Speaker 1: Welcome Stuff to Blow Your Mind, a production of I
Speaker 1: Heart Radios How Stuff Works. Hey, you welcome to Stuff
Speaker 1: to Blow your Mind. My name is Robert Lamb and
Speaker 1: I'm Joe McCormick, and we're back with part two of
Speaker 1: our exploration of Sagittarius, a star, the compact radio source,
Speaker 1: the supermassive black hole we think at the center of
Speaker 1: the Milky Way galaxy. Yeah, this is uh so, so,
Speaker 1: as we mentioned in the last episode, we had what
Speaker 1: three episodes we've done previously just on black holes in general,
Speaker 1: and in these two episodes deal with supermassive black holes
Speaker 1: more specifically. Uh and uh yeah, So if you're listening
Speaker 1: to this episode, you do need to have at least
Speaker 1: listened to the previous supermassive black hole episode. But I
Speaker 1: think the supermassive black hole episodes are are are tailored
Speaker 1: to stand on their own without necessarily having listened to
Speaker 1: the previous black hole episodes. In either case, it is
Speaker 1: recommended that you have seen either Walt Disney's The black
Speaker 1: Hole or Event Horizon, so they have a proper basis
Speaker 1: for all of our terrible jokes. Which one of those
Speaker 1: two is more kid friendly? You think, Oh, blow. I
Speaker 1: think it's the Disney movie, but the Disney movie is
Speaker 1: also surprisingly dark. Like, uh, Anthony Perkins is eviscerated by
Speaker 1: a killer robot um Like this is awful scene where
Speaker 1: Maximilian the robots coming at him with the spinning blade
Speaker 1: arm and he holds up like a giant dictionary to
Speaker 1: block it, and he like cuts right through the dictionary
Speaker 1: and uh and you know, apparently like just disembowels Anthony Perkins.
Speaker 1: It cuts out the definition of in trails. Well you
Speaker 1: don't see any in trails, but it's still pretty horrific.
Speaker 1: There's some scary moments in it. But I loved it
Speaker 1: as a kid. I really need to sit down and
Speaker 1: watch it again. Now, speaking of a visceration, we're gonna
Speaker 1: be talking about some somewhat violent events going on around
Speaker 1: a black hole, or at least they presumed black hole today.
Speaker 1: And one thing we promised you last time is that
Speaker 1: we would answer a few questions every You've always wanted
Speaker 1: to know about the supermassive black hole at the center
Speaker 1: of the galaxy, but we're afraid to ask. And one
Speaker 1: of the questions people most often ask about black holes.
Speaker 1: If you're ready to jump right in robert Is. With
Speaker 1: this big supermassive black hole at the center of the
Speaker 1: Milky Way, will the rest of the Milky Way, including Earth,
Speaker 1: one day gets sucked into this black hole? And I
Speaker 1: was trying to find a good answer for this. I
Speaker 1: think the short answer is no, or at least that's
Speaker 1: not a given. All evidence indicates that, of course, the
Speaker 1: Milky Way does have this supermassive black hole at its center.
Speaker 1: The galaxy is sort of orbiting around it, or at
Speaker 1: least roughly orbiting around it, But our Solar system is
Speaker 1: in a stable orbit that is pretty far out. It's
Speaker 1: something like light years away from the galactic center. And
Speaker 1: black holes, even unbelievably giant black holes, still basically behave
Speaker 1: like stars until you get really close to them. They're
Speaker 1: not vacuum cleaners just sucking down the entire universe. You know.
Speaker 1: They're objects traveling through space with a gravitational attraction that
Speaker 1: is a product of their mass and your distance from them,
Speaker 1: and like other objects, if you're far enough away, they're
Speaker 1: gravitational attraction is negligible. So we've got no indication that
Speaker 1: there is a risk of a black hole swallowing our
Speaker 1: Solar system or the Earth or the rest of the
Speaker 1: Milky Way. But of course, if anything as massive as
Speaker 1: a black hole pass near our Solar system, I think,
Speaker 1: I mean that that would be a problem. It might
Speaker 1: not swallow our Solar System, but it's gravitational influence could
Speaker 1: alter the orbits of the planets, which would be not good. Obviously,
Speaker 1: life on Earth depends very heavily on us being where
Speaker 1: we are relative to the Sun and other objects in
Speaker 1: the Solar System staying where they are. You don't want
Speaker 1: to say the orbits of comets and other objects like
Speaker 1: that thrown out of whack, because then that can lead
Speaker 1: to interplanetary bombardment. Yeah. I think the fact that a
Speaker 1: black hole is an object is something that we do
Speaker 1: have to come back to again and again because especially
Speaker 1: with science fiction treatments, especially those especially the Disney black Hole.
Speaker 1: So you know, there's this idea of like thinking of
Speaker 1: it as a whirlpool it's a hungry, hungry hippo, yeah,
Speaker 1: or thinking of it as a tunnel or just an
Speaker 1: open like some of these you know, these analogies. They
Speaker 1: they may be useful to a certain extent. It gives
Speaker 1: us something to picture in our mind, but it kind
Speaker 1: of drifts away from the idea that this is an object.
