Alhazen
Defining Moments and Heroes
Historians, as historian will do, sometimes look for a defining moment and decisive changes in the rhythm of progress. The big changes were 1) from pondering to experimenting, 2) the use of mathematics as expression of reality and 3) the new paradigm called the scientific method.
And as historians will also do, they look for heroes, someone who can perhaps be called the father of science. Take your pick: Thales of Miletus (c.624–c.546 B.C.) who first postulated natural explanation for such godlike phenomena such as lightning and earthquakes. Alhazen, whose Book of Optics, translated by dutiful monks from Arabic to Latin and widely distributed throughout Europe in the Middle Ages, detailed his experiments and his scientific method. Any one of the trio of famous Franciscan friars, Roger Bacon (c. 1214–1294), Duns Scotus (c. 1266–1308) and William of Ockham (c. 1288-1348). Copernicus, Kepler or Galileo. And, of course, Isaac Newton (1643-1727).
Photons by the Millions
Scientists who study the problem of visual perception talk about information derived from light entering the eye. The 11th century scholar, Alhazen who first figured this out. The information can be just about anything: a dot, a squiggle, a line, a blob of color. It consists of shapes and textures. It consists of complex relationship between one bit of information and another. At its most primitive level it is a photon here and photon there by the millions.
But the eye doesn’t figure out anything. It only takes in the signals it receives, focusing and scanning mechanically, and passes the information on to the brain as a series of neuronal signals. It is left to the brain to make sense of it, to interpret what we are looking at. And the brain can be easily fooled as anyone who has looked at optical illusions can attest. And we suspect that the brain can be fooled by a sort of cognitive bias. It is perhaps why so many of us see faces in rock formations and wood grains and on pieces of toast. It isn’t that the information isn’t there for us to interpret and misinterpret, it’s just that our brains see things differently. Given enough information we’ll all see things rightly or wrongly. And the shroud has a great deal of information on it.
Alhazen Better that Leonardo
I would have done better. I would have chosen Alhazen. Although not a great Italian painter like Leonardo—which we tend to forget these days as we imagine him a leader of a totally fictitious secret cult, the Priory of Sion, and a schemer who hid a picture of Mary of Magdala in his Last Supper—he was everything else that Leonardo was and much more. Born in Basra around 965, he became the greatest scientist of his era. He was a physicist, a chemist, an anatomist, a mathematician and a philosopher. He is regarded by some as the first philosopher of science and the founder of the scientific method. His Book of Optics, translated in Toledo during the 12th century in a scriptorium much like the one at the monastery of San Nicola of Casole, is a classic. His descriptions of the camera obscura rival those of Leonardo. His knowledge of the way light is reflected from surfaces, so wonderfully shown in Leonardo’s Mona Lisa. If we can imagine that Leonardo invented photography, used it once, made no record of the fact—he was a prolific documenter—we can imagine that Alhazen did so. He might have travelled to Constantinople and found an opportunity to exchange the Image of Edessa with the fake relic of his own making. Might we imagine a motive. Surely: He was Muslim.
Herschel Even a Better Choice
Herschel, however, is my favorite choice. Room sized cameras obscura were scattered about England in his lifetime, although they were a far cry from being able to produce life-sized images, as was the case in Leonardo’s days. They were a favorite amusement in public parks and at the beach. Hanging a crucifixion victim out in the sun for several days might have been a problem in merry old England of the time. But then, too, many strange things were done in those days in the name of science. As for opportunity, Herschel was a world traveler—he met up with his friend Charles Darwin in South Africa. Sir John Herschel, knight of the Royal Guelphic Order, a Fellow of the Royal Society, someone whom Charles Darwin called “one of our greatest philosophers,” would have certainly been welcome in Savoy’s royal palace. As for motive, we might be able to weave one, just as we might for Leonardo or Alhazen. Herschel was an English Christian in the middle of the 19th century—his grandfather was Jewish. It might well be supposed that in this time of turbulent Catholic revival in England—the Tractarians, the Newmanites and the Puseyites—that Herschel like many of his peers were prejudiced against the Roman Catholic Church.
Continuous Tone Negative
It's possible to imagine that this appearance is what a crafter of fake relics wanted to create; perhaps to portray some imagined idea of what the Resurrection was like. But the reason they look ghostlike is that they are continuous tone negative images. When photographed, the negative of what is already a negative become the extraordinarily photographic like image we commonly see. Could the image on the Shroud, in fact, be a photograph?
Near the end of the fifteenth century, about 130 years after the Shroud's first public exhibition in Europe, Leonardo da Vinci described a camera obscura (a pinhole camera) in his notebooks. Aristotle (384-322 B.C.) understood the principle and so did a tenth century Arabian scholar, Alhazen who used a tent-sized camera obscura for observing the cosmos. In Alhazen's tent images were projected onto a wall where they could be traced or copied by hand. It wasn't until 1727 when Johann Heinrich Schulze discovered that silver mixed with nitric acid created a photosensitive compound that turned dark when exposed to light. And, it wasn't until 1816 when Nicéphore Niépce used a camera obscura with a sensitized paper to create an image. In 1834, Henry Fox Talbot created the first stable photographic negative on paper soaked in silver chloride.
Had someone, perhaps, invented photography several centuries earlier even though there is no written evidence or samples of photographic experiments or works? Is the Shroud the work of a scientific genius whose accomplishments are lost to history? While some people have opined that it might be, there is ample evidence the Shroud is not a photograph.