Speaker 1: Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2: Hey, welcome to Stuff to Blow Your Mind. My name
Speaker 2: is Robert Lamb.
Speaker 3: And I'm Joe McCormick, and today we are coming back
Speaker 3: with part two in our series on stickiness. This is
Speaker 3: a topic I got interested in after feeding my ten
Speaker 3: month old various fruits and fruit based smoothies and stuff,
Speaker 3: and noticing the way that a kind of stealth stickiness
Speaker 3: can easily migrate outside of the direct vicinity of eating
Speaker 3: and contaminate surfaces beyond. There's a kind of stickiness fallout
Speaker 3: effect after the initial meltdown. Rob I think you said
Speaker 3: last time, you've had similar experiences.
Speaker 2: Oh, yes, and I'm still finding sticky spots in the house,
Speaker 2: you know. Now here's a question about your daughter. Has
Speaker 2: she used the stickiness to scale walls yet?
Speaker 3: No, she has not figured this out yet, but she's
Speaker 3: crafty and I think she could be getting there very soon.
Speaker 2: More on wall climbing in a bit.
Speaker 3: Yeah, the creature will not be contained. But so in
Speaker 3: the last episode we started off talking about difficulties and
Speaker 3: even defining stickiness rigorously. This is one of those subjects
Speaker 3: where I expected there to be a pretty simple, straightforward,
Speaker 3: well understood physics or chemistry answer to what makes things sticky?
Speaker 3: And it turns out no, the answer is super complex
Speaker 3: and in some ways not fully understood, and we'll be
Speaker 3: talking more about that some at the beginning of today's episode.
Speaker 3: But in the last episode we also discussed one of
Speaker 3: the most glorious of sticky foods, glutinous rice aka sticky
Speaker 3: rice aka sweet rice, the unstoppable amylopectin avalanche.
Speaker 2: That's right, I hope if nothing else, we inspired everyone
Speaker 2: out there to seek out some sticky rice or sticky
Speaker 2: rice derived food products in wake of listening.
Speaker 3: Did you have some sticky rice over the weekend after
Speaker 3: we did the episode?
Speaker 2: I had some mochi, and I really I think it
Speaker 2: enhanced my enjoyment of the mochi, and I'm looking forward
Speaker 2: to having sticky rice the next opportunity I get nice.
Speaker 3: Well, today, we wanted to further explore the concept of stickiness,
Speaker 3: and one place I wanted to start was with a
Speaker 3: chapter in a book that I've been reading. It's a
Speaker 3: very good book called Sticky The Secret Science of Surfaces
Speaker 3: by Laurie Winkless. This is a popular science book from Bloomsbury,
Speaker 3: twenty twenty three. So this is just recently published. And
Speaker 3: this book is not just about stickiness. It's about all
Speaker 3: different kinds of surface interaction, so it covers slipperiness and
Speaker 3: friction and all that stuff too. But there is a
Speaker 3: great chapter early in the book about stickiness. And this
Speaker 3: book is full of interesting stuff about the world that
Speaker 3: I never thought of before. For example, in this chapter
Speaker 3: on stickiness or adhesion, Winkless is talking about how oil
Speaker 3: based paints are made. Typically, so an oil based paint
Speaker 3: is usually going to be a solid pigment of some kind,
Speaker 3: little colored particles that are suspended in a liquid medium
Speaker 3: that might be something like linseed oil. And then it'll
Speaker 3: also have additives in it that will be things like
Speaker 3: stabilizers to help thicken the mixture and disperse the pigment
Speaker 3: particles evenly. But the thing that really caught my attention
Speaker 3: is she gets to an interesting fact, which is when
Speaker 3: you use an oil based paint. Maybe you're painting a
Speaker 3: painting on a canvas with some oil based paint. What
Speaker 3: do you do when you're done painting? You let it dry.
Speaker 3: We say that it dries, but actually the paint does
Speaker 3: not dry drying would mean that it loses moisture through evaporation,
Speaker 3: but moisture does not leave the oil based paint. Instead,
Speaker 3: what oil based paints do is polymerize. This is sometimes
Speaker 3: called curing. So instead of losing water molecules to the
Speaker 3: air through evaporation, these paints steal oxygen from the air
Speaker 3: and use that oxygen to form bonds between molecules, which
Speaker 3: allows the paint to harden into a solid film and
Speaker 3: form these layers of hard solid films. And because oil
Speaker 3: based paints remove oxygen from the air rather than drying
Speaker 3: by losing moisture, they actually get heavier, not lighter, as
Speaker 3: they cure. So Winkles says that paints based on linseed
Speaker 3: oil can sometimes increase their weight by over fifteen percent
Speaker 3: during curing, so a painting would be heavier after it's
Speaker 3: dry than when it was wet if you use one
Speaker 3: of these paints. Now you can contrast this to water
Speaker 3: based paints, which actually do dry by losing moisture, and
Speaker 3: these will leave behind only the solid pigments held in
Speaker 3: place by binder compounds. So when you buy a can
Speaker 3: of water based paint, most of the volume of that
Speaker 3: can is not actually going to end up on your wall.
Speaker 3: It will instead evaporate. And in illustrating this, she writes,
Speaker 3: quote Colin Gooch, technical director of paint manufacturer Racine, told
Speaker 3: me that a four liter can of high quality waterborne
Speaker 3: paint might contain just over one point five leaders of
Speaker 3: volume solids. That's what actually forms the film that stays
Speaker 3: on the surface. The job of the other two point
Speaker 3: five leaders is to keep those solids dispersed. It allows
Speaker 3: us to carry the pigment from the can to the wall.
Speaker 2: This is crazy. I'd never thought about this before either.
Speaker 2: It makes me wonder if I were using oil based
Speaker 2: paints in painting minis instead of the acrylic paints that
Speaker 2: I use. Like what the difference would be like all
Speaker 2: the you know, sort of the fine art of the thing.
Speaker 2: Do you have to factor that in to how much
Speaker 2: paint you're applying. I don't know. I'd love to hear
Speaker 2: it doesn't out there with experience painting anything, you know,
Speaker 2: minis or canvas or houses.
Speaker 3: Yeah, the book doesn't get into how the material the
Speaker 3: differences and the materials affect the craft itself, but I
Speaker 3: expect they probably do.
Speaker 2: Yeah.
Speaker 3: But anyway, coming to the more general topic in the
Speaker 3: same chapter of What Stickiness Is, I wanted to talk
Speaker 3: about some of the things that Winkless explains here. And
Speaker 3: there are two very important concepts for stickiness. One is
Speaker 3: adhesion and the other is cohesion. Adhesion is the attraction
Speaker 3: between two different materials, and it's defined usually by the
Speaker 3: work or the effort that it takes to separate the
Speaker 3: two materials. And then cohesion is the attraction of a
Speaker 3: material to itself. How the molecules of the substance, how
Speaker 3: well they stay stuck together to each other. Now, to
Speaker 3: discuss the different physical models of adhesion, how two different
Speaker 3: substances stick together, Winkless starts by imagining a hypothetical interface
Speaker 3: between two different things. So you imagine a drop of
Speaker 3: some kind of liquid, some kind of adhesive liquid, sitting
Speaker 3: on top of a clean, flat block of solid material.
