Neuroscience of reality; Quest for dark matter; Folklore of geoscience (New Scientist Live Special)

0:01Chamkaur Ghag:This episode is brought to you by Google Chrome. You think you know a browser, but Gemini and Chrome? That's new. It can help you with practically anything on the web, like restoring a vintage motorcycle from a 50-page restoration block, or finally break down that long article you've had open for weeks. Gemini and Chrome is here for it. Ready to make anything online make sense? There's no place like Chrome. Check responses set up required, compatibility and availability varies 18+. Welcome to a special recording of The World, the Universe and Us, recorded live at New Scientist Live here at the Excel Centre in London.

0:34Anjana Khatwa:It's so good to be here. Thank you for coming. Let's get straight into it, shall we? I'm Dr Penny Sashay.

0:40Chamkaur Ghag:I'm Dr Rowan Hooper.

0:41Anjana Khatwa:We've got a scientist, an author, Anjana Kapwa. We've got physicist Jamko Gag from the UCL and Daniel Yon. He's a neuroscientist from Birkbeck. While we've got these experts on stage with us, we thought we'd just take advantage of your time and ask you to tell us something we don't know or something really interesting from your fields of research. Antonia, shall we start with you? Thanks very much. I'm a geologist, so I deal with very deep time stories about creation and the origins of our Earth. Today I'm here at New Scientist because I've been introducing my brand new book. Here it is, if you haven't seen it already.

1:16Anjana Khatwa:It's called The Whispers of Rock, Stories from the Earth. And this book brings together Western scientific knowledge about the evolution of our Earth, together with indigenous knowledge and stories, and my own experiences working as a geologist for over 25 years. Now, one of the wonderful stories I shared on stage today was about the origins of the formation of the Hawaiian Islands. And they are located on a magma hotspot, a mantle plume. And essentially what this means is that there's a kind of a cord of magma that stretches from the outer core. And it moves all the way. It pumps superheated molten fluid, semi-molten fluid, up to the Earth's crust, the lithosphere, where it begins to melt the crust.

2:01Anjana Khatwa:So this is on the Pacific plate. And that Pacific plate is gradually migrating over that point of connection. So what happens is that the magma reaches across all rocks. it melts them and it shoots through and creates volcanoes at the bottom of the ocean. Over time, that lava builds up into an island which will breach the sea level and form a volcanic island. And that's how Hawaii formed. The Pacific plate is moving over that mantle plume, that hot spot. And as it migrates, the volcanicity that creates that island switches off. And then it will start again and create a new island as that plate is moving over the hot spot.

2:40Anjana Khatwa:Now, the native indigenous Hawaiians, they arrived in the island about one and a half thousand years ago. And as they traveled along this archipelago, they could see and sense that the volcanism on each island was changing. Some were weathered, some were older. And as they traveled along the chain, volcanism became more active. And they created and told beautiful stories that manifested their experience of the geological world. And the story that I shared on stage earlier was about the story of Pele, who, in the legend, she is fleeing the clutches of her sister, who's very angry with her because Pele's fallen in love with her husband.

3:20Anjana Khatwa:And her sister, Namokaukahae, chases her, and Pele tries to escape, and she hides using her digging tool, Pa 'au. And every time she digs an island to hide, she creates a volcano, naturally. she's a goddess of fire and her sister is drawn to those volcanic eruptions to try to murder her which is rather scary obviously and so they she keeps fleeing and as she as she escapes each time she tries to hide she creates an island which are the hawaiian islands eventually they have a battle on the on the big island of hawaii where pele is killed by her sister and then as her sister is walking away pele rises her spirit is shimmering and she creates kilauea which becomes her ancestral home and you know every time kilauea at the moment is very active native indigenous hawaiians see that as an expression of mother earth as an expression of pele you know showing showing the islanders that she is there with them that she's present and i think the story is essentially an oral history of how to tell other islanders how to make their way across the sea to locate the descendants, but also it's this beautiful story of how indigenous knowledge ties in with science and helps us to feel a sense of connection with rock and landscape.

4:41Anjana Khatwa:I think it's beautiful.

4:42Chamkaur Ghag:It makes me wonder how indigenous stories are adapting to modern times, especially with sea level rise. Do you see evidence of that? sort of the stories being changed and interwoven with new things that are happening?

4:59Anjana Khatwa:I think that's an interesting point. I think the stories evolve and change as they are told through the descendants. But how they are changing is they are advising, interestingly, they're advising scientists, particularly those working in natural hazards, how to live alongside natural processes. So in Aotearoa, New Zealand, Maori are working with geologists and geoscientists in kind of protecting communities from lahars. You know, these are volcanic eruptions of ash and lava. And they are basically advising scientists in how to work empathetically, ethically with natural processes. So actually, it's the other way around.