Speaker 1: This is a highly dense thing, and now, of course
Speaker 1: in the region really close to it, it doesn't behave
Speaker 1: like most other objects too. But once once you get
Speaker 1: farther away, I would say that the ways in which
Speaker 1: it is unique become less relevant to you. Does that
Speaker 1: make sense? Yes? Now, Um, you touched on some of this,
Speaker 1: but but I was looking around like, Okay, what is
Speaker 1: the scenario in which the supermassive black hole at the
Speaker 1: center of our galaxy uh could conceivably destroy us? And
Speaker 1: that there is one very strong possibility. So and we've
Speaker 1: mentioned that our system is again in a stable orbit
Speaker 1: around the galactic center. Um, we're not being pooled pulled
Speaker 1: into Sagittarius M A star. But in four point five
Speaker 1: billion years, the Milky Way galaxy will likely merge with
Speaker 1: the Andromeda galaxy. And when this happens, all bets are off.
Speaker 1: It's possible that everything gets pushed around, gets shuffled around,
Speaker 1: and our solar system then could be gulped up or
Speaker 1: just hideously disrupted by Sagittarius A star in the process. This,
Speaker 1: according to Fabio Pacucci, b Hi Fellow at Harvard University
Speaker 1: and Clay Fellow at the Smithsonian Astrophysical Observatory. He has
Speaker 1: a wonderful ted Ed video about this. So if you
Speaker 1: just go to if you go to YouTube and you
Speaker 1: look up, just look up ted Ed in general, because
Speaker 1: they're great educational short form videos to watch with the
Speaker 1: entire family. We watch them all the time in my household.
Speaker 1: But they have an extra excellent one about black holes
Speaker 1: that Fabio is the contributor for. Yeah, now, when we
Speaker 1: talk about the collision of galaxies, maybe someday we could
Speaker 1: do a whole episode just on the upcoming collision between
Speaker 1: the Milky Way and the Andromeda galaxy because yeah, so
Speaker 1: they're on a collision course. Uh. On one hand, that
Speaker 1: sounds like, okay, so that's just the end of everything, right, Actually,
Speaker 1: I think not necessarily, because you have to remember, well,
Speaker 1: you know there is a lot of space in between stars, right,
Speaker 1: you know, there's there's a lot of space for things
Speaker 1: to go by. But one of the big fears I
Speaker 1: think is not necessarily that like Earth will smash directly
Speaker 1: into a star from Andromeda or something. That the fear
Speaker 1: is about gravitational disruption. Right, things moving past each other
Speaker 1: in space can still have a perturbation effects on on stars,
Speaker 1: on the planet's orbiting stars, on the objects and junk
Speaker 1: in space all around stars. Well, none of that's good. Yeah,
Speaker 1: I mean it's kind of like, and this is a
Speaker 1: terrible analogy, I'm sure, but it's like, if two companies merge,
Speaker 1: your your concern is not that, you know, if you're
Speaker 1: an editor at one company and you emerge with another company,
Speaker 1: you're not concerned that there's another editor over there that
Speaker 1: you're just going to smack into so hard that you
Speaker 1: both explode. No, you're worried about redundancies. You're worried about
Speaker 1: reshuffling of titles and priorities, etcetera. Which you know, all
Speaker 1: of that can be can can certainly be catastrophically disruptive
Speaker 1: to your life. Um, but you're not worried about, you know,
Speaker 1: like physically, you know, exploding or you know, melting into
Speaker 1: them like Ron Silver and time coop. So I guess
Speaker 1: that is possible. I mean, whenever things drift past each
Speaker 1: other in space, there's always a potential for a collision.
Speaker 1: It's just you know that that's not necessarily the thing
Speaker 1: you should be worried about. I think the bigger thing
Speaker 1: would be, Yeah, do you get thrown out of place?
Speaker 1: You get thrown in? You getting thrown into the near
Speaker 1: orbit or towards the black hole would obviously be bad
Speaker 1: and and catastrophic in its own right for sure. Alright,
Speaker 1: So the next big question that that you might be
Speaker 1: wondering about. Could intelligent life forms live of and or
Speaker 1: operate in orbit around a supermassive black hole, specifically our
Speaker 1: supermassive black hole? Uh? You know, how would this factor
Speaker 1: into a like a galactic civilization? Yeah? Or in the
Speaker 1: in the galaxy center more generally, right, can you get
Speaker 1: close to the galaxy center and have life there? This
Speaker 1: seems debatable, right, Like, So there are some scientists who
Speaker 1: think that just the way solar systems have a habitable
Speaker 1: zone for planetary orbits, the galaxy as a whole has
Speaker 1: some kind of habitable zone for star systems. Now in
Speaker 1: star systems, of course, this habitable zone has temperature as
Speaker 1: a primary variable, right, And this depends on the radiation
Speaker 1: coming off of the parent star and how far away
Speaker 1: that planet is from the star. So if your planet
Speaker 1: is too close it's too hot to have liquid water,
Speaker 1: you'd be something like mercury, or could be a hot
Speaker 1: gas planet too far away, it's too cold to have
Speaker 1: liquid water. You might be like Jupiter or Saturn, And
Speaker 1: it's generally believed that liquid water is sort of a
Speaker 1: prerequisite for life, or at least the kind of life
Speaker 1: that we understand. Could it be the galaxies as a
Speaker 1: whole have zones kind of like this where life is
Speaker 1: statistically more likely to emerge, thrive, and survive than in
Speaker 1: other zones of the galaxy. Some scientists have proposed this.
