ocular proof

In one of my favorite episodes of Numb3rs, Charlie -- the mathematical genius -- faces off against his old grad school rival, who is publicly challenging the revolutionary (fictional) proof that made Charlie the youngest tenured professor at his university. Said rival claims to have found a fatal error in the proof that renders it just plain wrong. Tensions run high, and what should have been a civilized, albeit heated, academic debate quickly escalates to the acerbic, and then to outright acrimony, ending with a crude, mean-spirited barb from the usually good-natured Charlie regarding his rival's lack of manly endowment. Two fascinated FBI agents are watching the exchange; one murmurs to the other, "Oooh... math fight!"

That scene captures a fundamental reality: academic debates aren't always pretty. Or polite. And sometimes they get downright nasty. I once likened academic warfare to being slashed quickly with a very sharp scalpel; you don't even feel the cuts until you look down and realize you're bleeding out. Personally, I prefer a direct stab in the back.

Take the debate currently -- still! five years later! -- raging in the art world over David Hockney's controversial thesis that some Renaissance painters, including Jan van Eyck, used optical devices to achieve certain "realistic" effects. The so-called "Hockney-Falco Thesis" was the subject of the artist's 2001 book, Secret Knowledge. Art historians, to put it mildly, were far from universally pleased; to many, it seemed like Hockney was accusing the Old Masters of "cheating." But the ugliest skirmish has revolved not around the art, but the science.

In one corner, we have Hockney's scientific collaborator, Charles Falco, a professor of optical sciences at the University of Arizona with more than 250 scientific papers to his name. In the other corner, we have the challenger, David Stork, chief scientist at Ricoh Innovations, who can trot out his own long list of publications. What started out as genteel sparring has escalated over the past two years into a gloves-off, below-the-belt, bloodied, brawling free-for-all. (Okay, the metaphor is over-ripe, but you must admit, it's colorful.) The latest development was reported last week by Nature: Falco has publicly accused Stork of "fabrications and manipulations" that are "at significant variance with accepted standards of scientific publication." In other words, "Who's a cheater now?" Stork, in turn, calls the accusation "insane."

Ooh... art fight. Or optics fight. Take your pick.

(I won't even try to summarize the details of the debate here, which I've been following off and on since 2001. Interested parties can look up my original 2001 review of Hockney's book in Discover, or a short update I wrote in 2004, or just Google the damn thing and peruse the millions of hits you'll get. If you want to go straight to the source material and weigh all the evidence yourself, Falco's FAQ and Stork's FAQ both contain more than you probably ever wanted to know about the details of the controversy.)

Falco was on hand this morning at the APS March meeting in Baltimore for a press conference, being a featured speaker at an invited session called "Physics for Everyone" (my kind of topic!). Naturally the "Stork affair" came up -- in the context of Falco's ruminations on what he's learned about being a scientist in the midst of a very public storm. Falco's association with Hockney catapulted him to sudden fame -- some might say notoriety. It is not without its perks. Falco has given more than 60 invited talks and public lectures in nine countries, and been featured in an hour-long BBC special and a segment on "60 Minutes." He's had the rare privilege of sitting for a portrait with Hockney. (I forgot to ask whether Hockney used an optical device -- a camera lucida, perhaps? -- for the initial sketching.) And after all those years as a condensed matter physicist -- his optics specialty is the characterization of thin film materials -- Falco jokes, "I get a theory in art history named after me."

But being in the spotlight also casts a shadow, and over the last five years Falco has discovered just how long, and how dark, that shadow can get. It might result in minor inconvenience; Falco advises fellow physicists contemplating similar national media exposure on controversial topics to get an unlisted phone number before the excrement really hits the fan. It might make you a lightning rod for harmless crackpots, like the person who sent Falco a thick sheaf of diagrams and excerpts from old books, asking that he analyze the materials to help the sender prove that aliens from outer space used optics to design Mayan temples. And it's bound to draw attention from detractors, some of whom can be quite impassioned and vocal about their displeasure.

Still, for the most part, Falco has found both the public and private discourse -- even with those who rabidly disagree with his findings -- to be "reasoned and thoughtful." But one group became so upset that it circulated a petition on the Internet and picketed the Metropolitan Museum of Art in New York, denouncing Hockney and Falco for supposedly "defaming" the Old Masters. And when Falco spoke at a meeting of the Optical Society of America, the organization placed plainclothes bodyguards in the audience as a precaution.

