TAC_breaking-the-solar-system

追加: 2026-05-19

[00:00:00][Music] okay so yeah we're talking about breaking the solar system today um i just want to thank uh the team astronomy cafe from for inviting me to do this this is great um and i really love talking about science like this so it's it's a great opportunity for me as well as for you to learn things um so just a little bit about me to begin with um i grew up in england as you can probably tell from my accent i was i come from just about 100 miles north west of london when i turned 18 i went to college i went to university in northern ireland in belfast and i did a degree in physics with astrophysics so i had an astrophysics research component of the in the final year and i studied exocomets so these are comets in other solar systems so i did a little project in that and then i carried on queens um at the same university doing my phd in planetary science and so i moved back to observing objects in our own solar system uh mainly transneptunian objects these are minor pies these are icy objects sort of in the same region of the solar system as pluto beyond neptune right at the edge where it's very cold and so i looked at trying to figure out what these objects are made of i also looked at observing those objects as well when they have commentary activity so sometimes they have outputs like in that in the picture on the right here they have a commentary comma and so sometimes we we suspect that they um the surface composition changes as a result of that activity so i did a little bit of work on that too and so today i uh i'm a science fellow as uh jamika very very nicely introduced me uh i'm a science fellow at gemini observatory at nylab i support observatory the observatory era on mauna kea at gemini north and i also do my own solar system research so what do we mean by breaking the solar system this is this is a very sort of evocative title for the uh for the talk i think it's it's a really good one but what do we specifically mean by it um really it's it's uh so we're talking about the orbits of the planets and asking how how is the solar system changed has it always looked like it does now um are the orbits of the planets stable they look pretty stable but are they really stable and what does it take to move a planet my plants are enormous as we all know they're very massive um but it is it possible to move them and if so how um and if we change the the orbit of a planet of one of the planets does that affect the other planets how does it affect the other planets um does the solar system effectively break as we understand it like desired desire is um can we change the way the solar system looks uh enough that it doesn't look familiar to us and so has it broken in the past um how is it broken and it doesn't seem broken anymore and so why is that uh so we'll move on first of all to the orbits and orbital elements of uh the planets just as a as a beginning concept uh all planetary orbits are elliptical they have the they have a number of parameters that define the size and the shape and the um sort of the orientation of the orbit in space and so there's the six parameters that define this uh all clients have elliptical orbits with the the sun at one focus of the ellipse uh so the first of these parameters is the semi-major axis and uh this is the um either it's the uh it's the the furthest distance a planet gets from the center of its orbit uh so this is effectively if you take the long axis of the ellipse what's the um it's half of the dis half of the length of the longest axis essentially and it's basically a proxy for the size of the orbit the eccentricity of the orbit is how elliptical the planet's orbit is so a perfectly circular orbit has an ellipticity eccentricity of zero um and as you squash the orbit more and more as you stretch it out it gets closer and closer to one until an eccentricity of one is basically a straight line um and then at the anything that's bound to the sun in uh in the solar system has an eccentricity of less than one uh but objects like in interstellar objects like uh one eye um or the more recent uh 2i borisov the interstellar comet that came through the solar system they have eccentricities higher than one they're they're on a hyperbolic orbit is what we call it um and so the moon had an eccentricity of 1.2 and uh borisov had an enormous eccentricity of 3.4 which is uh which is very very high for for a planetary object um but most of the time the eccentricities of the planets are much much lower than that they're in there's the range of zero to one so uh the further uh we have four more of these parameters that define the orbits uh a major one is the inclination and so if we can think of the the all of the clients are residing in a in sort of a plane of the solar system and so the solar system is kind of flat and in this flat sort of section the um the orbits can have a tilt relative to that and so this tilt is the inclination uh elements four and five here are the um uh the longitude of ascending known the argument of periapsis these basically just describe the orientation of the orbit in space and then the true anomaly is essentially a parameter that defines where the planet is within its orbit at a given time [Music] of course when talking about orbits uh it would be completely remiss of me to uh ignore the concept of gravity this is the the driving force behind uh the motion of the planets it's a really really important uh thing in orbital mechanics and we define gravity uh the strength of gravity using this equation here and so on on the left side of the equation we obviously have the force of gravity fell by each object if you have two massive objects interacting with each other the gravity of the force on the left for this equation uh g is the gravitational constant that's a constant throughout the universe as far as we know and then we have uh the two masses of the objects we multiply those together and then we divide by the square of the distance between those two objects um this means that object the strength of