WEBVTT - TechStuff is Caught in a Tractor Beam 0:00:02.480 --> 0:00:05.480 Get in touch with technology with tech Stuff from how 0:00:05.559 --> 0:00:14.280 Stuff Looks Common Hated everyone and Welcome to tech Stuff. 0:00:14.480 --> 0:00:16.599 My name is John and Strickland. I'm one of the 0:00:16.640 --> 0:00:19.279 two hosts of our show, and I'm Lauren Volke Bam 0:00:19.280 --> 0:00:21.240 and I'm not going to laugh at all this episode. 0:00:21.520 --> 0:00:24.040 All right, that's fair. Podcasting is a very serious business. 0:00:24.040 --> 0:00:26.000 It is. Let us, let us be somber, despite the 0:00:26.000 --> 0:00:29.680 fact we're talking about a really cool futuristic technology. Tractor 0:00:29.760 --> 0:00:32.640 bean tractor beans. Yes, yeah, this is This was something 0:00:32.680 --> 0:00:35.440 that Lauren had suggested because she saw an item in 0:00:35.479 --> 0:00:37.840 the news, and at the time, I would imagine Lauren 0:00:37.920 --> 0:00:41.360 had no idea how incredibly complex a topic this would 0:00:41.360 --> 0:00:43.080 turn out to be. Yeah, as it turns out, particle 0:00:43.080 --> 0:00:47.519 physics is not simple necessarily, but we're gonna tackle it anyway. 0:00:47.640 --> 0:00:49.279 We are. We are indeed, because you know what, we've 0:00:49.280 --> 0:00:51.080 watched a lot of Star Trek between the two of us. 0:00:51.159 --> 0:00:53.560 We have faith in ourselves. So let's let's talk about 0:00:53.560 --> 0:00:56.640 what tractor beam is, especially in that realm of science fiction, 0:00:56.640 --> 0:00:59.240 because I think that's where most people have encountered the 0:00:59.360 --> 0:01:02.640 original Ida, right sure, and especially since tractor beams do 0:01:02.680 --> 0:01:06.360 not exist as such in three dimensions in the real world, 0:01:06.440 --> 0:01:09.480 yet not on the macro level anyway, right, not not 0:01:09.640 --> 0:01:12.080 nothing that you could see with your own two eyeballs. Right, 0:01:12.360 --> 0:01:17.600 So essentially it's a intergalactic tow truck kind of thing 0:01:18.680 --> 0:01:21.680 beam of light that can be used to pull objects 0:01:21.720 --> 0:01:24.160 towards the source of that light. Yeah, which is that's 0:01:24.160 --> 0:01:28.639 pretty phenomenal because, as we understand in physics, light does 0:01:28.680 --> 0:01:33.480 in fact exert a pressure. You might push stuff. Kepler 0:01:33.520 --> 0:01:37.120 said that, Yep, exactly, Yep, yep, Kepler. Kepler observed this, 0:01:37.200 --> 0:01:40.200 and in fact it serves as the basis for uh 0:01:40.360 --> 0:01:44.560 futuristic technologies such as sun sales somewhere sales. These would 0:01:44.600 --> 0:01:49.120 be enormous sales, literally sales that you would extend from 0:01:49.240 --> 0:01:53.760 a spacecraft and allow sunlight to press against the sale 0:01:53.800 --> 0:01:57.320 and thus propelled the StarCraft. Because you're talking about being 0:01:57.360 --> 0:02:00.600 in an environment where there's no there's no graby that's 0:02:00.640 --> 0:02:03.600 affecting you apart from well, I mean, they're gonna have 0:02:03.640 --> 0:02:06.600 gravity within the Solar System, but you're not working like 0:02:06.640 --> 0:02:09.000 trying to escape gravity. At that point. You're actually already 0:02:09.000 --> 0:02:12.959 out in space, so you're not having to worry as 0:02:13.040 --> 0:02:16.120 much about things like friction and gravity, so smaller forces, 0:02:16.160 --> 0:02:22.519 for example, photons can so. So to have a kind 0:02:22.520 --> 0:02:25.560 of light that would be able to trap an object 0:02:25.639 --> 0:02:29.600 and even pull it in is sort of counterintuitive based 0:02:29.680 --> 0:02:33.400 upon the knowledge that photons can push stuff away. So 0:02:33.960 --> 0:02:36.760 we've seen tractor beams used in lots of different science 0:02:36.760 --> 0:02:38.720 fiction you. Star Trek, of course, is one of the 0:02:38.760 --> 0:02:41.480 big examples. Yeah. The first reference was actually in The 0:02:41.480 --> 0:02:44.080 Skylark of Space, which was a drama by East Smith, 0:02:44.080 --> 0:02:49.800 originally serialized and published a novel in I did not 0:02:49.880 --> 0:02:52.000 know that. I do know that it's used in Star 0:02:52.080 --> 0:02:55.000 Trek quite a bit. Uh. There are two things that 0:02:55.080 --> 0:02:57.480 you have to remember about Star Trek tractor beams. They 0:02:57.480 --> 0:03:00.720 can pull just about anything any air, and if you 0:03:00.760 --> 0:03:03.480 reverse the polarity, you can turn it into a weapon. Well, 0:03:03.560 --> 0:03:05.760 reversing the polarity, as we all know, is how you 0:03:05.760 --> 0:03:08.360 do things in Star Trek. Yeah, I was explaining earlier. 