Speaker 1: And if that is the case, what characterizes this zone? Uh?
Speaker 1: First of all, if the proponents of the idea of
Speaker 1: a galactic hapitable zone are correct, the zone of the
Speaker 1: galaxy most suitable for life would tend to be a
Speaker 1: sort of wide ring around the center of the galaxy,
Speaker 1: so not farther out in the galactic halo, not not
Speaker 1: way out there, but also not deep in the middle
Speaker 1: near the galactic center. Now, why would this region be
Speaker 1: potentially better to live in than say, the galactic center. Uh?
Speaker 1: Just the short and basic version of your main consideration
Speaker 1: here would be first of all, conditions that give rise
Speaker 1: to life, and then the conditions that can sustain life.
Speaker 1: So to give rise to life, we assume you need
Speaker 1: first of all, terrestrial planets with stable orbits, right, and
Speaker 1: and this means solar systems with a moderate amount of
Speaker 1: metal in them. If you've got a solar system that's
Speaker 1: like mostly hydrogen and doesn't have much that looks like
Speaker 1: it could turn into rocky terrain, that probably means you're
Speaker 1: not going to have life forms at least as we
Speaker 1: understand them. But this isn't the primary concern for our question. Uh.
Speaker 1: A big one for our question would be conditions that
Speaker 1: can sustain life, Like how often or how intensely would
Speaker 1: a planet in a given region be subjected to outside
Speaker 1: damaging influences. Examples of this could be radiation from violent
Speaker 1: nearby phenomena their stars. Uh, you know, violent things going
Speaker 1: on Obviously nearby supernova would be a huge problem. If
Speaker 1: a star anywhere near I you goes supernova, it will
Speaker 1: blast your planet and could potentially sterilize it. Uh. The
Speaker 1: near passage of of other massive objects like stars or
Speaker 1: black holes is a huge issue that could potentially disturb
Speaker 1: planetary orbits or bring about a bombardment of terrestrial planets
Speaker 1: by comets and other junk from space. So like, if
Speaker 1: something passes through your Solar System, and it's really heavy.
Speaker 1: It will disturb these commetary orbits and then suddenly, you know,
Speaker 1: things that haven't been hitting your planet for a long
Speaker 1: time suddenly are This even makes me think about the
Speaker 1: Lisa Randall dark matter and the dinosaurs hypothesis. I can't
Speaker 1: remember if we ever talked about that on the show,
Speaker 1: but basically her idea was that, you know, it's possible that, uh,
Speaker 1: some extinction events in Earth's history are correlated to Earth's
Speaker 1: passage through a region of the galactic plane where dark
Speaker 1: matter is concentrated, and the extra gravitational influence of that
Speaker 1: dark matter along that plane, uh disturbs the orbits of
Speaker 1: some objects in the Solar System and makes you know,
Speaker 1: the Earth get bombarded by stuff or maybe influences. I
Speaker 1: can't remember. I think it was mainly comments she was
Speaker 1: talking about, but maybe it was also vulcanism. I didn't
Speaker 1: actually read the book, but I remember reading articles about
Speaker 1: it when it came out. It seemed interesting. Maybe we'll
Speaker 1: have to come back and take a look at that someday. Yeah,
Speaker 1: that sounds frightening. I don't know whether that theory is
Speaker 1: widely believed to to you know, have credence or not.
Speaker 1: But but generally, if something disturbs the gravitational field of
Speaker 1: your of your star system, that can be really bad
Speaker 1: for anything living there. Yes, and so there are a
Speaker 1: lot of variables at play, but generally these kinds of
Speaker 1: dangerous conditions, like being subjected to more intense or more
Speaker 1: frequent radiation or radiation events, and more more frequent disturbances
Speaker 1: of gravity by large objects, that's going to be more
Speaker 1: likely in densely packed regions of a galaxy, like closer
Speaker 1: to the galactic center. The higher the density of nearby
Speaker 1: stars and other stuff, the more dangerous there are. And
Speaker 1: a very crude analogy is you're more likely to have
Speaker 1: some kind of auto accident or mishap on a busy
Speaker 1: city street than on some empty country road. Right, Yeah,
Speaker 1: they're just well there's you know, there's just more going
Speaker 1: on there. But then again, I do want to say
Speaker 1: it seems like a lot of the writing about galactic
Speaker 1: habitable zones is subject to ongoing criticism and dispute. Uh,
Speaker 1: it does seem clear that there are at least some
Speaker 1: risks to life associated with moving closer to the galactic center.
Speaker 1: But you know where exactly this habitable zone of a
Speaker 1: galaxy would be if it in fact is true that
Speaker 1: some regions of the galaxy or on average more habitable
Speaker 1: than others. I think that's highly disputed. So this is
Speaker 1: not settled science. Alright, We're gonna take a quick break.
