                                                    employing a visible-light-block-
                                                                                                                                                    ing filter. Figure 3 displays the
                                                                                                                                                    IR image of the bosom area
                                                                                                                                                    that was laser-divested of
                                                                                                                                                    heavy overpainting. Dr. Bes-
                                                                                                                                                    so added the hand-written
                                                                                                                                                    annotation displaying a cus-
                                                                                                                                                    tomary Melzi signature which
                                                                                   Figure 3. Annotated infrared photograph of the laser-divested    appears similar to the en-
                                                                                   bosom-region of the “Mona Lisa” painting in the Besso`s art      hanced pentimenti geometry
                                                                                   collection.                                                      of that region.


                                                          338
   2.2. Comparison of signatures

    The initial approach to the possible Melzi authorship of the Besso Mona Lisa was
the study of the autograph (signature), which was found as a result of IR imaging of the
pentimenti. We resolved to compare the pentimenti image with known autographs by
Melzi. Some authentic Melzi signatures were found in the book “Leonardo da Vinci on
painting” written by Carlo Pedretti [1]. In this book Pedretti reproduced several of
Melzi’s signatures including one of 1511 (Figure 4). This seems to be a strange writing
of his name (“Francescho di Melzo”), but in any case, the style of this writing script dif-
fers significantly from that of the pentimenti.


                                                                                  a


                                                                                  b


          Figure 4. Signature of Melzi (a) and pentimenti in the Besso Mona Lisa(b).


   2.3. Comparison of chiaroscuro data of the Besso Mona Lisa with Melzi
        paintings

     To more deeply investigate the hypothesis of the authorship of Francesco Melzi to
the Besso “Mona Lisa”, we applied our approach to image processing, which is based
on the use of luminosity histograms of digitized images. This approach is based on the
following general concept. As any painting requires a great many brushstrokes in its ex-
ecution, it follows that the resulting painted surface will have spatial and spectral mor-




                                                                                                    CONSERVATION SCIENCE IN CULTURAL HERITAGE
phologies that are characteristic of that artist’s eye for composition, the types of brush-
es used, the palette, the mixing technique, the speed of execution, the use of glazes,
the care in blending, the viscosity of the paint medium, etc. This means that paintings
may possess spatial and spectral characteristics that are typical for one particular indi-
vidual. One possible way of portraying statistical characteristics of an image is through
an amplitude (luminosity) histogram. An amplitude histogram is a graphical plot that in-
dicates the distribution of brightness levels throughout a pictorial scene. Histograms are
essentially “fingerprints” of the distribution of light and dark shading in the image of a
painting. In other words, it is a quantification of chiaroscuro, which is of central signifi-
cance in the paintings of some artists (see, for instance [2] and [3]). It is possible that
every artist in executing his works develops an envelope of shadings that are a unique
characteristic of his hand and eye. If so, one can find a digital “fingerprint” for each art-
ist by means of histograms from digital images of his paintings.
     Basically, sfumato/chiaroscuro pertain to the blending of color saturation and albedo
from one region of a painting to adjacent zones. When a connoisseur visually assesses
a painting, this spatial blending and contrast are significant features that the expert per-
ceives and mentally evaluates. This impression is then correlated in the inspector’s mind
with impressions of similar authenticated works by the relevant artist. The problem with
this approach to attribution is that it is highly subjective. From this point of view, luminos-
ity histograms provide an alternative and/or supplement to conventional stylistic analy-
ses, because it can be done objectively and with mathematical precision.


                                                                                                  339
                                                                                        Pixels in all typical digital image formats range over 256 intensity levels. Many dig-
                                                                                   ital image-processing computer programs incorporate a “histogram” feature. The his-
                                                                                   togram “luminosity” option counts the number of pixels (of an image or a specified re-
                                                                                   gion of an image) for each of 256 intensity levels. The graphical plot of these counts
                                                                                   versus intensity is an amplitude histogram. When there is a high degree of pigment
                                                                                   blending extending from the light to dark portions of a painting, this will yield a uniform
                                                                                   and gentle gradient in pixel distribution between the highest and lowest intensity val-
                                                                                   ues. Thus, histograms of features in paintings of masters, which are characterized by
                                                                                   a very precise technique (i.e. exhibiting sfumato/chiaroscuro) should be smooth with-
                                                                                   out discontinuities or abrupt transitions. In such a case, if another painting, which was
                                                                                   most likely created by the same artist, also has similar very uniform distribution of his-
                                                                                   tograms, there is a high probability that this is a “fingerprint” candidate. It is important
                                                                                   to add that each luminosity histogram is characterized by two main mathematical pa-
                                                                                   rameters: mathematical mean and standard deviation. The latter is an important pa-
                                                                                   rameter for the characterization of chiaroscuro. Therefore, obtaining histograms of dig-
                                                                                   ital images of different paintings allows one to compare the shape of the distribution of
                                                                                   intensities and value of their standard deviations. It is obvious that paintings created by
                                                                                   the same artist may have similarities in technique following these two criteria. This is
                                                                                   the central concept of our method for quantifying style. Previously, we successfully ap-
                                                                                   plied this approach to analyses of a number of paintings by various artists [4-8].
                                                                                        In response to preceding arguments, we have compared the digital chiaroscuro
J. Asmus, V. Parfenov - Special relativity: Albert Einstein to Leonardo Da Vinci




