Astrobotany & Plant Intelligence with Simon Gilroy

Are plants more aware than we think? Do they have feelings? Neil deGrasse Tyson, Gary O’Reilly, and Harrison Greenbaum explore the intelligence of plants with astrobotanist Simon Gilroy. From venus flytraps to space farming, we dig deep into the secret world of plants.

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

• 0:00Neil deGrasse Tyson?

  I was skeptical, but now I'm all in on plants as people.

• 0:06Neil deGrasse Tyson?

  Plants have feelings and they know their environment and they have sensors and they want to live too. And they don't want to die and they have reaction functions to preserve that.

• 0:14Gary O'Reilly?

  There's a lot more going on in plants than we've realized.

• 0:17Harrison Greenbaum?

  All this technology and research and we're still going to be stuck with kale and Mars.

• 0:22Neil deGrasse Tyson?

  Coming up on StarTalk, special edition.

• 0:27Neil deGrasse Tyson?

  Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:40Neil deGrasse Tyson?

  This is StarTalk, special edition. Neil deGrasse Tyson here, your personal astrophysicist. And if it's special edition, it means we've got Gary O'Reilly.

• 0:49Gary O'Reilly?

  Hi Neil.

• 0:50Neil deGrasse Tyson?

  Hey Gary, former soccer pro.

• 0:51Gary O'Reilly?

  Yes.

• 0:52Neil deGrasse Tyson?

  And I still, I still can't get out of my head the Google search on you that delivered your Wiki page where you, you got sexy legs on the field, on the pitch.

• 1:03Gary O'Reilly?

  I'll have that deleted.

• 1:07Neil deGrasse Tyson?

  Today, this is a topic you and fellow producers have picked.

• 1:11Gary O'Reilly?

  Yeah, it's something we've been wanting to do for quite some time. And it's finding the right guest and the right time to bring it forward. So we feel this is about, just about right.

• 1:21Neil deGrasse Tyson?

  This is the right time.

• 1:22Gary O'Reilly?

  Yeah.

• 1:22Neil deGrasse Tyson?

  And then we comb the streets and we found this guy. Harrison Greenbaum. Not your first rodeo with us.

• 1:29Gary O'Reilly?

  Yes.

• 1:29Neil deGrasse Tyson?

  No, no, we love you Harrison. And you just finished a production.

• 1:34Harrison Greenbaum?

  Yeah, my Off-Broadway magic show, What Just Happened.

• 1:36Neil deGrasse Tyson?

  What Just Happened, you're gonna take, you're gonna take it on tour?

• 1:38Harrison Greenbaum?

  Take it on the road, yeah.

• 1:39Neil deGrasse Tyson?

  HarrisonGreenbaum.com.

• 1:40Harrison Greenbaum?

  HarrisonGreenbaum.com, yeah.

• 1:41Neil deGrasse Tyson?

  And you're a magic guy.

• 1:43Harrison Greenbaum?

  Magic guy, I went to space camp.

• 1:45Neil deGrasse Tyson?

  You went to space camp?

• 1:45Gary O'Reilly?

  Oh.

• 1:47Neil deGrasse Tyson?

  Okay.

• 1:47Gary O'Reilly?

  You're in the right place.

• 1:48Neil deGrasse Tyson?

  There's a street credentials for this show, alright. Alright, so, so Gary, what is the setup for today?

• 1:55Gary O'Reilly?

  In previous shows, we have looked at many forms of intelligence, both artificial or otherwise. But where does intelligence start? For that answer, we look to the tree of life, more specifically trees and plants.

• 2:08Neil deGrasse Tyson?

  Literal trees.

• 2:10Gary O'Reilly?

  Yes.

• 2:10Neil deGrasse Tyson?

  Not just the figurative tree of life.

• 2:12Gary O'Reilly?

  Not the metaphoric kind, no. We know plants are aware of their surroundings, but how deep does it go? Can they communicate? Can they count? Can they feel pain? Can they learn? Do they have memory? What happens if we send them into space? Do plants know they are in space? And how does this impact future food production for spaceflight? This means expert time. And I must warn you, he's a fellow Brit, has a flowing white mane and a penchant for Hawaiian shirts. Neil, if you will introduce our guest.

• 2:46Neil deGrasse Tyson?

  Simon Gilroy, welcome to StarTalk. Oh, thank you for having me. Yeah, I've got you down here. You're Professor of Botany at the University of Wisconsin. So there's still botanists out there. You're head of the Gilroy Science Lab. What a coincidence. What are the chances of that? I know.

• 3:05Neil deGrasse Tyson?

  What we like here is your research includes plant nutrition. Also, the why we have you on this show is you think about the surface of planets and the moon and what interaction a plant might have with those surfaces. Because we don't even call the surface of the moon soil. No. No, it's like pulverized rock. So we call it rigolith. Rigolith. And your whole space-leaning interest, interest us. And that, in a way, you are not only an astrobiologist, you're an astrobotanist.

• 3:47Neil deGrasse Tyson?

  See, I didn't know astrobotanists existed until now.

• 3:52Harrison Greenbaum?

  I don't want to brag here, but when I did go to space camp, we went on a fake mission to the moon and I was the astrobotanist on the space shuttle. So I took care of a fake plastic plant and I measured the effects of fake gravity on this fake plastic plant for a full half hour.

• 4:09Neil deGrasse Tyson?

  And it was fake that you rode a space shuttle to the moon because space shuttles can't reach the moon?

• 4:13Harrison Greenbaum?

  That's right. None of it was real, but I did have to take measurements of a plant. They did not change because we were not in space and it was made of plastic.

• 4:19Neil deGrasse Tyson?

  See how good space camp is?

• 4:20Harrison Greenbaum?

  But I was an astrobotanist for about a half an hour.

• 4:23Neil deGrasse Tyson?

  All right, so Simon, let's lay the foundation here. We know plants are alive. But how aware are they? And do we have to loosen our definition of the word aware? To enclose everything it is that they do? So that we can speak of their properties? In the same sentences as we speak of our own awareness?

• 4:44Speaker 03

  All biology is aware. Uh, if we use awareness as monitors the environment around it? And deals with it, whatever? The appropriate dealing with is because if you couldn't do that? You can't stay alive. The environment's changing. The lion is chasing you. The insect is chewing on you. It's rain, it's dry. You have to monitor all of that. So all that's an intrinsic part of being alive.

• 5:11Harrison Greenbaum?

  You just described the world's worst honeymoon.

• 5:15Neil deGrasse Tyson?

  Insects chewing on you.

• 5:17Harrison Greenbaum?

  Yeah, lion chasing me. This safari has gone awry.

• 5:20Speaker 03

  I didn't say the world was necessarily a benign place. In fact, it isn't. That's, that's why you have to be aware of what's going on. You've got to roll with the good times and deal with the bad times.

• 5:31Neil deGrasse Tyson?

