Caught in a Tractor Beam

that would be a later podcast. Right now, we're talking about science fact, science fact factor. Tractor beams. Yeah, tractor beams are a real thing. Yeah, using fact like f a k T fact exactly like f a k T. So you're you're telling me, they're telling you're telling me they're a real tractor beams in the world. It's amazing to me that you don't know this because you wrote the script for that particular episode and I've already recorded it. But yes, there are. Do you just not believe your

own research. We're playing a little fantasy game. I'm sorry, Okay, yes, what tractor beams? Well, I'll admit that even though I did write a script about it. It's still blowing my mind. You know what. It blows my mind too, because you're sitting there talking about a phenomena that is incredibly counterintuitive, right right, Well, I mean, you know when when we see it in Star Trek, it looks like this beam of light is pulling something towards it. And how does

how does that work? Because light pushes on right, Well, we actually are talking about light. I don't want to nerd out on you, but in star in wait, did you say Star Treker star Wars? Oh? Then you're right, You're totally right. You're totally right. I'm so sorry. I thought you said Star Wars and I was gonna be You don't see anything, okay, you just feel it. You're just being pulled in, right, They got us locked in, that's true. Yeah, they got us locked out of the track.

You don't see waiting until one is right there over at the tractor beam controls that are rightly located next to the enormous pit, that big beam going up and down. Yeah. Okay, so I will save that for the next podcast, all the sci fi stuff. Just just let it be known, okay, for the like one person in the world who doesn't

know what a tractor beam from science fiction is. It's a force that pulls you toward it, right, right, So in science fiction it's often used for a ship to be guided into the docking bay of some other vessel or spaceport, or it's some way of capturing another object peacefully without blowing it to smithereens and kind of grabbing it taking it with you. Yeah. Yeah, so it's kind of like a nons like a like a beam winch right, right. Yeah.

If you don't want the equivalent of having to fire out grappling hooks from the side of your spaceship so that you can pull some other spaceship in so you can board it and and be space pirates, then you need some sort of electronic electromagnetic version of that. And and tractor beams tends to be the go to um magical thing that we talk about to have this happen.

And as it turns out, we actually have developed a type of tractor beam, a couple of different types of tractor beams, but they're on a very small scale and they use light. Astonishing, Yeah, they use light. They use light, so they can shine light and pull something toward the light source, which is incredibly counterintuitive. Like you were saying, Lauren, I mean the light is something that pushes, right, It

has momentum. It behaves as both a particle and a way. Yeah, it's even that's not totally intuitive, right, we should stop in. Some people might be going, wait a minute, what light pushes? Yeah, it does. It does have momentum. It has a relativistic mass, which mostly means it as a mass that works out in math, if not in what we would consider real life situations. But it does have momentum. It can press against something. Yeah, you call this the term is radiation pressure.

So you if you imagine the Sun, it's got raised coming out of it in all directions. It's also got solar wind. So you can understand why solar wind would push because that's massive particles. So that's a little lasting

particles out into space. So if you have something like a solar sale, which is a spaceship that's designed to ride the force of the Sun outward from the solar system, that's taking some of the force from that solar wind those massive particles coming out, but some of the force pushing it is just all it's light Yeah, it's photons.

It's just photons pressing against that solar sale. And because you're not dealing with gravity in any in any appreciable sense, once you get out into interplanetary space, as long as you're not getting too close to any particular large body, then you can use that to accelerate your spacecraft and and travel and use that as a propulsion force. In fact, that's one of the ones that that scientists have proposed as a potential propulsion force once we're building spacecraft in space.

In fact, you don't even have to look at a hypothetical spacecraft to see the force of radiation pressure in our solar system. Right, you can look at like a comet. Right, Comets tails always point away from the Sun. Yep, yep. That tail is always going to be pointing away. And that's because of this this pressure that we're talking about. So that's Kepler discovered that, by the way, which which comes up a lot in a lot of these articles. Yeah, Kepler was a smart cat, let me tell you. So

we're getting into a smart human being. But yeah, well Shortinger had a smart cat only half the time. So anyway, the the the whole point of this is that if you're thinking about an energy that has a pressure, like it's pressing against something, how could that then draw an

object toward the source of that pressure. I mean, that is very much counterintuitive, right, And the thing is is that physicists have figured out ways of getting around this, so that what's really happening is the light is pushing on objects from behind and and thereby making the appearance