gravity felt by by an object uh between one object and another or one planet in another is dependent on the masses of those objects so the the more massive objects will feel a stronger force they will be more attracted to each other and the force also weakens as you uh make them more distant but it's important to note that it's not a linear um it's not a linear drop it actually drops as one over r squared so if you increase the distance between two planets by a factor of two then the uh the force of gravity drops by a factor of four and so if you just increase the distance by factor of three then it decreases the gravity by a factor of nine and uh so if things are very distant apart everything within the solar system attracts everything else but if they're very far apart then the gravity um is quite small although over time it can have a big effect so uh next we have angular momentum this is a really really important thing to understand um if uh you take nothing else away from this talk is that uh the angular momentum is really important in the in the way the planets uh their orbits evolve over time so any mass that rotates around a central point has uh probably called angular momentum and uh this is given by the letter l here on the left and it's essentially a multiplication of the linear momentum or the mass of the planet times its velocity multiplied by its uh distance from the sun which means that if a planet is more massive and further from the sun it has much higher angular momentum and this is really interesting because although the sun has most of the mass in the solar system it's it's easily the most the majority of the mass of the entire solar system is contained within the sun it's actually the planets that have most of the angular momentum because they're further from the center of the solar system it's jupiter has the lion's share of that it has a very large charity of the angular exists this uh predicted planet that's beyond neptune like way out in the distant solar system beyond pluto um then it's because of its enormous distance from the sun it will have um most that actually have most the most angular momentum of all the planets um so what's really important as well is that objects can exchange angular momentum when they interact with each other through gravity uh and we exploit this fight when we use plants to speed up spacecraft with gravity assists uh we essentially send the spacecraft past the planet um in a certain way that it picks up a little bit of the uh the client's angular momentum it's it essentially steals that momentum and that velocity from the planet um because the planet is so big it loses like a tiny tiny bit of momentum but it gives a really big boost to the spacecraft and so this is how we send probes like voyager and new horizons to the to the outer sole system so in terms of concepts uh this is the the last one uh orbital resonance is also really important in planetary dynamics so this is essentially when planets fall into a into a pattern of orbits where they uh they have sort of regular interval interactions with a really famous example of this is the the large moons of jupiter so on the left here in the in this animation you can see the moon's io europa and ganymede and they have uh they're all in a mutual resonance with each other where i for every orbit that io performs um europa does sorry but like against backwards it's easy so uh yeah for every two orbits that europa does so sorry every two orbits that io does europa does one orbit and then for every four orbits the io completes ganymede completes one of them so this is it's it's a like very regular numbers of orbits and this has really interesting gravitational effects this can uh cause a stabilizing effect where the the planets essentially become locked together and their orbits can't evolve very much they're kept in a sort of in sort of a static configuration which is the way that the universe likes to be likes to find like a lot of sort of a low energy state that's very stable so in terms of the moons of jupiter this is what we get um in other cases it's like it's it they have unstable resonances where planets actually force objects out of onto onto different orbits so this is this is the case with the asteroids um as you can see in the plot here this is so this is a a part of the the distribution of asperger's the number of asteroids as uh plotted against the the distance from the sun so it's so many major axises in astronomical units one astronomical unit is just the distance the average distance between the earth and the sun so on the left here uh the left left side of the body is just two times the distance from the earth to the sun and on the right is 3.5 times the distance the circle context uh mars is at one point five times so it's over on the on to the left side or off off the block here to the left and then jupiter is at five point two av and the orbits of duke have a big effect on the asteroids um the these these resonances uh here on the the three to one the five to two the seven to three and the two to one resonances actually clear objects out of the asteroid so these are unstable resonances and these are known as these gaps are known as the kirkwood gaps and they're basically regions of the asteroid belt that asteroids don't last very long inside they get they get kicked out of these areas because of jupiter and its resonances so this uh brings us to what does the solar system look like so i'm just going to to dip out of the um presentation i want to show you something i think is really cool and that is this um so this this is this is this is a nasa tool uh this is on the website this is this is free free to look at uh it's essentially you know a tool for for mapping orbits in the solar system uh this is what the solar system looks like today this is it's the the second of april 2022 and this is what the solar system looks like so you have all the planets there's mercury venus earth mars jupiter going out saturn uranus neptune and then finally pluto on the outside and this grid here is the