Speaker 3: So you can think of a drop of water sitting
Speaker 3: on a piece of wood, or a piece of metal,
Speaker 3: or a drop of whatever of glue. You know you're
Speaker 3: going to be measuring how well this thing adheres. And
Speaker 3: coming back to the level of uncertainty that I've found
Speaker 3: surprising in this subject, she writes that the general consensus
Speaker 3: is that there are quote three or four ways that
Speaker 3: these materials could interact.
Speaker 2: Yeah, this is a familiar thread, it seems that one
Speaker 2: finds when you start researching stickiness is that, Yeah, we
Speaker 2: don't necessarily know On one l hand, we might not
Speaker 2: necessarily know like the one thing that is making something stick,
Speaker 2: and it may more honestly be various things, and there's
Speaker 2: disagreement on to what extent each thing is contributed to
Speaker 2: the stickiness.
Speaker 3: That's right. So the first one of these models of
Speaker 3: interaction for adherents is chemical adherents, and this means there's
Speaker 3: an actual chemical reaction. There are molecular bonds between the
Speaker 3: adhesive and the surface, so some kind of reaction has
Speaker 3: taken place, resulting in essentially a new compound where they
Speaker 3: meet and winkless. Here uses the example of paint. Quote.
Speaker 3: In paint, this sort of adhesion is enabled by the
Speaker 3: binder molecules that surround the pigment particles. So the pigment
Speaker 3: particles are the little solid particles that give the paint
Speaker 3: its color, and then they have these binder molecules that
Speaker 3: surround those pigment particles and help stick them to the surface.
Speaker 3: She says, quote they react with molecules on the surface
Speaker 3: sharing and borrowing electrons, effectively forming a new compound at
Speaker 3: the interface. So this is actual chemical interaction here. Second
Speaker 3: model of action is mechanical adhesion. Here there's not a
Speaker 3: chemical reaction going on between the adhesive and the surface. Instead,
Speaker 3: Winkless uses the analogy that one sticks to the other,
Speaker 3: like the way a rock climber clings to the surface
Speaker 3: of a cliff by like sticking fingers and toes into
Speaker 3: cracks and crevices in the rock. So the drop of
Speaker 3: the adhesive wants to stick to itself. Of course, it
Speaker 3: wants to stay intact, much like the rock climber's body
Speaker 3: wants to stay intact and stick to itself. And parts
Speaker 3: of this adhesive are jammed into recesses in the surface
Speaker 3: of the solid material. Now you might think, well, okay,
Speaker 3: but what about smooth surfaces. And the fact is that
Speaker 3: basically all surfaces, even if they're pretty smooth as far
Speaker 3: as you can tell at the macro scale, they've got
Speaker 3: lots of little irregularities when you zoom in. If you
Speaker 3: get a high sensitivity microscope, you can zoom in and
Speaker 3: see mountains and ravines the microscale, most surfaces you will
Speaker 3: find in the real world are like this. Third model
Speaker 3: of adhesion is diffusion. This typically happens when the solid
Speaker 3: material in the scenario is a polymer, for example, rubber
Speaker 3: or cellulose or nylon. There are lots of different kinds
Speaker 3: of polymers in the world, and structurally, polymers are long
Speaker 3: molecules with a repeating structure, sort of like the links
Speaker 3: in a chain. In diffusion, these long chains can sort
Speaker 3: of intermingle and tangle with several nanometers of material on
Speaker 3: the other side, on the other object or the other substance,
Speaker 3: even though they're not reacting chemically. And this might be
Speaker 3: a kind of crude analogy, but for a rough picture,
Speaker 3: just sort of like imagine surfaces that have a bunch
Speaker 3: of chains and ropes and strings at the edge of
Speaker 3: them getting tangled up with the edge of the other object. Now,
Speaker 3: remember you said there were three or four. This last
Speaker 3: one seems more debatable, but Winkless notes that the adhesive
Speaker 3: product manufacturer three M also identifies a fourth possible type
Speaker 3: of adhesion, and this is electrostatic. Sometimes, if you are
Speaker 3: about to attach a strip of adhesive tape to a
Speaker 3: piece of paper, you will see the paper actually kind
Speaker 3: of move through the air like it's reaching out toward
Speaker 3: the tape. You know, they want to you know, it
Speaker 3: wants to be found, like the one ring, and it's
Speaker 3: kind of like it's being attracted by a magnet because
Speaker 3: it's sort of is This is because the tape accumulates
Speaker 3: charged particles as you peel it off of the roll,
Speaker 3: and there is attraction due to static electricity there same
Speaker 3: reason you know, you get static electricity on a balloon
Speaker 3: or something and then it lifts your hair off of
Speaker 3: your head.
Speaker 2: Yeah, or occasionally in that scenario where there's some little
Speaker 2: bit of plastic garbage or packaging that you are trying
Speaker 2: to throw away and it just clings to your hand
Speaker 2: and you can't fling it away, even though there's obviously
Speaker 2: nothing sticky on your hands. You weren't just messing around
Speaker 2: with glue, you haven't, you know, you've washed your hands.
Speaker 2: But yeah, it's sticking to you because of the static.
Speaker 3: So that is a real force. But Winkles says that
Speaker 3: she doubts whether this should really be considered a true
Speaker 3: adhesive force that like meaningfully sticks objects together, because while
Speaker 3: it might cause an initial attraction, this is not really
Speaker 3: what would like hold a you know, an adhesive tape
Speaker 3: firmly to the paper, what prevents it from peeling off?
Speaker 3: But it's important to note she says that no single
Speaker 3: one of these forces fully explains stickiness, and she writes quote,
Speaker 3: for any given adhesive product, it's almost impossible to determine
Speaker 3: exactly which model or models might be operating.
Speaker 2: That's that's interesting just even to think of in terms
Speaker 2: of hobbyists, you know, because there's so many different types
Speaker 2: of glues, and you get into any given hobby, you
Speaker 2: might think, well, all clues are the same, but of
Speaker 2: course they're most certainly not. You know, some expand some don't.
Speaker 2: You know, some are more about like essentially melting one
Speaker 2: bit of plastic into another. So yeah, it's I guess
Speaker 2: the thing we keep running up against is like everything
Speaker 2: involving stickiness. There's like this level of language you have
Speaker 2: to get past, as well as sort of the level
Speaker 2: of human perspective, you know, like we're just we're just
Speaker 2: too big. We're not on the same level where all
Speaker 2: of this is actually taking place.