0:03:08.400 --> 0:03:10.480 It is the have you tried turning it off and 0:03:10.520 --> 0:03:13.520 on again approach in Star Trek. If if it's something's 0:03:13.560 --> 0:03:17.480 not working, reverse the polarity and then it works. Uh. 0:03:17.680 --> 0:03:19.760 And then of course in Star Wars it was used 0:03:20.200 --> 0:03:24.120 the Death Star catches the Millennium Falcon in a tractor 0:03:24.200 --> 0:03:26.799 beam and a series of tractor beings a whole connexus 0:03:26.800 --> 0:03:28.840 of tractor being right and pulls it back into the 0:03:28.840 --> 0:03:31.239 Death Star so that the Millenium Falcon cannot make its 0:03:31.400 --> 0:03:34.800 daring escape. This, of course allows Darth Vader to face 0:03:34.840 --> 0:03:37.520 off against Obi Wan Kenobi, and I could go on, 0:03:37.680 --> 0:03:40.000 but that's not what this episode is about. Also, I 0:03:40.040 --> 0:03:43.120 suspect that a few of our listeners have seen Star Wars, 0:03:43.120 --> 0:03:46.720 maybe one or two. Episode four is amazing. If you 0:03:46.720 --> 0:03:48.360 have not seen it, you need to go check it out. 0:03:48.600 --> 0:03:52.040 But anyway, Yeah, so, so science fiction is one of 0:03:52.040 --> 0:03:56.120 those things that is a really useful tool for storytellers. Uh, 0:03:56.280 --> 0:03:59.840 if they have a story about a ship encountering so 0:04:00.120 --> 0:04:03.400 sort of wreck or other kind of of body out 0:04:03.400 --> 0:04:05.880 in space, it needs to be pulled away. And the 0:04:06.000 --> 0:04:08.200 nice thing is is that we've got scientists here on 0:04:08.240 --> 0:04:11.520 Earth who are saying, hey, how can we do this 0:04:11.600 --> 0:04:16.200 science fiction thing for reels? Right? Knowing how light behaves 0:04:16.279 --> 0:04:18.880 and uh, and maybe finding new ways to make light 0:04:18.960 --> 0:04:23.080 behave in perhaps an unexpected fashion. Well, I suspect that, 0:04:23.120 --> 0:04:26.160 in fact, Star Trek used some actual research that was 0:04:26.200 --> 0:04:28.280 going on in the nineteen sixties as a basis for 0:04:28.279 --> 0:04:31.279 their tractor beam, because according according to the Star Trek universe, 0:04:31.320 --> 0:04:33.960 the way that their tractor beam works is it's actually 0:04:34.040 --> 0:04:36.440 a graviton force beam. And I just made a little 0:04:36.520 --> 0:04:38.799 quote marks in the air for the benefit of nobody. Really, 0:04:38.839 --> 0:04:44.120 so that was weird. Gravitons are hypothetical particles that that 0:04:44.320 --> 0:04:49.000 essentially mediate the force of gravity. Uh, they're hypothetical because 0:04:49.000 --> 0:04:52.280 we have not observed an actual graviton. We don't know 0:04:52.360 --> 0:04:54.920 how we would. We don't we know that in order 0:04:55.040 --> 0:04:58.720 for our quantum model of the universe to make sense, 0:04:59.360 --> 0:05:03.320 we need something like a graviton to exist to explain 0:05:03.360 --> 0:05:06.640 the force of gravity. There are four fundamental forces in 0:05:06.680 --> 0:05:11.440 the universe. There's strong, nuclear, weak nuclear, electro magnetic, and gravity. 