The Telescope in the Ice
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The first thing the Zeuthen group did—before they officially joined the collaboration—was to implement the new supernova idea. This required a relatively simple data acquisition system on the surface of the Ice, a so-called hardware trigger, that would count all the photons that the array picked up in rolling time-slices of about ten seconds, roughly the length of a supernova’s neutrino flash, and send an alert if the count reached a certain threshold. The Germans built the trigger, paid for it, and installed it in AMANDA-A during the 1995–96 Antarctic season—before Francis and his students submitted their updated paper to Physical Review. (Francis likes to joke that if the paper had been rejected he could have told the editors that the idea was already working in the ice.) Between AMANDA and IceCube, the collaboration has been monitoring the cosmos for a nearby supernova now for more than twenty years.
This engenders a certain anxiety, because what if a supernova were to occur while the instrument was down or being repaired? In fact, who knows? They may already have missed one. AMANDA was taken down frequently during the austral summer when it was being added to or updated, and IceCube also had a lot of down time during the years it was being installed. Blood pressures are dropping since the larger instrument was completed and has become increasingly stable, but as a sign of how critical this issue remains, “detector uptime” is displayed in large letters on the first page of the On Ice Report that is sent north every week. It hovers mercifully in the range of 99.8 percent.
Since the neutrinos from a supernova arrive a few hours before the photons do, it would be ideal if a neutrino detector were capable of telling optical telescopes where to look. And although IceCube can’t tell the direction of supernova neutrinos very well, the community has come up with a creative solution. At this moment, IceCube and several other neutrino detectors, including Kamiokande’s successor, Super-K, are wired in to the SuperNova Early Warning System, or SNEWS, which will broadcast an automated e-mail message the moment one or more of the instruments senses what it thinks is a supernova neutrino flash. Since the instruments are located in different spots on the globe, the general direction of the event can be inferred through triangulation: the flash will pass through the different instruments at slightly different times. SNEWS will then alert a network of earthbound and space-based optical telescopes of the impending fireworks and give them a rough idea where to look.
* * *
During a discussion of supernovae at an IceCube collaboration meeting in 2010, Francis pointed out that only at that meeting had he begun to appreciate that if a supernova were to go off at a distance of about one kiloparsec, IceCube would be so overwhelmed with signal that it would probably miss the event. A certain register in the supernova trigger would saturate after about twenty seconds, the instrument would crash, and all record of the neutrino flash would be lost.
A kiloparsec (kpc) is a thousand parsecs, which is about 3,200 light years—one-fiftieth the distance to Supernova 1987a. A so-called stellar nursery, a region of active star formation, lies at about that distance in the constellation Cygnus, and supernovae are expected to occur more frequently in such nurseries. Francis was implying that the instrument ought to be fixed, obviously, in case this possibility happens to bear fruit. That night I had dinner with Per Olof Hulth, who explained that actually there was no need to fix the instrument, for if a star were to explode that nearby, the human race and most of life on Earth would be extinguished. I checked this with Francis, who did a short calculation and assured me in one of his typically pithy e-mails: “No, 1 kpc is safe. To kill the dinosaurs you need 10 pc”—about a hundred times closer than the Cygnus nursery. When he was presented with Francis’s calculation, Per Olof did “not disagree.” It is comforting that the collaboration has gone ahead and fixed the instrument.… And such is the logic that neutrino astronomers occasionally entertain.
11. Doubling Down
Francis is fond of pointing out that the collaboration didn’t have a speakers committee in those days. Now, with more than two hundred members and several significant accomplishments to its credit, the IceCube collaboration is asked to present at one conference or another roughly once a week, all over the world. The speakers committee has rules about what can be said and who is authorized to say it, and there is some competition about who will travel to the more important meetings or exotic locales. In the days of the bubbles, however, Francis was the only member of the AMANDA collaboration who was willing to make a fool of himself in public: “I have no pride. I’m a theorist. What did I care?” Although he also admits that he wasn’t just giving a scientific talk, he was also campaigning for more money. The funding agencies take the views of the community into account, so it’s important to maintain one’s visibility and credibility.