Speaker 3: Yes, And I think also when we think about it,
Speaker 3: we're usually thinking, we're trying to think too simply, we
Speaker 3: think about it in one direction. We think, like why
Speaker 3: does X stick to why? Like why does duct tape
Speaker 3: stick to the wall, And we think that there would
Speaker 3: be one answer for that. There is one cause. But
Speaker 3: it might be better to think about stickiness as an
Speaker 3: emergent system that relies on many different things interacting, rather
Speaker 3: than a property one thing does to another. Now, remember
Speaker 3: all of everything I've been saying so far was about adhesion,
Speaker 3: how two different materials cling to each other. Another important
Speaker 3: factor in stickiness is cohesion, the tendency of a material
Speaker 3: to stick to itself. So in order for a sticky
Speaker 3: material like paint to work the way that it's supposed to,
Speaker 3: it has to be both adhesive meaning it sticks to
Speaker 3: the wall, and cohesive, meaning it sticks to itself. If
Speaker 3: either of these properties fails, then it's not going to
Speaker 3: be good paint. Another interesting factor that Winkless discusses in
Speaker 3: this chapter is what's known as surface energy. So when
Speaker 3: you come back to that image of you put a
Speaker 3: drop of some kind of liquids, some adhesive liquids, sitting
Speaker 3: on a flat, solid surface, the nature of the solid
Speaker 3: material that the liquid is sitting on also influences how
Speaker 3: well the adhesive sticks and one of the carearacteristics that
Speaker 3: matters is that solid material's surface energy. So technically, the
Speaker 3: surface energy of a material is the extra energy present
Speaker 3: at the outside of a solid mass compared to the
Speaker 3: energy present inside the mass. And this extra energy is
Speaker 3: there because of imbalances of molecular bonds on the surface
Speaker 3: of the object. But for a more intuitive understanding of
Speaker 3: surface energy, you can think about it basically as equivalent
Speaker 3: to wet ability. Usually, you can predict how well and
Speaker 3: adhesive will stick to a surface by looking at how
Speaker 3: easily the surface gets wet, how well it attracts water.
Speaker 3: And a common test used to measure surface energy is
Speaker 3: to look at what's known as the contact angle of
Speaker 3: a drop of water on the surface of the material.
Speaker 3: That might sound kind of abstract, but it's actually when
Speaker 3: you see it illustrated, it's pretty easy to understand. So
Speaker 3: imagine you put a drop of water flat on a
Speaker 3: solid surface, and it can be it could be wood, metal, cardboard, whatever.
Speaker 3: Watch what the water does. Does it spread out and
Speaker 3: form a wide, flat disk or kind of a lens shape,
Speaker 3: or does it stand up a little bit taller and
Speaker 3: form kind of a flat bottomed hemisphere or does it
Speaker 3: sit way high up in almost kind of a full
Speaker 3: sphere or bead shape. The first one I talked about,
Speaker 3: the wide flat lens of water is what or has
Speaker 3: what's known as a low contact angle. If you measure
Speaker 3: the angle between the water droplet and the flat surface,
Speaker 3: it's going to be pretty narrow, well below ninety degrees.
Speaker 3: A low contact angle means that this surface likes water.
Speaker 3: It attracts water, and it has a high surface energy.
Speaker 3: And you can kind of see that because the water's
Speaker 3: like spreading out. It's the water wants to touch the surface. Meanwhile,
Speaker 3: the bead of water that sits almost like a sphere
Speaker 3: or a ball up on the surface has a very
Speaker 3: high contact angle. It minimizes contact with the solid, and
Speaker 3: this indicates that the solid has a low surface energy,
Speaker 3: and it's a substance that wants to fight off wetness.
Speaker 3: It wicks away the moisture. So you might think of
Speaker 3: like a think of like a waxy leaf, you know,
Speaker 3: where that you see water hidden and it just rolls
Speaker 3: right away. It's like what you know, it almost seems
Speaker 3: like it's impossible for it to get wet. In most cases,
Speaker 3: this quality the surface energy correlates with stickiness. Surfaces with
Speaker 3: a high energy that attract water then and form that
Speaker 3: flat disc shape are also usually easier to stick things too,
Speaker 3: and Winkless writes, this is kind of interesting. Surface energy
Speaker 3: also tends to correlate with the coefficient of friction. It's
Speaker 3: not a hard and fast rule by any means, but
Speaker 3: if a material has low surface energy, if it's slippery
Speaker 3: to liquids, it is often also low friction slippery to solids.
Speaker 3: So I thought that's kind of interesting. As she says,
Speaker 3: it doesn't hold in every single case, but generally, the
Speaker 3: easier it is to kind of like slide smoothly over
Speaker 3: something without rubbing or sticking to it, also that surface
Speaker 3: that you're sliding over is going to be harder to
Speaker 3: like stick sticky things to. But also on the subject
Speaker 3: of surface energy, this coming back to what we were
Speaker 3: talking about earlier. I was really not expecting a book
Speaker 3: chapter about the science of stickiness and adhesion to contain
Speaker 3: much controversy. But you know, again, this just feels like
Speaker 3: one of those topics that you would find already pretty
Speaker 3: much settled and more just kind of standardized textbook explanations,
Speaker 3: like we all know how this works, but once again,
Speaker 3: this topic still does contain a lot of mystery and
Speaker 3: room for disagreement. And one of those areas of disagreement
Speaker 3: that Winkless documents is disagreements between materials scientists and chemists
Speaker 3: about how important surface energy actually is when you're making
Speaker 3: things like glues or adhesives that are supposed to hold
Speaker 3: together to different solid materials. So she cites a professor
Speaker 3: named Stephen Abbott, who is a fellow with the Royal
Speaker 3: Society of Chemistry, who argues that, and these are abbots
Speaker 3: words quote, surface energy is undoubtedly useful for paint, but
Speaker 3: for practical adhesive systems where we're actually sticking stuff together,
Speaker 3: it's basically irrelevant, thousands of times too small to give
Speaker 3: us what we need, and yet people are obsessed with it.
Speaker 3: So he seems almost mildly annoyed by this. Maybe I'm
Speaker 3: reading too much tone into that, but either way, I
Speaker 3: thought it was fascinating that this topic is has so
Speaker 3: many more questions within it than I realized, Like and
Speaker 3: the fact that we have lots of adhesive products that
Speaker 3: work pretty well, Like you know, they're companies that make
Speaker 3: tapes and glues and sticky notes and all kinds of things.
Speaker 3: They stick to one another pretty effectively. And we know
Speaker 3: at least some and may all of the underlying mechanisms
Speaker 3: by which these by which these products work, and they
Speaker 3: do work, and yet you still can't say in every
Speaker 3: case which mechanism or mechanisms are making the difference. And
Speaker 3: part of this is because stickiness is not merely a
Speaker 3: property of one material, but, as we were saying, an
Speaker 3: interaction between two or more materials and the conditions under
Speaker 3: which they interact. And at the later on in this chapter,
Speaker 3: Winkless quotes the same researcher, Stephen Abbott, saying, quote, adhesion
Speaker 3: is a property of the system. It's not a property
Speaker 3: of like the individual substance. But it's all these things
Speaker 3: interacting together. They have adhesive behavior as a whole or not.