  Obvious things that they'd have to track the sun. They know when the sun is up and down? And the seasons, these are some obvious ones. Are there other ones that are less clear and present to a casual viewer?

• 5:41Speaker 03

  Yeah, yeah, um. So one way to think about it is that we as animals, we have the luxury of movement. So if stuff happens around us? You don't have to precisely know what's going on. You just have to know it's bad. And then, then inevitably what we do is we vacate? The area where the bad stuff is happening? If you're a plant? You're, you're rooted to the spot, absolutely, literally rooted to the spot. So your array of senses? Has to be broader than our array of senses because? You not only have to deal with it, you have to know exactly what's going on. So direction of the sun, uh, but.

• 6:20Speaker 03

  What's the time of day? You have to know that because plants do a lot of predictive biology. So if the sun comes up, there's an absolutely fantastic video of a sunflower doing a thing called solar tracking. So sunflowers put their leaves and point them flat towards the direction of the sun. And you could go, well, that feels almost like a machine. You know, it's the, it's just monitoring the sun's direction and pointing for the optimal amount of photosynthesis. But if you watch it, there's a great movies on, uh, online of this solar tracking during the whole day. The plant actually, at the end of the day, it goes like, uh, and the leaves flop down. But then it predicts where the sun's going to come up and the time of dawn.

• 7:05Speaker 03

  And it pops its leaves up predictably to point to where's the sun is going to come up. So it's got an internal clock. It knows what the time of day is. There's a lot of environmental factors that I think, if you're a gardener, you would just guess it has, they have to know this. They have to know how much water there is. They have to know what the nutrients are around. It's kind of important if you're a plant and if you're being eaten. Um, that's a big one. What the temperature is, the time of year. Um, just, you can go through a litany of, of environmental factors. And if you can imagine that it would impact on a plant's success, there's going to be a sensor for it. Because otherwise plants wouldn't be around.

• 7:44Neil deGrasse Tyson?

  All right, you're describing reaction to an environment that are all positive for it. But if there's an assault on the environment, uh, what kind of defenses might a plant have against it?

• 7:56Speaker 03

  So again, you can imagine you're rooted to the spot, what kind of defenses that you're going to have. They're not going to be avoiding. There are a couple of plants that can actually do incredibly rapidly movements. There's a thing called mimosa, the sensitive plant. And if you touch it in real time, it looks like an animal, the leaves collapse down. Uh, and we think that that is to sort of like flick off a caterpillar or make yourself just less obvious. So that's a response to touch, uh, which is a movement related one, but that's kind of the one weird ones. The general things, what plants are really, really good at doing is make. stuff. Photosynthesis is an incredibly powerful and productive way of doing biology. And so plants build things to deal with the world.

• 8:39Speaker 03

  So defenses can be pre-existing built things, things that we would all interact with, you know, things like spines and prickles and just like the barbed wire approach to defending yourself. Oh, okay, of course. But then one, what they are real masters of is chemistry and just making nasty stuff. And there are an enormous number of poisonous plants, all those psychoactive drugs which are extracted from plants, they are not there for us. They are there as defenses. And those defenses can either be pre-existing, you know, they can just make the chemical and just go, I'm defended, or what is a much sort of cleverer way to do it is to go, I'm being attacked.

• 9:22Speaker 03

  I'm going to make my defensive chemical now because these defenses cost me something. So I'm just going to switch them on when I need them. And so there's a lot of inducible chemical defenses. As soon as an insect or a herbivore starts chewing on a plant, it knows it's being chewed on and it switches on just a ton of stuff to defend itself. So none of that happened with your plastic plants?

• 9:43Harrison Greenbaum?

  Oh, yes, exactly. It stayed very, actually, space had very little effect on it. Turns out plants are great in space. There was zero change and the plant stayed vertical the whole time. How about that? I am nervous that plants are aware because I've killed many houseplants. So does that mean they know that I'm like the Jeffrey Dahmer of houseplants? Is that my, do I have a reputation with plants?

• 10:05Speaker 03

  We work a lot on those sort of like the sensory events and what they trigger. And so one of the things is, imagine you're eating a salad. You didn't cook the salad. Everything in the salad is alive. So if there is, you know, that classic silent scream, that silent scream is going on inside your mouth as you're chewing on it because everything is alive. Does that make me not eat salad? Absolutely not. You know, salad, healthy for you. Uh, but it is so easy to just sort of forget that plants are alive. And the all biology, again, there's this linguistic minefield that we're going to walk into.

• 10:46Speaker 03

  And I, there's no way to get around it. We should be stepping on those landmines of, of how we describe things. Because I don't think there's a better way to do it. We're going to use the language of human experience and human consciousness and how we work, because, you know, that's really the only relatable thing we have. And so when we start talking about the plants know they're being eaten, that comes with a lot of baggage. That comes with you thinking you're being eaten and you can't get away from that. That's just built into the power and the problems of language. So plants are sensing what's going on around them and responding. Does that mean they know anything?

• 11:29Neil deGrasse Tyson?

  Yeah, they're not in harmony with herbivores.

• 11:32Harrison Greenbaum?

  Right.

• 11:33Neil deGrasse Tyson?

  I thought they, that's part of the circle of life. What are you saying? They're pissed off.

• 11:36Harrison Greenbaum?

  Yeah, they're screaming for their life. Yeah. I didn't realize when I was eating a salad in front of a plant, it was like eating sushi in front of a fish.

• 11:43Gary O'Reilly?

  So the thing is, Simon, I mean, we know plants don't have what we would classically interpret as a brain. So what systems are engaged for their communication, for their behavior?

• 11:55Speaker 03

  Ah, it's a, so that we've now stepped to the edge of our knowledge. Um, so.

• 12:01Neil deGrasse Tyson?

  Okay, that's the end of the show. Okay.

• 12:04Neil deGrasse Tyson?

  We're done here.

• 12:07Speaker 03

  No, wherever, wherever they are, science is stepping to the edge of knowledge and then hypothesizing what the next step should be.

• 12:15Gary O'Reilly?

  Ooh.

• 12:15Speaker 03

  So we, we, I think we literally have stepped to kind of, we're getting to the point of where there's active research and debate about what's going on. So we know a lot of the molecular machinery.

• 12:25Neil deGrasse Tyson?

  I want to pose Gary's question more precisely.

• 12:27Gary O'Reilly?

  All right.

• 12:28Neil deGrasse Tyson?

  So we attribute our sensory world to neurochemical synaptic phenomenon in a very complex nervous system that we call our brain. Given that, if we look at plants where we know there's no corresponding. Gathering of neurons. Yeah. Then, in order to port our emotional state and our sensory vocabulary onto a plant, and to do that botanically, in a way that makes botanical sense, are you going to have to point where that is sensing it and by what electrochemical means it's reaction? It's reacting.