that it's pulling that object towards right. So so really what's happening is that there's some sort of pressure building on the back side of an object in relation to where the source of light is, so that that pressure on the back is pushing it towards that light source. It's not truly pulling, Like It's not like if I grabbed Joe and then just started to pull him towards me, that that would be one thing. But this is more like I signal to you, Lauren, and I pushed Joe

and towards you. By the way, this happens constantly in our podcast, and I meant to bring that up earlier suggest that we not do that, But really, I guess it's a discussion for another Come on, guys, the examples you're using are different in like eighteen ways. I want to see the proof. What does this really look like in the lab? What are they doing? All right, Well, there's a couple of different ways that scientists have looked

into using light to uh to pull objects. First of all, we should say that for a couple of decades now, scientists have been using light to immobilize tiny, tiny, tiny object right, So they're they're not wiggle. So in this case you're using light. You're using light, it's not it's not drawing it towards the source of light. It's just there to either move something laterally, or you're just immobilizing something.

This is really important if you're dealing with really really really tiny objects, like in organic chemistry or any kind of biomedical research, you would need to be able to to uh isolate and and uh and immobilize these tiny tiny particles. I imagine we're talking about like the microscale nanoscale is Yeah, microscale nanoscale is really what we're talking about. Not keep in mind not so a nanometer is one billionth of a meter, uh, a micrometer is one million.

So we're talking between the a few hundred nanometers to a couple of microns in size. Uh. Now, one of the ways that UH scientists have used is relying on something called a bessel beam, which is a very peculiar type of light. Yeah, a vessel beam. Uh. If you see a vessel beam shined against a wall, you would probably see something that looks like a target. It's like a bull's eye with concentric circles coming out. Um. But and that that's the way I've seen it in all

the videos and images I've seen online. But the essential thing about a vessel beam is that it's non refractive, right, so it stays focused over a really long distance. And so if you're using a laser beam, we think of laser beams as being really really concentrated beams of light that don't tend to diffuse, but they do over great distances,

whereas a vessel beam maintains that coherence. Yeah. And the other really weird and kind of interesting thing about a vessel beam is that, if I'm correct, I think it

reforms after passing over an object. Right. Right, It's a series of concentric circles of light that are formed around a single dot, and that center point is created by the light from the concentric circles, so it can it can your form when something want to encounter something that's path because it's not entirely being covered some of these I see, So some of the outer circle is getting around that object and therefore can reform that dot part

on the back side of that object. So it's not the same thing as if it were to encounter, say an enormous wall. It's more like if it had a smaller object that would normally block that little dot, but some of that concentric circle gets around, some of the outer bits get around and behind. So the interesting thing here is that you've got a laser beam that for very tiny objects is uninterruptible, like it'll just it'll. If you were to interrupt that light, it reforms on the

other side. It almost seems like magic when you think about it, because it's like, uh, you've you've blocked off that little dot from the source, and yet it still reappears on the other side of the object. So if a beam of light can reform on the other side of an object, I wonder if there's a way to time it so that when the beam hits the object, it's at a low energy in its wavelength, and when it reforms on the back of the object. It's at

a high energy. Well, gosh, Joe, it's almost like you read that script you road, because in fact, that's exactly what scientists have managed to do. They've managed to exactly yeah, well with with with with two of these vessel beams. When you when you yeah, yeah, when you when you when you bend two of them together and kind of focus them correctly, right right. What happens is you you create a greater amount of pressure on the back side of this tiny, tiny object. Remember we're talking about on

the micro scale here here. Uh, then you can create enough force to push it toward what is the source of that light. So, uh, it's exactly what you said, Joe. You've got a lower amount of pressure on the front side and a greater amount on the back side, and that's what creates this movement. So this is one way that scientists have discovered where you can actually use light to move objects. Now keep in mind this is tiny,

tiny scale. We'll get into scalability issue. I know, Joe, you're chopping at the bit to talk about that, But we have another unusual and exotic way of using light

to manipulate objects. And in fact, it's this the second method is incredibly technical, and we're really just going to give an overview of it because to go into great detail would one require that we'd actually bring someone in who is a particle physicist, a particle physicist, because that's how complex an optical physicist, Yeah right, you know, photons

of particles. But or we could uh this fight later, geek fight um, or we can uh you know, so we've had to either bring in an expert or we would spend a lot of time gesticulating wildly in an audio podcast room, which does not translate so well in audio format. It's it would be fine for us, but y'all listening might be a little bit, right, Yeah, so we'll do our best here. Let's let's talk about this.