Speaker 2: Yeah, I think that's key. That's key to keep in mind,
Speaker 2: and it's it also factors into what I'm about to
Speaker 2: discuss here in a minute, because originally the plan was
Speaker 2: that I thought, well, we'll roll through a few different
Speaker 2: animal examples of which ones are sticky and why are
Speaker 2: they sticky? Foolishly thinking again that we must have have
Speaker 2: this settled. It must be settled how this particular animal
Speaker 2: sticks to a wall. And we do know a lot
Speaker 2: about this topic, but it's maybe not as perfect of
Speaker 2: knowledge as one might expect. And and and I do
Speaker 2: have to, you know, to admit that. Of course, this
Speaker 2: is the case with plenty of plenty of other things
Speaker 2: about animals that we are even very familiar with. I mean,
Speaker 2: even a house cat has its secrets. There are things
Speaker 2: about house cat behavior that we have varying ideas about
Speaker 2: and we haven't completely worked out. But yeah, with stickiness,
Speaker 2: it's easy just to again to completely take it for granted,
Speaker 2: to approach it from our you know, look at it
Speaker 2: through the fog of our scale and our language and think, oh, yeah,
Speaker 2: well it just sticks right. It's like, you know, it's
Speaker 2: it's like a suction cup.
Speaker 3: Well, speaking of suction cups, that brings up an interesting thing,
Speaker 3: which is that on the macroscopic scale, you can get
Speaker 3: stickying forces that have nothing to do with any of
Speaker 3: the stuff we've been talking about so far, because we
Speaker 3: were just talking about like surfaces sticking to one another
Speaker 3: due to properties of the surfaces. But in the case
Speaker 3: of a suction cup, like if you want to stick
Speaker 3: a suction cup to a window and climb a skyscraper
Speaker 3: like Tom Cruise in one of those Mission Impossible movies.
Speaker 3: That's a totally different mechanism. What's going on there is
Speaker 3: the suction cup. By evacuating the air from the space
Speaker 3: between the cup and the smooth surface, you are creating
Speaker 3: a low pressure area inside, which allows the atmosphere to
Speaker 3: press on the outside of the cup and hold it
Speaker 3: against the wall. So when Tom Cruise is doing that,
Speaker 3: what he's really doing is letting the atmosphere, the weight
Speaker 3: of the atmosphere press his handholds against the building.
Speaker 2: Is Tom Cruise still climbing up buildings with the suction cups?
Speaker 2: Is that still happening in the current movies.
Speaker 3: I think he was in the most recent one of
Speaker 3: those I saw.
Speaker 2: Maybe that's the way. I can't remember did that, And
Speaker 2: I think I only saw the first Mission Impossible movie,
Speaker 2: And if you told me that he used suction cups,
Speaker 2: I would just assume, Well, I guess he probably used them.
Speaker 2: It seems like the sort of thing he would do.
Speaker 3: I think in the first one he uses magnets, because
Speaker 3: that's when he's on the top of that train, you know, Oh, no,
Speaker 3: John Voight, and they're fighting for a helicopter on top
Speaker 3: of a train.
Speaker 2: I remember John Voight, And don't they lower him into lasers?
Speaker 2: Is that the movie with lowering endo lasers.
Speaker 3: Lower him in the lasers.
Speaker 2: Yeah, like room full of like laser trip wires and
Speaker 2: they have to like it comes down from.
Speaker 3: The cel Oh I don't know, Yeah, yeah, yeah. The
Speaker 3: first one is where they put Tom Cruise on a
Speaker 3: rope and they lower him down through out of an
Speaker 3: air vent into a room that the floor is lava.
Speaker 3: You can't touch the floor or the alarms will golf.
Speaker 3: And that was so he could steal the knock list,
Speaker 3: you know, the knocklst I had VHS to the first Yeah.
Speaker 2: I guess I only saw it once. Then. Yeah. I
Speaker 2: don't have any strong feelings about it one one or
Speaker 2: the other, but I mean I admire, I admire the
Speaker 2: commitment to amazing stunts.
Speaker 3: Apart from like the coronal mass ejection of star power
Speaker 3: that is Tom Cruise. Most of those movies have a
Speaker 3: pretty cool supporting cast. Oh you know the first one
Speaker 3: it had Ving Raims and John Renau.
Speaker 2: Yeah, yeah, I believe you're right. Yeah, yeah, strong casts
Speaker 2: all right. Well, speaking of star power, and speaking of
Speaker 2: daring stunts. The main creature we're going to talk about
Speaker 2: here today is going to be the gecko. I'm also
Speaker 2: going to get a little bit into Spider Man later,
Speaker 2: but Spider Man's not real. The gecko is real, and
Speaker 2: the gecko is quite amazing, one of the most famous
Speaker 2: sticky animals of all, though to be clear, not all
Speaker 2: geckos have this ability. For instance, the oft domesticated leopard gecko.
Speaker 2: There's actually one of these living in my house. It's
Speaker 2: my son's pet, is a ground dwelling lizard and does
Speaker 2: not have this ability. But geckos are found on every
Speaker 2: continent except Antarctica various species of the infraorder Gekota. Of these,
Speaker 2: some sixty percent have adhesive toepads that enable climbing, although
Speaker 2: this ability has apparently been lost and gained many times
Speaker 2: over their evolution.
Speaker 3: Now, when you hear that a gecko has adhesive toepads,
Speaker 3: first of all, that might make sense because you've probably
Speaker 3: seen a gecko climbing up a flat surface like a
Speaker 3: you know, a window pane or a sliding door, or
Speaker 3: the wall of a building or a tree trunk, or
Speaker 3: even climbing on the underside of things. Again, much like
Speaker 3: tom cruise kind of doing overhang free climbs, going around
Speaker 3: on the ceiling. It is pretty amazing what they're able
Speaker 3: to do, and across the range of surfaces across which
Speaker 3: they're able to do it. So you might just assume, okay,
Speaker 3: well they got you know, toes that feel like glue.
Speaker 3: Like if you were to go put your hand on
Speaker 3: a gecko's toe, it would be a gross, sticky you know,
Speaker 3: almost kind of like a like a sugar seer or
Speaker 3: something like that. But no, no, that's not the case.
Speaker 3: If you go and look at the toe and feel
Speaker 3: the toe of a gecko, the kind that has these
Speaker 3: amazing climbing powers and clinging powers, it feels totally smooth.
Speaker 3: It is not covered in a sticky adhesive like the
Speaker 3: back of duct tape.
Speaker 2: Yeah, it's one of the things that's long fascinated us
Speaker 2: about the gecko. And again, geckos are widespread, so they've
Speaker 2: been there. They're around for great thinkers of different ages
Speaker 2: to potentially ponder them, and in fact, Aristotle mentions them
Speaker 2: in the History of Animals, the fourth century BCE text.
Speaker 2: If you start looking searching around in that text for
Speaker 2: mentions of the gecko, they do come up several times.
Speaker 2: But he also writes of the amazing climbing ability of
Speaker 2: the quote unquote gecko lizard to quote run up and
Speaker 2: down a tree in any way, even with the head downwards.
Speaker 2: So even Aristotle thought that this was pretty interesting, though
Speaker 2: I don't believe he offers any possible explanation for it,
Speaker 2: is just kind of an observation about you know, I
Speaker 2: think he's comparing it to another creature. Here.