• 13:11Speaker 03

  So, we know some of the nuts and bolts, the machinery. So, I can tell you how does the plant sense like. I can tell you the proteins it uses, just like biomedical researcher could tell you how your eye works at that level. You know, the nuts and bolts are photons coming in, flipping chemical bonds, generating signals. We also know that there's long-distance signaling within plants. So, if you, again, my favorite example is, it's so, it's so easy to think about, but so complicated. A caterpillar chewing on a leaf. That's a very local event. So, if you imagine it's you, imagine like a lion chewing on your fingers, right?

• 13:52Speaker 03

  It's a very local piece of stimulation, but it spreads throughout your entire body because you have a nervous system that transmits information. So, we know plants don't have nerves, they don't have a brain, but they have that long-distance signaling system because they have the same problem that, you know, if you've got a local piece of information, it's kind of important that the entire organism knows what's going on. The long-distance component of it is absolutely not nerves. We know what nerves are, and they just simply don't exist in a plant. We know what a brain is, there is no brain in a plant at the anatomical level, but there is a long-distance signaling system, and for that wounding system, we know what it is, and it turns out it's the plumbing system inside the plant with liquid flowing in it.

• 14:35Speaker 03

  That liquid carries chemical signals. And this is where you go like, really? One of the chemical signals for damage is an amino acid glutamate. That's like the MSG that you put on your food to make it taste yummy. That's a basic building block of plants, but when you damage a plant cell, it leaks it out.

• 14:55Neil deGrasse Tyson?

  MSG but without the MS?

• 14:57Speaker 03

  Yes. Okay. So just G. Just G. Glutamate, okay. The G. So that glutamate is flowing through the plant and it triggers long distance responses. So you can go, do a big analogy, that feels almost like nerve conduction, right? It's a very different thing, but it feels like the long distance conduction. Glutamate is a neurotransmitter. You have it firing off in your synapses at the moment, transmitting information between nerves. And there's a protein that has to be the receptor. And in our nervous system, that is a thing called, strangely enough, a glutamate receptor.

• 15:38Speaker 03

  And the glutamate receptors have a chemical binding site for the amino acid and it switches on their activity. Plants have almost identical proteins that bind glutamate and the glutamate triggers their activity. And glutamate is part of this long distance signaling system. So, you know, there's lots of parallels about how things work, but there's a fundamental difference, which is no nerves and no neurons. And if you think that what your brain is doing is building a model of the world, somehow encoded inside you is a model of the world that you can interrogate and get an idea about what's going on. Somehow that must be true inside plants.

• 16:21Speaker 03

  It must be true inside bacteria, that somehow they must have some kind of, but now it gets very philosophical, some model that they use in order to work out how the world is working around them to respond to it. But it's gotta be, it's not resident in a brain.

• 16:49Speaker 04

  I'm Ali Khan Hemraj and I support StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson.

• 17:04Neil deGrasse Tyson?

  So the most aggressive plants we we've all learned from childhood is I guess the Venus flytrap? Is this?

• 17:11Gary O'Reilly?

  Oh, yeah, but that's got we see it visually and we fascinated by.

• 17:15Neil deGrasse Tyson?

  Fascinated.

• 17:16Gary O'Reilly?

  But I think someone's gonna tell us something that we don't readily understand about the Venus flytrap.

• 17:21Neil deGrasse Tyson?

  Really?

• 17:21Gary O'Reilly?

  Yeah. Bust my bubble here, but can the Venus flytrap actually count?

• 17:26Speaker 03

  Absolutely.

• 17:27Neil deGrasse Tyson?

  Ooh, don't say that like everybody knows that. What?

• 17:30Gary O'Reilly?

  Everybody in his lab knows that.

• 17:33Neil deGrasse Tyson?

  The way you said it, it's stupid. You didn't know that?

• 17:36Gary O'Reilly?

  He was talking to me, not you. Don't worry.

• 17:37Harrison Greenbaum?

  Is that a mouth? Does it go, what?

• 17:41Speaker 03

  So, but again, like again, it's like absolutely accounts. What does it mean to count?

• 17:45Gary O'Reilly?

  Yeah.

• 17:46Speaker 03

  And so that Venus flytrap, the trap thing is actually some modified leaves. Evolution has turned them into this amazing trap. It's crazy. It's awesome. You know, it shuts at our timescale, which is why it's fascinating to us because it moves sort of plant responses into something that that feels almost animal-like.

• 18:06Gary O'Reilly?

  How does it close like that at that speed then?

• 18:08Speaker 03

  It closes. So one thing's a blow your mind, it grows shut.

• 18:12Gary O'Reilly?

  What?

• 18:13Speaker 03

  Right, which just go like, that can't be true. It uses the machinery that elsewhere in the plant is used to make cells get bigger and to grow. And at the base of the trap are some very specialized cells which are just pumped up to incredibly high pressures of water. And we're talking about pressures that are in the realms of, you know, like 10 times the air pressure in your car tyre. Just amazingly pumped up, ready to go cells. And the machinery just kind of loosens up the walls around the cells so that they can expand incredibly quickly. And so that that lever in shut is cells getting bigger, which is irreversible change in size, which in the botanical world, we call growth.

• 18:57Speaker 03

  But the cool thing about it is you imagine you've got the Venus flytrap and the trap's open. And it's windy or something like that and a leaf falls into the trap. That'd be crazy for the plant to trap a leaf. But the trap responds to touch. It responds to a fly touching it. So what's happened is that there are little sensory hairs on the inner surface of the trap. And when a fly touches them once, the plant triggers a response, but it doesn't trigger the shutting of the trap. It triggers a chemical signal. If it touch, if the fly touches the hair again, within a timeframe, about 30 seconds, that then triggers a second reinforcing signal and that triggers the shutting of the trap.

• 19:42Speaker 03

  So in order to get the trap to shut, the plant has to count to two. I mean, it's the minimal counting you can imagine.

• 19:48Harrison Greenbaum?

  I think the minimal counting is one.

• 19:52Speaker 03

  So yeah, there's a chemical signal memory that's built up. When you get down to the machinery of it, it doesn't sound quite so magic, right? It's you trigger something, you get part almost to a threshold and then you trigger it again and you pass the threshold. But it is counting. It's accumulating two pieces of information.

• 20:11Gary O'Reilly?

  So Simon, do plants then begin to learn? And can they retain in a form of what we would call a memory?

• 20:19Harrison Greenbaum?

  Can they go from two to calculus?

• 20:21Neil deGrasse Tyson?

  I know.

• 20:22Gary O'Reilly?

  Not quite that.

• 20:23Harrison Greenbaum?

  Can we teach them algebra?

• 20:24Neil deGrasse Tyson?

  Algebra.

• 20:25Speaker 03

  They're not into complex differential equations.

• 20:28Harrison Greenbaum?

  They're like most teenagers.

• 20:30Speaker 03

  We will now firmly walk into the minefield of linguistic issues because we're going to talk about learning and memory and eventually it's you're just, you can't help but process it. Well, I know what memory is. I remember things and I know what learning is. I learn things. We'll keep that in the background. I'm just going to use those words because what else?