Things got really ugly in 2004, when Stork bounded onto the scene with his public refutation of the Hockney-Falco Thesis, providing the nay saying art historians with their own scientific champion.  January 2005 brought an especially acrimonious confrontation and Falco decided he'd had enough. He carefully analyzed and dissected Stork's various arguments -- sifting through a daunting pile of articles and lecture notes in the process -- and concluded there was evidence of misconduct in several of them. (You can see one of Falco's examples here.) He alerted the publishers to his conclusions. Most of the questionable articles had appeared in conference proceedings. But last December, Nature published a review by Stork once again attacking the Hockney-Falco Thesis. When Falco confronted the editor about the review, it turned into a major story.

Last week's Nature article is a fascinating artifact in its own right, if only for the reporter's strangely loaded choice of wording in odd places -- though he's clearly bending over backwards to be even-handed. Anyone who doesn't think a reporter's tone and choice of wording can create bias has never watched Fox News. Even when it's unintentional and we're just trying to be clever, biases can sneak in. For instance, Falco is described as an "optics scientist." Fair enough, that is his academic title. But Stork merits the moniker "optics expert" -- even though his research specialty, as stated on his corporate bio, is pattern recognition and neural networks. The wording of a later paragraph, in turn, seems to imply that Stork deliberately exploited a past association with Stanford to beef up his academic credentials. (Shrugs Jen-Luc, "At least they're being smeared equally.")

One bit of wording in particular I found interesting: the Nature article stated that Falco "decided to go public" with his accusations after they ran the December book review. I asked Falco about this "decision" at the press conference, since it seemed out of character. (Full disclosure: I've interviewed him repeatedly over the years, on several optics-related subjects, although today was the first time I'd actually met him.) His reply was carefully circumspect: "Well, if writing to the editor of Nature about my objections and concerns [about Stork] constitutes 'going public,' I suppose I did." Implication: he didn't intend to have the dirty laundry aired quite so publicly. Perhaps he was just a wee bit peeved that his private email communication with an editor was treated as "on the record," although that's just speculation on my part. If so, he didn't figure on the rapacious journalistic instinct for scandal: Nature caught whiff of a scoop and pounced on it. (Jen-Luc Piquant thinks we should be more cautious in the future whenever we communicate delicate matters to our own editors... just in case.)

The jury is still out on Stork's alleged guilt -- or innocence, since Stork "categorically denies" any wrongdoing. But Stanford, for one, has opted for prudent withdrawal. The university removed Stork's Web page and email from its server last November, and even Stork acknowledges that the dean of research has asked him not to represent himself as being affiliated with that institution.

Shakespeare's Othello demanded "ocular proof" of his beloved wife's alleged infidelity, but he forgot about the necessity of corroborating evidence, with tragic results. For similar reasons, the debate over the Hockney-Falco Thesis will likely rage on, even if Stork leaves the stage. After all, you can point to all the internal optical evidence you like, on either side of the debate. Barring any supporting textual evidence from other sources (say, a handwritten note by van Eyck mentioning his use of a "mirror lens"), it basically comes down to arguing over artistic intent -- something that is notoriously difficult to prove, especially when said artists are dead. I personally favor the Hockney-Falco Thesis; I'm just not prepared to call it "proven."

Comments

[wheatdogg]

Wow. I had heard of the camera obscura hypothesis before, but had no idea it had caused such a ruckus in the supposedly genteel art world. I guess learning your favorite artists may have "cheated" kinda takes the gloss off all that art history/appreciation stuff.

A colleague of mine has a similar hypothesis regarding the camera obscura and prehistoric art like cave paintings. Anthropologists seem more willing to accept his idea than these art experts Hockney-Falco. The link to his page is www.paleo-camera.com. Give it a look-see.

[JenLucPiquant]

Actually, the Hockney-Falco thesis doesn't involve the camera obscura specifically, although it's based on a simiar optical effect. A simple curved lens, called a "mirror lens," the precursor to spectacles, is the cornerstone of the thesis. But of course, as your friend's site (looks great, BTW, I'll forward it to Falco, just cause he might be interested) points out, the camera obscura is one of the oldest known optical effects. Vermeer used it in many of his paintings. Some historians believe ancient Chinese illusionists used it, the origin of the term "smoke and mirrors." Hockney claims Ingres, eg, used a later device called a camera lucida for some of his paintings.