5:40Anjana Khatwa:Indigenous knowledge is guiding Western science, if you like, which, again, is quite extraordinary when we think about it.

5:46Chamkaur Ghag:The other thing it just made me think of then was some geoengineering projects that they're starting to think about in Greenland. And they're actually not doing it because the local people they spoke to, after being really informed of what they were planning, this was like a curtain they were going to build to try to block off some of the water going under the glacier. They didn't want that to happen. And so at least they are engaging with local and indigenous people and hearing what they want rather than just going in there and doing what the scientists want, as might have happened in the past.

6:25Chamkaur Ghag:Champa, you're a physicist. Do you want to give us a bit of a spiel about your stuff? Yeah, it's hard to follow when there's like gods and stuff going on with Marvel movie. In the Dark Matter game, we're trying to find rare interactions, rare particles, lots of particles out there, but the likelihood of them interacting with a detector, a target that we've built, is so low, so infinitesimally small, that you need very large detectors. You need to have lots of protection for these experiments. And so the very first thing that we have to do is be deep underground. So the rock comes in again, deep geological time has allowed us to be able to get into the earth.

7:13Chamkaur Ghag:And so the current experiment LZ is a mile under the Black Hills of South Dakota. And it's a former gold mine. And it's sort of an absurd amount of work to be done to just get to your lap. You've got to kit up and everything and get down and everything to then go start the science. but the it's one example of what we have to do in terms of backgrounds and so i guess it's nice to or for me always nice to kind of think about and talk about that these experiments when we're looking for science we're looking for a new signal dark matter let's say it's not that we'll have found dark matter it's more that we'll have characterized our backgrounds so well that we've seen a bump on top of it.

7:59Chamkaur Ghag:So we understand what could happen in that experiment. So when we go deep underground and we've got the rock shielding us from cosmic rays, we understand what that means. After that, we then have to construct the experiment from really pure materials, incredibly low uranium and thorium and lots of like rare earth metals that we have in rock. So we've got to make sure that all of that is incredibly, incredibly low. And then there's a bunch of other techniques, lots and lots of time, lots of, you know, from multiple detectors around our central detector to analysis teams that are trying to pick out particular events.

8:37Chamkaur Ghag:But what this is all leading to is that we came across what I think is the most fun background so far in the field and we've not, no experiment had ever come across this. I remember what we're trying to do is sort of understand everything that is happening and then look for something on top of So we had understood, you know, we've constructed this experiment very cleanly. There's only about four events or so, at best, a day happening in this experiment. And it looked like we understood where our, you know, our calibrations, everything all makes sense. But then it looked like somewhere around our, some events were misbehaving.

9:14Chamkaur Ghag:They're just acting a little bit weird and they're making it look like this could be signal. So, okay, there's something that no one's really seen before. Either it's a new standard model process or it's dark matter. What it turned out to be was that in the detector, we have natural isotopic xenon, which has lots of different isotopes in it. Mostly it's xenon-131 and 129. But one of them is xenon-124. And there's only a few percent of this stuff in the overall mix. And it itself will decay. It'll have a half-life, just like radiation. and this thing will decay and spit out gamma rays or whatever.

9:52Chamkaur Ghag:It has a half-life of its own, but it's a very, very long half-life. It's a trillion times the age of the universe. So if you had a single Xenon-124 atom, you're waiting a very long time for it to decay. Is that even radioactive? How can you call it radioactive if it takes that long to decay? It's still a problem. But the joke of it is it's still a problem for us because when it does decay, there's still more of that than the dark matter we're looking for oh my god and so eventually we figured it out it's like ah there's something funky going on with inner shell electrons when they're being liberated from xenon 124 really getting into the atomic physics of it and on the one hand kind of fun that we had no idea this was happening and that's sort of the way the deeper we get the more sophisticated these experiments are getting the more we're peeling back backgrounds until eventually we find one that we'd never thought of, because this is really weird.

10:49Chamkaur Ghag:And we're always going to get caught up and think, oh, is that Dark Matter? Oh, no, it's another background. But having the ability to peel back to that level now is just getting really funny for me. So just to go back a bit, is this detector that's in the gold mine, is this like one of these massive tanks of ultra-pure water under there, or is there a different kind of detector you've built? It's a different kind of detector. We've been successful as physicists and engineers at building large detectors like large water tanks that have high thresholds. They're good at seeing high energy signals, so maybe neutrino beams or things like that, but they give you a big wallop of energy that you can spot.