• 20:50Neil deGrasse Tyson?

  These are your disclaimers. We get that. So we don't think you're crazy new age person off a farm somewhere.

• 20:56Speaker 03

  No, I, I.

• 20:57Harrison Greenbaum?

  Now the, the long hair mustache and Hawaiian shirt are doing that. You look like if Weird Al saw a ghost and I love it.

• 21:04Speaker 03

  My disclaimer is just so that. You are like have that filter in there. So the like when we talk about, well, what does, what does memory mean? Does memory mean an event has occurred encoding it in your biology and then using that information later? If I define that as what memory is, right? Which may not be the memory that you're thinking about. You're thinking about the memory of emotions and stuff like that and past experiences. But if it was something happens, it's encoded within the biology and there is a response to it later on, or it changes other responses later on. That's what biology does. Like, that's how you survive as an organism is you adapt to what's going on around you. The world's constantly changing.

• 21:45Speaker 03

  We've already established it's not always a nice place. And so being able to change what you do with a history of what's gone on, that's just part of being alive. So plants do that, bacteria do that. The answer is yes. Yeah. But then when you start talking about memory, right? You begin to layer on all of these other things, which gets a little bit complicated. But if we just limit ourselves to that, plants had memory. Whether it's cold will determine what happens next many months down the road. So if you imagine, there are a bunch of seeds in the soil at the moment. Some of them have a very clever way of working out when they should germinate. They want to produce a little seedling in the spring when it's nice and warm. And so

• 22:27Speaker 03

  you could go, oh, that seed's just going to sit in the soil and it's going to wait for it to be nice and warm. But nice and warm increasingly is happening in the middle of winter and it gets cold again. So if all you did was not have any kind of concept of anything which is going on around you other than, oh, today it's nice and warm, I'm going to germinate, you'd make a tiny little seedling and then that seedling would freeze. So there are a lot of plants, the seeds go into the soil and they have to accumulate a long freezing cold period. And you can go, well, what they're doing is they're sensing that the temperature has got cold and they're remembering that it's got cold for a long

• 23:07Speaker 03

  period of time. And once that memory is established, then when it gets warm again, oh, now we're probably in the spring and we're not in that weird, you know, like it's got warm for three days and now it's minus 20 degrees again. So there's very clear that biology has memory at that level. Learning, again, that's a complicated one because generally in the world of learning. The learning that we immediately think about, again, it's sort of built into how we talk about it, is experiential learning, which is what we do, where we experience something, we take that information in, we process it, and then that helps us do something in the future. There's much less evidence for that sort of of process in plants.

• 23:52Speaker 03

  But again, we're talking about this experiential component of it, which is a very, very sort of animal-y human concept.

• 24:00Gary O'Reilly?

  So we're discussing here the internal systems of plants. But if we throw that out into the communal aspect of it, do they, and how do they, I'm guessing it's again biochemical, communicate between them, or do they have other strategies that they employ?

• 24:16Speaker 03

  Yeah, yeah, there's, there's no, no question that they talk to each other. Again, you're right, the chemistry is going to be the way they do it.

• 24:26Harrison Greenbaum?

  That's also how I communicate. With chemistry? With chemistry.

• 24:29Speaker 03

  You know, if you mow a lawn, there's that classic smell of new mown lawn.

• 24:34Harrison Greenbaum?

  Yeah.

• 24:35Speaker 03

  So what you're interacting then is with is the volatiles that have come from damaged plants. And we know chemically what those are. One of those is a group of chemicals based around hexadal. And, and if you smell those chemicals, just in a lab, in a chemistry lab, and you pulled out the, the hexadal thing and smelled it, it would totally smell of new mown grass. If you take that pure chemical and you treat a completely intact, undamaged plant with it, it will switch on a bunch of damage-related responses as if it was being attacked. Lawns really didn't evolve to be mown. When you cut them, they think they're being eaten, and so they switch on the damage-related stuff of being eaten.

• 25:19Harrison Greenbaum?

  So the smell is just a bunch of silent screaming?

• 25:22Speaker 03

  Yeah. Yeah, exactly.

• 25:24Harrison Greenbaum?

  All pleading for their lives, "No!"

• 25:26Speaker 03

  So take that chemical, treat another plant with it, it will switch on preemptive defenses. They have an internal stress hormone, a defense hormone called jasmonic acid, which is, you can, you know what it smells like, it's in a lot of perfume.

• 25:38Harrison Greenbaum?

  And what is that chemical? Jasmonic acid?

• 25:40Speaker 03

  Oh, yeah, so the, the, a large proportion will get switched on.

• 25:43Harrison Greenbaum?

  I only remember that because that's my drag name. Jasmonic acid. Jasmonic acid. Very good.

• 25:49Speaker 03

  So, chemical given off by damaged plant switches on responses in other plant. Is that plant, the original plant, communicating in the like ham radio way? Yeah, but I think we would, we would class it in a group of communication called eavesdropping. Which is that there's, there's no, it's very difficult to talk about it without making it sound human. There's no intent to pass information between those two plants. It's just like, go back to the lion chewing on your hand again. If the lion's chewing on your hand and you scream, you aren't using the scream to inform everyone else around you that the lion is chewing on you. But everyone else around you can use that information to understand what's going on.

• 26:33Speaker 03

  So that chemical sort of communication at that level, we, I think we would think that is this eavesdropping phenomenon, which is the information is useful and plants have evolved to use it. More plant to plant communication? Well, we know that, for instance, there are fungal bridges between plants that work underground. These things called mycorrhizal fungi. They help the plant, they're in an interaction with plant roots where the plant feeds the fungus, the fungus helps the plant.

• 27:04Neil deGrasse Tyson?

  Is this the same thing as the mycelium? The mycelium?

• 27:07Speaker 03

  Yeah, exactly the same thing. Yeah.

• 27:09Neil deGrasse Tyson?

  And, but you called it something else. What did you call it?

• 27:11Speaker 03

  Mycorrhizal fungus.

• 27:12Neil deGrasse Tyson?

  Mycorrhizal fungus, okay.

• 27:14Speaker 03

  I, it's probably like Latin or Swahili or something for fungus word.

• 27:19Neil deGrasse Tyson?

  Okay.

• 27:20Speaker 03

  But it's a very, very close association. It's one of the oldest associations, symbioses that we know of plants. It probably happened as soon as plants came onto the land. So, information will flow from plant to plant through that, that intermediary, through that fungus. But again, if we talk about communication, there is this sort of um language component to it where we're putting intent in there and that may not, that may not be the right sort of framework, but in what is happening there. It, it might just be, again, be eavesdropping. What about plants versus plants? Uh, so plants know that other plants are near them and they have other things other than the chemistry to do that. And one of them is light. So if you imagine the closer plants

• 28:05Speaker 03

  get to each other, the more one plant is absorbing light relative to the other, it actually changes the spectrum of light that that each plant is seeing because some of the spectrum is being absorbed, some of it's being transmitted. So the quality of light changes depending on how close you are to another plant. And one of the big agricultural uh, success stories, which is gonna sound a little like, is that all it is? But it's absolutely amazing. The reason that that corn crops have gone up, one of them, is that we can plant plants, the corn, closer to each other. And one of the things that's helped us do that is an understanding of this, this sort of proximity sensing that plants have around them and working out how to get around that so that we can basically

• 28:50Speaker 03

  shove the corn plants really, really close to each other.

