Short Wave - Picking Up Cosmic Vibrations

Episode Date: November 8, 2024

A pivotal week in Corey Gray's life began with a powwow in Alberta and culminated with a piece of history: The first-ever detection of gravitational waves from the collision of two neutron stars. Corey was on the graveyard shift at LIGO, the Laser Interferometer Gravitational-Wave Observatory in Hanford, Washington, when the historic signal came. This episode, Corey talks about the discovery, the "Gravitational Wave Grass Dance Special" that preceded it and how he got his Blackfoot name. (encore)See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. So, Oki, 10nitapi, nitaniku, mako yuksu, Ki, Corey Gray. Hi, I was just giving a greeting in Blackfoot, and I gave my Blackfoot name,

which is Wolf's Path, and also my name, Corey Gray. I'm Regina Barber, and I've known Corey for years. We've connected at conferences as fellow scientists of color. I am a senior operation specialist at the Ligo-Hanford Observatory in eastern Washington State. LIGO measures ripples in space called gravitational waves.

Yeah, so what are gravitational waves? I guess the main thing I would say that all of this comes from Albert Einstein. It comes from his general theory of relativity in 1915. Basically, gravity is just how masses bend the space around them. And that's the idea of what gravity is in general relativity. If you take this mass and accelerate it in space or space time, those accelerations vibrate space time, and those vibrations, those wiggles in space time are what gravitational waves are. LIGO stands for Laser Interferometer Gravitational Observatory, and Corey has worked there since the beginning.

He waited 17 years to see evidence of two black holes colliding into each other. The first direct evidence of gravitational waves. hundred years almost to the day after Einstein's prediction. Yeah, you can't write a script to make it better than what actually happened. Wow, yeah, tell me more. My shift was from 4 p.m. to midnight. And so I handed off to the operator who's doing the graveyard shift starting at midnight. And I always joke that around by the time I got home and was putting my head on my pillow and

closing my eyes, that's about when the signal passed through the earth, passed through me, and it passed through all of us. I'm looking at my arm because I have a tattoo. it's September 14th, 2015. Tell us a little bit more about, like, what this meant to you that it meant so much you got a tattoo. I don't have any kids, but that's what I would think it would feel like to have a kid. Like to see the sonogram or see an image of your child for the first time,

and that's how it felt to me. And when I saw it, I knew that I would have it on my body. And right around Einstein's birthday or pie day, that's when I went to a tattoo parlor in Olsaan, Puerto Rico and asked them to Google GW 150914, and they did that, and they found the image, and they put it on my body. Oh, my God. Okay.

For our listeners, can you describe what that waveform looks like? Yeah. I mean, it just basically looks like a wiggly, two wiggly lines. One line is red, and that's the data from the detector here in Washington State. And the other line, wiggly line is blue. That's the data from the detector in Livingston, Louisiana. Then a couple years later, the first detection of two neutron stars colliding occurred, and the week leading up to that event connected aspects of Corey's life.

Today on the show, we're talking vibrations through space and the instruments and people that detect them. I'm Regina Barber, and you're listening to Shortwave from NPR. Gravitational waves are really elusive, and Corey Gray says that when the detection happens, there's a little signature in the data that, can be processed into a sound. The merger detections, we term it, we call it a chirp.

And it's basically, if you look at what the signal looks like, what you're seeing and hearing is the frequency increasing and the amplitude increasing. So some of them are going to be higher in frequency, some are going to be lower. Like I think for our first detection, it's much lower, so it's a little like, whoop. But for this first detection, we had a loud signal, which was capturing the first detection. final fraction of a second of two black holes smashing into each other after dancing together orbiting each other for millions of years. And that's what we need because these signals are so, so tiny because they happen from so far away, so long ago. And we need the strongest ones to be

able to see with our instruments, which are the most sensitive instruments that have ever been made by humanity. And that's what we need. Strong sources, most sensitive instruments, to see these really faint ghost-like signals that are passing through us all. all the time. So tell us about those instruments. Like what is LIGO? How does a laser interferometer measurement work? So we use an optical setup called an interferometer.

So we have a light source, which is a laser. And we take this laser and we shoot it at a piece of glass called a beam splitter. And so half of the light goes right through this piece of glass. And then the other half of the light is reflected off of another surface of this. glass and you have these two twin waves of light that are born and then split from that beam splitter they go down four kilometer long arms in an L shape so one's going straight and the other one's going orthogonal to that so 90 degrees in another direction okay so you have these two identical beams yes going down 2.5 miles yeah and then those waves of light hit those mirrors

and then they come back to the beam splitter and then they interfere with each other We wait for anything to move those mirrors that are four kilometers away down each arm. So any type of length change over that four kilometers we can hopefully see at a sensor back here at the corner of that L of our detector. And you're saying that like you're looking for this length change in these like 2.5 miles. And this gravitational wave that's bending space time actually changes in my mind. I like to say change is reality, but change is that length, right? It's changing space. Definitely, yes.