11:32Chamkaur Ghag:what we need for dark matter is that they need to be large because we have to have a lot of target material in there but they also have to be very low threshold we need to be able to see as i said in my talk the equivalent of a single nucleus of a single atom moving by a thousandth of a hair's width and so that gives you a photon or two to play with yeah and so it's not these large ones there the current one is about a meter tall a meter wide in a cylinder the next one xlzd which which is what the stand is all about, at Balby Mine in the UK, would be something like three metres wide, three metres tall, holding about 80 tonnes of liquid xenon.

12:09Chamkaur Ghag:So they're not crazy scale. They're kind of the size of that moon at the moment, and will get a bit larger.

12:15Anjana Khatwa:And as you're sort of gradually peeling your way down through all the possible background, you know, casually just measuring xenon, like randomly, radioactively decay, is that of any use to you? Can you spin off anything out, or is that just kind of something cool you observe and you just keep going deeper and deeper?

12:33Chamkaur Ghag:Oh, no, often we absolutely spend, so, you know, the excitement is then we've just measured the, so in this scenario, this example, we rely on electrons being liberated and then recombining in a certain way. But it turns out that electrons coming from deeper shells are having interactions and recombining ultimately in a different way. So it has an immediate impact on all of our science, our future projections. So in terms of building the next experiment, now we have to factor in 0124. And so hang on, there's actually going to be these events as well. And so measuring the charge yield or the yields of these kinds of events has never been done.

13:11Chamkaur Ghag:And it allows us to push the lower and lower threshold as well. So it's immediately like we get very excited when it's like, oh, what the hell? Because it's either signal or something brand new that no humans ever kind of come across. And we need to understand it anyway. So often those papers are more interesting than the, we look for dark matter, we didn't find it. The why we didn't find it and how we're confident we didn't find it is stuff like this. There's an one, two, four.

13:35Anjana Khatwa:Every Sunday, we talk about the week's tech news on This Week in Tech. Hi, this is Leo Laporte from the Twit Podcast Network. Inviting you to join me this week. I have Dan Patterson of Blackbird AI, Jennifer Patterson-Tui from The Verge, and Daniel Rubino from Windows Central. We'll talk about Microsoft extending the life of Windows 10 yet another year, why Apple prices are going up, and Mythos out of jail. That's this week on This Week in Tech. You'll find it at twit.tv and wherever you get your podcasts. It's an incredible story. And what struck me is the location of where your experiments are taking place.

14:12Anjana Khatwa:And I talk about the Black Hills in my book because the Black Hills, essentially, if you don't know the geology of it, it's a granitic peak it's a peak of granite so magma that intruded into the crust and then cooled to form a great big body of granite now the indigenous people because the gold mine you referred to was illegally prospected the black hills are the ancestral lands of lakota first nations which i'm sure you have worked with when you've gone over there but what i find extraordinary is the black hills are also known as paha sapa in their native languages you know the heart of everything that is and what gives me goosebumps is your conversation about kind of finding this these particles this dark matter in alliance with this what the Lakota know as as the center of their universe is absolutely mind-blowing absolutely incredible yeah no I I agree that for you know at some level there was kind of trepidation you know it's like the history of the place

15:16Chamkaur Ghag:the Fort Laramie Treatment, all this kind of stuff that is happening. And then it's like, well, okay, now it's a lab, and there were certain missions in terms of no extraction, things being put back in. So a great kind of trying to honor and trying to... In fact, in our results paper, we were trying to sort of expand. We had for the first time kind of acknowledgments through that, and we were trying to make it more substantial and really bring in the wisdom of it as well, So the heart of the planet, like the Amazon, the lungs of the planet, the Black Hills being referred to in that way, but you can feel it.

15:55Chamkaur Ghag:It's a really holy, it's really odd, especially when you get out into the wilderness as well. Being able to kind of listen very quietly, because sometimes I think of these detectors as listening devices. It's incredibly quiet, and rather than binoculars or a telescope, we're using this thing to try and hear the smallest interactions. And to be doing that in somewhere like South Dakota, the history is all, is icky, but the actual, when dropping that and really just being with the rock, it's crazy, like actually being inside the mind, like surrounded by it.

16:32Anjana Khatwa:What's extraordinary is what you're describing is what the indigenous people, the First Nations, Lakota, they call it vision questing. and they will spend days, weeks being within nature, being with the rocks, searching for meaning and story and lessons to take back. And I find it extraordinary that you as a scientist are doing that. I as a geologist do that when I interact with rock. It's a beautiful synergy. Thank you. Thank you for sharing that. Over to you, Daniel. How are you going to follow up?