It's a fascinating topic, and I confess, I don't see what the fuss is all about, in terms of the protests adn general level of rancor. Hockney/Falco have never, EVER, said the use of optical devices constitute "cheating"; they have always said exactly the opposite: that the devices are merely tools, like a paint brush. It actually requires a great deal of skill to use them correctly, and Falco thinks van Eyck was even more of a genius than he originally thought to have figured this stuff out.

Over and over again they have said this, yet they are still frequently mis-represented as saying the Dutch masters cheated. People don't really listen, is all I can figure -- they hear what they want/expect to hear.

Thanks for commenting!

[wheatdogg]

Not a problem. I came across your site by happenstance, and now really enjoy it. I have yet to try the black hole cocktail, though. Two glasses of wine are enough to push me toward the event horizon. In fact, I can almost see it from here ...

I'm a would-be physics major who ended up a comparative lit major who went back to physics in grad school to be a physics teacher. So, personally speaking, I welcome an English major to the "table." We're fence-sitters, so we provide a service to both cultures, whether they want to admit or not.

Thanks for referring Matt's site to Falco. Matt will be taking his "show" to France later this spring to see how the anthropologists there take to his hypothesis. For me, it obeys the Occam's Razor rule. It's simple and it works. Ditto the Hockney/Falco hypothesis.

Besides, these painters had to make money, didn't they? They used whatever tools were available to pay the rent and get the job done. For example, does using a calculator make a physicist any dumber? He still has to interpret what the calculator tells him. (A point some of my students still don't get.)

[David G. Stork]

Here are some facts followers of the debate should keep in mind:

* More than a dozen scholars in the relevant fields (history of optics, history of art, image analysis, optics) have published full journal articles and expert peer-reviewed publications rebutting and rejecting all or part of the Hockney-Falco tracing theory. My own research has passed rigorous double-blind triple review and been selected among the top 8% of all submissions to a major conference, passed expert peer review in standard journals, been published in Scientific American. To my knowledge, Hockney and Falco have never published such a peer-reviewed publication.

* The first full symposium addressing the tracing theory, subtitled "Reflections on the Hockney-Falco thesis" (in which I did not participate) rejected in no uncertain terms the tracing theory: "Taken together, the material, the visual and the textual evidence presented in these articles, makes the Hockney-Falco thesis extremely unlikely as far as its application for the period before the first textual reference to image projection around 1550 is concerned. The material evidence flatly contradicts the Hockney-Falco thesis, and while the textual evidence on its own cannot fully exclude the discovery of image projection, taken together with the material evidence of poor quality mirrors, the painterly use of image projection becomes extremely unlikely."

* In two recent publications it appears that Hockney himself has retreated from his claim that early Renaissance artists actually traced optical projections (feeling that they saw and were influenced by projected images).

* Contrary to one poster's statement, the optical projector is not simple at all: In the early 15th century it would have been the most precise optical system and complicated optical procedure in the western world -- their "Hubble telescope." I have made this statement in journal print, in lectures to thousands of people and in person and email to numerous optical scientists and historians of optics, and no one has ever provided a counter-example.

* Falco and I agree that the purported use of optics would not be "cheating," a bugaboo that clouds the discussion.

* I have given numerous lectures to groups that had heard only the "pro tracing" claim and as far as I know, in every case the audiences reject the tracing claims. Likewise, I recently spoke at a major university, unaware that Falco had spoken there the previous year. After my talk, Falco's host came up to me to express agreement with my conclusions, not Falco's.

* Falco's posting of alleged data errors in my work is riddled with errors. For instance, he circles sharp shadows on St. Joseph's leg and alleges I failed to include such shadows in my cast-shadow analysis. In fact, such shadows cannot be used because the location of the occluder cannot be determined (see http://diatrope.com/stork/delaTourRebuttal.html). (Further, there is a paper in press that employs even more sophisticated methods to corroborate the rejection of Hockney's claim for this painting.) Nevertheless I urge Falco to try to publish through peer review his allegations of purported errors.

--David G. Stork
www.diatrope.com/stork/FAQs.html