0:05:11.680 --> 0:05:14.200 Out of those, gravity is the weakest, but it's also 0:05:14.240 --> 0:05:18.160 the one that we cannot easily incorporate into the quantum 0:05:18.320 --> 0:05:22.240 model of physics. Right, It's sort of assumed by Einstein's 0:05:22.279 --> 0:05:25.680 general theory of relativity that gravitational waves are a thing 0:05:25.760 --> 0:05:30.400 that exists that ripples in the spacetime continuum caused by 0:05:30.640 --> 0:05:34.600 very large moving objects, particularly, but nobody has detected these 0:05:34.760 --> 0:05:37.320 so so really the way we observe this is through 0:05:37.760 --> 0:05:40.039 the force of gravity. I mean, that's that's that's we 0:05:40.080 --> 0:05:42.880 can see the outcome. We just can't we can explain 0:05:43.520 --> 0:05:46.640 exactly so, And to to explain to you guys how 0:05:46.720 --> 0:05:49.919 weak gravity is in comparison to the other forces, here's 0:05:49.920 --> 0:05:53.800 a very simple, uh experiment anyone can do anyone who 0:05:53.800 --> 0:05:57.120 has access to a comb and a balloon. So let's 0:05:57.160 --> 0:05:59.360 say you've got you know, get a balloon. You've just 0:05:59.600 --> 0:06:02.640 inflay the balloon with oxygen. Don't do helium because that 0:06:02.640 --> 0:06:06.359 will negate the results of this test. Check. So oxygen 0:06:06.440 --> 0:06:09.720 inflated balloon, you sat down on a table. Gravity is 0:06:09.760 --> 0:06:14.000 pulling the balloon downward. I am oversimplifying here, so physicists 0:06:14.000 --> 0:06:17.400 please don't don't write in and complain. But the balloon 0:06:17.520 --> 0:06:20.040 is held to the table in part due to friction, 0:06:20.080 --> 0:06:22.880 but also in part due to gravity. If you were 0:06:22.880 --> 0:06:26.120 to take your comb and rub it against say a sweater, 0:06:26.520 --> 0:06:28.839 and get built up some stag electricity on the comb, 0:06:28.880 --> 0:06:31.240 and then touch the comb to the balloon and lift, 0:06:31.640 --> 0:06:34.400 you would see that the stag electricity that was generated 0:06:34.720 --> 0:06:37.240 while you were rubbing the comb against your your sweater 0:06:37.760 --> 0:06:40.960 would be enough to attract the balloon and lifted off 0:06:40.960 --> 0:06:44.520 the table. That means that the any amount of electromatic force, 0:06:44.680 --> 0:06:47.080 the static is stronger than the gravity. And the gravity, Yeah, 0:06:47.080 --> 0:06:50.640 You've got an entire planet beneath you that that is 0:06:51.160 --> 0:06:55.560 got this very strong gravitational pull, strong in comparison to 0:06:55.720 --> 0:06:58.960 other things that we directly observe throughout the day. And 0:06:59.080 --> 0:07:02.120 yet it is dwarfed by strong enough comb Yeah, strong 0:07:02.200 --> 0:07:04.440 enough to pull a bowling ball from the top of 0:07:04.520 --> 0:07:08.120 tower right right, so, and and gravity just so. To 0:07:08.720 --> 0:07:12.360 complete the whole picture here, it depends on two things. 0:07:12.440 --> 0:07:15.760 It depends on really you have to have two different bodies, 0:07:15.800 --> 0:07:18.760 but it depends on the body's mass and their distance 0:07:18.840 --> 0:07:23.280 from one another. But they do exert gravity, a gravitational 0:07:23.280 --> 0:07:26.400 pull against each other. So, for instance, I have a 0:07:26.440 --> 0:07:29.520 cup of tea in front of me. I am exerting 0:07:29.560 --> 0:07:32.400 a very tiny gravitational pull on the cup of tea, 0:07:32.440 --> 0:07:35.520 and it is exerting a very tiny gravitational pull on me. 0:07:35.560 --> 0:07:38.440 Now this is dwarfed by the fact that I'm also 0:07:38.560 --> 0:07:40.600 on the planet Earth, and that the Earth is exerting 0:07:40.640 --> 0:07:43.960 gravitational force on both of you. Right, So I you know, 0:07:44.000 --> 0:07:46.280 I can't observe this. I don't really, I'm not aware 0:07:46.320 --> 0:07:50.080 of it in any way, but that's that's yeah. So 0:07:51.160 --> 0:07:55.600 keeping that in mind, one easy, relatively easy way of 0:07:55.680 --> 0:07:58.880 having a tractor beam like effect, even though you wouldn't 0:07:59.040 --> 0:08:03.040 be being mean anything, is to use the gravity of 0:08:03.160 --> 0:08:08.040 one object to influence the movement of another object. Now, 0:08:08.080 --> 0:08:11.800 this is something that we've talked about before on tech stuff, 0:08:11.800 --> 0:08:14.760 when we were chatting about could an asteroid destroy the 0:08:14.800 --> 0:08:18.560 Earth if, if, if some space agency. I was gonna 0:08:18.560 --> 0:08:21.240 say NASA because that's the one that I'm most familiar with. 0:08:21.240 --> 0:08:25.440 But if NASA