wJon Hakkila, professor of physics and astronomy, made history this past year when his international team of astrophysicists claimed to have discovered the largest structure in the universe. And their revelation may change the way we look at everything.
by Mark Berry
Photography by Chris M. Rogers
He really didn’t want to believe it. It didn’t make sense – scientific sense, that is. But the statistical analysis suggested otherwise.
This is disturbing, he thought. Really disturbing. This could open us up to so much criticism and maybe even ridicule. What if we’re wrong?
But numbers don’t lie. Yet, as he knew and had seen countless times in the history of scientific thought, sometimes they do lie. Or, really they don’t – the scientists just didn’t know how to read them accurately and perhaps didn’t grasp the full picture because they were missing a crucial detail. Science is a lot like the poetry he enjoyed so much dabbling in as a younger man – it’s all about interpretation. Just as two poets can look at the same ocean and evoke very different emotions, two scientists can look at the same numbers and come away with conflicting ideas.
And what is the right interpretation of these statistics? He had to trust that his understanding of the numbers was correct. He had to trust his decades of experience in astrophysics and astro-informatics. He had to trust that his team had done the appropriate methodology – that they had measured the 283 gamma ray burst redshifts correctly, had subdivided the nine radial parts accurately and had applied the two-dimensional Kolmogorov-Smirnov test, the nearest-neighbor test and the Bootstrap Point-Radius Method all the right way. But, most important, he had to trust in his belief in the scientific method and observation.
It was much like a diver walking to the edge of a cliff. It didn’t matter how many times you had successfully made the jump before, there was always a certain amount of fear and doubt mingling in the pit of your stomach as you stood there looking down, feeling the dizzying height and the churning sea below. But nothing would be gained by just standing there.
And with that, Jon Hakkila took the leap, putting his name with collaborators István Horváth and Zsolt Bagoly in their discovery of the largest structure in the universe.
The Fault in Our Stars //
How is this even possible? How can we discover the largest thing in the universe now? Shouldn’t that have been pretty evident early on?
If you’ve been keeping up with everything cosmological in the scientific journals, the “biggest in the universe” has grabbed headlines several times already over the last decade. In 2003, there was the discovery of the Sloan Great Wall (about 1.38 billion light years across), and there is also the Large Quasar Group, announced in 2013, that is perhaps 4 billion light years across.
These discoveries are problematic. Size matters when talking about the universe. For a sense of scale, between 100 and 400 billion stars make up just our galaxy of the Milky Way alone (cue Carl Sagan’s voice in your head). And from there, a hierarchy exists to categorize larger groupings (from smallest to greatest): galaxies, groups, clusters, superclusters and walls. When it comes to large-scale structures, like the Sloan Great Wall and the Large Quasar Group, they are made up of superclusters. According to prevailing scientific thought (i.e., the Big Bang Theory), the universe should be expanding at a constant rate and that means the largest structures in the universe should be no more than roughly 1.2 billion light years across. These recent large-structure discoveries challenge that notion and call into question the age of our universe (13.8 billion years, in case you skipped that day in Physics 101) as well as a few other basic tenets.
But that’s the beauty of science. It’s less black-and-white than you may think. Its rules are constantly changing as we gather more data and learn more. Like the lives of stars, some theories die out, new theories form and other theories just evolve with more information. And that’s where Hakkila’s team comes in. Together, Hakkila and his Hungarian colleagues Horváth and Bagoly are experts on gamma ray bursts, which are forms of light that are the most energetic, most violent explosions in the universe. As Hakkila describes, “most gamma ray bursts are thought to originate in hypernovae, which are beamed supernovae occurring when massive stars die. If you take the immense energy of an exploding star and focus it into a narrow beam, then the light from that beam will be significantly brighter than that of a normal supernova.”
A relative newcomer on the astronomical scene, gamma ray bursts weren’t even discovered until the late 1960s, when the U.S. launched satellites to make sure the Soviet Union was not conducting atmospheric nuclear tests in violation of the SALT I treaty. These satellites picked up flashes of light that were unexplained, and scientists eventually determined that these luminous bursts were coming from space. For those needing a pop culture reference, gamma rays are the culprits in transforming Bruce Banner into the Incredible Hulk, although, as Hakkila points out, “thank goodness the Earth’s atmosphere shields us, or we would all be fried.”