Speaker 1: When we come back, we have a little more information
Speaker 1: about just how chaotic and destructive uh, the inner reaches
Speaker 1: of the galaxy seem to be, and then we'll move
Speaker 1: on to some other possibilities for uh, extraterrestrial activity in
Speaker 1: the inner galaxy. All right, we're back, all right, So
Speaker 1: we were just talking about this question of like, could you,
Speaker 1: you know, could you tend to find life for intelligent
Speaker 1: life forms in orbit around a central supermassive black hole
Speaker 1: in our galaxy or in the galactic center more generally,
Speaker 1: would you expect to see something like that? Would it
Speaker 1: be a survivable region? And and it uh, it seems
Speaker 1: like this is not fully settled, but we were discussing
Speaker 1: some potential risks of living in the galactic center. Yes,
Speaker 1: I was looking around for some more details on this,
Speaker 1: and this brought me as questions like this often due
Speaker 1: to Centauri Dreams, which is a wonderful space website and
Speaker 1: I was reading a blog post by the writer Paul
Speaker 1: Gilster of The Planetary Society, in which he looks to
Speaker 1: the work of Sergey n Action at Leicester on the
Speaker 1: idea that the doughnut shaped dust clouds obscuring half of
Speaker 1: supermassive black holes might be the you know, the result
Speaker 1: of crashes between planets and asteroids occurring at a thousand
Speaker 1: kilometers per second speeds, pounding everything into micros copic dust.
Speaker 1: So it's a realm of you know, of a violent
Speaker 1: collision high radiation. But he points out that while those
Speaker 1: planets are doomed, you know anything, actually any of the
Speaker 1: planets actually in that region or potentially doomed, the resulting
Speaker 1: dust blocks harmful radiation from all of this chaos from
Speaker 1: reaching the rest of the galaxy, the host galaxy. That's interesting.
Speaker 1: I mean, yeah, we were talking in the last episode
Speaker 1: about how dust clouds obscure the galactic center from our
Speaker 1: point of view, like it's harder to do astronomy looking
Speaker 1: towards the galactic center. I mean, I would imagine that
Speaker 1: brightness has something to do with it. But also, yeah,
Speaker 1: the dust blocks our view and does significant dimming. It
Speaker 1: causes many magnitudes of extinction to the sources coming from
Speaker 1: that direction. But we do have methods of looking that
Speaker 1: way now, and we can do astronomy focused on the
Speaker 1: center of the galaxy, I think, you know, due to
Speaker 1: stuff like looking at infrared and X rays. I was
Speaker 1: also looking around, uh and found some writings on this
Speaker 1: from Phil Plate of Bad Astronomy, always a great read
Speaker 1: on space related topics, and he points out in some
Speaker 1: galaxies called active galaxies, gas and dust fall into the
Speaker 1: yawning black hole at the center of the galaxy, forming
Speaker 1: a disc of material sometimes hundreds of light years across. Again,
Speaker 1: this here is going to be a realm of high temperatures,
Speaker 1: high radiation, and intense light that outshines the rest of
Speaker 1: the galaxy, and that would mirror some of the phenomenon
Speaker 1: we were talking about in the last episode, where yeah,
Speaker 1: like you've got like this quasar or something super powerful
Speaker 1: in the middle of the galaxy that just sort of
Speaker 1: like you know, it sort of is the galaxy, right,
Speaker 1: But fortunately, the Milky Way galaxy is not an active galaxy.
Speaker 1: It's a quiescent galaxy, so it's not quite the cosmic
Speaker 1: forge we find in other galaxies where you know, it's
Speaker 1: just super intense. It is to a certain extent slumbering,
Speaker 1: and we're able. I mean, I keep coming back to
Speaker 1: the idea of their just being like an awful, all
Speaker 1: powerful eldric deity the center of the cosmos, and we're
Speaker 1: just lucky that it's that we're in a cosmos. It's
Speaker 1: a little worn out and take in a lengthy slumber.
Speaker 1: I think at the end of the last episode you Were,
Speaker 1: You Were, you sort of fought against the idea of
Speaker 1: thinking of black I know, I don't want to think
Speaker 1: of a black hole as being you know, and this
Speaker 1: has his off figure, but it's hard and it's hard
Speaker 1: not to when we used to read things like this.
Speaker 1: So I guess we've been looking at answers for mostly
Speaker 1: like no, we're looking at the idea of the inner
Speaker 1: galaxy is a place where you're probably not encountering um,
Speaker 1: you know, planets where life is evolved. There. There are
Speaker 1: a lot of risks in the galactic center because you know,
Speaker 1: the things are more densely packed. There's probably more radiation risk,
Speaker 1: probably more gravity disturbance risk. But at the same time
Speaker 1: there are more stars. You might just get more chances
Speaker 1: for things to evolve there. So it's it's like I
Speaker 1: was saying, it's not settled science, but you can point
Speaker 1: to some things going on there and say it looks
Speaker 1: like there are are risky phenomena near the galactic center. Now, indeed,
Speaker 1: if we are dealing with habitable zones and uh, you know,
Speaker 1: uninhabitable zones of the galaxy, one thing to keep in
Speaker 1: mind is that technology can potentially change things. Like just
Speaker 1: look to our solar system. Yes, Earth is the like
Speaker 1: it's it's the bowl of porridge. That's just right. But
Speaker 1: we've discussed on the show plenty of times that you know,
Speaker 1: there are plans, there are ideas and concepts where with
Speaker 1: sufficient technology, humans could live on Mars, they could live
Speaker 1: in the clouds of Venus. Even here on Earth we
Speaker 1: have a neutrino observatory at the South Pole. You know,
Speaker 1: we've got or at least yeah, deepen Antarctica. That's not
Speaker 1: a place that's inhabitable by mammals. So you know, so
Speaker 1: like we we have found technological ways of overcoming the
Speaker 1: environmental limitations imposed by the universe. And you can see
Speaker 1: that even without us leaving our host planet. So you know,
Speaker 1: if you can build a research station on the South Pole,
Speaker 1: where no mammal like us should be able to survive
Speaker 1: if you can potentially build it. Oh, if you can
Speaker 1: build an I. S. S. Yeah, and live out in space.