were too identified that an asteroid twenty 0:08:25.520 --> 0:08:32.360 years away has the the uh, the potential to h Yeah, 0:08:32.400 --> 0:08:35.160 that would be a bad thing. Yes, as we all 0:08:35.240 --> 0:08:38.480 learned in the documentary Armageddon. Yes, that wonder whole documentary 0:08:38.520 --> 0:08:40.360 that taught me that Steve Busimmy is a better singer 0:08:40.400 --> 0:08:44.080 than Ben Affleck uh, which I had no way of 0:08:44.120 --> 0:08:47.280 knowing until I saw that anyway, that one way of 0:08:47.400 --> 0:08:52.199 potentially deflecting the asteroid would be to send a spacecraft 0:08:52.280 --> 0:08:55.040 up so that you move the spacecraft so it's close 0:08:55.160 --> 0:08:57.560 enough to the asteroid so that they are are pulling 0:08:57.600 --> 0:09:01.240 one another with a gravitational hole, and then you use 0:09:01.280 --> 0:09:05.560 thrusters with the spacecraft to just very slowly push just 0:09:05.679 --> 0:09:09.040 not really really it's pull. You're yeah, you're pulling the 0:09:09.080 --> 0:09:12.240 asteroid because as you move the spacecraft away, the gravitational 0:09:12.280 --> 0:09:15.200 pull makes the asteroid move with it, and all you 0:09:15.240 --> 0:09:17.320 have to do is move it. The further out you 0:09:17.400 --> 0:09:20.080 go from Earth, the less you need to move the 0:09:20.080 --> 0:09:23.240 asteroids so that it has it misses the Earth, right, 0:09:23.280 --> 0:09:26.360 because you're talking about angles, So a couple of degrees 0:09:26.800 --> 0:09:29.720 of difference way the way way the heck out in 0:09:29.800 --> 0:09:32.760 space to make enough difference to not kill everything on it, right, 0:09:32.760 --> 0:09:34.959 it will miss the planet entirely. So that's the idea. 0:09:35.040 --> 0:09:37.640 So that's kind of like a tractor beam in the 0:09:37.640 --> 0:09:40.280 sense that you're using an object to tow another object, 0:09:40.760 --> 0:09:43.160 in this case objects that are in space, but you're 0:09:43.160 --> 0:09:46.640 not actually shooting a beam of anything, right, However, it's 0:09:46.640 --> 0:09:48.560 not it's not made of light. It doesn't do that 0:09:48.640 --> 0:09:51.400 cool visual effect. Does you have a sound effect, which 0:09:51.480 --> 0:09:55.040 obviously that would not not anything in space anyway? Sure, 0:09:55.720 --> 0:09:59.319 but hey, why why should we start criticizing Now that's 0:09:59.320 --> 0:10:01.920 a that's a whole of an episode. Um and and 0:10:02.400 --> 0:10:05.520 so in the nineteen sixties, people were really excited about 0:10:05.559 --> 0:10:09.160 detecting gravitational waves, and a few people in fact suggested 0:10:09.240 --> 0:10:12.800 that we might make a gravity laser. A couple of people, 0:10:12.800 --> 0:10:16.360 Helper and Laurent, proposed that this could be called a gazer, 0:10:16.520 --> 0:10:19.320 which I think is a terrific word. Yeah, and I 0:10:19.360 --> 0:10:22.640 think means something entirely different. These are modern times, I think, yeah, 0:10:22.679 --> 0:10:24.319 I think I agree with you. I think at this 0:10:24.400 --> 0:10:28.640 point the scientific community would say, can we can? We can? 0:10:28.640 --> 0:10:33.000 We can? We vote on this um. They proposed that 0:10:33.080 --> 0:10:35.959 we could vibrate sometimes of electric crystals and create a 0:10:35.960 --> 0:10:38.400 whole thing, And but that's it's never really come to 0:10:38.480 --> 0:10:42.280 fruition because the above re we have never discovered gravitons, 0:10:42.360 --> 0:10:45.320 We have never measured gravitational waves. Right, for us to 0:10:45.400 --> 0:10:48.480 be able to create an object that would use gravitons 0:10:48.600 --> 0:10:51.440 to to make a tractor beam, we first sort of 0:10:51.520 --> 0:10:54.559 need to prove that gravitons in fact exist, yes, because 0:10:54.559 --> 0:10:56.800 again they're hypothetical right now. It's sort of like the 0:10:56.880 --> 0:11:00.840 Higgs boson, right The Higgs boson was a theoretical particle 0:11:00.960 --> 0:11:05.280 that physicists said for our understanding of the universe to 0:11:05.440 --> 0:11:09.760 make sense, we need this thing