Speaker 3: The quest to understand how gecko toes cling to all
Speaker 3: these different surfaces and allow it to walk straight up
Speaker 3: vertical walls of any roughness or smoothness, to cling to
Speaker 3: ceilings and overhangs. This goes way way back, and people
Speaker 3: have put forward tons of hypotheses over the years. Again,
Speaker 3: coming back to our mission, impossible digression was due to
Speaker 3: talking about suction cup climbing, and for a long time
Speaker 3: a lot of people thought that the geckos did climb
Speaker 3: by essentially using suction cup grips. But that's not the case.
Speaker 2: Yeah, At different points they you know, hypotheses included sticky
Speaker 2: secretions like we've mentioned, suction cups, also tiny hooks. You know,
Speaker 2: these are all decent hypotheses to work with but it
Speaker 2: didn't take too long for various naturalists and ultimately scientists
Speaker 2: and thinkers in general to realize, well, none of these
Speaker 2: are really explaining it. Something else is goinging on, and
Speaker 2: it seems like it's something maybe more you know, more
Speaker 2: physical certainly than chemical. But once again, like it's our
Speaker 2: perspective and our language kind of get in the way
Speaker 2: of like simple understanding of what the get go is doing.
Speaker 2: And I find my experience with researching this it was
Speaker 2: kind of like like the Powers of ten sort of
Speaker 2: experiences ZUSA in you know, yes, because you start off
Speaker 2: with like a simple question, well, why can gecko's climb walls?
Speaker 2: And the answer is, well, because they have special flexible
Speaker 2: adhesive ridges on their toes. And if you wanted, you
Speaker 2: could stop there and be like, okay, question answered, I
Speaker 2: can go home now. But but then you might ask
Speaker 2: the follow up question, well, how do their adhesive toes work? Well,
Speaker 2: the answer is the toes have special tiny hairs like
Speaker 2: even you know, far smaller than what we think of
Speaker 2: as hairs called ceta on them. And then you might say, okay,
Speaker 2: I got it. I can go home now, that's what's
Speaker 2: doing it.
Speaker 3: But wait, yeah, how are the tiny hair What do
Speaker 3: the tiny hairs do? Or how are they sticky? How
Speaker 3: do they stick well?
Speaker 2: Each of these has even smaller bristles called spatula on them.
Speaker 3: Right, So, one way I've seen this described is all
Speaker 3: these tiny little hairs. If you can zoom way way in,
Speaker 3: like smaller on a scale smaller than you can see
Speaker 3: with visible light. You have to use like a scanning
Speaker 3: electron microscope, you can see that each hair like frayse
Speaker 3: like a rope that just goes out to like millions
Speaker 3: of little fibers that are beyond microscopic. They're down on
Speaker 3: the nanoscale. They're super super tiny, frayed out to uncountable ends.
Speaker 2: Yeah, I mean, there's so many that a given gecko
Speaker 2: i've read have somewhere in the neighborhood of two billion
Speaker 2: of these on the pads of their toes combined.
Speaker 3: Okay, so on their toes they have these ridges. The ridges,
Speaker 3: by the way, are called lamelli, and then on the
Speaker 3: lamelly they have the setae, and the setae are little hairs,
Speaker 3: and those hairs fray out into these little frayed bristly
Speaker 3: ends called spatchel. But what does the spacially do. What
Speaker 3: are those how do they work?
Speaker 2: Well? The answer here is well, it's complicated, but the
Speaker 2: basic idea is that their stickiness seems to depend on
Speaker 2: a combination of intermolecular forces.
Speaker 3: Yeah, it does seem like there are maybe multiple forces involved,
Speaker 3: though the sources I was looking at zeroed in on
Speaker 3: the most agreed upon explanation having to do with what
Speaker 3: are known as Van Derval's forces.
Speaker 2: Yes, van der Waals force named for Johannes Diedrich van
Speaker 2: der Waals who lived eighteen thirty seven through nineteen twenty three.
Speaker 2: There's an excellent two thousand and two article I've been
Speaker 2: shouse that I that I One of the sources I
Speaker 2: turned to for this section is you can find on
Speaker 2: science dot org has the just perfect title how Geckos
Speaker 2: stick on de valls at Waals spelling for walls. So yes,
Speaker 2: that as of two thousand and two is to gused
Speaker 2: in this article like that is the primary hypopsis for
Speaker 2: how the gecko's toepads are ultimately sticking to the wall.
Speaker 2: But another one that was being looked at at this
Speaker 2: time in an article I'm going to side here is
Speaker 2: this idea that it could have been water based capillary forces,
Speaker 2: so like a thin film of water between pads and
Speaker 2: the climbing surface. Quote. Because water molecules are polar, their
Speaker 2: electrical charges aren't evenly distributed. They might stick to some
Speaker 2: polar molecule in gecko's feet.
Speaker 3: Oh okay. Now on the opposite side of that, what
Speaker 3: I've been reading about gecko's feed is that they seem
Speaker 3: to be composed largely of water repelling hydrophobic materials. But
Speaker 3: that again, I think it's complicated.
Speaker 2: Yes, yeah, Now to come back to vander Walls here,
Speaker 2: science writer Eleanor Nelson put together a great explainer on
Speaker 2: this whole topic for ted D several years ago. You
Speaker 2: can look this up. There's a video on ted ED
Speaker 2: about the gecko to search for ted ed gecko and
Speaker 2: you can watch it as great visuals to help explain
Speaker 2: all this. But she stresses that what we're talking about
Speaker 2: here isn't attraction between charged molecules positive or negative, but
Speaker 2: rather attractiveness between uncharged molecules that experience patches of negative
Speaker 2: and positive charges due to the movement of atoms with
Speaker 2: different electro negativities in the same molecule. So we're talking
Speaker 2: about flickering patches of weak attraction. It's not strong in
Speaker 2: isolation like each of those you know, tiny spatula are
Speaker 2: not you know, pulling things across the room or anything
Speaker 2: remotely like that. But when you have two billion of
Speaker 2: these on a single gecko exploiting the force, it adds up.
Speaker 2: In fact, it adds up so much that a gecko
Speaker 2: can hang by a single digit, you know, from a
Speaker 2: like a ceiling, you know. And it has complete control
Speaker 2: over this as well, so you know, because they can
Speaker 2: manipulate the angle and surface area of those tow ridges
Speaker 2: in just the right way to activate and release that
Speaker 2: stickiness on demand.
Speaker 3: Yeah, it is amazing, especially when you notice like the
Speaker 3: motor activities that the gecko has to coordinate to orient
Speaker 3: these little harris correctly to always cling the right way.