So it's this is from uh some some researchers who are working out of both Scotland and the Czech Republic. It's kind of a it's a it's a consortium of of scientists and engineers who are working on this. And and then this was just first published in on January. So this is really cutting edge. Yes, this is really really new and exciting stuff. But it's also the closest thing to the Sci Fi tractor beam that we've seen yet. It is and what's being used. They're using a Gaussian

laser beam. A linearly polarized polarization is referring to if you think about the movements of a photon, they tend to move generally speaking, this is really simplifying, but they tend to move into planes, a horizontal plane, in a vertical plane. Polarized light you can you can polarize light in such a way so that it all moves within a single plane, and then you can manipulate that plane so that you are working with a very specific type of light. We actually use this in UH practically in

three D applications. If you have passive three D glasses that are the polarized lenses, then those lenses are polarized in such a way to allow one type of light through the lens while blocking another type. This allows you to get two different um UH types of light in you know, one in each lens, so that your brain then combines the images that you're receiving into a single image that gives you that illusion of depth. Right, So it's it's tricking your brain into thinking that there's depth

there when really you're just looking at two different flat images. Okay, but how do they use it so and to move a little balls. All has to do with the geometry of the light. First of all, we should say what they are doing. They are moving tiny, tiny, tiny little balls a little little styrene spheres that are suspended in fluid.

And I think one thing that's interesting is a lot of these tests they seem to be dependent on the conditions, right, so like we can move something this size in air, or we can move something this size and a vacuum, or and in this they were talking about suspended in water, right And and this would obviously be something that would be interesting again in biomedical UH applications, where you're talking about lots of different fluids and particles that you might

want to be able to move around. One of the cool things about this is depending upon the geometry of the light that they used, they could manipulate certain sized objects while leaving everything else alone. So you could be very specific and hone in on exactly the size of particle that you want to UH to manipulate while ignoring all other particles. Wow, I bet that makes a lot

of people in medical apps salivate. Yeah, because you're talking about sorting on an incredibly precise basis very exciting, like a laser sifter, right right. What was really exciting to me about this research is that they said that under certain conditions, objects held by the beam would automatically rearrange themselves to make the pulse stronger. I don't even know

what that means. That's yeah, it's we're getting into star trek territory here with reversing the poet, and you're like brain washing the balls the polystyrene spears, your brainwashing them to do your bidding. Okay, all right, so these spears tended to be but for the for this particular research project, we're between about four and ten nanometers to one thousand nanometers or one micron in size, and one thousand nanometers that's huge to an atom. Yes, to us, it is

incredibly tiny. It's pretty big for being pulled by light. Yeah, I being pushed around by photons. That's not bad at all. Yeah. I can actually quote a little bit of this. So here here's an example of how complex this gets, right to the point where we would need to have a specialist in here to really explain in Layman's terms, what's

going on there? We go The optical force originating from the Galcian intensity profile normal distribution along the z axis attracts the particles towards the center and so acts against both the pulling or the pushing forces, as it was explained in figures to A. B. C. Of the main text. Therefore, if the beam is switched on or its polarization has changed, the pulling or pushing forces propelled the particles to their

new equilibrium positions established in the Gaussian beams. To develop an appropriate theoretical description of the geometry, we need to take into account not only the Gaussian beam intensity profile dragging particles to the beam center, but also the influence of the scattered field reflected on the mirror back towards

the particle. This means that they were using a mirror to um to help create interference within this Gaussian beam, and Gaussian beams, we should say, are our beams that are stronger in the center than they are at the at the outsides. So again, it's similar to that vessel beam approach where they were using two vessel beams in order to interfere with one another and create that pressure but in this case, you're using a beam to interfere

with itself, one beam in a mirror. Yeah. And the other thing that's interesting that uh you you might not have caught from that passage you read, but they can change how the beam interacts with the particles by messing with the polarity. Right, So if you tweak the polarity of the beam, you could say push instead of pull. Right. Yeah, So it gives you a lot of different options for manipulating these these uh, microscopic or smaller objects. Now it's

you know, this lends itself to lots of different applications. Uh, and that we're just starting to kind of consider right now because we're still in the very much the early early stages of developing this technology. But you could hypothetically sort um different kinds of particulates out of something that you didn't want in there. You could use it to sort um diseased cells versus healthy cells, or or bacteria

versus healthy cells. Right. If the stuff you wanted to take out of a solution, whether it was within a person or in a you know, some some sort of chemical whatever. Um, as long as that stuff was of a very specific size, that was different from all the stuff you wanted to leave in. This would be a great way of doing it because you would know automatically that your methodology you was not going to pick up anything you didn't want. It was just gonna concentrate on