Speaker 1: Yeah you can imagine. Okay, just extra appellate that up. However,
Speaker 1: many orders of magnitude of whatever scale you're talking about
Speaker 1: to our power to live beyond our original organic means. Yea.
Speaker 1: So we have to come back to something we've discussed
Speaker 1: in the show before, sort of a propose technological ladder
Speaker 1: to um to godhood if you will. The Cardassie of
Speaker 1: scale an old favorite. Yes, so you got you got.
Speaker 1: Basically you've got type one, Type two, and type three,
Speaker 1: and you know, I've also seen people discuss the possibility
Speaker 1: of the type four. But a Type four is so
Speaker 1: far beyond where we are now it's almost not even
Speaker 1: worth thinking about. Well, I'd say even like type three
Speaker 1: is hard to imagine what that would look like. Uh,
Speaker 1: you know, we've got more like science fiction that kind
Speaker 1: of deals on the realm of one and two. Yeah,
Speaker 1: so we're not even type ones yet. Time close. Yeah,
Speaker 1: Type A Type one civilization, the cardassi of scale should
Speaker 1: be capable of harnessing all the energy of their planet,
Speaker 1: because basically that's what the scale is about. It's about,
Speaker 1: you know, civilization's ability to to harness in yeah, to
Speaker 1: take what's there in the universe and turn that into
Speaker 1: the ability to do work. Now, of course that doesn't
Speaker 1: necessarily mean work, like it's hard to do. That could
Speaker 1: be you know, operating the video game systems of the
Speaker 1: future or whatever to turn it into usable energy. Right. Yeah.
Speaker 1: So so again we're not type one yet. If we
Speaker 1: could harness all the power, all the energy of our planet,
Speaker 1: we would be type one. The next step is is
Speaker 1: a is a type two in which a civilization has
Speaker 1: become masters of their own star, essentially solar solar system
Speaker 1: level power. And then that type three, which is an
Speaker 1: an enormous step. Then from from from step to tow
Speaker 1: a step three civilization has the power of an entire
Speaker 1: galaxy at its disposal. That's hard to imagine, it is,
Speaker 1: It is very difficult to imagine it. It It gets so
Speaker 1: difficult to imagine it's almost ridiculous to try and think
Speaker 1: of what is beyond that, you know, uh, and and
Speaker 1: so most of our contemplations deal with one, two and three.
Speaker 1: Most deal with one and two. So level one and
Speaker 1: two on the Kardaship scale would theoretically have access to
Speaker 1: technology we refer to as a Dyson sphere, named for
Speaker 1: theoretical physicist Freeman Dyson, and these are essentially means of
Speaker 1: surrounding a power source and harvesting all of its energy.
Speaker 1: There are different varieties of this. You don't need to
Speaker 1: necessarily think of a hard sphere, um though I love
Speaker 1: too because it should pops up in that episode of
Speaker 1: Star Trek. But it could also be you know, more
Speaker 1: like a dice in cloud. It could be you know,
Speaker 1: satellites surrounding something and absorbing its energy. Um. So it's
Speaker 1: maybe oversimplified, but the classic example would be just surrounding
Speaker 1: the Sun with something like solar panels, so you get
Speaker 1: all of the energy out of it. You can just
Speaker 1: sort of like release the waste exhaust outside and and
Speaker 1: use everything the sun can give you. Yeah, the still
Speaker 1: suits of Dune are sort of like Dyson spheres for
Speaker 1: human sweat, you know, for human moisture. Don't waste to drop.
Speaker 1: So how does this tie into supermassive black hole old holes?
Speaker 1: You might wonder, Well, I was reading a very interesting paper. Uh,
Speaker 1: this is from a two thousand and eleven edition of
Speaker 1: the Journal of the British Interplanetary Society. And this is
Speaker 1: by an o U and you Ku titled Type three
Speaker 1: Dicen sphere of highly advanced civilizations around a supermassive black hole.
Speaker 1: Uh So, I'm gonna read a quick quote from this quote.
Speaker 1: A society of a highly advanced civilization is supposed to
Speaker 1: require a huge amount of energy to operate the social system.