Speaker 3: But I wanted to clarify one thing because it took
Speaker 3: me a minute to understand what was going on with
Speaker 3: the Vandervals forces. The vanderwalls or Vanderval's forces are something
Speaker 3: that is different from like the attraction you get in
Speaker 3: a polar molecule like water, which is permanently polarized in
Speaker 3: terms of a charge, so it's always going to be
Speaker 3: able to attract one way or another because it's got
Speaker 3: a you know, negative charge on one side, positive on
Speaker 3: the other. The Vanderval's forces are, Yeah, they're due to
Speaker 3: the fluctuations in the orientation of electrons around an atom
Speaker 3: that are just random. So they just randomly change over time,
Speaker 3: even when an atom is electrically stable, so this atom
Speaker 3: is not polarized, but things just sort of flicker in
Speaker 3: and out of existence. A charge attraction going one way
Speaker 3: or the other flickers in and out of existence because
Speaker 3: of just random fluctuations of where the electrons are lined up.
Speaker 3: And that in cases where where atoms are packed close
Speaker 3: enough together can actually have an attractive effect, but usually
Speaker 3: atoms are not packed close enough together for that to matter.
Speaker 2: Yeah, this is a if you're still foggy on this,
Speaker 2: I do recommend that ted Ed video because they have
Speaker 2: a nice animation that kind of that illustrates what's going
Speaker 2: on here. At least for me, it helped clarify the
Speaker 2: whole thing.
Speaker 3: Yeah, and so the reason the spatuely are able to
Speaker 3: take advantage of the Vanderwolts force is because they're so
Speaker 3: tiny and there's so many of them.
Speaker 2: Forests of them, I've seen it described a right. So
Speaker 2: coming back to the two thousand and two time period here,
Speaker 2: there was a paper that came out in a two
Speaker 2: thousand and two edition of Integrative and Comparative Biology titled
Speaker 2: Mechanisms of Adhesion in Geckos. This was by Keller autumn
Speaker 2: at All and in this they were exploring the vendor
Speaker 2: val and the water based capillary forces explanations to you know, see, okay, well,
Speaker 2: let's look at these two possible ideas and see which
Speaker 2: one seems to seems more evident when put to the test.
Speaker 2: And they used the aid of semiconductors, so they ruled
Speaker 2: out water droplet hypothesis as it depends on polar surfaces.
Speaker 2: They found in their experiments that geckos could equally climb
Speaker 2: a non polar surface. In this experiment they used a
Speaker 2: semiconductor called gallium arsenide, which is a compound of gallium
Speaker 2: and arsenic. By the way, it is also interesting that
Speaker 2: gecko feet can not adhere to teflon. You may have
Speaker 2: heard this or seen some headlines about this over the years,
Speaker 2: but according to Sarah Chodesh on Popular Science back in
Speaker 2: twenty eighteen, teflon disrupts the Vanderval's force effect here that
Speaker 2: enables them to climb other or seems to be one of,
Speaker 2: if not the primary factors in their ability to climb
Speaker 2: other surfaces. Quote. Vanderval's forces depend on being able to
Speaker 2: induce a positive and negative end of a molecule or atom.
Speaker 2: But the layer of fluorines in Teflon just have this
Speaker 2: permanent negative charge to them. The electrons stay in one place.
Speaker 3: Teflon's not having any of it. Yeah.
Speaker 2: So anyway, that twenty and two study backs up the
Speaker 2: vandervals explanation. In their own words, their findings at the
Speaker 2: time provided quote direct evidence that Vanderval's force is the
Speaker 2: mechanism of adhesion in get Go ceta and that water
Speaker 2: based capillary forces are not significant. So again not to
Speaker 2: say it couldn't be doing something, but it's not the
Speaker 2: significant factor.
Speaker 3: Yes, though it's interesting. In uh the chapter in Winkless's
Speaker 3: book on gecko toes, she talks about, how you know,
Speaker 3: it seems like most researchers in this area kind of agree, Yeah,
Speaker 3: it's Vanderval's force. That's that's the explanation or the main explanation.
Speaker 3: But she says, they all kind of have this bit
Speaker 3: of hesitation when they talk about it, like maybe there's
Speaker 3: something else going on too that we haven't fully figured
Speaker 3: out yet. Yeah.
Speaker 2: I kept thinking about like the experience of trying like
Speaker 2: a fancy cocktail somewhere and you're trying to pick out
Speaker 2: the ingredients just on taste. You know, generally you can
Speaker 2: you can pick out some of the major flavors. But
Speaker 2: are you gonna, you know, absolutely put your money down
Speaker 2: that there are only three ingredients in this cocktail and
Speaker 2: you're there are not four, they're not five, and so forth.
Speaker 3: That's right. What's that tingling in the back of your mouth?
Speaker 3: Could that be an absentthe rense?
Speaker 2: So one sample of this concerning gecko feed This comes
Speaker 2: up in a twenty fourteen article that I was looking
Speaker 2: at role of contact electrification and electrostatic interactions in gecko
Speaker 2: adhesion by A. Zadi at All published in the Journal
Speaker 2: of the Royal Society Interface, and this one discusses the
Speaker 2: CE driven electrostatic interaction. This refers to the contact electrification phenomenon,
Speaker 2: and I understand that this is still controversial. For example,
Speaker 2: in a twenty twenty three paper by song at All,
Speaker 2: in published in the journal Friction. The author's cite the
Speaker 2: controversial aspect of the CE driven explanation, though to be clear,
Speaker 2: it's ultimately more about the level of contribution that's controversial,
Speaker 2: because again it's like saying, well, yes, I think there's
Speaker 2: absinth in this cocktail, but maybe it's just a drop.
Speaker 2: It's like three drops of absinthe I'm not saying it's
Speaker 2: anything more than that, Whereas there might be someone else arguing, actually,
Speaker 2: I think they put an ounce in there, and then
Speaker 2: the fighting and controversy. But anyway, in this song at
Speaker 2: all paper the way they explain it, it seems like
Speaker 2: CE may be part of the situation, but their study
Speaker 2: suggests that its impact is low, perhaps contributing only around
Speaker 2: three percent of the adhesiveness, and this may also be
Speaker 2: why it doesn't help them out with something like teflin,
Speaker 2: which again essentially cancels out Vanderval's force, which, as far
Speaker 2: as we can tell, seems to be the primary factor
Speaker 2: in play here. However, they note that quote long range
Speaker 2: electrostatic forces may play other roles in a distance range
Speaker 2: where the Vanderwals interaction cannot function, So again there could
Speaker 2: be certain situations where it's more important to some degree
Speaker 2: than other times.
Speaker 3: But it does seem clear that whatever else is going on,
Speaker 3: the main ingredient, the whiskey in the cocktail is the
Speaker 3: vandervals interaction. Yes, and another interesting thing here, Rob you
Speaker 3: alluded to this earlier, but it's something that you can
Speaker 3: notice if you watch a gecko actually climbing, which is
Speaker 3: the question of wait, how do they make their toes
Speaker 3: stick and then unstick? So they've got this really powerful
Speaker 3: sticking force, and in some cases the sticking force it
Speaker 3: can hold so much more than the weight of a
Speaker 3: gecko's body. There's one estimate in Winkliss's book about a
Speaker 3: test showing that a gecko I can't remember, I didn't
Speaker 3: write down the number, but it's like a gecko's grip
Speaker 3: could hold hundreds of pounds up on the wall, despite
Speaker 3: the fact that the gecko itself only weighs like half
Speaker 3: a pound. Now, on one hand, you might think, well,
Speaker 3: that's kind of overkill, but of course that would be
Speaker 3: testing it in sort of ideal conditions in a lab,
Speaker 3: whereas in nature a lot of times the surfaces it's
Speaker 3: climbing on are going to be dirty, which will reduce
Speaker 3: the adhesive potential, might be wet, which would potentially reduce
Speaker 3: adhesive potential. Some of their toes might be injured or something.