• 28:52Harrison Greenbaum?

  I just scored so many points with my Nebraska in-laws that we went to corn. This is, this is fantastic. They're gonna be so excited. They really love corn there. They love it so much.

• 29:04Gary O'Reilly?

  So Simon, we've, we've discussed about plant smarts, intelligence, et cetera. But your lab, the famously named Gilroy Lab, um, does a lot of work with plants in space. And the very first day question is, do plants know they're in space if you do actually take them out there?

• 29:24Neil deGrasse Tyson?

  And just to be clear.

• 29:25Gary O'Reilly?

  Yes.

• 29:26Neil deGrasse Tyson?

  Generally, when we think of space, because we're trained to think this way, we think of a weightless environment.

• 29:31Gary O'Reilly?

  Yeah.

• 29:32Neil deGrasse Tyson?

  But if you, if you're either in a rotating space station or your rockets are firing.

• 29:37Gary O'Reilly?

  Yeah.

• 29:38Neil deGrasse Tyson?

  You could do that at one G. And so the space environment can be thought of as zero G and or regular G, but then other phenomenon, like you have to control the sunlight because you're not on a rotating earth, you know, so.

• 29:53Harrison Greenbaum?

  You're whipping, you're living around it.

• 29:55Neil deGrasse Tyson?

  Yeah. So how did you get interested in space? Did you go to space camp with?

• 30:02Neil deGrasse Tyson?

  With Harrison?

• 30:03Speaker 03

  I was that plastic plant.

• 30:05Harrison Greenbaum?

  Yeah, I took very good care of you for at least 30 minutes.

• 30:11Speaker 03

  As everyone will appreciate who's listened to this podcast, space is an awesome place.

• 30:16Neil deGrasse Tyson?

  Everything is funner in space, everything.

• 30:18Speaker 03

  Yeah, you can do awesome experiments you could never do on the surface of the earth. And for a biologist, it moves into a realm where there is no history for biology to draw on about how to deal with it, which is a very, very weird mental space to get to.

• 30:37Harrison Greenbaum?

  There is a movie, it's called Little Shop of Horrors, and that space plant was very dangerous.

• 30:42Gary O'Reilly?

  So, I mean, what are we confronted with as now, now I'm a plant, I've joined the group.

• 30:49Harrison Greenbaum?

  One of us, one of us.

• 30:52Gary O'Reilly?

  Not grown here. So radiation, you've got zero G, there's no up, there's no down.

• 30:59Neil deGrasse Tyson?

  Right.

• 30:59Gary O'Reilly?

  How are we working with our, with our light intake? Do we need water to grow plants once we're off world? What, go on, what are our challenges?

• 31:08Speaker 03

  So everything that you know, that if you're a gardener, everything that you know is important in space. So what do plants need? They need light, water, nutrients, they need something to grow into. All of that is going to be important, but we're going to move into a realm. And the one that we're concentrating a lot on at the moment is that microgravity, the zero G weightless environment. And then we're beginning to now transition to thinking about things like the surface of the moon. But if you think about the weightless environment, that's a very weird environment, you know, very annoying. A lot of times physics gets in the way of a good idea.

• 31:47Neil deGrasse Tyson?

  Deal with it, deal with it.

• 31:52Neil deGrasse Tyson?

  Physics is the ultimate judge, jury and executioner of your ideas. Just want you to know.

• 31:57Speaker 03

  And the executioner bit is the one that we're worried about. So a lot of things you take for granted on earth are going to be different in a weightless environment. And the one that just seems so trivial, but actually turns out to be a really, really big deal is water. Because on earth, you know, if I say, think of flowing water. Almost inevitably, the picture in your mind is going to be something that's driven by gravity. It'll be a river flowing or the ocean and tides and waves. And we're going to remove that. And so the characteristics of water in space is it the molecular forces within water take over. Things like hydrogen bonding and stuff like that. But the great way to think about it is that in space, water is creepy and sticky.

• 32:39Speaker 03

  So it wants to stick to surfaces and it wants to creep over surfaces. So imagine I just do a thought experiment. If you've got your plant in a pot and you're going to water it and you've got your watering can. Well, first of all, you turn the watering can aside, nothing comes out because you can't pull the water out with gravity. So I'll give you a syringe and you can squirt the water into the soil and that will totally work. But now, rather than just sort of sitting in the soil and being drawn down as it does on earth, the water is going to stick to the soil particles and then capillary forces are going to take it over the surface of the soil. Then it's going to hit the roots. It's going to stick to the root and then creep over the surface of the root. And if you add too much water, and let's be honest, everyone overwaters their houseplants.

• 33:24Harrison Greenbaum?

  I feel like you're looking directly into my soul when you say that. Like on behalf of all the other plants, stop.

• 33:32Speaker 03

  And you know what happens if you overwater your plants? They're very unhappy and so sticky water encases the plant.

• 33:39Neil deGrasse Tyson?

  So when you say sticky, this is surface tension and capillary action?

• 33:42Speaker 03

  Absolutely, yeah.

• 33:43Neil deGrasse Tyson?

  Okay, okay.

• 33:44Speaker 03

  Yeah, like you say, physics is getting in the way of a good idea. I just want to water my plant and now I've got surface tension and capillarity, which have become the dominant forces.

• 33:55Gary O'Reilly?

  So can you grow plants without water then? If water's such a pain in the butt, can we?

• 34:01Gary O'Reilly?

  Yes, there's another word. Can you grow plants without using water?

• 34:06Speaker 03

  So if there is one.

• 34:10Speaker 03

  Fundamental feature of biology and it dominates how biology works on the earth. And it is one of the the guiding principles of when we send probes out to find life. Liquid water is part and parcel of the biology that we understand. And we don't know how to do biology without water. So unfortunately, we're stuck with water.

• 34:34Gary O'Reilly?

  Sticky and creepy.

• 34:35Speaker 03

  Yeah.

• 34:36Gary O'Reilly?

  There's so many jokes I want to make. Well, don't hold back, go for it. Really, I mean, if you just think about getting off of earth and going into a low earth orbit, going into space, we are going to have to find lunar water. We're going to have to find other solutions off of this planet. Otherwise, you're just dealing with a payload because you can't be bringing dirt, tons of dirt to grow things on any sort of industrial scale, not a chance.