Speaker 1: As the gravitational energy released by the accretion of matter
Speaker 1: into a supermassive black hole is huge, a system must
Speaker 1: be developed to use this energy. In such a society,
Speaker 1: the condition around a supermassive black hole at the center
Speaker 1: of a of a galaxy would be more efficient both
Speaker 1: in extracting energy and exhausting the waste energy for advanced
Speaker 1: civilizations than those of a Dicen sphere. So basically they're arguing, like, hey,
Speaker 1: like we've touched on before, there's a lot going on
Speaker 1: on at the center of the galaxy. There's a lot
Speaker 1: of energy at the center of the galaxy. Any sufficiently
Speaker 1: advanced civilization would go where the energy is and presumably
Speaker 1: have the technology to harness it right, extract that energy
Speaker 1: and do something with it rather than letting it just
Speaker 1: turn into radiation and in space. Yeah. So yeah. They
Speaker 1: point out that a huge amount of radiation energy generates
Speaker 1: in close vicinity to a supermassive black hole, and here,
Speaker 1: you know, this accretion disc rotates around it, so the
Speaker 1: potential energy of the accreting matter releases to form a
Speaker 1: hot and dense disk. Sorry, I was just for a
Speaker 1: moment trying to imagine what we would do with it,
Speaker 1: and it would be like, I, let's load up, you know,
Speaker 1: ten billion spaceships full of coal and take them to
Speaker 1: the center of the galaxy and let the supermassive black
Speaker 1: hole burn the coal and then we can use the
Speaker 1: heat from the cold power. So yeah, that's our solution.
Speaker 1: Uh yeah, that's not quite the system that that that
Speaker 1: they're proposing. Here, this is what they add quote, radiation
Speaker 1: from the accretion disk will be collected by a mirror
Speaker 1: system as a type three dycen sphere. Waste material and
Speaker 1: energy could be thrown off towards the central supermassive black hole,
Speaker 1: and the supermassive black hole would be the final reservoir
Speaker 1: for all the waste materials for any civilizations. Thus, the
Speaker 1: most advanced civilizations would develop their activities using a supermassive
Speaker 1: black hole efficiency, putting the power plants around the supermassive
Speaker 1: black hole at the center of their home galaxy. Wow, well,
Speaker 1: I mean that's pretty out there. Yeah, that that's interesting. Yeah.
Speaker 1: So from here they lay out a power plant system
Speaker 1: that amounts to a sort of Dyson's sphere or shell.
Speaker 1: The energy from the power plants is then transferred by
Speaker 1: electromagnetic waves the habitats of advanced civilizations, which would be
Speaker 1: as imagining more sustainable, stable regions. And then these transmissions
Speaker 1: would also serve would serve as a power grid, but
Speaker 1: also as highways, four vessels, uh, you know, more or
Speaker 1: less sailing them as if they were sailing, you know,
Speaker 1: the solar wind. So putting power plants on a supermassive
Speaker 1: black hole, well, well, not quite on, but close to.
Speaker 1: And then they touched on that to uh you know,
Speaker 1: basically asking asking answering the question how close would these
Speaker 1: power plants be. Yeah, they say that considering Sagittarius a star,
Speaker 1: that the closest you would be dealing with the closest distance,
Speaker 1: the closest orbit would be six hundred r s. That's
Speaker 1: a swords child radius, and uh, they say that the
Speaker 1: proper area for the power plants and their model would
Speaker 1: be around one hundred three to one hundred four r
Speaker 1: s is um. Also basically just like a hundred of
Speaker 1: the radius of the black hole region itself out And
Speaker 1: that sounds frighteningly close. But then again, conceivably this would
Speaker 1: be a civilization that assuming they're not entirely technological by
Speaker 1: this point, you know, and they even have any kind
Speaker 1: of like you know, a physical remainder in their their
Speaker 1: their being and their culture. Again, it's difficult to imagine
Speaker 1: some of these civilizations with him they could consist of.
Speaker 1: But even if they were in some way organic, still like,
Speaker 1: surely this would be the domain of robots that they
Speaker 1: send out, sending the robots in to do the hard
Speaker 1: work at the center and then being that energy back
Speaker 1: to the centers of civilization. I feel so two ways
Speaker 1: about this, because on one hand, it's like, I love
Speaker 1: the idea of people trying to work out how CARDASHEV
Speaker 1: level three power plants would work out would function. But
Speaker 1: on the other hand, it's just like, we don't even
Speaker 1: we're not even you know, level one yet, So you
Speaker 1: you have to imagine that even if these authors are
Speaker 1: totally on the right track, there's probably a lot of
Speaker 1: details we haven't we haven't really faced yet and and
Speaker 1: don't really know how to incorporate. But at the same time,
Speaker 1: this is this is such a blessed project, trying to eagine.
Speaker 1: All right, maybe like a billion years in the future,
Speaker 1: what does what does the civilization do to get their power? Yeah?
Speaker 1: I love I love papers like this. Now, now to
Speaker 1: be clear again, this is all theoretical and it's something
Speaker 1: the authors say we might look for, but there's no
Speaker 1: evidence that something like this is actually going on anywhere
Speaker 1: in the universe. Okay, So this is another example, as
Speaker 1: has often been done before, where working out the details
Speaker 1: of a potential uh Dyson sphere type project would be
Speaker 1: mostly useful in the search for extraterrestrial life. Right, right,
Speaker 1: What would be the signatures of this type of technology?
Speaker 1: Do we look out into the universe and see anything
Speaker 1: like that? Right? And and and Astronomers have observed objects
Speaker 1: that could potentially be explained by dimming due to a
Speaker 1: Dyson sphere. For instance, in two thousand and sixteen, scientists
Speaker 1: observed a dimming of the star Epic to zero four
Speaker 1: to seven eight, nine one six that was out of
Speaker 1: keeping with a large planet, you know, passing between us.