And that's mind-blowing. And I've heard you say that you're basically using a very advanced ruler that can measure these minuscule changes in length. Can you explain that like a bit further? Over four kilometers, we can resolve length changes on the order of a thousand times smaller than the diameter of a proton. That's a sensitivity that we have for these LIGO detectors. All right. So now we're going to go in the way back machine. We're going to go on a time machine.

And you're going to tell me the story of how you came to LIGO. So when I was a kid, I always had an inkling towards the sciences. Me too. Me too. I received bachelors of science degrees in physics and applied mathematics at Humboldt State University. And then eventually saw a job announcement in the. LA Times for a job up in eastern Washington State. You were there at the start of this construction, and you waited 17 years, and I remember

back in 2001, somebody came from LIGO to my university in Washington State, and they're like, any day now, we're going to detect something, any day now. And it was 14 years later, but so this first detection happens, and it's a huge deal. And being there must have felt amazing. When I woke up the next morning after the detection was recorded, that's when it hit me for the first time. That's when I know that we're officially connected forever to Albert Einstein. We're a part of history. LIGO's goal was to announce the first detection in as many languages as possible.

Corey instantly thought of his mother, Sharon Yellowfly. He recruited her to translate news of this breakthrough into the Blackfoot language. My mom did an amazing job. My mom grew up with Blackfoot as her first language, but for some technical words, there weren't Blackfoot words. So my mom had to invent new Blackfoot words. It's a new Blackfoot words. It just sounds like poetry.

Do you think that there was some contribution to science that you and your mother were doing? that like is overlooked or has been overlooked for hundreds of years yeah i mean this is kind of a path that i'm kind of learning on my own now because i mean being an indigenous physicist or indigenous scientists was kind of for me a lonely uh uh path but i think with with my mom's work it it kind of taught me a few things it taught me that our language is important enough to translate astrolet And it also raised my awareness or my curiosity and looking into indigenous sciences. For a lot of indigenous peoples, there is that connection to the sky and to space.

I mean, my Blackfoot name that I just received a couple months ago is related to the Blackfoot story for the Milky Way. Can you tell us that story? As far as what I know is, I think it's basically, I think it was a winter or sometime when the people were struggling, living, they were having a rough time living through winters, getting food, they were starving, and they were approached by these group of people. They were actually wolves that were in the form of humans. And they kind of imparted their knowledge to these suffering people to kind of give them ways to survive, like what sort of animals to hunt. And then they they went away.

And then the story is that every spring in the sky, this light that you would see up above you at night, is the path of these wolves that visited our people. I can kind of understand why you would get that name because you are sharing this knowledge. Oh, dang, I'd never even thought of that. That's so cool, Gina. Wow.

That's crazy. You're welcome. Which brings us to the powwow you had just attended up in Alberta. Right before you came back to work for that groundbreaking discovery, can you take us to that powwow? This particular powwow, we actually had an event that my cousin and I both had thought up. We called it a gravitational wave grass dance special. And so grass dance is a style of dance in powwows. And for people who don't know, powwows are kind of.

kind of social events, like intertribal social events for Native peoples in the kind of the United States and Canada. And so when I think of that kind of after the fact, when I was there for this event, we had 17 dancers out there. And I just think of all that power from their prayers, from their their dance for this gravitational wavegrass dance special that occurred that night. I just think there's power in that. And it led right up to this huge moment in your career. Did you feel any connection there? So, I mean, that's one of the things that I obviously made a connection to that week prior,

or the week and a half prior, because after the Grass Dance Special on August 10th, I had to basically drive all the way home for graveyard shifts. And that was my first time sitting in the chair to ever have that happen. That first week, that first shift of mine coming back from Sikika, that's when, our first binary neutron star was recorded by LIGO. And then that one's just a completely different type of detection compared to all of the other ones prior to that, because instead of two black holes,

we recorded two neutron stars crash into each other. Okay, Corey, so what's next for LIGO? We'll have an improved detector, and what's going to happen? We're going to have a much more sensitive machine, so we'll be able to reach further out into the United States. universe. But I'm always holding out for what's going to be new, what's going to be new, supernovas that are close to us. If we could be online when one of those occurred, that would be a first for us. That'd be so cool. But I think my favorite one would be something that would be

a complete surprise to theorists and to all of us that we hadn't thought of. Do you feel that there's like the Blackfoot way of understanding the universe? It can teach scientists like the kind of, what do I want to say, Western science as well. Yeah, I mean, when I sat back and thought about what is general relativity, and it does make me think about or harken back to indigenous science, that connection that indigenous people have to the world around them is such a prevalent concept, and you see it in all these other cultures. And so that's what I think about when I think of Einstein and his general theory of relativity,

because that's what, he's kind of explaining how all masses are connected to the space, space time, around them. Corey Gray, thank you so much for coming to talk to us and telling us all about your work at LIGO. And thank you, Gina. It was a pleasure. This episode was produced by Devin Schwartz, edited by Gabriel Spitzer and fact-checked by Ubi-Lavine. I'm Regina Barber. Thanks for listening to Shortwave from NPR.