Interviewing Joe Incandela, head of the CMS experiment at CERN's Large Hadron Collider where they are searching for the "God particle," extra dimensions, and particles that make up dark matter.
Photo by Ben Eshbach, who also wrote the following about the interview: "When Steve explained to him the gist of his film Incandella's eyes lit up. He had a lot to say about the history of attempts to explain the world around them, and Steve's film -- by addressing various ancient and modern ways humans have approached these questions -- seemed right up his alley. In particular, as I will describe below, Incandella had articulate opinions about the different answers mankind has arrived at depending on how dedicated we have been to observation.
Incandella was asked to give a brief history of the particle physics which led to the research at CERN. Beginning with Maxwell, Incandella gave a whirlwind history up through quantum mechanics (which he described as "fundamentally foreign to our intuitions") and the eleven dimensional mathematics of string theory to quantize gravity. "What I learn here is not going away," he said, "This is the fundamental stuff, looking for the genetic code of the universe. We're looking for simplicity, a single field, we're looking for an origin... But the darned thing is, we don't see any evidence in the places we look."
"We're already thinking about redesigning our experiments in case no Higgs appears," he said. This remark touched on my interest as to when researchers will know that they haven't found a Higgs because there isn't a Higgs. Incandella answered it with confidence, "The LHC energies are so great that there will be no excuse as to why [no Higgs was spotted]. If we don't [find a Higgs particle] the impact is very large. Our whole viewpoint will have to be adjusted."
Incandella gave us a rundown of some of the impressive features of CERN - 178 institutions and 40 countries working together - 80 million channels of electronics - single nanosecond timing - CMS weighing in at twice the weight of the eiffel tower - video conferencing and communication - "Everything works," he said. "I've never seen an accelerator this beautiful."
When asked to elaborate on his earlier remarks about experiment and observation, Incandella seemed (to me anyway) to be on turf for which he had a strong conviction. He mentioned two of his influences in the history of science, Bertrand Russell and Shmuel Sambursky. He mentioned Sambursky's book "Physical Thought from the Pre-Socratics to the Quantum Physicist's". He didn't mention what Russell he had read. Russell wrote a few books on the topic in the first quarter of the 20th centurty - The ABC of Atoms (1923) The ABC of Relativity (1925) and more notably, The Analysis of Matter (1927). Sambursky's book was written in 1975.
Incandella's exposure to the history of science - and his exposure to the activity of working scientists - has given him the conviction that science has always been at its best - has "gotten it right" - "when the theorists paid attention to the experimentalists." He remarked that the Stoics had great ideas because they were close observers. But eventually the Aristotelians came along and got carried away with the beauty and complexity of their models - the theory - and lost sight of the physical world through observation. "The Aristotelians thought that their theories were right just by their beauty."
Clearly Incandella fell on the experimenter's side. He held Farraday as the paradigm observer, and contrasted Farraday by referencing Paul Dirac's opinion that theorists should prefer beautiful equations even if uglier ones yield closer agreement with experimental data. I got the impression that Incandella's historical examples were meant to serve as lessons for contemporary work in particle physics. He seemed to be implying that even today, the theorists do not always pay attention to the experimenters as much as they should. "I had a nobel prizewinner ask me, 'Why do you call these discoveries? We theorists have already predicted them?' And I said, 'You predicted one thousand of our last three discoveries!'."
Incandella had no animosity for theory, he just wanted theory and experiment to sit in proper relation to each other. I wanted to press Incandella to elaborate on his historical remarks about the Aristotelians' devotion to theory at the expense of observation. By my lights, the most well-known Aristotelians were the Ptolemaic astronomers, who were in one very important sense very close observers. By observing the motions of the heavenly bodies for close to thirteen centuries, they had devised a model that was able to predict the positions of the planets with remarkable accuracy. However, the Ptolemaic model had accrued a list of complex theoretical entities - the epicycle, the equant and the deferent - which in retrospect (and only in retrospect) appear to have been necessities constructed to account for observations given circular (non-elliptical), earth-centered orbits. The point, however, is that the "observation" of these entities rested on the accuracy of predictions assuming their existence. Sound circular? Well that's because it is. Indirect observation is always theory-laden. Sometimes even what passes for direct observation is too. Einstein was famous for having told Heisenberg that, "It is the theory which decides what we can observe." A year later Heisenberg himself remarked that once the indeterminacy principle is deduced from quantum mechanics that "experiments are unlikely to produce situations that do not accord with quantum mechanics." With this in mind it becomes salient to ask an experimentalist like Incandella how a CERN experiment might produce observations that do not accord with a Higgs-dependent theory.
"We don't see it. We crate images, we create displays and so forth. But we don't know exactly what an electron looks like. We only know these things indirectly. We only know them because the rules are followed so well for what we've developed and how we've modeled things. Fundamentally they may be different. We don't even care. The point is, we're trying to find the rules or a model that will describe the phenomenon that we observe in the experimental sense." [emphasis mine]
It wasn't clear to me if Incandella believed that CERN experiments can provide some extra-theoretical observation of a Higgs boson or, to put it differently, how much of an Instrumentalist he is. His remarks sounded like an Instrumentalist's evaluation but not enough was said to give a definitive answer. Would Incandella have agreed that the functionality of the Ptolemaic model constituted its truth? Would he have accounted for their millennia-long drift into deeper geocentric waters as the unfortunate consequence of having been unable to perform experiments on the heavenly bodies? Or would he have accounted for it by their being Aristotelians? Was the equant ever observed in the Incanella-ian sense? Had we more time with him I would have liked to ask him these things.
After talking about the $80 to $90 million dollar annual electric bill for CERN, Incandella addressed the practical application of CERN research. His take on it was similar to Goldfarb's take - namely that CERN research eventuates in trickle down (what Incandella called "spinoffs").
"We're not producing something that we can immediately market," said Incandella, "By looking for these laws we're finding things that may eventually impact technology, but we don't know what these technologies will be. What we're doing now is way out on a limb, and we have no idea what would be the applications. It may be five-hundred years. I don't know."
He, like Goldfarb, mentioned the World Wide Web as a spinoff from CERN research, but then said, "These are some of the things that we use to help justify what we're doing financially, but fundamentally we're interested in the fundamentals."