With an apparent failure to his credit, however, he was having trouble in the credibility department. He encountered aggressive criticism almost every time he spoke. He observes that “there’s an infinite possibility of being cynical, right?” It can be surprising how little an expert in the exact same field sometimes understands about a competing project even when he tries. Details can be subtle, and scientists are just as susceptible to hearing what they want to hear as anyone else is.
John Learned of DUMAND and Leo Resvanis of the Greek project, NESTOR, were especially vocal. “AMANDA will never work!” Resvanis would yell from the back of the room. (Leo continued in this vein all the way through IceCube.)
Physicists being a witty lot, there were humorous moments as well. About a month after Francis had worked out the random walk problem in Venice, David Nygren, a by-then legendary experimentalist at Lawrence Berkeley Laboratory, a Department of Energy facility perched high on a hill above the Berkeley university campus, convened a meeting on neutrino astronomy in Arcadia, California, near Caltech’s Jet Propulsion Laboratory. He and a group from JPL were thinking of building a kilometer-scale instrument, which they called Km3, and wanted to take stock of the field. AMANDA’s bubbles were common knowledge by then, and overhead projectors were the lecture-giving technology of the day. The Monte Carlo expert from DUMAND gave a talk, and near the end he put a blank transparency on the projector and said, “This is what AMANDA sees.” Francis was sitting nearby. He reached over, switched off the projector, and responded, “And this is what DUMAND sees!”
* * *
The thing is that Francis actually believed his own propaganda: “It’s not like I was trying to convince myself or deceive the world. I believed one hundred percent what I was saying.” Dave Nygren remembers having breakfast with him in Berkeley’s wonderful old Women’s Faculty Club at about this time. “It’s amazing,” Dave remembers. “He announced that the scattering length was ten centimeters but the attenuation length was two hundred meters or something, and he declared victory! You know, I thought, ‘What is this guy talking about?’ … But he persevered”—and convinced Dave to join AMANDA a year or so later. Criminal optimism can be a good thing.
* * *
It is a measure of the professionalism of John Lynch at the National Science Foundation that twenty years after the disaster in the bubbles, his friends from Madison still believed they had almost lost funding, when in fact it was never in doubt. John says the foundation was “not dissuaded.” “We’re used to initial failures. Any funding agency is used to initial failures. They better be or they’d never get anything done.”
Thanks to its huge programs in the polar regions, NSF has extensive connections in the glaciology community. Several eminent glaciologists assured John that AMANDA-A simply wasn’t deep enough. They were surprised that there were bubbles at a thousand meters, but not shocked.
“I don’t remember thinking, ‘Oh, Christ, it’s failed, it’s never gonna work,’” he says. “I knew Peter [Wilkness] wasn’t gonna cut my budget because there were bubbles in ice. I knew that.”
But Bob Morse believes John isn’t giving himself enough credit. “He was a lot more out on the edge than a lot of the other people at the NSF. And
when he used the word ‘we’ he was being charitable to the rest of that group … because they’re pretty goddam conservative.… [And] if it had been anyone with less courage and what you’d call sense of daring and risk-taking than Wilkness, it might have turned out differently. So, we had the combination of Lynch and Wilkness, and it worked magic for us.”
Near the end of 1995, NSF and the Wisconsin Alumni Research Fund doubled down. The foundation increased its support for AMANDA by the better part of $1 million a year, funding a second four-year proposal to the tune of $6.4 million, and WARF, at the urging of the ever-enthusiastic John Wiley, added another million.