And Hakkila should know, he’s had a front-row seat in the research of gamma ray bursts since its inception in the mid-1970s.
As a boy growing up in Los Alamos, Hakkila couldn’t escape the stars. The New Mexico night sky radiated with flickering pinprick lights – each evening providing a backyard show of splendor, a performance so grand that Hakkila felt he was seeing into forever. Awestruck by the natural artistry above him, he wanted to see even more, to know even more. Like many of his friends (also children of scientists at the Los Alamos National Lab), he purchased a telescope and then a clock drive and camera to start recording his own observations. Later, as president of his high school’s astronomy club, Hakkila was able to attend an astronomical conference at the lab, where he heard astrophysicists make the first announcements about gamma ray bursts.
Roughly 15 years later, after earning his Ph.D. from New Mexico State University’s astronomy program (co-founded by Clyde Tombaugh, Pluto’s discoverer), Hakkila worked with leading astrophysicist Jerry Fishman (2011 winner of the Shaw Prize, a prestigious international astronomy award now on par with the Nobel), serving as a member on Fishman’s science team for the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory – a satellite edged with eight blocks of rock salt that detected gamma ray bursts. Because gamma ray bursts cannot be seen with the naked eye, the sodium in the rock salt interacts with the gamma ray bursts and produces a visible light, which can then be recorded and tracked. From BATSE, the scientific team collected the largest catalog of gamma ray bursts in existence.
A few years later, Hakkila’s own research on gamma ray bursts took center stage in what is called astronomy’s second “Great Debate”: on whether gamma ray bursts were galactic or cosmological, meaning did they originate near the Milky Way or did they come from the distant reaches of the universe. For the astronomy history buffs, the first Great Debate was held in 1920, when scientists deliberated on whether the Milky Way was the center of the universe (spoiler alert: it’s not).
In April 1995, more than 350 astronomers, journalists and students filed into the Smithsonian Institution’s Baird Auditorium in Washington, D.C., to hear astrophysicists Donald Lamb and Bohdan Paczynski square off. Like a political convention, scientists in the crowd wore bright-colored buttons proclaiming on which side of the argument they stood: “GRBs are COSMOLOGICAL,” “GRBs are GALACTIC” and “GRBs are OTHER” (some scientists just can’t commit). While attending another gamma ray burst conference in the Netherlands, Hakkila was astounded to hear that these renowned scientists both supported their claims by citing his research. Although no conclusion was reached at the end of their debate (a gentlemanly agreement among scientists), later observations provided the proof for Paczynski’s argument that gamma ray bursts were indeed cosmological in nature.
“In a particular moment, science can be very gray. Then, something new is learned, and that gray becomes black-and-white – until another discovery, and that black-and-white becomes gray again,” laughs Hakkila.
Bigger Than Big //
Everything has its moment. Clothes, hairstyles, music, literature, art. Even science is subject to fads.
“We were the cat’s pajamas from about the 1990s until the mid-2000s,” Hakkila observes. “Now, no one seems to care about another gamma ray burst.”
It was a good run, but other areas became hot topics (such as extrasolar planets, dark matter and dark energy). And the scientific community moved on, so to speak, eager for the next discovery, the next big thing. But Hakkila and his colleagues did not move on. They felt they had only scratched the surface in understanding this amazing cosmological phenomenon and that gamma ray bursts were a rich area to be mined more fully – an astronomical mine that would lead them to their unexpected discovery.
Knowing for certain now that gamma ray bursts came from great distances, Hakkila’s team started seeing distinct patterns in the statistics, or “clumping,” as Hakkila calls it. Imagine standing on stage, he explains, and looking out over a darkened arena. You know there is a crowd out there, but you just don’t know how many. You only have one way of knowing it, and that’s by seeing the occasional flashes from their cameras. If you chart those flashes, you can assume where groups of people are gathered and areas where they are not. Over time and with enough flashes, you can get a pretty good sense of where everyone is. That, essentially, is how Hakkila’s team found the largest structure in the universe, which spans 10 billion light years.
But as Hakkila well knows, every observation has uncertainty. There may be a bias blinding the researchers – that maybe the arena crowd was not really a crowd or perhaps some of the flashes were missed in other areas. And that’s what made him nervous.
“I know where the flaws are in our research,” he says, “but the data looks good. We’re not trying to judge whether this thing makes sense in terms of theories. If I were somebody else, I would criticize it, too. But, this is an observation, and we had a strong enough statistical case to make it.”