Speaker 3: Some of the lamilly might come off. In nature, you know,
Speaker 3: it's better safe than sorry. When you're a gecko, have
Speaker 3: a lot of sticking power. But yeah, anyway, the question
Speaker 3: is how does it stick and unstick and climb in
Speaker 3: different directions? And a lot of this comes down to
Speaker 3: how it lifts and attaches its toes to the surface
Speaker 3: and how it orients them. So like you, if you
Speaker 3: watch a gecko crawling up a wall, it will tend
Speaker 3: to sort of like peel its peel its toes up
Speaker 3: and then lay them down with all of the toes
Speaker 3: facing upward on the wall. But if you see a
Speaker 3: gecko climbing down a wall, it will rotate its back
Speaker 3: feet so that its toes are facing up. Because the
Speaker 3: ceta and the spatually on them, they sort of only
Speaker 3: grip effectively when laying in one direction.
Speaker 2: Yeah, one way to think about all this is that again,
Speaker 2: our understanding of what's going on when a gecko climbs
Speaker 2: has not reached a level of perfection, but their exploitation
Speaker 2: of it has reached perfection, like they are the perfect
Speaker 2: manipulators of this force. So it's pretty amazing to watch.
Speaker 3: Now, whenever evolution achieves something this ingenious, you will bet
Speaker 3: that human engineers come running to see, how are they?
Speaker 3: How are they doing that? What's going on there? Could
Speaker 3: I make robots that could do something like that?
Speaker 2: Yeah? Yeah, So of course biomimicry has gazed longingly at
Speaker 2: the gecko for a while now. There have been various
Speaker 2: efforts to create artificial ct with some working prototypes and
Speaker 2: robotics and even human climbing suits popping up in headlines.
Speaker 2: I think there was a DARPA project that made the
Speaker 2: news in twenty fourteen. These have certainly not reached a
Speaker 2: level of perfection yet, but you know, there are some
Speaker 2: interesting applications out there potentially for this, and they're not
Speaker 2: all of them involved like super soldiers climbing the windshield
Speaker 2: or robots cleaning you know, high rise buildings, for instance.
Speaker 2: It's been put far that they could be used in
Speaker 2: low gravity environments. They could even be used, you know,
Speaker 2: to collect space debris in orbit, that sort of thing.
Speaker 3: So the amount of weight that can be supported by
Speaker 3: a gecko's toes and the range over the range of
Speaker 3: different surfaces that they can crawl over is truly astounding
Speaker 3: and sort of a superlative in nature. But there are
Speaker 3: lots of other animals that can crawl up walls, and
Speaker 3: I wonder do many of them make use of similar
Speaker 3: mechanisms or forces well.
Speaker 2: Spiders climb in a similar way and also depend on
Speaker 2: tiny set that make use of Vanderval's force. Though they're
Speaker 2: ultimately like masters of these structures, they also use them
Speaker 2: for other purposes as well, like like sensing sense sounds, vibrations,
Speaker 2: and air currents. But this does lead us back to
Speaker 2: the topic of Spider Man, because, as everyone knows, Spider
Speaker 2: Man can do whatever a spider can, and it's this.
Speaker 3: He can liquefy your innards and slurp them out through
Speaker 3: his mouth orifice.
Speaker 2: Maybe he can, and he chooses not to, But I
Speaker 2: guess that's more of a Isn't there a man There's
Speaker 2: a man spid. I know there's a batman and a
Speaker 2: man bat there's also like a spider man monster creature,
Speaker 2: but I don't know if that's man spider or not
Speaker 2: off the top of my head. But it gets it
Speaker 2: gets so complicated when you start comparing Spider Man to
Speaker 2: spiders because, of course there are all these things that
Speaker 2: don't match up. For example, it's easy to think of
Speaker 2: Spider Man. What does Spider Man do well? He swings
Speaker 2: around on webbing through the through the streets, though he
Speaker 2: does so in a way that's not particularly spider esque,
Speaker 2: and while in some adaptations of Spider Man he's using
Speaker 2: like organic like mutations, like he has like he's you know,
Speaker 2: he's been by a radioactive spider and now he can
Speaker 2: he can shoot webbing out of his wrists. Most versions
Speaker 2: of Spider Man you encounter he has these little gadgets
Speaker 2: that he built that shoot some sort of nylon like webbing.
Speaker 2: So he's this weird mix of like, Okay, I'm part
Speaker 2: Spider but also I have like super crazy sci fi
Speaker 2: weapons as well, and all of these combined to make
Speaker 2: me able to do whatever a spider kit.
Speaker 3: It's not really satisfying that way, is it. He's one
Speaker 3: foot in each world. He's half a Charles B. Griffith
Speaker 3: script where yes it was atomic radiation. But he's half
Speaker 3: Batman and we already have Batman. He makes gadgets.
Speaker 2: Yeah, I mean, I guess I'm not a Spider Man
Speaker 2: purist or anything, but I like the mutant version. I
Speaker 2: like the idea that he's shooting it out of his wrist,
Speaker 2: even though that doesn't really match up. Like spiders don't
Speaker 2: they have spinnerets, they don't have wrist openings or whatever.
Speaker 2: So you know, it's still not one to one.
Speaker 3: I guess Spider Man fans, please don't hate me. I'm
Speaker 3: just joking around. I don't know much about Spider Man.
Speaker 2: I mean, Spider Man is great. But one of Spider
Speaker 2: Man's abilities that is or seems to be universally accepted
Speaker 2: as an ability brought on by the radioactive spider bite
Speaker 2: is his ability to climb walls and stick to ceilings
Speaker 2: with out the aid of his wedding. How does he
Speaker 2: do this well? On one hand, we have to admit
Speaker 2: like this is a fool's errand to try and make
Speaker 2: sense of this. Spider Man climbs walls because he's Spider Man,
Speaker 2: and any kind of like scientific explanation to this comes
Speaker 2: after the fact they were not thinking long and hard
Speaker 2: about the anatomy of a spider when they came up
Speaker 2: with this character. As fun as this character is, so
Speaker 2: any attempt to scientifically explain everything about him is is.
Speaker 2: It can be very fun, but it's not going to
Speaker 2: get you to a place of absolute certainty.
Speaker 3: You might as well ask, exactly scientifically, how do the
Speaker 3: crabs in attack of the crab monsters eat your brains
Speaker 3: and gain your knowledge exactly?
