How To Tap Into The Hidden Histories Of Rocks

Geologist Anjana Khatwa explains how embracing wonder and awe adds to our scientific understanding of the rocks that form our planet.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Ira Flatow?

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• 0:17Flora Lichtman?

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• 0:43Flora Lichtman?

  Hey, I'm Flora Lichtman, and you're listening to Science Friday. When we commune with nature, I think most of us turn towards the living, a walk in the woods with big trees, chirping birds, blooming flowers, humming insects. But my next guest says, don't overlook the inanimate. Don't sleep on rocks. Dr. Angena Kotwah is an earth scientist, but her love for rocks isn't just scientific. It's spiritual, poetic, and lyrical, which she writes about in her new book, The Whispers of Rock: The Stories That Stone Tells About Our World and Our Lives. Angena, welcome to Science Friday.

• 1:21Speaker 02

  Oh, thank you for having me, Flora.

• 1:23Flora Lichtman?

  I'm so excited to talk to you today, to learn all the things that I, you know, have been overlooking about rocks. Where did this love story begin for you?

• 1:32Speaker 02

  Oh, it began a long time ago, when I was about 13 years old. I was a teenager, and my parents are from Nairobi in Kenya. And whilst on a holiday there, we stopped off at this quite incredible place called the Shetani Lava Flows, which is now in the Sava West National Park in southeast Kenya. And I grew up in a town just on the outskirts of London, a place called Slough. And it's not a place where you tend to go to see nature, let's just say that. It's very, very urban and walking across this incredible African savanna. It was covered in this jagged black rock and when I was walking across these rocks, I didn't really understand why they were there, why they looked the way they did.

• 2:15Speaker 02

  But I knew that they had an incredible story to tell. Now, the interpretation signs said they were lava flows and of course, my imagination ran riot. And I could imagine seas of lava, you know, churning over this landscape. And as I walked over those rocks, they spoke to me. And on that day, I, my parents took a photo of all of us, you know, kind of standing by the obligatory tourist sign. But also I picked up a rock and here it is. And it's a, it's a piece of basalt.

• 2:44Flora Lichtman?

  You still have it.

• 2:46Speaker 02

  I still have it. And, you know, I think about, you know, the passage of time, passage of deep time, obviously, but my own life. It's all recorded in this moment that I picked this rock up. I was thirteen and I made the decision, I thought, oh, this is what I want to do, I want to tell stories about rocks. This is what I want to do as a job. And now I'm fifty, I've written a book about it, so it's quite, it's quite a journey.

• 3:10Flora Lichtman?

  You did it, you did it. I mean, you know, the thing that I love about that story is that most people go to Kenya to see these charismatic megafauna. The amazing animals and your takeaway from Kenya was a rock.

• 3:24Speaker 02

  Yeah, I, I've heard that a lot. When I went back two years ago as part of the research for the book, I went back to that place where I picked up this rock. And that was one of the key conversations I had with some of the wildlife rangers I went with. Like, you're not here to see the elephants or the, or any of the other wildlife. I said, no, no, no, no, I want to see these rocks. They were very, very puzzled. That's generally the reaction that I get.

• 3:47Flora Lichtman?

  So how did you go from a thirteen year old who had this experience to doing what you do now? What was that journey like?

• 3:54Speaker 02

  It was tough, I'm not gonna lie. I I kinda grew up in a traditional South Asian culture in the UK. That where my parents just felt maybe I should choose a sensible career like working in a bank or becoming a lawyer or a doctor. And as soon as I said, you know, actually, this is what I want to study. I want to study rocks. I want to study the creation of our earth. They were very, very puzzled. There's a movie like Bend It Like Beckham, you know, where that young Asian girl says, and I want to be a footballer. And the parents say to her, who's going to want to marry a girl that, you know, wants to kick a football all day? These are the kind of conversations I had with my parents. So I I kinda went on to university nonetheless to study a degree in earth sciences and then a PhD at the University of Southampton.

• 4:36Flora Lichtman?