ecliptic this is this is like the average plane of the solar system so i remember how i said it was it's a flat is it relatively flat then all of the objects fall in most of the objects fall into this plane and so just to sort of show you an example if we if we look down on oh i'm looking in the wrong menu there it is um this is what the solution looks like from above and all the planets have some eccentricity to their orbit but you obviously see the pluto as a very eccentric orbit compared to the others um but then the neptune and the earth have probably the most circular orbits of the planets and you'll see also that mercury here is a little bit elliptical too uh and we get different review from the ecliptic we can also see how inclined pluto's orbit is to the rest of the solar system i think it's about 17 degrees if i remember correctly um and so you get a lot of objects especially the smaller objects they fall into this uh ecliptic kind of absolutely inclined site kind of orbit and what's also really cool about this tool is i can play this forward so i can make i can move the planets and so we're running time forward now you see the the clients are moving uh the outer clients obviously are moving a lot slower than the inner ones and if we zoom in on the center there's a very imp very important concept is that everything in the solar system the gravity of everything acts on everything else it might only just be a tiny amount depending on the distance but everything acts on everything else and this includes the sun so although the sun is pretty close to center you'll notice here that it actually moves over time it moves very very slightly uh you can i hope you can see this but yeah it's it's orbiting the center of mass of the solar system so every everything always the the what we call the barycenter of the solar system this is the center of mass and uh this is actually one way that we detect planets we know the planets especially massive ones they cause their stars to wobble like this they move around the center of mass and so we can detect that with spectroscopy and also detect planets in other solar systems by looking at the wobble of their stars and that's the known as the radial velocity method uh so this is basically the planets um this is just really cool i love showing this tool it's uh it's a lot of fun but uh we'll get back to the talk and i'll be i'll be totally remiss if i didn't talk about the the minor planets of the solar system so this these are animations from the uh my iae minor planet center the international astronomical union um and this is real data the these are real asteroids um and so for the context the on the left is the inner solar system you have the orbits of mercury venus from into out in from the center to outwards you have mercury venus earth mars and jupiter and then the inner circle on the right hand side is jupiter's orbit as well and so you have from the center outwards you have jupiter saturn uranus and neptune and the all the all the asteroids are slight that are have different kinds of orbits uh in the red in the red in the left blocks in the center they have the near earth asteroids these are potentially hazardous ones that we have to be careful about we have to watch to make sure they don't hit the earth uh in green is the main asteroid belt this is where a huge number of objects exist between uh mars and jupiter uh these are these are varied various different kinds of asteroids and then in blue uh are the trojan asteroids and these are trapped in in a metastable resonance with jupiter and they essentially follow jupiter around its orbit there's the there's one there's there are two clouds is the the l4 cloud uh that's leading jupiter and then there's the l5 cloud that trails it and then in outer solar system we have a lot of objects a lot of these light blue colored ones are centaurs they're on sort of comet like um orbits and in red we have the kuiper belt and this is where pluto exists way out in the distant solar system all these objects are very cold and tend to be very icy so the solar system as we see it now it looks pretty stable um nothing is moving obviously the plants move but the orbits aren't changing very much um we're not in any sort of danger of things being coming unstable anytime soon but was it always this way and we actually have some evidence that uh that isn't the case and so we suspect what we know from protoplanetary disks when we observe um forming star systems in other parts of the galaxy and from our own theories of uh the physics of these disks we suspect that the minor planets should start off from center from the center of the solar system they should have started kind of rocky and then they should have been carbon rich and then icy as the temperature drops from close to the sun further up and we do generally see that still but there's a lot of mixing so for example in the asteroid belt you get a lot of rocky and carbon-rich objects mixed together it's all it's all jumbled up together um and a lot there are a lot of them are on kind of similar routes and we wouldn't really expect that if things have been static uh for the whole age of the source system similarly in the kite belt way out at the edge you get a lot of icy objects but you also get a lot of carbon-rich objects and in some extreme cases you even get uh incidences where you find icy objects right in the asteroid belt where you wouldn't expect them to be because it's too hot and also you get uh rocky objects out in the kuiper belt and so everything looks a bit scrambled up and that makes us wonder uh you know how how is this how has this happened because asteroids on their own the robots don't change that like i said before with the exchange of angular momentum you need to move you need objects to interact with each other to get them to move their orbits and so this implies that the planets themselves have actually not been where we find them today though they didn't form where they they are today they've actually moved over time so we find other evidence for disruption