Speaker 1: And they presented a few possible explanations, but the last
Speaker 1: of them was a dicense fhere, because there's always aliens,
Speaker 1: should always be the last explanation we turned to, no
Speaker 1: matter how exciting that explanation might be. But which of
Speaker 1: their potential explanations made the headlines? Well, of course it's
Speaker 1: the dicense fhere right. In fact, I think one of
Speaker 1: the headlines I was looking at was researchers just found
Speaker 1: a second dicense fhere star, What what happened to the
Speaker 1: first one? That's brilliant? Well, I mean, like, like I said,
Speaker 1: there have been at least a couple of cases where
Speaker 1: people have seen something and they're like, we don't really
Speaker 1: fully understand what it is, but here a list of
Speaker 1: things it could be. And yeah, number three or four
Speaker 1: or five is sometimes a dicense here. Yeah. Um, I
Speaker 1: just like that. It sounds like it was assumed that
Speaker 1: the first one they found actually is a license fhere,
Speaker 1: and not just like there's an off chance that it
Speaker 1: could be and that would be consistent with what we saw.
Speaker 1: All right. On that note, We're gonna take one more break,
Speaker 1: but when we come back, we have some more mysteries
Speaker 1: to consider, not about uh, you know, hypothetical you know,
Speaker 1: super advanced technological societies, but rather mysteries concerning the supermassive
Speaker 1: black hole at the center of our galaxy. Thank all right,
Speaker 1: we're back. Now it's time to talk about how our
Speaker 1: own galaxy supermassive black hole, Sagittarius A star has been
Speaker 1: showing some weird and mysterious behavior lately, just just in
Speaker 1: the past few years or this year. Yeah, that's right.
Speaker 1: NASA Schandra X ray Observatory has observed a mysterious daily
Speaker 1: flares from Sagittarius A Star, and it leads us to,
Speaker 1: you know, wonder what's going on? Um so. One theory
Speaker 1: is that the dust cloud around it contains comments and
Speaker 1: asteroids stripped away from other stars, and then when collisions occur,
Speaker 1: it's sometimes sends one off into Sagittarius A Star. And
Speaker 1: according to a NASA report from two thousand twelve, quote,
Speaker 1: if the asteroid passes within about one million miles of
Speaker 1: the black hole, roughly the distance between the Earth the Sun,
Speaker 1: it would be torn to pieces by the tidal forces
Speaker 1: from the black hole. So basically, you know, you're just
Speaker 1: ripping apart a huge chunk of metal or rock in space, right,
Speaker 1: and this produces a flare as the asteroid than as
Speaker 1: the pieces of it consumed by the black hole. Comets
Speaker 1: have been observed to impact our Sun with almost identical
Speaker 1: frequency uh and with a resulting flare. You can even
Speaker 1: get a really cool flare in astronomy just looking at
Speaker 1: like Jupiter. Have you seen some of these when like
Speaker 1: a comet goes into Jupiter. Yeah, amazing. Now there have
Speaker 1: been other recent observations of of big flare ups right. Yeah.
Speaker 1: In May nineteen, a sizeable flare was was observed by
Speaker 1: a team using the CAT ten meter telescope, and this
Speaker 1: was in the near infrared range. There they're also variable
Speaker 1: blasts from Sagittarius a star, and other frequencies like the
Speaker 1: X ray range. This was the brightest flare we've ever
Speaker 1: observed in the infrared or near infrared. In fact, according
Speaker 1: to the u c l A astronomer Twine Doe, who
Speaker 1: was the lead researcher on these uh, these latest latest
Speaker 1: radiation bursts are our telescopes only caught the tail end
Speaker 1: of the flare. It was probably much brighter right before
Speaker 1: we started looking at it. Yeah, as Phil Play reported
Speaker 1: in Bad Astronomy, the flare was well over two thousand
Speaker 1: times more luminous than the Sun in the infrared. Right.
Speaker 1: But yeah, and and furthermore, the scientists judged it to
Speaker 1: be basically a one and two thousand occurrence compared to
Speaker 1: two past observed fluctuations. Right, so it's probably not just
Speaker 1: a random fluctuation in the brightness of the radio source
Speaker 1: there it is. It is a an event, right. So
Speaker 1: this led researchers who think it might be tied to
Speaker 1: a star known as S two, which regularly makes a
Speaker 1: super close pass by the supermassive black hole. Uh, super close,
Speaker 1: you know, in astronomical terms. But in doing so, it
Speaker 1: drags a kind of wind of particles with it. Well,
Speaker 1: I think the star puts out a stellar wind, just
Speaker 1: like our sun does. Yeah, and and but then there
Speaker 1: in their particles within that wind, And so it could
Speaker 1: be that that wind of particles is crashing into the
Speaker 1: black hole. Uh. They considered this, but they decided, well,
Speaker 1: I don't I don't think this would be strong enough
Speaker 1: thing to actually make that flare. So another possibility, though,
Speaker 1: is that S two's pass disturbed clouds of gas and
Speaker 1: caused them to fall into the black hole. It's also
Speaker 1: possible that an unknown object known as G two on
Speaker 1: a two hundred and sixty year orbit around the black
Speaker 1: hole might have caused such a you know, in an
Speaker 1: area of gas to fall into it. You know, it
Speaker 1: moved close enough. In fact, it moved close enough that
Speaker 1: you have G two itself were a dust cloud, as
Speaker 1: some have thought it might be, it would have just
Speaker 1: fallen in. But we don't know for sure exactly what
Speaker 1: G two is, right, right, I thought it was maybe
Speaker 1: gas or dust, but it didn't behave like that when
Speaker 1: it went by the supermassive black holes. Right, there's at
Speaker 1: least one idea that it could be a star. There
Speaker 1: could be a star in the middle of a of
Speaker 1: a cloud of of of of gas and or a particle, etcetera.