                                                                                   statistics of the Besso portrait with those of accepted Melzi paintings, as well as Leon-
                                                                                   ardo works, in order to discover the provenance of this painting. These results may re-
                                                                                   inforce the contention that the Besso “Mona Lisa” may have been painted by Melzi.
                                                                                   This result is also consistent with the supposition that as student, heir, and companion,
                                                                                   Melzi would certainly have produced his own version of what became Leonardo’s most
                                                                                   notable work. With the autograph on the Besso “Mona Lisa” it is possible that the por-
                                                                                   trait (Figure 3) in the Besso family collection was painted by Melzi. However, it may not
                                                                                   be rigorously possible to distinguish whether the faint signature pentimenti revealed in
                                                                                   the Besso painting is by the hand of Melzi, a forger, or a restorer.
                                                                                        An initial “baseline” was established through a comparative analysis of the Besso
                                                                                   “Mona Lisa” and the Louvre “Mona Lisa”. Significant differences between histograms
                                                                                   of these 2 paintings (Figure 5) leads to the conclusion that the Besso “Mona Lisa” was
                                                                                   not created by Leonardo Da Vinci.




                                                                                   Figure 5. Histograms of image of the Mona Lisa face: Louvre Mona Lisa (left), Besso Mona Lisa
                                                                                   .
                                                                                   (right)

                                                                                      The next stage in this study was to carry out a comparative analysis of the Besso
                                                                                   “Mona Lisa” and some of the most famous paintings by Melzi: “Flora” (The State Hermit-
                                                                                   age Museum, St. Petersburg, Russia), “Vertumnus and Pomona” (The Gemäldegalerie,
                                                                                   Berlin) and “Madonna and Child in a Jasmine Bower” (The Frick Art Museum, USA),


                                                     340
which are most reliably attributed by art experts to a Melzi authorship. However, these
analyses did not reveal any matches between histograms of the Besso “Mona Lisa” and
all the Melzi paintings. However, it must be noted that histograms of all 3 of the Melzi
paintings fail to match, as well: indicating possible limitations in such analyses (Figure 6).

                                                                                     a




                                                                                     b




                                                                                                   CONSERVATION SCIENCE IN CULTURAL HERITAGE
                                                                                     c




Figure 6. Histograms of paintings by Melzi: a) “Flora”; b) “Vertumnus and Pomona”; c) “Madonna
and Child in a Jasmine Bower”.


   3. Conclusion

    The story of Besso`s “Mona Lisa” is an unusual and interesting case of the “mixing”
of science, history, art and cultural heritage. In the Besso Mona Lisa story, Albert Ein-
stein, Leonardo Da Vinci, LACONA and laser techniques unpredictably intersect. In the


                                                                                                 341
                                                                                   studies, described in the paper, there was an effort to find similarities in histograms of
                                                                                   the Besso “Mona Lisa” and other paintings by Melzi as well as similarities of the signa-
                                                                                   ture in pentimenti and images of signatures in manuscripts written by Melzi. Unfortu-
                                                                                   nately, no clear matches were found between histograms, histogram statistics, or sig-
                                                                                   nature appearances. Of course, differences in histograms cannot be considered as a
                                                                                   reliable way to conclude that the Besso “Mona Lisa” was not executed by Melzi but by
                                                                                   some other painter. However, for these analyses, the available digital images of the
                                                                                   Besso “Mona Lisa” and other Melzi paintings were of poor quality. In addition, it should
                                                                                   be taken into account that all had been restored and it is obvious that restoration inter-
                                                                                   ventions would have changed both the chiaroscuro and histograms, respectively. How-
                                                                                   ever, differences between signatures argue against any assumption that Melzi created
                                                                                   the Besso “Mona Lisa”. However, all of the previous experimental data are not suffi-
                                                                                   cient to support a final conclusion stating that the Besso “Mona Lisa” was painted by
                                                                                   Melzi. This issue remains an open question until higher-quality digital images are em-
                                                                                   ployed. Further study is needed to reach clearer indications concerning the hypothe-
                                                                                   ses on the creation of the Besso “Mona Lisa” by Melzi.


