DEREK MULLER: Can you tell me how you first realized that LIGO might have detected gravitational waves?
RANA ADHIKARI: I think I was traveling on that day so I didn't know. I came back here I believe on the day after and I was wandering around in the building and people were sort of whispering and looking over their shoulders but didn’t want to spill it. They were like did you hear, did you hear? Have you seen it? What do you think? [And I said] I don't even know what your talking about. And they said yeah it's like “there’s an event and it looks really real.” And it’s like, whatever, I don't have time for this nonsense. I got things to do man.
MULLER: Why weren’t you more interested. This could be it, right? You’ve been working for a decade, two decades?
ADHIKARI: Two decades.
MULLER: And you didn’t want to say like “I’ll have a look” at least?
ADHIKARI: No. We had just turned the detectors on, barely, I was ready to wait for some month or 6 months...I don’t know. We were going to take data for 3 or 4 months. And I thought maybe in a month or two something will pop but it'll be really tiny and we won't find it and then maybe we'll spend another six months combing through the data and developing the algorithms to eventually find it, but, you know, no way would it be like, you turn it on and immediately there’s a signal, which is what people were saying.
So I said I said look, just settle down a little bit. You don't understand how the world works, it's not like this. You turn on your device and there's some burps and glitches and it's a kind of growing pains at the beginning. And I said, when you've been around as long as I have you understand how complicated it is, young people, so just go back about your business and nothing to see here. And that's all.
And then it just wouldn't die. Everyone was still looking at it. And I just didn't bother to look at it for another week, probably, because it just seemed, like... there's always fake events, right?
MULLER: But how did you finally convince yourself that it was real?
ADHIKARI: I downloaded the data and I looked at it, and I [made] a lot of plots. When I looked at it it just seemed like... there's no bells and whistles to it. It’s two black holes, and it’s spinning a lot, and they merge together and it swoops up in frequency and it chirps in just the right way and then what emerges is no craziness — it just emerges and goes “whoop.” And then it settles down and the final black hole is not spinning. It just seems like something that...if you were trying to fake a signal, that seemed like a fine fake signal to make.
And the peak frequency of that signal…and there are a lot of astonishing things…the peak frequency of that signal happens to be at the frequency where our detector is most sensitive. What are the chances that nature would engineer a signal right in our sweet spot?
The easiest thing to calculate is black hole [to] black hole mergers because black holes are simple and don't have a lot of stuff inside of them, it’s just a black hole in space. And these two are about the same mass so the calculation of what the waveform should look like it's really simple, so it’s the easiest thing to find in so many ways.
And I have always wanted to find a signal which is about this heavy because I thought, wouldn't it be great to find the black hole that was heavier than what everybody else wanted? And the signal would be really loud, and if the universe made black holes this heavy we could detect them way back in time to the beginning of the universe and we’d be able to see by looking at how these things got distorted as the universe expanded we could figure out a whole thing about how the universe expanded. This is just my dream.
I thought, fantastic! And then I see you signal like that … I said, uh, it's too good to be true. How could there be a signal that would be just like what I wanted, and as soon as we turned the thing on? That would mean that these black holes are so numerous that we're going to get these signals, you know, a hundred or a thousand times more frequently than we estimated, and how… that's not how the world works, right? It can't be everything is great. So I just didn't believe it.
Then I went through and with a lot of other people we examined all of the different conspiracy theories that we had for how the signal could have been faked.
Like, someone was mad and tried to do it. Someone hacked in and changed the software. Someone went in and pushed something and had someone else on the phone at the other side and pushed something in the same way, and set up devices…
But you see what kind of mess it is here. If I had a little Gadget that made a little thing like that I could probably hide it underneath some place and cover it with some aluminum foil or trash. And so we had people walk around physically with a flashlight and look around everywhere to look for hidden conspiracy devices that would be sneakily putting in fake signals, because, you know, what if what if it got to the point where if we haven't had signals for so long, and someone who's really been waiting a long time and whose career depends on it…
MULLER: ...who needs their PhD or something…
ADHIKARI: Yeah, right, and their career will be made by something like this so they just get desperate and unethical and then they spend a year building a really maniacal plan to somehow do this and evade everybody. And eventually we came to the conclusion that there was only maybe like five or six people left in our whole thousand person collaboration who had enough know-how to do all of these things, and so we all just stared at each other for a while and said, did you do it? Did you do it? And we couldn't come up with any way that it could have been done because you need at least two people to do it. One person alone wouldn’t be able to do it.
So I’d say by two or three weeks after the detection I was pretty well convinced that it was real.
MULLER: How did that feel?
ADHIKARI: It was like a slow boil. Nothing dramatic.
MULLER: You did go crazy and go to Vegas?
ADHIKARI: No because it didn't happen all at once. It was just each day I believed a little more. And each day I still had enough doubt.
