Looking for Multiphysics Answers in the Library of Babel

In “The Library of Babel,” a short story by Argentinian writer Jorge Luis Borges, the search for meaning in mythical books becomes a metaphor for the quest for knowledge, often futile. In the keynote delivered by William Vetterling at the recent COMSOL Conference, “The Library of Babel” becomes a metaphor for the search for answers in multiphysics, often fraught with unforeseen challenges.

“Any piece of information you need to know is somewhere in that library, if you can only find it. That’s what struck me as a similarity to COMSOL Multiphysics,” said Vetterling. “Here is a capable tool that solves second order, differential equations. Since the vast majority of engineering and science depends on second order differential equations, the tool could provide you with the answer to any question you’ll pose.”

Overwhelmed by the volumes available in the infinite library, Borges’ narrator wondered if he might find “the catalogue of catalogues.” But even that would only be of limited help, as the library contains not just “the faithful catalogues of the Library” but “thousands and thousands of false catalogues.”

In his presentation, Veterling drew a comparison: “Each choice of geometry, mesh, coefficients, and boundary conditions corresponds to a book in the library, usually nonsense but occasionally very important ... WE are the shadowy monks, roaming the library, looking at solutions to see if any of them spell out something really important ... Some of the solutions are difficult, and give results that we don’t understand. They may be in code, or in a foreign language or written all backwards. Millions of them have 1 error, and trillions have 2 … But hidden among them are the greatest prizes of all time.”

A physicist by trade, Vetterling is also a research fellow at ZINK Imaging, which specializes in a full-color printing technology that bypasses the use of ink cartridges or ribbons. It was a technology born out of Polaroid Corporation’s experiments in thermal imaging. All the color required for printing an image or text is embedded in the ZINK paper itself, the company explained. So what brings out the color in the paper, you might ask. It’s heat. That’s why Vetterling and his colleagues began using COMSOL Multiphysics.

“It’s a fairly sophisticated use of heat,” said Vetterling. ZINK’s papers are multi-layered composite materials coated in special chemicals. “So we used COMSOL Multiphysics to understand exactly how the heat travels through the media, where the heat is located, and how we isolate colors from one another. The problem involves both heat and mechanical operations [the thermal print head’s interaction with the paper]—That’s why it’s a multiphysics problem.”

“Simulations are never quite the same as what you’re simulating,” he cautioned, “because you don’t really know all the properties of the materials. The real-world instances of the physical systems are always more complicated.” When he’s using simulation, he’s merely trying to get insights, he said: “Like, what would happen if I increase the heat by 2 degree?”

Vetterling’s use of simulation has now expanded to his studies of the manufacturing process itself.—developing a method for producing and coating the media.

For more on COLSOL Conference and the keynote speakers, visit the event site here.

For ZINK Imaging, visit the company’s home page here.