                                                                                         References

                                                                                   [1]     Pedretti, C., (1964) Leonardo da Vinci on painting. A lost book (Libro A). Univer-
J. Asmus, V. Parfenov - Special relativity: Albert Einstein to Leonardo Da Vinci




                                                                                           sity of California, Berkley and Los Angeles.
                                                                                   [2]     Clark, K., Leonardo da Vinci, Cambridge: Univ. Press. 1952.
                                                                                   [3]     Pedretti, C., (1973) Leonardo: A Study in Chronology and Style, Berkeley Univ.
                                                                                           of Cal. Press.
                                                                                   [4]     Asmus, J. F., (1992) Computer Image Studies of Rembrandt Self Portraits, Hu-
                                                                                           man Vision III, Vol.1666, pp. 436-445.
                                                                                   [5]     Asmus, J. F., (1994) Spectral and Spatial Statistics of Raphael Paintings, Appli-
                                                                                           cations of Digital Image Processing XVII. doi: 10.1117/12.186550.
                                                                                   [6]     Asmus, J., Parfenov, V., and Elford, J., (2016) Seeing double: Leonardo`s Mona
                                                                                           Lisa Twin, Journal of Optical and Quantum Electronics. Vol. 48. doi:10.1007/
                                                                                           s11082-016-0799-0.
                                                                                   [7]     Asmus, J. F. and Parfenov, V.A., (2018) A Scientific Method for the Attribution of
                                                                                           Paintings with application to Leonardo’s Mona Lisa twins // Electronic Imaging &
                                                                                           the Visual Arts: EVA 2018. Florence: 9-10 May 2018, ed. by V. Cappellini. Firen-
                                                                                           ze: Firenze University Press (Proceedings e report; 118), pp. 48-55. 2018.
                                                                                   [8]     Asmus, J. F. and Parfenov, V A., (2019) Characterization of Rembrandt self-por-
                                                                                           traits through digital-chiaroscuro statistics // Journal of Cultural Heritage. Vol. 38,
                                                                                           July-August 2019, pp. 167-173. doi: 10.1016/j.culher.2018.12.00


                                                                                         Biographical notes

                                                                                       John Asmus is Emeritus Professor, University of California, San Diego. Since
                                                                                   1973 John Asmus has been a Research Physicist with the Department of Physics at
                                                                                   the University of California, San Diego. He earned his PhD from the California Institute
                                                                                   of Technology (physics and quantum electronics) and is a co-founder of the Center for
                                                                                   Art/Science Studies at UCSD. Prior to 1973 he held positions with The US Naval Ord-
                                                                                   nance Laboratory, General Atomic, The Institute for Defense Analyses, and SAIC Inter-
                                                                                   national (VP and Bd. Mbr.) In 1990 he was awarded the Rolex Laureate for Enterprise


                                                        342
(Xi’an Terra Cotta Warriors) and became a Fellow of the Explorers Club. He has pub-
lished 140 articles in professional journals and holds 25 patents in the fields of astro-
physics, high-energy plasma physics, high-energy lasers, and laser applications. During
his career Prof. Asmus has performed pioneering research in the use of holography, la-
sers, ultrasonics, inside-out (X-ray and NMR) imaging, and digital image processing in
art conservation. He has applied these tools to the problems of divestment, analysis,
interpretation, and presentation associated with diverse art conservation activities. He
has also been instrumental in the founding of professional art conservation and laser
societies. He is a member of UNESCO and EU conservation commissions on World
Heritage Sites and the Parthenon, respectively.