and planet migration over time the first one on the left here is that mars is actually much smaller than we expected to be as a mass that is half the mass of the earth oh no sorry no it's it's uh it's sorry radius is half the it's half that of earth but its mass is only 10 percent out of it it's a very low density planet uh and this implies that given that it formed in a location that we would expect there to be you know an earth size or a venus sized planet forming but it didn't form into something that big it suggests that maybe there was less material in that region than we originally thought uh and possibly that this material has been cleared out by something else possibly the planet uh we also observe interstellar objects uh this is only in the in the last few years that we've these have been expected to be suspected to exist for a long time it's only been the last few years that we've been observing them and these the way that we think these objects form is that uh through planet migration and interactions with the plants these small objects get kicked out of their solar system completely and actually there's predicted to be lots and lots and lots of these objects out in the in the galaxy but because a lot of them are very very small we haven't had the capability until now to detect them and then another really interesting uh sort of piece of evidence for planet migration is that uranus is tilted over by 97 to 98 degrees and it's all in its inclination so um the the earth is tilted by about 23 degrees but uranus is like it's almost it's basically it's on its side which is really interesting and it's predicted that a collision with something about the size of the earth is actually caused sway back in the early time sources which would suggest that things have been moved around a lot things have been scrambled up uh by planetary interactions and so we have a lot of this of evidence for this um and so if we look at planetary migration uh i just i just want to go over a little bit about how this works this is actually very complicated complicated and complex um sort of topic is that there's a lot of nuances i'm just going to try and provide a sort of an overview in a nutshell here it's all about exchange of angular momentum like i i talked about at the beginning of the talk um so small objects can steal angular momentum from from planets they can also if in different um under different circumstances if they interact in different ways they can also lose angular momentum to planets as well so the the exchange works both ways and so uh the idea is you could have an asteroid exchange angular momentum with a planet you could also have any any any mass so this is like gas molecules or dust particles or asteroids or even other planets uh can change the orbits of over any given part and for asteroids and dust and gas especially even though these are tiny tiny objects when there's a lot of this stuff like a lot of material around the star like there is uh in the protoplanetary disk uh like for example on the right here in this image this is a this is a real image of a protoplanetary disc that was observed with alma and so basically what you're observing here is the the the hot dust in uh this proto planetary disk the dust is heated up by the the light and the radiation from the central star and you'll notice as well there's gaps in this disc and this is actually where planets are actively formed this is this is a basically a star system being born and you'll part the pi itself forming in these gaps uh but what's really important to remember is that this is although this particles are tiny there's a lot of dust a lot of gas in here and it doesn't although on their own these particles don't act very strongly on the plants if there's a lot of this material if you have enough time then although all this exchange of angular momentum adds up very quickly and enough to move a planet the size of jupiter even even bigger planets so that they uh they have this migratory effect um so this is this is the hypothesis is that uh planets have moved over time and that uh you know we can we and the the the protoplanetary disk itself the dust and the gas actually has an effect on why it such that it can move the planetary orbits and so how do we test this idea so one obvious thought would be well we could look at other planetary systems to see if we can detect this planetary vibration and unfortunately what is a great idea and we have a lot of data for the we have a lot of images of these these discs as you can see on the right these are all these are all different real images of protoplanetary disks um as the uh because these products these discs form so slowly it would take millions and millions of years to actually see the full process uh in action so we can we can only really get snapshots of the process so that this is great this is really important information but if we want to understand the physics a lot better we need to be able to watch the whole thing in action and the way we can do this is actually through end body simulations these are dynamical computer simulations you essentially build a solar system virtually on the computer and apply physics and scene uh see how it behaves basically and one simulation can really show us the entire evolution of the planetary system and it's really useful as well because we can pick apart the different physical effects of the different physical uh properties of solar systems to really understand in a detailed way how the dynamics behaves and so the actual process that we use for uh testing our ideas on a computer is we we take our hypothesis and we set the initial conditions of the simulation build the simulation and the virtual solar system how we think it used to be or how uh set it up in a way that we can test the our hypothesis and then we apply the physics we apply the gravity and the uh sometimes as hydro this hydrodynamics is that if there's a lot of gas and um and dust involved uh sometimes there's approximations that have to be made uh but in general we apply the physics to