to exist to explain 0:11:09.840 --> 0:11:13.080 why matter has mass same sort of thing. In order 0:11:13.120 --> 0:11:16.280 for our understanding of gravity to make sense within the 0:11:16.920 --> 0:11:19.719 within the framework that we have of our knowledge of 0:11:19.760 --> 0:11:23.439 the universe, knowing that we are by our very nature 0:11:23.559 --> 0:11:27.720 limited in our understanding, a graviton needs to exist for 0:11:27.880 --> 0:11:32.640 that model to really make sense. So we're talking about mathematically, yes, 0:11:33.160 --> 0:11:35.960 these things have to exist, but in reality we just 0:11:36.160 --> 0:11:38.640 haven't tracked it down yet. So if we ever do, 0:11:38.920 --> 0:11:42.319 maybe we can make some sort of technology that can 0:11:42.360 --> 0:11:45.400 take advantage of that. But until then, until then, maybe 0:11:45.400 --> 0:11:49.719 no gravitational lasers. Yeah, I personally hope that we do 0:11:49.960 --> 0:11:52.559 crack that nut, because that would be I mean, it 0:11:52.600 --> 0:11:55.920 would be an incredibly useful tool, and not just in 0:11:56.000 --> 0:11:59.160 the context of space exploration. That's the one that we 0:11:59.200 --> 0:12:01.480 all think about, but us again in science fiction, that 0:12:01.520 --> 0:12:04.280 tends to be where tractor beams come into play. But 0:12:04.320 --> 0:12:07.640 as it turns out, tractor beams can have a really 0:12:07.760 --> 0:12:11.880 useful uhuh, well in implementation here on Earth and space 0:12:12.000 --> 0:12:15.319 on the planet, and I mean, moving things is hard, 0:12:16.000 --> 0:12:19.000 they're heavy or even if they're or they're really small, 0:12:19.720 --> 0:12:23.040 and so uh yeah, we'll talk a bit in a 0:12:23.200 --> 0:12:29.520 second all about how some scientists are making micro versions 0:12:29.600 --> 0:12:32.960 of tractor beams here on Earth and what those could 0:12:33.000 --> 0:12:35.679 be used for. But first, let's take a moment to 0:12:35.720 --> 0:12:38.920 thank our sponsor for this episode, and now back to 0:12:38.920 --> 0:12:41.559 the show. All right, So we've talked about using gravity 0:12:41.920 --> 0:12:46.040 to create a tractor beam like effect, or possibly even 0:12:46.120 --> 0:12:49.800 using gravitons, assuming we ever understand them. But that's not 0:12:49.880 --> 0:12:53.480 the only way scientists are looking into creating a tractor 0:12:53.520 --> 0:12:56.760 beam like device. There's actually been quite a bit of 0:12:56.760 --> 0:13:01.959 news over the last decade about scientists using various ways 0:13:02.160 --> 0:13:06.160 of manipulating light to pull an object as opposed to 0:13:06.200 --> 0:13:09.959 push it away. Right, Starting way back in six people 0:13:10.120 --> 0:13:14.079 started playing with what's called optical tweezers, which are lasers 0:13:14.080 --> 0:13:18.160 that are capable of manipulating molecules and moving them with precision. 0:13:18.600 --> 0:13:22.840 And now this is not pulling a particle towards the 0:13:22.920 --> 0:13:26.120 light source, so it's not technically attractor beam, right, but 0:13:26.200 --> 0:13:30.160 it is. It is a method of manipulating microscopic particles 0:13:30.280 --> 0:13:32.920 very precisely. So if you're thinking about a plane like 0:13:32.960 --> 0:13:37.040 an X and y axis, you could move particles within 0:13:37.120 --> 0:13:39.439 the X and y axis, but you're not moving them 0:13:39.440 --> 0:13:42.360 along the Z axis. That would be you know, from 0:13:42.400 --> 0:13:45.480 the source of light to wherever the particle is. So 0:13:45.600 --> 0:13:47.840 in relation to the source of light, the particle would 0:13:47.880 --> 0:13:51.200 not get closer further away, but you could trap it 0:13:51.320 --> 0:13:54.920 and move it within that x y plane. That's that's 0:13:54.920 --> 0:13:57.800 my understanding. Yeah, yeah, and these are well, I I 0:13:58.120 --> 0:14:00.719 that's my understanding as well. These the laser beams that 0:14:00.760 --> 0:14:03.640 are being used for this have a Gaussian intensity profiles, 0:14:03.679 --> 0:14:05.960 which means that they're brighter in the center than they 0:14:05.960 --> 0:14:09.040 are at the edges. Right. A Gaussian distribution is a 0:14:09.080 --> 0:14:13.839 normal distribution, and it can be for anything from lasers too. Really, 0:14:13.960 --> 0:14:16.240 you can even see this in social sciences where you 0:14:16.280 --> 0:14:18.840 do a survey and you have a bell curve that 0:14:18.840 --> 0:14:23.600 shows a normal distribution that's essentially a Gaussian distribution. So, okay, 0:14:23.720 --> 0:14:26.360 light has momentum right, right, and so when it hits 0:14:26.360 --> 0:14:29.680 an object, the object bends the light, which changes its momentum, 0:14:30.040 --> 0:14:33.400 and thus the object is pushed back equally and oppositely 0:14:33.520 --> 0:14:36.320 by the light. Okay, I see, so the lights momentum 0:14:36.320 --> 0:14:39.560 has changed. The object's momentum is also changed, correct according 0:14:39.560 --> 0:14:41.960 to the conservation of momentum, which you can see in 0:14:42.360 --> 0:14:48.280 normal non microscopic classic physics. Right, And so the Gaussian 0:14:48.320 --> 0:14:50.480 beam is important because if the sample gets off center 0:14:50.560 --> 0:14:52.280 in the beam, the weaker light of the edges is 0:14:52.320 --> 0:14:54.720 bending around the object and pushing it out, but the 0:14:54.720 --> 0:14:57.120 stronger lighted center is bending around it and pushing it 0:14:57.160 --> 0:15:00.920 back in, and the stronger force winds. I see. Oh okay, yeah, 0:15:01.000 --> 0:15:03.400 that makes way more sense than everything else I read, 0:15:04.040 --> 0:15:06.760 because everything I read was a lot of this. This 0:15:07.120 --> 0:15:09.520 research that we did for this particular podcast is in 0:15:09.840 --> 0:15:12.440 is from scientific journals and uh, and this is a 0:15:12.440 --> 0:15:15.200 good point for us to make. Lauren and I we're 0:15:15.280 --> 0:15:20.600 advocates of science education. We both love science. That being said, 0:15:20.640 --> 0:15:23.840 neither of us are scientists, and we certainly are not 0:15:23.920 --> 0:15:26.960 particle physicists. And so when you get down to the 0:15:27.040 --> 0:15:30.640 quantum level, there's a certain level of understanding that we 0:15:30.680 --> 0:15:33.760 are able to achieve. And beyond that, this stuff is 0:15:33.840 --> 0:15:36.280 my It is like magic to us. So we're going 0:15:36.320 --> 0:15:39.520 to explain things as best we can, but please understand 0:15:39.560 --> 0:15:44.000 there are subtleties to this that we cannot easily uh explain, 0:15:44.040 --> 0:15:47.360 because we haven't dedicated our lives to understanding them exactly. 0:15:48.000 --> 0:15:50.320 And and but so if we get anything wrong, please 0:15:50.360 --> 0:15:52.600 do right us in Um, we love getting that kind 0:15:52.640 --> 0:15:56.040 of feedback, right, Yeah, No, we definitely want to to 0:15:56.080 --> 0:15:59.440 communicate the correct information as best we can. But uh, 0:15:59.480 --> 0:16:02.240 you know this, this is exciting stuff. So in this case, 0:16:02.320 --> 0:16:06.400 what Laurence talking about is using light to to uh 0:16:07.120 --> 0:16:13.120 to isolate and then manipulate microscopic particles. But at this 0:16:13.160 --> 0:16:15.960 point the stage what we're talking about does not include 0:16:16.040 --> 0:16:20.560 pulling those particles towards the light source. However, we have discovered, 0:16:20.720 --> 0:16:24.240 or rather I should say we not reedibly smart people 0:16:24.280 --> 0:16:27.360 have discovered ways of using light to actually pull things 0:16:27.440 --> 0:16:31.080 towards the source in a bunch of different ways. Actually, um, 0:16:31.120 --> 0:16:35.240 there's one of those is called an optical vortex. Um. 0:16:35.400 --> 0:16:39.680 Sounds kind of kind of freaky, uh people. The the 0:16:39.680 --> 0:16:42.400 main research that I've read from this was from Australian 0:16:42.480 --> 0:16:47.600 National University around so pretty recently, and the the idea 0:16:47.600 --> 0:16:50.160 of this one is that they use a hollow laser 0:16:50.160 --> 0:16:55.160 beam to trap light absorbing particles, and um, they get 0:16:55.200 --> 0:16:57.320 trapped