* * *
Bruce Koci had “had the good sense to stay home” for the previous two years. Somewhere in there, the Polar Ice Coring Office moved back to Nebraska, but he and his wife chose to stay in Alaska. He shifted from full-time employment to consulting with PICO, mainly as an advocate for AMANDA, and from that time forth split his time between the South Pole project and his expeditions with Lonnie Thompson. AMANDA became his central interest, mainly because it offered a challenge and a chance to learn. He and Thompson had more-or-less perfected the art of high-altitude ice core drilling by then, but Bruce was still the best troubleshooter in the game, so his friend continued to request his support in the field. And Bruce, for his part, had a hard time turning down these requests, since they took him to spectacular locations in the Himalaya, Africa, and the high Andes.
* * *
The plan for AMANDA-B was to double down on the drilling, too: five strings in a pentagon and a sixth in the center, all dropped to 2,000 meters in the hope that Buford’s hunches about the ice were true.
After the success of AMANDA-A, Bruce was reasonably confident that he understood the physics of the drilling, and at the same time aware that they were plunging into the unknown again. He and Bob Morse have frequently expressed gratitude to Simon Stephenson, the NSF Program Manager for Antarctic Support and Logistics, for taking “a gigantic leap of faith” in supporting them. The drill cost more than $1 million at that point (the Swedes again paid for it), and NSF’s Antarctic Program provided a tremendous amount of logistical support, for which AMANDA paid not a penny, to transport the drill to Pole, install it, and use it.
The hose was the most vexing aspect, as always, and Bruce spent a good deal of time developing specifications for it. In order to send enough heat into the ice to be confident that they would be able to reach the new depth, he expanded the diameter again, to one and a half inches. He also specified the wall thickness so that enough heat would flow laterally into the surrounding water to keep it from refreezing during the drilling. (After the season, when he analyzed the results, he found that he’d nailed the heat transfer coefficient to within 3 percent.) Then he found an industrial partner to manufacture the thing. It came in 800-foot lengths and ended up being the largest synthetic hose that had ever been made.
He also “a little more than doubled” the size of the heating plant, going from less than one to about two megawatts. Counterintuitively perhaps, this increased the fuel efficiency: the new drill would burn more fuel per hour, but it would more than compensate for this by working much more rapidly. The previous drill had taken 72 hours to get to 1,000 meters and burned 4,500 gallons of fuel in the process, while the new drill would do the same job in 24 hours, with 2,500 gallons of fuel. This was steady progress: their first drill, Bucky-1, which is still acting as a radar marker in its eternal grave in the ice, burned 12,000 gallons to reach something less than 1,000 meters.
Meanwhile, the drill head was becoming quite a contraption, and the whole system was getting smarter. The head weighed in at a few hundred pounds. It was equipped with an inclinometer, calipers, and temperature and pressure sensors, and it sent the signals from these devices up to a control shack on the surface of the ice via telemetry.
There is no real way to steer the head in a hot water drill. The idea is to create just the right conditions down where the action is, right at the nozzle, to allow gravity to pull it straight down into the ice. That means spraying just the right amount of liquid heat out of the nozzle and lowering it at just the right corresponding speed to allow nature to take its course. If you lower the drill too quickly, the calipers will tell you that the hole isn’t wide enough: you might not be able to lower a string through it, or, worse yet, you might freeze the head in place. Or perhaps the head will become cocked in the hole and wander off course. If you lower it too slowly or stop it altogether, the hole will get too wide.
This was still an exploratory process in those days. The physicists weren’t exactly sure what the specs for the holes needed to be, but they figured its diameter ought to be constant, and they wanted it to be ridiculously straight. “They want these things plumb within a foot in eight thousand,” Bruce once commented. “You couldn’t measure that with any inclinometer on Earth.” The inclinometer didn’t tell them much at all about the verticality or straightness of the hole, incidentally; it was mainly used as a finger on the pulse of the situation below. (This was like building a telescope in a darkroom.) They found that as long as everything was in sync the head could be cocked in the hole by as much as three-quarters of a degree and still fall free in a straight and plumb line.