• 35:04Speaker 03

  Yeah, I think at the moment it's feasible because we're very, very much in the sort of exploratory world of like, how are we ever going to do this? What happens to biology when it's in space? And we can deal with, you know, the plant growth facilities that we have on the space station are awesome, but they are two feet by two feet by two feet. And feeding the crew may not be the the eventual goal, like self sustaining, completely self sustaining with plants, but getting to the fresh fruit and vegetables thing where it supplements a lot of the the freeze dried food. That may be in our, like, at least in the near future. But psychologically as well, growing plants turns out to be quite a big deal.

• 35:44Speaker 03

  Being in a spacecraft, if you're an astronaut, astronauts absolutely the most awesome job in the world. But you're in a built environment, you're in a very small enclosed space for many, many months. And you're with, let's say, five of your closest friends.

• 36:03Speaker 03

  And at the end of that journey, you might only have zero close friends left, right? It's just such a hard, hard environment at a psychological level. And it's very built and, you know, on the space station, you can see the earth, but you can't get back. You know, and, and so growing plants at a psychological level, that may be the only justification that you need in order to take plants with you on a long journey is that they are very, very calming. And nurturing something and growing it and then eating it. I mean, that, that would be a pretty awesome goal for an astronaut.

• 36:36Neil deGrasse Tyson?

  Okay, so naively, coming to this as a physicist, you just put a seed in the soil and it grows, right? So in zero G, how does it know what direction to send a root versus what direction to send the leaf? A, B, when you get to the moon, that's not soil. And earth soil is full of nutrients and microbes and, and there's a whole relationship that the plant has with what's going on already in the soil, not so much on earth or Mars. So what's your plan to feed astronauts on the space, not, not only on the space station, but on, on world?

• 37:21Neil deGrasse Tyson?

  What'd you say, on world, off-world, off-world?

• 37:24Speaker 03

  Yeah. Biology is awesome. Biology is incredibly robust. Plants grow okay in space, in that microgravity world. And the shoots grow in the direction of the light, so that's an easy one. And, you know, we, we build growth chambers into space that are like growth chambers on the earth with lights at one end. We'll call that the top.

• 37:43Neil deGrasse Tyson?

  Wait, wait, wait. If it's in the soil, how does it know which way the light is if it's buried in the soil?

• 37:48Speaker 03

  The roots have a random distribution. So as the roots go through the soil, that directionality is completely lost.

• 37:55Neil deGrasse Tyson?

  How are you sensing light if you were covered in dirt?

• 37:58Speaker 03

  How deep do you plant?

• 38:03Gary O'Reilly?

  You're planting, you're burying.

• 38:04Speaker 03

  Light penetrates soil quite deeply.

• 38:07Neil deGrasse Tyson?

  Okay.

• 38:07Speaker 03

  Especially red light. So there is, there's a gradient.

• 38:10Neil deGrasse Tyson?

  There's your answer. Okay.

• 38:11Speaker 03

  Uh.

• 38:11Neil deGrasse Tyson?

  This is my answer. Okay.

• 38:12Gary O'Reilly?

  So, okay, so.

• 38:13Neil deGrasse Tyson?

  Fine, thank you.

• 38:14Gary O'Reilly?

  We're talking about earth soil and I think having decided we're now lunar based or using regolith, lunar regolith. Um, what are the challenges when you're saying, well, there are zero microbes or there are lunar microbes and there's no what we would classically define as dirt, there's just this rubble. So how, how, how is that experiment coming along?

• 38:36Speaker 03

  So growing in lunar regolith is, like for plants, is challenging at, partly at a nutrient level. So you know, there's, there's a lot of the nutrients that plants would need, but it's locked up in chemical forms which are not immediately accessible.

• 38:51Gary O'Reilly?

  Right.

• 38:51Speaker 03

  So you could imagine you might chemically process that lunar regolith or you might use microbes and, and you know, seed some regolith with the microbes that then turn over the rock and then make it available to the plants.

• 39:04Neil deGrasse Tyson?

  Hmm.

• 39:05Speaker 03

  One of the biggies, which is a, it's a limit to a lot of plant growth on earth is nitrogen. So biologically available nitrogen, form of like nitrates or ammonia. Uh, that's what plants want to take up and there is zero biologically available nitrogen in regolith on the moon. There is nitrogen there, it's been deposited, but it's just not in that nitrate ammoniary sort of chemical form that plants could take up.

• 39:31Neil deGrasse Tyson?

  Okay. So on Mars, which is also has equally hostile surface chemistry, we learned from Mark Watney in the movie The Martian, that you, you just, just slap some poop in there and, and put a little seed in it.

• 39:50Gary O'Reilly?

  It took us how long to get here?

• 39:53Harrison Greenbaum?

  I was on a countdown as soon as he mentioned nitrogen. I was like, the poop is coming.

• 39:57Neil deGrasse Tyson?

  The poop is coming. So you, you want fertilizer? He made poop potatoes. So can, can you, and he was a botanist. He was an authentic botanist. Even though he was an actor playing a botanist. He was a botanist. So how authentic was that solution to his food problem?

• 40:14Speaker 03

  If only that had been a documentary, it would have been awesome.

• 40:19Speaker 03

  There's a lot of good stuff there in, in like the science behind it. Take human waste, you can compost it and process it and you can turn it into fantastic nitrogen rich fertilizer. That, that's all done by microbes, but you know, human waste has a lot of microbes in it. You have to process it. You can't use raw human waste at many, many levels. One of them is the, you know, the reason we don't use raw human waste is there's a tremendous possibility of getting parasites and things like that in it. And you know, they're by definition, they're going to be bad for humans. So that's one reason. And the other is that it's an incredibly concentrated form of all of those bioavailable nutrients and you need to process it.

• 41:01Speaker 03

  So imagine that there was composted, that would work, but you know, composting is going to take some time. The other aspect of it is I seem to remember he shoveled Martian regolith into the habitat and then just planted in that. And there are some issues with Martian regolith, which are more than just it doesn't have all of the nutrients. It's very salty, which is generally bad for plants, but it also is very high in a group of chemical called perchlorates. And perchlorates are toxic. They're toxic to people. Um, so you can totally go down the poop road. Um, it's not far fetched. It requires some work.

• 41:40Harrison Greenbaum?

  Down the poop road is the name of my next comedy special. Yeah, that's just, that's a Flip for it on Disney plus. Yeah, that's a keeper.

• 41:48Neil deGrasse Tyson?

  So what you're saying is, and I, and I grant sort of hall passes to movies. In this way all the time. What you're saying is, he meant well in this intent. So you give it to him because you had to think about fertilizer. You had to know that the Martian soil was not, was hostile to plant life. And so all the rest of those details, you, you would give him a pass on that. Because he, he went there at all in the storyline. Is that, is that fair?

• 42:16Speaker 03

  That is absolutely fair. And also he gets a, a lifetime pass because he made botany cool.

• 42:21Neil deGrasse Tyson?

  Yeah.

• 42:22Speaker 03

  Um, and that, that is a feat.

• 42:24Neil deGrasse Tyson?

