My Photo


  • Jen-Luc Piquant sez: "They like us! They really like us!"

    "Explains physics to the layperson and specialist alike with abundant historical and cultural references."
    -- Exploratorium ("10 Cool Sites")

    "... polished and humorous..."
    -- Physics World

    "Takes 1 part pop culture, 1 part science, and mixes vigorously with a shakerful of passion."
    -- Typepad (Featured Blog)

    "In this elegantly written blog, stories about science and technology come to life as effortlessly as everyday chatter about politics, celebrities, and vacations."
    -- Fast Company ("The Top 10 Websites You've Never Heard Of")
Blog powered by Typepad
Bookmark and Share

« graphene dreams | Main | silly science songs »


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 Give it a look-see.

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!

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.)

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 (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

The comments to this entry are closed.

Twitter Updates

    follow me on Twitter

    Physics Cocktails

    • Heavy G
      The perfect pick-me-up when gravity gets you down.
      2 oz Tequila
      2 oz Triple sec
      2 oz Rose's sweetened lime juice
      7-Up or Sprite
      Mix tequila, triple sec and lime juice in a shaker and pour into a margarita glass. (Salted rim and ice are optional.) Top off with 7-Up/Sprite and let the weight of the world lift off your shoulders.
    • Listening to the Drums of Feynman
      The perfect nightcap after a long day struggling with QED equations.
      1 oz dark rum
      1/2 oz light rum
      1 oz Tia Maria
      2 oz light cream
      Crushed ice
      1/8 tsp ground nutmeg
      In a shaker half-filled with ice, combine the dark and light rum, Tia Maria, and cream. Shake well. Strain into an old fashioned glass almost filled with crushed ice. Dust with the nutmeg, and serve. Bongos optional.
    • Combustible Edison
      Electrify your friends with amazing pyrotechnics!
      2 oz brandy
      1 oz Campari
      1 oz fresh lemon juice
      Combine Campari and lemon juice in shaker filled with cracked ice. Shake and strain into chilled cocktail glass. Heat brandy in chafing dish, then ignite and pour into glass. Cocktail Go BOOM! Plus, Fire = Pretty!
    • Hiroshima Bomber
      Dr. Strangelove's drink of choice.
      3/4 Triple sec
      1/4 oz Bailey's Irish Cream
      2-3 drops Grenadine
      Fill shot glass 3/4 with Triple Sec. Layer Bailey's on top. Drop Grenadine in center of shot; it should billow up like a mushroom cloud. Remember to "duck and cover."
    • Mad Scientist
      Any mad scientist will tell you that flames make drinking more fun. What good is science if no one gets hurt?
      1 oz Midori melon liqueur
      1-1/2 oz sour mix
      1 splash soda water
      151 proof rum
      Mix melon liqueur, sour mix and soda water with ice in shaker. Shake and strain into martini glass. Top with rum and ignite. Try to take over the world.
    • Laser Beam
      Warning: may result in amplified stimulated emission.
      1 oz Southern Comfort
      1/2 oz Amaretto
      1/2 oz sloe gin
      1/2 oz vodka
      1/2 oz Triple sec
      7 oz orange juice
      Combine all liquor in a full glass of ice. Shake well. Garnish with orange and cherry. Serve to attractive target of choice.
    • Quantum Theory
      Guaranteed to collapse your wave function:
      3/4 oz Rum
      1/2 oz Strega
      1/4 oz Grand Marnier
      2 oz Pineapple juice
      Fill with Sweet and sour
      Pour rum, strega and Grand Marnier into a collins glass. Add pineapple and fill with sweet and sour. Sip until all the day's super-positioned states disappear.
    • The Black Hole
      So called because after one of these, you have already passed the event horizon of inebriation.
      1 oz. Kahlua
      1 oz. vodka
      .5 oz. Cointreau or Triple Sec
      .5 oz. dark rum
      .5 oz. Amaretto
      Pour into an old-fashioned glass over (scant) ice. Stir gently. Watch time slow.