  Wait, pause for a second, because because that's actually quite difficult. If you're hearing your family or community say, why would you do this? To say, well, I still am gonna do it, whether you think that's a good idea or not. Well, how did you make that decision? Sort of how did you get through that period?

• 4:55Speaker 02

  That was probably the toughest part because caused a rift in my family between me and my parents and that rift went on for a couple of years. And I had to make a decision. I thought, well, this is this is actually what I want to do. This is what where my heart is calling me. And my dad in particular didn't quite understand it. My mum was sympathetic. But I needed a few years away from that kind of

• 5:19Speaker 02

  debate about who I wanted to be. And that those few years away when I was studying my PhD, they allowed me to become the woman that I was, you know, strong, stubborn, you know, very hard headed about what I wanted to achieve. Now, of course, they couldn't be prouder. They're so delighted with what I've done.

• 5:37Flora Lichtman?

  Hmm, that's amazing. Well, transmit some of that passion to me. What do you think most people just don't get about rocks?

• 5:46Speaker 02

  I think rocks, they look at objects like this and they'll walk past them every day and they won't talk to you, they won't sing a song, they won't even move for the most part because they take hundreds, if not millions of years to to actually change and and shape themselves, if you like. And I'm gonna hold one in my hand. It's a green coloured rock and the mineral that makes it green is a mineral called chloride. It's quite hard and on the surface of the rock, there are these chevron type ripples that that kind of run across the rock. There are layers and the chevron zigzag kind of texture is because this rock marks a moment when a mountain was born. And it's called a green

• 6:28Speaker 02

  schist and a green schist is a rock that's formed under intense heat and pressure. The moment it was born was when two continents began to move towards each other and collide. And in between them was an ocean called the Iapetus Ocean. At the bottom of that ocean were some muddy sediments like silts and clays. And as those two continents, and this is North America where you are, and me, well, I say Baltica, but but that kind of continent which became Scandinavia in Northern Europe, those two continents were very gradually moving towards each other. They closed that ocean and the sediments at that bottom of the ocean were squashed and moved upwards to create an incredible range of mountains.

• 7:11Speaker 02

  Now, that heat and pressure changed those muddy sediments into this rock. And so when I'm looking at these kind of beautiful chevron zigzag texture in the rock, that's the mo- moment when that mountain was born. And I think it's when you recognise that those are the stories that the rocks hold inside them. If we can unlock them, it just gives you this immense sense of gravity of the time that passes, the immense sense of planetary processes that creates our earth. I find it awesome, actually.

• 7:44Flora Lichtman?

  It is awesome. I mean, hearing you talk about it, I I have that same feeling of awe and wonder that I feel when we talk about outer space or the universe, you know, the cosmos, but it's our own planet, which makes it sort of even more special somehow.

• 8:01Speaker 02

  It does. And I mean, you can contrast it with this rock. So this one is a piece of silt stone from Boscastle in Cornwall. And what you can see in this rock, it's very gray, and it's it's interleaved with kind of brown layers. It's very, very finely laminated. It's almost like a ream of papers that have been stacked up.

• 8:20Flora Lichtman?

  It looks like puff pastry, like brown, like black puff pastry.

• 8:24Speaker 02

  Yeah, yeah, exactly. And in contrast to the other rock that signifies immense planetary power, continents crashing together, in my hand, this signifies silence, silence and solitude. Because what this rock is, it's a rock that signifies that moment when silts and clays, which are so tiny, tiny, tiny grains of sediment, they're settling on the bottom of the seafloor, and it's utterly quiet, and they're able to settle in such undisturbed conditions, they're able to build very, very fine layers, and those layers have eventually become this rock. So it is, it's like holding silence in my hands.

• 9:07Flora Lichtman?

  We've got to take a quick break, but don't go anywhere. We have got lots more when we come back.

• 9:16Ira Flatow?