  Yeah. He said the attractiveness for Astro Botanists very high. Yeah. No, it's an interesting point because I take for granted that any space movie is going to have physicist and astrophysicist in it. Mm-hmm. So we're, we're in all the movies, but you got a botanist like, where did he come, who ordered that?

• 42:41Gary O'Reilly?

  Well, see, look, I mean, the, the question now becomes, do we need in our future generations to become space farmers? And

• 42:49Neil deGrasse Tyson?

  Therefore we would need Astro Botanists.

• 42:51Gary O'Reilly?

  Then we're gonna need these guys.

• 43:12Gary O'Reilly?

  Now you work with NASA's Gene Lab, correct? With some of your experimentation?

• 43:17Speaker 03

  Yep.

• 43:18Gary O'Reilly?

  So are we, are we looking at our own experimentation with plants here on Earth? So for things that are drought resistant, fire resistant, you know, work in extreme conditions. Has that empowered the sort of experimentation you're thinking about bringing to space?

• 43:37Neil deGrasse Tyson?

  Cause we have a lot of variation of conditions here on Earth, plants. Plus, why is it that all it takes to grow a perfectly healthy plant is a crack in the pavement?

• 43:48Harrison Greenbaum?

  That's a fair point.

• 43:48Neil deGrasse Tyson?

  Answer me that.

• 43:49Harrison Greenbaum?

  If a plant can survive in New York, it can survive on Mars.

• 43:52Speaker 03

  Anyway.

• 43:53Neil deGrasse Tyson?

  Thriving in the crack of the pavement. I'm saying, take that, transplant that into the space and then, then you get something good there.

• 44:01Speaker 03

  We're in the era of big data and so NASA has, what Gene Lab is, is basically a data repository where a lot of data sets just are being brought together from around the world. A lot of things like, we have technology which will allow us to ask in an organism, which genes get switched on and which genes get switched off in space? Across every single gene that that organism has. So, one answer to that question of how, how are we sort of navigating this world towards a space crop is, we're, we're still in the discovery phase of trying to work out what happens to biology in space. So we're getting all of this sort of characterization that's coming back and we're using that to go,

• 44:46Speaker 03

  well, what do we think happened to these plants while they're in space? Did they feel like, that was in the fuel. Did they feel like they were, um, they were under drought conditions? Did they feel like the light was high or low? You know, and we're getting that sort of, of landscape and then we can go to plants that exist on Earth and go, well, do we have plants that deal with that? And is this a characteristic that we can sort of take and then build into a space crop world? And then the other aspect of it is that it doesn't matter how great the plant is. If the goal is for an astronaut to eat it, there's a food science component of it. They want to have to want to eat it. You know, being in space is tough.

• 45:30Speaker 03

  Astronauts tend to have suppressed appetites, you know, and having something which is like, just the, absolutely the freshest, best thing that they want to eat is another component of it. And so we have to bring in all of these, these various aspects of what a successful space crop is going to be.

• 45:47Harrison Greenbaum?

  Oh, do we know if like a space tomato though tastes like a Earth tomato? Like do that, do they taste the same if we grow them in space?

• 45:54Neil deGrasse Tyson?

  They taste like space.

• 45:59Speaker 03

  So I think we know that chillies grown in space, they've been grown through an entire crop to harvest the chillies. Those chillies pretty much taste like chillies. The tomatoes, I don't think, they have been tomatoes that have been grown in space. I don't think we know what they taste like.

• 46:19Neil deGrasse Tyson?

  It tastes like tomatoes, not tomatoes.

• 46:23Gary O'Reilly?

  Sorry, sorry. Tomato.

• 46:25Harrison Greenbaum?

  Yeah, their box is made of aluminium.

• 46:28Speaker 03

  Yeah.

• 46:28Gary O'Reilly?

  Thank you. See what you did.

• 46:30Neil deGrasse Tyson?

  Yeah.

• 46:32Gary O'Reilly?

  So you get polymorphism in animals, Simon.

• 46:34Harrison Greenbaum?

  Polymorphism, that was also my drag name. Polymorphism.

• 46:37Gary O'Reilly?

  You've reinvented yourself so many times.

• 46:40Neil deGrasse Tyson?

  I forgot, what is polymorphism?

• 46:41Gary O'Reilly?

  So when you get a species and all of a sudden you'll look at, say, three birds next to each other. They'll be the same bird, but they'll be different colorations. So do you, do you get that in plants? And is that any benefit to the research? So all of a sudden it reinvents itself and one of those three could become something that has a benefit to conditions that you're experiencing.

• 47:02Neil deGrasse Tyson?

  This is, these are the forces of natural selection.

• 47:04Gary O'Reilly?

  Correct.

• 47:04Neil deGrasse Tyson?

  In this case.

• 47:05Speaker 03

  So at an individual level, plants show a form of, of sort of growth and development that we call plastic.

• 47:12Gary O'Reilly?

  Ah.

• 47:12Speaker 03

  We have very rigid growth, like your parents knew exactly what you were gonna look like when you grew up.

• 47:18Harrison Greenbaum?

  Did they?

• 47:21Harrison Greenbaum?

  Did your parents know you were gonna look like Weird Al if he saw a ghost?

• 47:25Speaker 03

  They knew I had one head, two arms, two legs.

• 47:28Neil deGrasse Tyson?

  There it is, there it is.

• 47:29Speaker 03

  But for plants, you can't necessarily predict how many branches and, you know, they, they, they, their growth is sort of entrained to the environment. Right? So we call that plastic. They sort of, they're malleable in how they're gonna grow.

• 47:40Neil deGrasse Tyson?

  Right. You're not gonna grow a third arm just because you needed one.

• 47:43Harrison Greenbaum?

  I mean, that would be incredible.

• 47:45Speaker 03

  Exactly, yeah.

• 47:46Gary O'Reilly?

  So the other, the other thought now, we were talking about the polymorphism is if you've got, you're on an exoplanet, you wanna grow stuff, plants that have been green, do they, because of an atmospheric change, a soil change, they're no longer green, they go red, or they change to a different, different color? Is that a plausible development in these areas, in these environments?

• 48:06Speaker 03

  I think with the, how photosynthesis works.

• 48:10Speaker 03

  We have a pretty good idea of the molecular underpinnings of that. It's an amazing machine, like mind blowing machine.

• 48:16Neil deGrasse Tyson?

  Yeah.

• 48:16Speaker 03

  I would guess it's difficult to think that those fundamentals will change. Like our, moving our Earth biology onto Mars, for instance. This would just be kind of the way I would imagine it. I think photosynthesis is going to be photosynthesis.

• 48:30Neil deGrasse Tyson?

  Let, let me come at it from a slightly different angle. I agree. Photosynthesis is going to be photosynthesis. It's a highly successful way to convert light into all of your energy needs. Got it. But as we go forward, as we have greater and greater command over the genomes of life, what is to prevent you and your brethren from just creating a life form? By gene editing, gene stitching, gene assemblies? And to create a life form that can eat the regolith? That can eat the, that can thrive without, you know, in UV? But why, what's to prevent that from being the future? Rendering all of these experiments obsolete? Because you're just creating the life form you need.

