Along with replicas of Leonardo’s inventions, we had selected a copy of one of Leonardo’s drawings, that subsequently appeared on the dust jacket of my book. At the opening of the exhibition, I showed the drawing to two physicist friends, Prof. Norman Ramsey of Harvard and Dr. William D. Phillips of NIST, both uncommonly gifted scientists, both Nobel Prize Winners in Physics. I remember that they were awe struck in seeing the drawing, one of them even exclaiming, “That’s the telescope!”
In Math and the Mona Lisa, I had quoted Leonardo’s words, “In order to observe the nature of the planets, open the roof and bring the image of a single planet onto the base of a concave mirror. The image of the planet reflected by the base will show the surface of the planet much magnified” (Codex Arundel, c. 1513)
André Buys, Pretoria, SA. (Photo by the author, July 2010)
Unbeknownst to me in the 2005 PICMET talk, André Buys was in the audience. A professor at the University of Pretoria in South Africa, Buys was a nuclear engineer, and an avid amateur telescope maker. In the following two years Dr. Buys delved deeply into Leonardo’s surviving codices, and even built a replica of an instrument that I had speculated was Leonardo’s design for a reflecting telescope. Buys’s research goes a long way toward establishing the validity of the conjecture, and is far more important in establishing the primacy of the invention than my efforts had been.
I ran into André Buys again in 2010 at PICMET ‘10, but this time in the exotic venue of Phuket, Thailand. The morning preceding my keynote talk, we spent almost two hours reviewing the slides in his Power Point Presentation, a presentation initially created for a meeting of the Pretoria Centre of the Astronomical Society of Southern Africa in May 2007. It was immensely gratifying to have the private presentation, and many of Dr. Buys’s slides have been integrated into this blog.
Dr. Buys included in his history of the telescope, the basic design of telescopes, including the two reflectors, Isaac Newton’s (created in 1669 and presented to the Royal Society in the following two years) and William Herschel’s (1780). He also presented the quote from Leonardo:
“As I propose to treat of the nature of the moon, it is necessary that first I should describe the perspective of mirrors, whether plane, concave or convex; and first what is meant by a luminous ray, and how it is refracted by various kinds of media; then, when a reflected ray is most powerful, whether when the angle of incidence is acute, right, or obtuse, or from a convex, a plane, or a concave surface; or from an opaque or a transparent body.”
Elsewhere, Leonardo adds, “It is possible to find means by which the eye shall not see remote objects as much diminished as in natural perspective… and so the moon will be seen larger and its spots of a more defined form.”
Professor Buys includes many of Leonardo’s drawings from a variety of Leonardo Codices — ray diagrams based on experiments on reflection of light from flat and concave surfaces, of designs for machines and tools for polishing flat and concave mirrors, and an apparatus that resembles a modern battlefield weapon, the mortar, but one that can just as easily be a reflecting telescope. The latter is the instrument that Professor Buys created from bronze. The holes at the base, he speculated, might just have been to hold a variety of magnifying glasses, effectively the “eye-pieces” of telescopes. We should add that Leonardo left behind a drawing of a howitzer, shown lobbing shells in parabolic trajectories, but the apparatus is considerably heavier in design.
Buys includes some of Leonardo cosmological pronouncements, including a rejection of the Ptolemaic earth-centered universe, and recognition of universal gravitation:
“The earth is not in the center of the Sun’s orbit, nor at the center of the universe, but in the center of its companion elements, and united with them.” — Leonardo
“The sun does move.”
“Gravity is limited to the elements of water and earth; but this force is unlimited, and by