  Hi, it's Ira Flato. The Sci-Fi Book Club's December pick is The Biggest Ideas in the Universe by Sean M. Carroll. And we're bringing those ideas to life with a special live event. So if you're in New York City, join Sean and me at The Green Space on Friday, December 5. We'll also be streaming it live for free, so everyone can be part of the fun. Sign up for the Sci-Fi Book Club now at sciencefriday.com/bookclub.

• 9:48Speaker 03

  Support for Science Friday comes from the Heising Simons Foundation. Unlocking knowledge, opportunity, and possibilities. More at hsfoundation.org.

• 10:03Flora Lichtman?

  Okay, you you travel the world for this book. Tell me one of your favorite trips.

• 10:10Speaker 02

  One of my favorite trips was to Petra archaeological site in Jordan. I think that's on a bucket list for any geologist or anybody that's interested in how people have lived in very challenging environments like deserts. Now Petra was incredibly special because the rocks there are probably some of the most beautiful rocks I've seen in my life, actually. They are the colors of the rainbow. They're pink, orange, yellow, turquoise. And it was special for me because I could witness how the ancient Nabataeans had survived in quite a harsh landscape, but also how they had harnessed the way nature had carved

• 10:50Speaker 02

  a niche into the rocks so they could live and survive and prosper in that region. I just thought it was one of the most extraordinary places I'd ever been.

• 11:00Flora Lichtman?

  What did it feel like to be there?

• 11:03Speaker 02

  It felt magical because when I place my hands on the rocks, I'm feeling, I'm listening to their stories. And when I look at those beautiful arqueat bands of sandstone with all the amazing colors, I can sense that it's a river literally dancing over a plain, carrying in the waters grains of sand that eventually come to rest on a riverbed or in a riffle or on a bank. And also sand grains collect, they cement together over time and they form a sandstone. And then much later, mineral-rich groundwater filters through that rock, staining the cement, creating the beautiful spectacle that we can see in Petra. And all of this is something that I feel implicitly when I was in that environment.

• 11:48Flora Lichtman?

  You spoke with with many indigenous leaders about their tribal histories with rocks. What did you learn?

• 11:55Speaker 02

  I learnt that science sits in a space that needs to reflect and understand and be tolerant of different belief systems. I realised that we need to come to a place of equity in how we tell stories about the way the world was created. And the more I kind of delved into the origin stories that I I had the privilege to retell in this book, the more I understood how our understanding of the scientific creation of the world is very much built upon indigenous stories and myths and legends and folklore.

• 12:35Speaker 02

  Because actually, their understanding of natural processes and change over time can be charted back ten, twenty, thirty thousand years. And it's this building of human experience and observation upon our scientific research and understanding that makes our appreciation of of how the world has come to be so much richer.

• 12:57Flora Lichtman?

  Hmm. You also write about a granite peak in Yosemite, Half Dome, as as some of us know it. Tell us that story.

• 13:06Speaker 02

  That's perhaps one of the most magical stories that captured my heart. Half Dome, as it's known in the Awonichi language, Miwuk First Nations. She's known as Tisayak, and the story goes as follows because the Awonichi people were living in Yosemite Valley for perhaps about six thousand years before the white settlers came. And the story is that a man and a woman were travelling through Yosemite Valley and they were hungry and thirsty and tired. The man was walking with a stick and his wife was carrying a a heavy basket. And as a woman reached a lake, she drank the lake dry because she was so thirsty. And when her husband arrived, he was angry because she'd left him no water to quench his own thirst.