• 49:15Speaker 03

  So that might sound sci fi, but the idea of being able to engineer traits.

• 49:21Neil deGrasse Tyson?

  Yes.

• 49:21Speaker 03

  That, that's real modern palm biology.

• 49:24Neil deGrasse Tyson?

  That's real, that's going on now.

• 49:25Speaker 03

  Sci fi at all. So you could imagine that we might be able to take the basic machinery of photosynthesis and hook some different pigments into it? In order to power it with a different part of the spectrum of life? That is engineering built around a piece of biology that already exists. And that's totally doable.

• 49:44Neil deGrasse Tyson?

  Say it, it's called GMO. Say it. You're genetically modifying organisms, okay? You don't want to say it, I'll say it.

• 49:51Speaker 03

  Uh, no, it is genetically modifying, modifying. English is now my second language. Genetically modifying organisms.

• 50:01Gary O'Reilly?

  So if we're genetically modifying, are we then ultra reliant upon the development of microbes to be equally as beneficial in these environments?

• 50:12Neil deGrasse Tyson?

  Oh, because it needs the whole rest of the, the ecosystem.

• 50:15Gary O'Reilly?

  There you go.

• 50:16Neil deGrasse Tyson?

  Oh, yes.

• 50:18Speaker 03

  So you can grow plants under sterile conditions and they'll they'll survive. But the really stable biology is ecosystems where there's, uh, forget the animals. You know, do you really need them like microbes and plants working together? That's how a lot of the stability is built into ecosystems on it. I mean, the animals are important as well.

• 50:39Neil deGrasse Tyson?

  I think everybody wants a space dog. This is part of the challenge with bringing back the mammoth. You can bring back the mammoth, but how about what the the plants, the mammoth ate? Which are all extinct today and other things in the mammoth environment. You know, plonk them into today's. We have very lonely, confused. Tweakers, you know, whatever.

• 51:00Neil deGrasse Tyson?

  So I'd I'd like the idea of photosynthesis using other wavelengths of light. That that's brilliant. That'd be one interesting.

• 51:08Gary O'Reilly?

  But we have plants on earth that do that anyway, do they not?

• 51:11Speaker 03

  Yeah, yeah, we have plants that make different pigments that feed into that basic machinery. Yeah.

• 51:17Gary O'Reilly?

  So it's the blueprint, pun intended, is is is basically there to be developed if if that's what's required. Is that right?

• 51:25Speaker 03

  Yeah, these are the ideas. These aren't sci fi ideas. These are ideas which are being played out as we're talking now.

• 51:31Neil deGrasse Tyson?

  All right, so just to bring some closure to this, it's not good enough if you're going to serve the needs of astronauts to make a plant that we can all admire. You want to make a plant that they can eat. So we're talking tomatoes, we're talking watermelon. Tomatoes. Tomatoes.

• 51:46Gary O'Reilly?

  Thank you.

• 51:47Neil deGrasse Tyson?

  We're talking watermelons, mangoes. Is that a pipe dream? Or you're going to make some kind of plant that has all the proper nutrients, but tastes nasty? Like, we shouldn't have space kale. Nobody wants to go to space. Just to eat kale. That would be, what's the point of going to Mars if that's all that's there? I'm staying on earth. Yeah, I'm staying on earth.

• 52:09Speaker 03

  This is going to be very disappointing for you, Arizona.

• 52:11Neil deGrasse Tyson?

  Oh, no.

• 52:12Speaker 03

  Kale is a target crop.

• 52:14Gary O'Reilly?

  Oh, why? Hilarious. Someone has a sense of humor, perfect.

• 52:19Neil deGrasse Tyson?

  Okay. Do you also have space garlic or something to change the taste? I ain't going to space. Yeah, no, thank you. What, what, how about mushrooms? How about mushrooms?

• 52:26Speaker 03

  Yeah, yep, yep. Mushrooms, but tomatoes are tomatoes. So they're a target crop as well. Biology is an immensely powerful force and it has shaped organisms to be really, really good. We're moving them into a, like this weird environment of space. But throwing away millions and millions of years of evolution of making organisms like affected is a crazy strategy, I think. We should capitalize on what we've got. So the

• 52:53Neil deGrasse Tyson?

  Yeah, okay.

• 52:54Speaker 03

  The crops which are going to be manipulated are gonna be the crops that we're used to. And also, why would you want to engineer crazy crop? That is not like, almost like the comforting crops are home. If we're thinking of people on Mars there for multiple years, there is that element of the psychology of being there, which is fantastically important. And I, I just think that the, you know, there are some things that you would like to take with you and maybe parts of your cuisine are gonna be part of that.

• 53:24Harrison Greenbaum?

  Kale, kale is not one of them. That, there's no, nothing comforting about. So now, now I'm like, oh, thank God for kale here.

• 53:31Gary O'Reilly?

  Space chicken, space cattle, space lamb.

• 53:35Harrison Greenbaum?

  I will take whatever weird GMO plant over kale.

• 53:41Neil deGrasse Tyson?

  And just, just to verify, you can grow mushrooms, right? I mean, I, I, I would go for portobello mushrooms.

• 53:47Harrison Greenbaum?

  Ooh, that, that I'm into.

• 53:48Neil deGrasse Tyson?

  Grill, grill portobello, I'm good.

• 53:50Harrison Greenbaum?

  Absolutely.

• 53:51Neil deGrasse Tyson?

  Yeah.

• 53:51Speaker 03

  No. I mean, the steak that goes with it might be problematic.

• 53:56Neil deGrasse Tyson?

  All right. So Professor Gilroy, we learned a bunch.

• 53:59Gary O'Reilly?

  Yeah.

• 54:00Neil deGrasse Tyson?

  And as a minimum, I learned that there's such a thing as an astrobotanist.

• 54:03Gary O'Reilly?

  Yes.

• 54:04Neil deGrasse Tyson?

  We love that. And it gives us hope for what may be the spacefaring future of civilization, not just the chosen few who get to visit that domain. Because what has always been true and will continue to be true, Earth's surface is the shoreline of the cosmic ocean.

• 54:25Harrison Greenbaum?

  Ooh. And kale is a seaweed.

• 54:31Neil deGrasse Tyson?

  Let go of the kale. There's too much of it and it doesn't taste good.

• 54:37Neil deGrasse Tyson?

  All right, this has been a delight. And Harrison, we'll find you on the road. Yeah, HarrisonGibbub.com. I got tour dates, I'm running around. Taking the show on the road. Yeah, absolutely. All right. Gary, always good to have you, man. Pleasure, my friend. All right, this has been StarTalk Special Edition, the poop potato. I would take that over kale.

• 54:57Neil deGrasse Tyson?

  Until next time, I am Neil deGrasse Tyson, your personal astrophysicist. Keep looking up.