the stuff you wanted to remove. Because again, that geometry only allows this light to interact with particles of a specific size and it ignores everything else as far as the pulling is concerned. You know, there's another good tangent on what these types of lasers can do in in tiny town. Uh, they said the vessel beams, So the one from the first study we talked about that. They said, those are really cool for what's called optical injection. So

what is that. That's where you use a laser to stab a hole right in a cell and that allows things that you're trying to put in the cell to flood in. Gotch. So if you wanted to without necessarily

killing the cell. Right. So, So, if you're doing some medical research and you really needed to be able to manipulate cells on an individual basis and see what a particular type of medication perhaps might do, or if you just need to study the cell and you need to insert some form of chemical so it will show up on whatever imaging technique you're using. Then these could be very useful techniques. It's kind of interesting stuff. So so Joe, let's let's talk a little bit about scaling this up.

So we figured out that we can use light to pull stuff what we want toward us. What if the stuff what we want is really big, Like, let's say it's not even that big. Let's say it's a I don't know the size of a soccer ball or football to our friends in Europe or or yeah, okay, or or size like a podcast host or something like that. Don't bring me into this. I don't want to get burned up by your laser. Yeah. Part of the problem is, uh so immediately, of course, when this study came out,

everybody is like, oh, yes, we've got tractor being. We can reel in ships. We can, you know we can. We don't have to worry about asteroids that because we can just use the tractor beam to reposition it. Who needs a tether for spacewalking anymore? Right? You know, you go outside for a stroll. That's how the International Space Station. You just take a walk. You get lost. Oh and you're back home, and it makes that noise too, even

in the reaches of space. No. Part of the problem is that, um, these beams require a lot of energy, and if you were to scale them up so that they were powerful enough to move heavier objects, they'd be delivering more and more energy as you did that, which, of course, when it strikes the object would turn into heat. So you're essentially developing a thermal weapon as opposed to a tractor beam. Yeah, it'd be like, well, it would be more like a blaster if we want to stick

with Star Wars or a phaser. If we're talking story, Hey, how about like a like a death Star planet killer weapon and something like that. Instead of moving the asteroid, you've just delivered a huge amount of thermal energy. Snow, it's a really hot rock that's heading to our Maybe maybe they were really just trying to move Alderan somewhere. Maybe they didn't want to destroy it. I'm pretty sure

got off. Tarkin was pretty clear on his intentions, and I don't even note see based on the scientists that I read, I don't even know if it's technically possible to pull things that at a huge scale, but I know that this this heating up objection exists, so you definitely destroy it in the process of pulling it, even

if you could pull it. So if you were if you were a space station trying to pull a shuttle into dock, then you would suddenly have this molten slag coming towards your space station as opposed to you know, that would be the best case scenario, right So anyway, Yeah, so that that's why even with this amazing breakthrough, and we don't mean to to diminish it at all. It

is phenomenal and really exciting stuff. It's it does not mean that we are going to arrive at some sort of science fiction future where we are going to have these tractor beams in regular use, either here on Earth or in space on the map acro scale. One thing that I think it's really interesting is it's come up multiple times now in this podcast. Is the place where they're really thinking that tractor beam is going to be useful is the small scale over and over inner space. Yeah,

I mean I wouldn't have even imagined that. Yeah, it's it's super awesome and interesting. It's just not the way that science fiction authors had envisioned it when they were first. And really, you know a lot of the stuff that science fiction authors create tend to be like placeholders, this idea of there's this one problem that you would face if you were out in space. How do we get around that? What? What kind of what kind of technology

can we invent? So everything from artificial gravity to inertial dampeners to warp drive things that help you get around what would otherwise be huge problems When you get into science fiction e. Space exploration type situations, Uh, you know, you have to invent these these somewhat magical devices that would counteract fundamental issues that you would run into otherwise.

Tractor beams are just one example of that. But there's those fundamental physics are it's you know, still existent on the small scale and are what we are much more capable of of working with here on Earth. Yeah. Yeah, And and there's no there's no reason to say that tractor beams themselves will always be impossible on a macro scale. They just won't be using lasers necessarily. We might be

using something else. But before we you know, dive into that, I think we should say that for a completely separate discussion, we're gonna talk about the science fiction of tractor beams, how they've been used, and also some potential you know, science fiction e kind of ways We might be able to attain that in the future, assuming that the math proves true and that some theoretical or rather hypothetical particles actually exist. But that's that's something we'll say for the

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