The telemetry data was fed to a computer in the control shack, which adjusted the speed of the winch and the water pressure in the hose, accordingly. Over the years, Bob Morse had recruited various undergraduates to write the software code that controlled the drill and logged the telemetry data, and it was becoming quite sophisticated.
* * *
Francis remembers wistfully that the AMANDA collaboration had no management in those days. The different participants mounted midnight raids and sneak attacks in the manner of Comanche war parties. There was a group ethic, to be sure, but this was academia after all: there was only so much a professor could ask a student to do. People tended to do what they were interested in doing. There were only about forty people in the collaboration, and only ten or fifteen did the key work. The way the PIs would decide what to do as an Antarctic season approached was to gather in a small lecture room, walk up to the blackboard one by one and write down how much money they had; they would add up the numbers and decide together what they could accomplish. “There were no spreadsheets, no software, no nothing. That’s how this was done.”
During those years, the collaboration often held meetings in Irvine or nearby Laguna Beach, and the group was small enough to fit in a regular classroom. The meetings lasted the better part of a week and generally ended with a science session on Saturday morning. Several people remember that an elderly gentleman would sometimes sit at the back of the room during these sessions, listening quietly. It was Fred Reines, who was in his late seventies by then. Now an emeritus professor, he was suffering from dementia, unfortunately. Francis remembers that Reines would approach him at the end of the science session every year, and always say the same thing: that he had started out as a theorist, too.
Christian Spiering, who was involved in Baikal as well as AMANDA, remembers presenting Baikal’s detection of the first-ever up-going muons at a meeting in Irvine, probably in 1995. Addressing Reines in the back row, he said, “I am proud to present the first underwater neutrino in the presence of the man who found the first underground neutrino!” “And then I looked to him and looked into these empty eyes,” Christian writes. “No reaction at all, other world.” Sadly, this was the year in which Reines finally won his Nobel Prize.
* * *
There was a certain amount of jockeying for position among the PIs, and so, while Francis was the de facto leader of the collaboration—meaning he was the one who spoke to NSF and had his head on the chopping block—he was by no means the decision maker. In truth, there was no decision maker; the group was too anarchistic for that. Collective decisions were unanimous perforce, and important ones were rarely made before the last possible moment.
A case in point was a decision that came up seve
ral times every drilling season: where to put the next hole. Bob Morse and Bruce Koci would get to Pole early each season, grab a surveyor, and map out the hole positions based on their reading of the group mind. Usually, they would not get an actual decision, however, until the drilling of the next hole was about to begin. The tower that was used both for drilling and deployment had to be set up beforehand, obviously, and it was moved into position by a large crane. Oftentimes the only thing that would goose the collaboration into making a decision was for the crane to begin making its way out to the dark sector. Bob would send a desperate e-mail north: “Crane’s on its way out; it’s got the tower up there … heh, heh, heh … ‘Come on guys!’ … Because there are guys down here that want to set a tower and they want to know where the hell to put it.’”
Bob remembers the 1995–96 season as being a “continual battle between PICO and Bruce Koci.”
With its return to Nebraska, PICO had reverted to its old ineffective ways—further exacerbated by the fact that Bruce was now seen as an outsider. The PICO managers wanted one of “their people” in charge, and even though Bruce had been with the organization since its inception and had even designed the drill, he didn’t fit their bill.
At Pole a few years later, I asked Bob and Bruce if there was a story to tell about that season.
“You mean like…,” said Bob, turning to Bruce, “… like why you didn’t kill Bill Jones?” (Not his real name.)
“That’s water over the dam,” Bruce responded placidly. He always downplayed interpersonal conflict. Bob had no such reservations.
“We had Bill Jones, who’d never drilled a hole in his life, coming in … as the chief engineer and the chief architect of this operation in the field. He showed up at PSL with an organization chart.… And I looked at that organizational chart and I thought, ‘Shit. We’ve got trouble.’ … It was, ‘We’re going to take this project back and we’re going to run it, even if we don’t know what the hell we’re doing.’