    Vadim Parfenov is a Professor at St. Petersburg Electrotechnical University (ETU
LETI). He holds a Ph.D. in Quantum Electronics (2002) and degree of Doctor of Scienc-
es (2018), both from ETU LETI. He has worked on research areas of diverse or cross-dis-
ciplinary interest, ranging from laser material processing to studies on phase conjuga-
tion, non-linear optics, wavefront sensing and laser 3D scanning, and development of
laser-based systems for interferometry and holography. For the last 15 years he has
been involved in research on the use of lasers and opto-electronic techniques in Cultur-
al Heritage preservation. He has worked collaboratively with museums including The
State Russian Museum, The Hermitage Museum, The museum-preserve “Tsarskoye
Selo” and St. Petersburg State Museum of Urban Sculpture, as well as with The State
Tretyakov Gallery, Moscow, in the use of 3D laser scanning for documentation and rep-
lication of artworks. He has organized and co-chaired several conferences and work-
shops such as: “Light for Artworks conservation” (2006, 2010 and 2012, St. Petersburg)
and “Laser Cleaning and Artworks Conservation” (2007, 2013 and 2016, St. Petersburg).
From 2005-2006 he was a member of the Management Committee of the European
Union COST Action G7 “Artwork Conservation by Laser”, and since 2014 he is a mem-
ber of the Permanent Scientific Committee of LACONA (Lasers for Artwork Conserva-
tion). He is the author and co-author of more than 100 articles and several books.




                                                                                               CONSERVATION SCIENCE IN CULTURAL HERITAGE
   Summary

    The final printing of “Albert Einstein Correspondence avec Michele Besso 1903 - 1955”
was released by Collection Savoir, Hermann, Paris, on “Nine-Eleven” 2001. Upon
collecting the full printed run of the Einstein/Besso correspondence, the heir to the Bes-
so estate, Dr. Vittorio Besso, was invited to attend the scientific conference LACONA V
(LACONA is the abbreviation of the words Lasers for Artworks Conservation, which is the
name of the most important international conference in the field) where he became
aware of the laser technique for the divestment of restorations from paintings. There-
after upon returning to his ophthalmological studio in Imperia, Italy, Dr. Besso performed
laser ablation of overpaints revealing pentimenti of the painter’s autograph on a “Mona
Lisa” painting in the family collection of inherited Renaissance paintings. An IR photo-
graph of the faint signature pentimenti was then compared with validated autographs
of Leonardo’s assistant and companion, Francesco Melzi, and found to be geometri-
cally inconsistent with validated signatures. Amplitude histograms of features of this
“Mona Lisa” were next compared with comparable validated original portraits by Melzi,
revealing chiaroscuro “fingerprints.” Any potential Melzi attribution would be consistent
with the Besso family history as illuminated in the fifty-two years of Einstein/Besso cor-
respondence concerning both art and science.


                                                                                             343
                                                                                      Riassunto

                                                                                       La stampa finale di “Albert Einstein Corrispondence avec Michele Besso 1903 – 1955”
                                                                                   è stata pubblicata da Collection Savoir, Hermann, Parigi, su “Nine-Eleven” nel 2001.
                                                                                   Dopo aver raccolto l’intera tiratura della corrispondenza Einstein/Besso, l’erede del
                                                                                   Besso Estate, il Dott. Vittorio Besso, è stato invitato a partecipare al convegno scienti-
                                                                                   fico LACONA V (LACONA è l’abbreviazione delle parole Lasers for Artworks Conser-
                                                                                   vation, che è il nome del più importante convegno internazionale del settore) dove ha
                                                                                   conosciuto la tecnica laser per il restauro dei dipinti. Successivamente, al suo ritorno
                                                                                   nel suo studio oftalmologico a Imperia, in Italia, il Dr. Besso eseguì l’ablazione laser di
                                                                                   pitture superficiali rivelando pentimenti dell’autografo del pittore su un dipinto della
                                                                                   “Monna Lisa” nella collezione di famiglia di dipinti rinascimentali ereditati. Una foto-
                                                                                   grafia IR della poco leggibile firma è stata quindi confrontata con autografi convalidati
                                                                                   dell’assistente e compagno di Leonardo, Francesco Melzi, e risultata geometricamente
                                                                                   incoerente con le firme convalidate. Gli istogrammi di ampiezza delle caratteristiche di
                                                                                   questa “Monna Lisa” sono stati successivamente confrontati con ritratti originali conva-
                                                                                   lidati comparabili di Melzi, rivelando “impronte digitali” in chiaroscuro. Qualsiasi poten-
                                                                                   ziale attribuzione a Melzi sarebbe coerente con la storia della famiglia Besso come ri-
                                                                                   velata nei cinquantadue anni di corrispondenza Einstein/Besso riguardante sia l’arte
                                                                                   che la scienza.
J. Asmus, V. Parfenov - Special relativity: Albert Einstein to Leonardo Da Vinci




                                                      344