Their paper, “Possible Structure in the GRB Sky Distribution at Redshift Two,” was accepted by the journal Astronomy & Astrophysics late last year and appeared in January. And with that publication, Hakkila readied himself for the onslaught.
But the heavens, you might say, have been quiet. Too quiet, for Hakkila’s taste.
“Maybe the theorists are thinking this is just statistical in nature,” he says, “and that our findings will go away because all the other evidence says it is unlikely.”
But more evidence coming in now is proving Hakkila’s team is most likely right: “We needed more bursts to determine the shape. And now that we have recorded more gamma ray bursts, this structure is becoming more obvious and is not getting washed out by statistics. It’s hard to argue with data.”
To him, this discovery doesn’t eliminate the Big Bang Theory, so don’t worry about Sheldon, Leonard, Raj, Howard and Penny needing a new name for their popular sitcom. No, as Hakkila believes, it simply changes our idea of how long the universe was in an inflationary period and what sorts of things were going on to cause the formations of these large-scale structures. This is a theory evolving, not one being disproved. And he is especially excited that their research approach may inspire other astrophysicists to use gamma ray bursts in looking at large-scale structures in the universe.
What’s in a Name //
Naming rights. It’s a big deal. People pay a lot of money for them. In the past, people even risked their lives for them. It’s validation. A form of immortality, especially in science. Just ask Niels Bohr, Heinrich Hertz, Edmond Halley, Sir Isaac Newton or Charles Darwin. Discoverers tend to command that type of respect. Unless you’re Hakkila’s team.
“Actually, we never thought of naming it,” Hakkila admits. “During the process, we were more concerned with whether it was real or not.”
For the most part, it was called just that: it. A name didn’t pop up for the large-scale structure until after a story ran online with Discovery News, when the writer Irene Klotz asked Hakkila in what basic area of the sky “it” resided. He told her the Hercules and Corona Borealis, but “it” was actually much larger than that and occupied several constellations.
Soon after that piece appeared, Hakkila, much to his surprise, discovered a Wikipedia entry dedicated to the Hercules-Corona Borealis Great Wall. According to the page’s view history, the site was created by Johndric Valdez, a teenager from the Philippines with aspirations to be an astronomer. Traveling as if at the speed of light, Valdez’ nomenclature quickly appeared in science blogs around the world and, most noticeably, was used last spring by Huffington Post science reporter Jacqueline Howard in her piece for the online video series “Talk Nerdy to Me.” And so, the name blazes on.
Reaching for the Stars //
The irony in all of this is that Hakkila doesn’t really want the Hercules-Corona Borealis Great Wall to be his sole legacy. While’s he proud of his contributions to this discovery, it’s only one small part of his oeuvre of research in gamma ray bursts.
It’s kind of like a concert violinist landing a Top 40 song and then being relegated forever to the one-hit wonder category in pop music. No, Hakkila is no simple crossover act. He’d rather be remembered as one of the early scientists in a new discipline – astro-informatics, which combines astronomy, astrophysics and computer science and engineering. He’d rather be known for his efforts with the Stellar Observations Network Group and their attempts to link a chain of observatories around the world in order to create a whole-earth telescope. And he’d rather be lauded for his groundbreaking research into gamma ray burst pulse shapes (his current passion project), which he believes has more far-reaching repercussions.
“Because if we can understand how nature works, can truly understand the order of the universe,” he says, “then maybe, just maybe, we can harness it.”
No matter how he is remembered, Hakkila says he really only wants to be considered an adequate scientist. We should all be so lucky to be that “adequate.” But for him, adequacy – yes, adequacy – will suffice. You see, in the scientific world, greatness is relative, even fleeting, while knowledge is the real pull. Because at his core, Hakkila is still that same teenage kid, filled with awe and questions, looking up into that glittering New Mexico sky wanting to know how things work.
“Ask scientists why they do what they do, why they study any subject,” Hakkila observes, “and they will tell you that it’s the moment when you realize that you know something that no one else does … that you are the first person to figure something out … that you asked the right question and found an answer. That satisfaction lasts a long time, and it makes all the years of research – all the years of failure and struggle – all worth it. That’s why I became a scientist: to answer questions, to see behind the mystery all around us.”
And perhaps that’s why Jon Hakkila’s star burns a little bit brighter.