the simulation and then we run the simulation um if you have a lot of dust and gas particles sometimes some simulations have millions of objects in them and they need a supercomputer to run luckily we don't need that for the simulations we'll be doing today we're only doing the nine planets um but if you want to get really sort of hardcore and go into this and do do a lot of objects then you need a super computer and when the simulation is finished this is really important you study what the final system the final virtual solar system looks like and does it does the the dynamical process that you wanted to observe has it had the effect that you expected it to and also you want to ask does the salt does the the virtual solar system you created look like the real solar system does it doesn't behave the way you expect it to and that's how we basically filter out well this simulation is a good simulator because it repeats what we observe and then you can find you can get rid of bad simulations because you know that it doesn't it doesn't have the effect that you expected or it doesn't reproduce the solar system as we observe it so i'll move on to our best theories of how the solar system formed and evolved uh there's the first step is the is the what's known as the grand tack model um and so just to set the scene uh this so this is on the right this is a plot uh basically stepping through time all of these panels uh start uh so basically the start of the solar system and then step forward by 70 000 years 100 000 years 300 000 years and then 500 000 years and then finally 600 thousand years at the bottom so this is like a time series going from top to bottom uh below i just added a little cartoon of the planets as they actually are today this is where this is the distance of uh mercury venus earth mars jupiter and saturn uh and approximately their their present locations um and in this simulation they had uh so the red asteroids here are rocky asteroids the light blue ones are carbon rich they remember how i said before that the close to the sun it's hotter so a lot there's no isons on its rocky ones these are all rocky asteroids and you have carbon rich asteroids and then you have the icy objects out of the edge of the solar system but we think the solar system actually started off a lot more compact so uh jupiter is do all right all the planets here all the they have the large black dots of the giant planet so we have jupiter saturn uranus and neptune and they all started much much closer to the sun than they are today uh these open circles are sort of they're like baby rocky planets like like the earth and beans they're very small they're maybe the size of the moon at the stake but as you can see easy step through time they get larger every time step and eventually get something the size of the earth or beam that's coming out at the end so the solar system started off compact and jupiter finishes forming within 5 million years which seems like a long time to us but compared to the age of the solar system if if you make this if the solar system four and a half billion years of the solar system until today if you put that into a year then jupiter is formed by the time of 9 30 a.m on january 1st like it's really quick really quick off the mark we've put the giant plants formed very very fast um the the terrestrial plants the rocky plants haven't formed yet they take a lot longer um on the same time scale they take about about a week to form which is about 100 million years or so um so jupiter has just finished forming there's a lot of gas and dust still in the disk um and there's also a lot of asteroids a lot of planets and so we want so we take this scenario and we see what happens when we put gas-driven planet migration into the mix what happens to the planets when they exchange the angular momentum for this disk so the singular simulation has run for 500 000 years or half a million years um and basically to start with jupiter loses angular momentum to the to the gas and dust in the disk and starts falling inwards towards the sun it captures a lot of these the the red asteroids here and some of the actually the light blue asteroids the the the rocky and the carbon rich ones they get caught in resonance with jupiter and also get shoved into the inner solar system and jupiter gets very very close to the inner solar system it gets about the orbit of mars at 1.5 a.d and by this time saturn has formed it's it's it's reached a certain reach a certain size where it starts moving as well and gets dragged in as well and saturn moves much faster than jupiter it catches it up and falls into two to one mean motion resonance with jupiter and at this point the exchange of angular momentum changes and they actually become coupled and they start moving back out again they start sort of drifting back out into the outer solar system again at the same time uranus and neptune are also interacting with the disc they're getting larger and forming and they start moving outwards as well uh all the time all these asteroids getting scattered all over the place but the solar system at this stage is the completeness um and there's objects all over the place and the rocky rocky objects are getting sent outwards and then a lot of objects are getting kicked out of the solar system completely uh eventually what happens is that uh jupiter and saturn kind of settle out close-ish to where we find them today and euros uranus and neptune are moving out and uh this actually explains a lot of the uh things about the solar system that we observe so we find a mixture of rocky and carbon rich objects in the escalator which is exactly exactly what we see and also mars the area around where mars formed is is basically where juventus stopped and a lot of the material there has been cleared out completely uh and it's been thrown out of the solar system um and it's been lost so these objects don't there's less material there basically to form ones and another really important thing if saturn hadn't migrated and stopped jupiter from moving like all the way