Lost and Wanted(32)
We sat down and Jason began explaining the way that previous studies had relied on simplified globular cluster models and assumed a static mass for the black holes in each group. Jason’s team used a Monte Carlo approach to generate more realistic models of dense star clusters in the Local Group. The idea was that those clusters would be a likely place for black holes to exist in revolving pairs—and to collide with each other, producing the powerful gravitational ripples that LIGO’s interferometers could detect. The paper was impressive, and I began to like Jason while he was talking about it. I’ve been aware recently that I’m getting older, and making the kind of judgments I used to despise in my parents, as if complicated facial hair could predict whether or not someone was serious about his or her work.
“He reminds me of Neel,” Arty said, when Jason was finished. “When you were first working with me.”
“Really?”
“Who’s that?” Jason asked politely.
“Neel Jonnal,” Arty said. “Her collaborator on the Clapp-Jonnal.”
“Oh, yeah—of course. I never knew his first name.”
“He’s at LIGO now,” Arty said.
Jason’s expression changed. “Really? Lucky bastard—I’d love to be there.” He looked from me to Arty. “How long do you think before they get a detection?”
“Neel thinks soon,” I said. “But he tends to be optimistic.”
“Is he at one of the sites, or—?”
“Caltech,” I said.
“Wrong!” Arty said, grinning in the way he does. “Or soon to be wrong—he’s coming back.”
I must have been staring at Arty; I couldn’t help it. What he’d said didn’t make sense. Neel and I had emailed about one of my grad students just last week, and he hadn’t said anything about coming to Cambridge, even for a visit.
“Coming back to Boston?” I said. “But not permanently?”
Arty nodded, still smiling.
I didn’t have to ask which university, since the only LIGO team in Boston was at MIT. My first thought was that I must have overlooked a message in which Neel told me this momentous news. From the time we were undergraduates we had talked about our eventually landing at the same university. It had happened temporarily here at Harvard early in our careers; the result had been some of the best work of our lives, not to mention the adult friendship we had now. That had tapered off a bit when I had Jack, but there wasn’t any reason it couldn’t pick up again now that he was older and Neel was moving back. As a LIGO research scientist, he’d be attached to MIT’s Kavli Institute rather than holding a professorship like mine, though that distinction hardly mattered. We’d attend the same lectures and colloquia; be at the same department-wide events; run into each other at the coffee shop. I just couldn’t understand why Neel hadn’t told me.
Arty seemed to know what I was thinking. “He must be under orders to keep it to himself before it’s official,” he said. In addition to the American detectors in Louisiana and Washington, and the Italian site outside of Pisa, the collaboration also included teams in Germany and Japan. There was even a project in the early stages in India; the more interferometers there were, the larger cross-section of the sky they could survey. If Neel had wanted a change of scene, there were plenty of places he could have gone; instead, he had chosen the one lab that happened to be at my university.
“He’ll be supervising some of the preparations for India, too,” Arty said. “IndiGO, they’re calling it, for LIGO-India—that’s clever. I once met a man in a restaurant in Athens who’d made a fortune in indigo—the blue stuff. He’d been orphaned as a teenager and just shipped out to Bombay. He ended up as the Greek ambassador there—fascinating guy.”
“They’re moving one of the Hanford interferometers to India,” Jason said. “Not building a new one, right?” He seemed accustomed to Arty’s digressions, and what was necessary to get him back on track.
Arty nodded. “Somewhere in Maharashtra, as far as I understand. Oh, and he’s getting married over there, so that’s convenient!”
It was as if a wave passed through my body. A dizzying swish, such that if you told me I had been squeezed in one direction while being stretched in the other, according to the principles of relativity, I would have believed you. That’s where the metaphor falls apart, though, because real gravitational waves aren’t something we feel.
“Neel is getting married?”
“He didn’t tell you that either? Don’t let him know I put my foot in my mouth!”
“Married to whom?”
Arty shook his head. “I don’t know, I can’t remember. He did tell me, I’m sure, but we were also talking about their NSF funding, that whole saga, and…”
If we’d been alone, I might have pushed him. But Jason was eager to get back to his chirp masses. We returned to his paper, and then I talked about the possibility of primordial black holes—black holes created during the Big Bang—actually becoming dark matter, as suggested by a recent paper from Johns Hopkins. I talked while Arty nodded and smiled, and once got up to modify an equation of Jason’s on the whiteboard. Both of them had forgotten Neel’s move, and his upcoming marriage. I could keep up with the numbers they were tossing back and forth, but at the same time there was another data set preoccupying me, one with which neither of them was likely to be familiar.