in the center of this laser beam because the 0:16:57.440 --> 0:17:01.320 heated air molecules around them are pushing in on them goutches, 0:17:01.440 --> 0:17:04.080 so they cannot they can't escape the laser beam. They're 0:17:04.080 --> 0:17:06.720 stuck in that little hollow center in the hollow center 0:17:06.840 --> 0:17:12.840 in the in the the doughnuts shaped laguer Gaussian laser beam. Yes, 0:17:13.359 --> 0:17:16.399 that right there, that thing exactly that you just said. Yeah, 0:17:16.560 --> 0:17:19.720 I have the note. I'm so glad that you did 0:17:19.760 --> 0:17:22.040 more research on this, because when I read that, my 0:17:22.119 --> 0:17:24.840 eyes kind of glazed over. Yeah. Apparently they were able 0:17:24.880 --> 0:17:27.879 to move particles about one and a half meters in 0:17:27.920 --> 0:17:30.520 the air. Yeah, it's it's really exciting. By they found 0:17:30.520 --> 0:17:34.480 out that by using too concentric hollow lasers, they can 0:17:34.760 --> 0:17:36.760 adjust to the brightness of the two of them, there 0:17:36.760 --> 0:17:40.360 by heating and cooling the air around the molecules and 0:17:40.359 --> 0:17:43.920 and then therefore have the molecules move up and down 0:17:43.960 --> 0:17:47.320 as they will through this hollow tube of light. Wow. 0:17:47.520 --> 0:17:49.720 So so you're using two different lasers in order to 0:17:50.280 --> 0:17:52.680 make that maintain this kind of movement. That makes sense, 0:17:52.680 --> 0:17:55.800 I understand now. Yeah, I was wondering how that worked beforehand. 0:17:55.840 --> 0:17:57.639 But yeah, that that totally makes sense. And yeah, and 0:17:57.640 --> 0:18:00.440 these are nanofoam particles that they were using to the 0:18:00.760 --> 0:18:02.960 got transported over a meter and and all of this 0:18:03.040 --> 0:18:06.359 is on the scale again of a very microscopic things. Right, 0:18:06.880 --> 0:18:08.800 That's something that's important, and we'll talk a little bit 0:18:08.840 --> 0:18:11.000 more about that when we finish with all the different 0:18:11.080 --> 0:18:14.920 laser methods. But yeah, the methods we're talking about are 0:18:15.080 --> 0:18:18.640 very exciting, Don't get us wrong. They are incredibly exciting, 0:18:18.680 --> 0:18:23.520 particularly in certain very specific implementations like in the medical field. 0:18:23.560 --> 0:18:26.200 Oh yeah, this is all going to be extremely exciting 0:18:26.240 --> 0:18:31.240 for for example, removing bacteria from samples, sorting cells, imnically 0:18:31.480 --> 0:18:34.119 manipulating DNA strands is something that optical tweezers have been 0:18:34.160 --> 0:18:37.000 used extensively for, right, so that there are really uses 0:18:37.040 --> 0:18:40.159 for this. But these are not the same technologies that 0:18:40.200 --> 0:18:43.960 will let us move spacecraft like toe spacecraft away. And 0:18:43.960 --> 0:18:45.639 we'll talk about why that is when we get a 0:18:45.680 --> 0:18:47.199 little further in, because there are a couple of other 0:18:47.280 --> 0:18:50.560 laser methods that we need to talk about, right right, Um, 0:18:51.119 --> 0:18:53.520 back back on the kind of sale, the sort of 0:18:53.520 --> 0:18:57.840 solar sale theme that we were discussing earlier. Optical lift 0:18:58.119 --> 0:19:02.359 is another version of of light that can be used 0:19:02.359 --> 0:19:05.920 to do stuff. It's it's actually just a really simple 0:19:05.960 --> 0:19:09.800 analog of aerodynamic lift, which of course is when um, 0:19:09.880 --> 0:19:13.960 you create huh, how is it it's higher pressure under 0:19:13.960 --> 0:19:16.640 awing than over a wing, and therefore letting a plane 0:19:16.680 --> 0:19:19.720 lift off the ground in the game. Before we get 0:19:19.720 --> 0:19:24.800 any further physicists, that's also an oversimplification, and we acknowledge that, yes, 0:19:25.040 --> 0:19:28.280 there's more than just there's more than just that when 0:19:28.320 --> 0:19:31.080 it comes to getting an airplane off the ground. Absolutely 0:19:31.080 --> 0:19:33.480 know all about the other forward momentum and everything else, 0:19:33.520 --> 0:19:36.440 but but