up to the sun then the earth wouldn't exist so we've got saturn to thank for basically saving saving the earth from from early destruction really early on that's not the full end of the story um we have the the nice instability so this has happened 500 million years after the solar system had settled into sort of somewhat stable sort of configuration this is maybe sort of around march time uh in this if you think of the the age of the solar system as a year and jupiter and saturn are mean motion resonance with each other but there's a lot of plant testimonials in the out of the edge of the solar system that's there's this proto kuiper belt there there's a lot of mass a lot of ic objects out there and these tug on the planets and the planets tug on each other and eventually saturn and jupiter pop out of residence suddenly and everything goes bananas again basically the soul the solar system just just breaks and planets start scattering off each other they move around their orbits go all over the place and the um essentially the planetesimals gets scattered as well and eventually everything settles down again into something that's a bit more stable and once once the planetesimals are gone they stop moving the plants so much uh but just so this is this is the plot here on the right this is basically what this is showing but i'll show you some some neat videos uh that go along with this uh because it's it's way more fun to see it as a video rather than an image so i'm just going to show you some clips here so this this is the actual simulation this is real data from from simulation and this is this is based on the plot that i just showed you um so you have all the plants uh in the giant plants and this this plant testimonial disc and essentially they seem fairly stable uh and there's a exchange of any momentum going on and right about i think it's about now coming up it will yeah it pops basically the solar system it explodes and all the planets go everywhere and the uh the solar system more or less kind of forms into what it is today um these plants are scattering off each other and they have really interesting effects so uh this is another simulation i'll just pause this and explain what's going on here so you can see a bit better uh so we have the four giant planets and another planetesimal disc around the edge on the bottom left here is basically this this is a this is a graph of like the resonance of jupiter saturn so when um like the period ratio is two exactly that's when the uh the when they're in resonance and so the the plantation was dragging them out of resonance and there's this gray region which is like an instability region and then and then after that uh it said things kind of settle down a bit after that on the right this is just a time step uh uh it's a time step and the it's the semi-major axes like the average sizes of the orbits of the planets that are being plotted so i'll just run this forward and what you'll see is that the the two outer plants will actually swap and so they swap around in their orbits and they basically pick her and expand so you get these really interesting effects where like you start off with for example the sources will go jupiter saturn neptune uranus and uh actually what happens is that the the two outer planets basically switch around which is uh it is kind of unexpected it's uh it's a strange sort of effect but it's possible this this could have happened interestingly neptune is actually more the more massive is more massive than uranus so it makes sense that you might have performed a more dense part of the disc closer to the center so this this might be what happened uh i'll show you another one um this is another similar effect but it's a bit more drastic um basically the the whole thing just goes bananas again and you get this sort of oscillation of the planets it settles down but yeah your uranus is really sort of uh shaking around and in its orbit here uh and then you get even more interesting ones this one i'll just pause here again just so just to explain so some simulations actually suggest that some of the better simulations that give us better results and what are closer uh view of the soul like closer match the real solar system start with five giant planets instead of four uh there's a prediction that's maybe one of these planets if if this is real and then we start off with five giant fights then one of them may have been kicked out of the solar system completely or in as in this simulation actually one of the plants will impact one of the other one will crash into the other and they'll basically form into one planet um so this is a really interesting concept where the solutions may have may have produced a rogue planet by kicking an entire planet out of the solar system completely or one might have collided with another so uh you'll see two effects the the red the red will crash into i think i think it's again so the the the blue the light blue and the purple will will sort of swap and then like this and then the red one crashes into the purple which is really really cool it's uh you get some really interesting effects when you when you tinker with this sort of thing so hopefully you'll be able to get to do this yourself uh towards the end of this uh this workshop uh just one last one basically so this is this is just a really crazy one that breaks down completely uh one of the points gets lost i think it's the red one yeah the red the red one is the name this one is it is it's a different one but you get these really crazy looking uh animations so yeah this this one doesn't really settle down and get this really eccentric on the outside this is really cool i think at least anyway so that's all the animations i have um [Music] i'm just going to leave up this slide just just to get you thinking about you know the tasks that you're going to be doing next what comes next uh thank you very much for listening it's been great to give this talk uh i think i've run over time just a little bit but i'm happy to take questions thanks very much [Music] you