• 13:51Speaker 02

  He was so angry, he reached for his stick to strike her. And she was terrified and she ran away with tears streaming down her face. And in her own anger, she threw her basket at him. Now, the great spirit that was watching all of this debacle unfold, he became quite angered. And so he turned the both of them into stone. The man became Washington Tower, which is on one side of Yosemite Valley. And the woman, Tisayat, was turned into what we call Half Dome. This incredible granitic peak that is one of probably, I think, the most iconic features in Yosemite National Park. Now, the reason why this is such a spectacular and moving story is that even after six thousand years,

• 14:35Speaker 02

  we can still feel a sense of gravitas and emotion when we look at Tisayat. Because you can still see the streaks of her tears lining the face of the granite. Now, scientists know the streaks, these black streaks on the grey rock, as lichen. The fact that this story is still told in Mewik First Nations communities gives us some indication as to how slowly the rock weathers and changes. And for me, it kind of helps us to view landscapes like this through a completely different lens. Because, as you and I probably know, Half Dome is quite an achievement for climbers that wish to scale it. But through First Nations eyes, we see it as a monument to regret and sadness, and essentially to be kind to each other.

• 15:20Flora Lichtman?

  Was Half Dome forged in a moment of geologic passion? I mean, is there some continuity there?

• 15:30Speaker 02

  I think there is. I think Half Dome was formed because of a plume of magma rising upwards due to the formation of the Sierra Nevada. So here you have the Farallon Plate, which is an oceanic crust, subducting, so it's sinking beneath the North American Plate. And as it does so, there are big plumes of magma that rise up and intrude into the crust above. Now, they don't achieve their destiny, which is erupting through a volcanic eruption. They get trapped within the crust and they take perhaps two to three million years to cool down these magma plumes. And over that time, they crystallize and they form granite. And I think what that

• 16:13Speaker 02

  Teaches us, especially in reference to the story of Tissayak, is patience, to remain calm underneath all conditions, to basically, you know, wait and see what transpires. If we can control and hold on to our emotions, beautiful things will happen.

• 16:33Flora Lichtman?

  Easier said than done.

• 16:34Speaker 02

  Easier said than done.

• 16:36Flora Lichtman?

  You have an emotional connection with rocks. We can hear it in your in your voice. Have you faced pushback from, you know, the capital S scientific community for that?

• 16:49Speaker 02

  Yes, I have. I think some people have called me romantic, and I think you can make of that what you will. Because I think that in itself has lots of different meanings, whether they look at me as a woman and think I'm less of a scientist because I bring emotion into the work that I do. But I think to counter that narrative, the most important lesson of the book is that through fostering a sense of love, we can perhaps rekindle that sense of custodianship and care and ethical thinking that we need to build into our science. Because one of the key things I've been told time and time again is that the book is challenging. It's challenging because of some of the concepts it discovers

• 17:32Speaker 02

  and reveals to the reader, but it's also very challenging in the sense that it's putting feelings, feelings of love that I don't think scientists talk about too much, it puts that up front and center. And I think it does take courage to do that. But what I'm hearing is that I think people are pleased that I've done that, that I've been the very, one of the first people to step forward and say, I love this. I genuinely am saying it with my chest. I love rocks and I want other people to see that joy in the same way that I do.

• 18:06Flora Lichtman?

  Do you think you got that courage from your, you know, from your own personal journey where you had to figure out what you believed in and stand up for it? And do you think you put that in your backpack for for this moment too?

• 18:18Speaker 02

  Yes, I think my whole background of having to challenge obstacles, to having to prove myself, not just as a woman, but as a woman of color in the science, I think it makes you slightly risk-taking. You know, I have nothing to lose. I really do want everybody around me to see rocks as a vivid, as an animate and exciting part of the natural world, as much as the trees and the wildlife and the rivers. And I think by saying that with my full chest, with my full heart, I think that's how you win people over, because that honesty and that force of feeling, people can't ignore it. But all of the hardships

• 19:01Speaker 02

  I've had to go through have strengthened me to do that.

• 19:05Flora Lichtman?

  Dr. Anjanakatwa, earth scientist and the author of the new book, The Whispers of Rock, The Stories That Stone Tells About Our World and Our Lives. Thanks for joining me today.

• 19:14Speaker 02

  Oh, thank you for having me, Flora. It's been an absolute joy.

• 19:18Flora Lichtman?

  Likewise.

• 19:24Flora Lichtman?

  Today's episode was produced by Shoshana Buxbaum. I'm Flora Lichtman. Thanks for listening.