17:04Chamkaur Ghag:With less poetry, I'm afraid. I've just come from the mind and body stage where I was also talking about my new book, A Trick of the Mind, How the Brain Invents Your Reality. So I'm a psychologist and a neuroscientist, and the main arc of the book is that you should think that your brain is really like a scientist too. It's building its own theories and hypotheses to make sense of the world, but these also become the sort of lens and filter through which you see everything in the world around you and how you see the world inside your own head. But the thing I guess I wanted to highlight now was something that I think is really interesting and where the science is currently going in that we're beginning to see how there are particular neurochemicals in the brain that seem to control how wedded we are to those theories and hypotheses and how open-minded we might be, how easy it is for us to undergo our own kind of paradigm shift.

18:00Chamkaur Ghag:And as we kind of begin to detect what these chemicals are, it also becomes possible you can take quite familiar drugs that already exist, drugs like propranolol, which is often prescribed for kind of anti-anxiety medication, or things like Ritalin, given its technical name methylphenidate. But these two drugs seem to have effects on this system in the brain, the neuroadrenaline system, that tracks how much we trust our existing theories of the world and how much we're willing to shift.

18:31Anjana Khatwa:And so is it a good thing to sometimes not trust how you see the world? Because then that opens you up to think about other things? Or is it better to trust your inner scientist?

18:42Chamkaur Ghag:Well, I think that there's probably no right answer in general. I think that one thing that you can see, for instance, is that though people don't necessarily combine this with drugs, this same system seems to be implicated when people undergo quite dramatic changes in what they think about the world. And those could be positive, but they also could include things like people coming to believe bizarre conspiracy theories. You can think that when this kind of chemical is surging in your head, it makes your mind more malleable. And the next message that comes in is going to have a powerful effect on what the brain thinks and feels.

19:15Chamkaur Ghag:but you might not always be in control of the messages you're receiving. So I think it's sort of an open mind can be a dangerous thing as much as something we'd want to price. When you're talking about people believing conspiracy theories, are we seeing more of that? Because certainly it seems like there's much more misinformation believed around at the moment. Certainly vaccine hesitancy in the US is a horrendous problem. but there's all sorts of other issues related to that is there more of it around at the moment and if so what is not just a small question what's underlying it and how do we tackle it no biggie no in short yes and I think that maybe and I think that people have maybe gone on a bit of a journey right and I think maybe a few years ago people would have thought that believing in a conspiracy theory was somehow to do with the individual you would kind of explain it away as there was something particularly wrong about the kind of particular impressionability or gullibility of a particular person and we would think you know we're not like them we think clearly but the rates of which people are beginning to endorse some of these unusual ideas suggest that it can't just be that there are a few kind of unusual people it seems that all of us have the potential to believe these strange things and I think that it's probably actually connected to this same kind of system what this system in your brain should be doing when it's working well is it should be listening out for changes in the environment and when you start to think that things are changing you should want to think something new so that's kind of what this kind of no adrenaline system does for you it means that it's easier for existing information to adjust what those kind of networks are believing when you think the world is volatile and there's change of foot And I think maybe that's just the kind of time we're living through.

21:03Chamkaur Ghag:There was some empirical evidence for this. For instance, during the kind of pandemic, I spoke about this in my talk, the lockdowns state by state in the US could lead to spikes in behavior that we know are connected to this system. So it looks like once you start to encounter something really unexpected in the environment, it has this effect of spiking that volatility in the brain and in turn making you open-minded, but possibly open-minded to things you might not want to think.

21:31Anjana Khatwa:It's quite interesting. It makes me think a little bit of things like anxiety and depression, which we used to unfortunately see as kind of a moral or character flaw. Now we much better understand it can be to do with just brain chemistry not being quite where we want it to be. Never really thought that falling down a rabbit hole and unfortunately getting very involved in the wrong kind of ideas could similarly be something just off with your brain chemistry.

21:55Chamkaur Ghag:Yeah, and I think, I mean, from a sort of personal perspective, I think I find, And I mean, I find this science itself very, really fascinating. And it's, you know, it's great to be in the lab doing the experiments. But on a more kind of human level, I find it quite humbling to think that when you look at how your brain is constructing that world that you live in, that grip you have in the world is always a bit tenuous. And you should maybe be a bit more humble when you see someone thinking or believing things that you don't think are right, because it's not that difficult to find yourself in that same situation.

22:25Anjana Khatwa:Do you have any news you can use on how to keep your grip on reality?

22:30Chamkaur Ghag:Well, I'm not going to suggest that we should all just take propranolol, but that is what happens in some of the studies. People become more stubborn in some recently acquired beliefs if they're under the influence of this drug. So maybe in the not-too-distant future, the way we'll get a grip on reality is by fiddling with the chemicals. I'm not saying I would recommend that. But I think we should also not be afraid of change. And this is something I actually wrote for the New Scientist about recently, the sense that when our brain's detecting this instability and uncertainty, it might make us feel anxious, but uncertainty isn't always a bad thing.