Speaker 2: But like I say, it's a fun exercise, and I've
Speaker 2: been enjoying this book marvel Anatomy by Sumeruk and Wallace,
Speaker 2: and the authors point out several things about Spider Man's
Speaker 2: adhesive abilities and how they match up or don't match
Speaker 2: up with the natural world. One of the main ishu
Speaker 2: that they keep talking about, though, is Okay, Spider Man
Speaker 2: can climb, and perhaps he does this because he has
Speaker 2: little CD on his hands at least or I guess,
Speaker 2: over his entire body, and it allows him to adhere
Speaker 2: to walls. But also he's wearing a full body costume.
Speaker 2: Spider Man is almost never naked when he's clinging to
Speaker 2: walls and so forth, so it raises questions like would
Speaker 2: vander walls work through a pair of spider gloves or
Speaker 2: would that weaken it to some degree.
Speaker 3: I don't think it would work, because the whole thing
Speaker 3: about Vanderval's force is you've got to be incredibly close,
Speaker 3: closer than solids can usually get to each other. That's like,
Speaker 3: that's why the gecko's foot works. It's the tiny little
Speaker 3: thing that can get in there in the cracks and
Speaker 3: crevices in the surface, unlike anything else.
Speaker 2: Well, the author suggests that, well, maybe the ceed poke
Speaker 2: through the costume, but that raises all sorts of questions,
Speaker 2: like then when he takes the costume off, when he
Speaker 2: peels off the sweaty Spider Man costume at the end
Speaker 2: of the day, does it just rich them all off
Speaker 2: and he has to regrow them or I don't know.
Speaker 2: It's a wonder fabric that Iron Man made for him,
Speaker 2: so it lets them out.
Speaker 3: I don't know.
Speaker 2: Again, it just raises more questions than anything.
Speaker 3: I think Spider Man should have finger gloves like a bandit.
Speaker 2: The authors here suggest that maybe Spider Man can actually
Speaker 2: quote consciously control the intra atomic attraction between molecular boundary layers,
Speaker 2: which I suppose sounds reasonable, though I mean this raises
Speaker 2: the question about to what extent this still makes sense
Speaker 2: as a sixties at comic book. Radiation Advancement of natural
Speaker 2: World spider abilities, but I'll take it. I'll take it.
Speaker 2: Sounds good to me. Now. They do point out that
Speaker 2: another character, Spider Woman. I don't know if you're familiar
Speaker 2: with Spider Woman. She was introduced in nineteen seventy seven.
Speaker 2: She just kind of like a red outfit. But she
Speaker 2: is said to be able to climb via secreted biological
Speaker 2: adhesive substances that are on her hands and her feet
Speaker 2: that I guess swiftly penetrate tiny pores in the climbing surface. Also,
Speaker 2: she wears gloves and booties as well, so this secretion
Speaker 2: would have to like rapidly soak through the fabric in
Speaker 2: these cases as well or through the booties and then
Speaker 2: allow her to stick to the walls. And again this
Speaker 2: raises more questions because when you look to the natural world,
Speaker 2: you do see adhesive secretions in some organisms, but they
Speaker 2: tend to be defensive rather than climbing aids. These are
Speaker 2: things that you would extrude when threatened, so that whatever
Speaker 2: was trying to eat you might decide, oh, I don't
Speaker 2: want any of this.
Speaker 3: Yeah, well, maybe I'm not thinking creatively enough, but it
Speaker 3: seems like if you had to secrete enough sticky stuff
Speaker 3: to hold you to a wall every time you wanted
Speaker 3: to climb. That'd just be a lot of stuff that
Speaker 3: sounds like you're secreting, Like do you get dehydrated? Do
Speaker 3: you run out of energy doing that? Well?
Speaker 2: I mean, Spider Man is leaving nylon thread all over
Speaker 2: the city, all over New York as he's fighting crime,
Speaker 2: and I guess somebody has to clean that up. They
Speaker 2: probably didn't think about it much in the sixties, and
Speaker 2: I guess it was acceptable in the eighties, but nowadays,
Speaker 2: like it's what's the what's the environmental impact of this
Speaker 2: crime fighting?
Speaker 3: But once again the genius of the gecko. The gecko
Speaker 3: climbs without goop.
Speaker 2: Yes, yeah, And the authors here they do include a
Speaker 2: bit on one of Spider Man's many enemies. You've perhaps
Speaker 2: heard of, the lizard. I think the lizard was in
Speaker 2: at least one of the movies. I can't remember which
Speaker 2: Spider Man this was, which Spider Man regime, But this
Speaker 2: is a man, a scientist who turns into a great,
Speaker 2: big green lizard and chases Spider Man around. And in
Speaker 2: many of the depictions, the lizard can climb around on
Speaker 2: walls and on the ceiling. In this particular book that
Speaker 2: I was referring to, they discuss it as more of
Speaker 2: a claw thing, which I think makes sense for a
Speaker 2: super villain, you know, big nasty claws. Can you know
Speaker 2: claw into the concrete? Is the creatures climbing around. But
Speaker 2: I've also seen some descriptions that discuss the lizard as
Speaker 2: having gecko abilities.
Speaker 3: Oh okay, so either way claw or gecko, that would
Speaker 3: be San's goop. That would be a mechanical grip of
Speaker 3: some sort or of Vandervohal's force. Yeah.
Speaker 2: But again, I think with a super villain like the Lizard,
Speaker 2: it makes more sense that his climbing ability is visibly destructive,
Speaker 2: though it raises the question like, where's the love for
Speaker 2: the gecko? Then in the creation of Superheroes, I was
Speaker 2: looking around looking at the various databases, and it looks
Speaker 2: like they're a couple of minor Marvel Gecko characters, or
Speaker 2: maybe it's two versions of one character that have existed.
Speaker 2: And it looks like DC Comics also has a Gecko
Speaker 2: or the Gecko. But I don't get this sense that
Speaker 2: these are based on anything, you know, true to the
Speaker 2: get go. But comic book fans out there let us
Speaker 2: know perhaps you have more detail on these Geckos.
Speaker 3: Who is Gordon Gecko? Is he some kind of gecko supervillain?
Speaker 2: I don't know. Maybe it's part of the shared cinematic universe.
Speaker 3: Okay, I think that's all we got for today.
Speaker 2: All right, We're going to go ahead wrap it up here,
Speaker 2: but yeah, write in let us know what you think
Speaker 2: about stickiness in general, the examples of stickiness that we've discussed,
Speaker 2: and yes, even fictional sticky comic book characters and so forth.
Speaker 2: Just a reminder that we're primarily a science podcast here
Speaker 2: at Stuff to Blow Your Mind, with core episodes on
Speaker 2: Tuesdays and Thursdays, listener mail on Mondays, a short form
Speaker 2: monster fact or artifact episode on Wednesdays, and on Fridays.
Speaker 2: We set aside most serious concerns. Who just talk about
Speaker 2: a weird film on Weird House Cinema.
Speaker 3: Huge thanks to our excellent audio producer JJ Posway. If
Speaker 3: you would like to get in touch with us with
Speaker 3: feedback on this episode or any other, to suggest a
Speaker 3: topic for the future, or just to say hello, you
Speaker 3: can email us at contact at Stuff to Blow your
Speaker 3: Mind dot com.
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