that that is the concept of lift. Yes, 0:19:37.000 --> 0:19:40.680 thank you, And so to get slightly fewer angry emails, 0:19:40.760 --> 0:19:43.040 it's only because Chris and I received all of those 0:19:43.040 --> 0:19:47.800 emails already, but but deservedly so, right, Oh no, absolutely, yes, 0:19:48.040 --> 0:19:53.120 we love negative feedback. But so I nearly spit tea 0:19:53.200 --> 0:19:56.560 all over my laptop. Please don't take that as a 0:19:56.560 --> 0:19:59.520 as a Please don't take Lawrence. Lawrence's statement as a 0:19:59.760 --> 0:20:02.000 knee means to send us the most negative feedback ever, 0:20:02.080 --> 0:20:06.000 because my feelings do get hurt. Oh and I, I 0:20:06.040 --> 0:20:08.119 apparent you just made a complete liar out of me. 0:20:08.240 --> 0:20:13.960 That you almost snorfing your tea completely made me crack up. Excellent. 0:20:14.240 --> 0:20:19.720 But anyway back to optical lift, it's uh. The scientists 0:20:19.720 --> 0:20:21.800 have discovered that that you can take an object with 0:20:21.840 --> 0:20:24.920 a differently shaped top and bottom surface, and it will 0:20:24.960 --> 0:20:27.560 experience a lift force when placed in a uniform stream 0:20:27.600 --> 0:20:31.640 of light that's fast. This is all blowing my mind 0:20:31.640 --> 0:20:34.800 because before we did this research, I never knew about 0:20:34.840 --> 0:20:37.480 these different properties of light and and it just it 0:20:37.560 --> 0:20:41.280 really stresses to me one amazing universe. This is, you know, 0:20:41.400 --> 0:20:44.760 to know that things behave on such a different level 0:20:44.800 --> 0:20:49.520 than my previous understanding, and also illustrates quite effectively how 0:20:49.560 --> 0:20:53.400 ignorant I am. But I love to learn, so that's okay, Yeah, 0:20:53.440 --> 0:20:55.159 we get we get paid to learn this stuff and 0:20:55.160 --> 0:20:57.120 pass it on to you, which is basically the most 0:20:57.119 --> 0:21:01.199 exciting thing. Um. One of the other categories that I 0:21:01.240 --> 0:21:05.040 ran across were optical conveyors, which are really fun. Those 0:21:05.040 --> 0:21:07.080 are those are the ones that are using bessel beams, 0:21:07.320 --> 0:21:09.240 and I think I think Jonathan has a whole section 0:21:09.280 --> 0:21:10.840 about this one. Yeah, not a whole section, but I 0:21:10.840 --> 0:21:12.959 can at least tell you what a bessel beam is, 0:21:13.040 --> 0:21:16.520 because when I encountered that term, I thought, huh, what 0:21:16.520 --> 0:21:19.280 what exactly do they mean by bessel beam? It's a 0:21:19.320 --> 0:21:24.640 specific type of radiation, and that sort of radiation can 0:21:24.680 --> 0:21:27.879 be a laser, it can be electromagnetic, it can be acoustic, 0:21:27.920 --> 0:21:30.840 it could be gravitational. It doesn't really matter what the 0:21:30.920 --> 0:21:34.600 type of radiation is. It's the form it takes. And 0:21:34.640 --> 0:21:38.600 that form as a radiation where the amplitude is described 0:21:38.640 --> 0:21:41.560 by a Bessel function of the first kind. Does that 0:21:41.640 --> 0:21:46.320 mean essentially, it means that as this radiation moves forward, 0:21:46.720 --> 0:21:50.040 it does not diffract in any way. It doesn't diffuse, 0:21:50.080 --> 0:21:53.720 it does not spread out. In other words, it remains concentrated. 0:21:54.160 --> 0:21:56.399 So what we think of that like a laser beam. 0:21:56.440 --> 0:21:58.880 When you shine a laser beam, it doesn't spread out 0:21:58.920 --> 0:22:02.240 like a flashlight does. But this is a very specific 0:22:02.320 --> 0:22:04.600 format of that. And in fact, because actually those those 0:22:04.680 --> 0:22:07.200 laser beams that were that you point at something are 0:22:07.359 --> 0:22:10.239 Gaussian laser beams. That's we discussed there, and so this 0:22:10.320 --> 0:22:12.840 is different, is different. This is different. It is it 0:22:12.960 --> 0:22:15.960 is focused, It does not diffract in any way, it 0:22:15.960 --> 0:22:19.160 does not spread out at all. And in fact, one 0:22:19.359 --> 0:22:23.480 a a a feature of a true vessel beam would 0:22:23.480 --> 0:22:26.520