Speaker 1: And the or it could be two stars that have
Speaker 1: merged due to their you know, proximity to the black
Speaker 1: hole and then blow they end up blowing off dust
Speaker 1: in the process. Okay, So if there's a star within it,
Speaker 1: that would explain like gravity holding it sort of together
Speaker 1: when goes by the black hole. Yeah, there's something strong
Speaker 1: inside it, or the flare could just be due to
Speaker 1: an asteroid or come it stripped away from a star
Speaker 1: system falling into the black hole. That's that's always a
Speaker 1: possibility that's discussed as well. You know. One of the
Speaker 1: sad things about trying to look at the center of
Speaker 1: the galaxy is that sometimes the Sun gets in the way.
Speaker 1: Like our our viewing window is limited because the Sun
Speaker 1: passes between the Earth and Sagittarius at a you know,
Speaker 1: a certain time each year. Also along the same lines
Speaker 1: of mysteries dealing with Sagittarius a star, I was reading
Speaker 1: an article from just a couple of days ago about
Speaker 1: weird observations regarding what are called Fermi bubbles and Sagittarius
Speaker 1: a star. This was on space dot com, authored by
Speaker 1: the Ohio State astrophysicist Paul im Sutter. Uh So, Okay,
Speaker 1: what you've got here are two giant bubbles of stuff
Speaker 1: including hot gas and cosmic rays, and they're globbing onto
Speaker 1: the middle of the galaxy, of the Milky Way galaxy.
Speaker 1: And we can see these bubbles are emitting high frequency
Speaker 1: radiation like gamma rays and X rays. They were discovered
Speaker 1: in two thousand ten by researchers working with the Fermi
Speaker 1: gamma ray space telescope, and they extend out vertically from
Speaker 1: the flat axis of the galaxy to a distance of
Speaker 1: roughly twenty five tho light years in each direction. So
Speaker 1: if you're trying to picture this and you're picturing the
Speaker 1: disc of the galaxy as a vinyl record, imagine a
Speaker 1: balloon tied to the middle of the record, like the
Speaker 1: hole in the middle of the record on each side,
Speaker 1: and this will give you an idea. So, these huge
Speaker 1: blobs of stuff are referred to as Fermi bubbles, But
Speaker 1: what are they and how do they get there? Well?
Speaker 1: An interesting development is that more recently, the Ice Cube
Speaker 1: Neutrino Observatory and in Antarctica has observed high energy neutrinos
Speaker 1: blasting directly from these bubbles, indicating that perhaps, in in
Speaker 1: Sutter's words quote, some crazy sub atomic interactions are afoot.
Speaker 1: He writes that the position of these bubbles right above
Speaker 1: and below the center of the galaxy could point to
Speaker 1: their origin, and that would be the supermassive black hole.
Speaker 1: Of course, Sagittary essay star Now, like what could have happened,
Speaker 1: that's not really known. He supposes maybe millions of years ago,
Speaker 1: something significant fell into the black hole quote with the
Speaker 1: infalling material heating up, twisting around in a complicated dance
Speaker 1: of electric and magnetic forces, and managing to escape the
Speaker 1: clutches of the event horizon before falling in. That material
Speaker 1: energized beyond belief, raced away from the center of the galaxy,
Speaker 1: riding on jets of particles accelerated to nearly a speed
Speaker 1: of light as they fled to safety. These particles spread
Speaker 1: and thinned out, but maintained their energetic state to the
Speaker 1: present day. So maybe we've got these gigantic, almost galaxy
Speaker 1: sized bubbles reaching out of the top and bottom in
Speaker 1: the milky way that it looks very possibly like something
Speaker 1: fell or almost fell into the black hole and created these.
Speaker 1: So possibly a star got too close, was torn apart
Speaker 1: and ejected by the gravitational forces, or maybe many of
Speaker 1: the stars in the dense core of the galaxy all
Speaker 1: went supernova around the same time. This created this highly
Speaker 1: energetic stuff to get ejected out in these these polar
Speaker 1: jets from the black hole. But anyway, it created these
Speaker 1: bubbles that are full of all this high energy stuff
Speaker 1: that's still ejecting neutrinos today, and you know, that's exactly
Speaker 1: the kind of thing that would interest be very interesting
Speaker 1: to uh type two civilization or a type three. Uh. Yeah, well,
Speaker 1: I guess at this point we've we've come to the
Speaker 1: end of the episode, uh, and come to the end
Speaker 1: of this uh this two episode exploration of Sagittarius a
Speaker 1: star and supermassive black holes in general. But obviously we'd
Speaker 1: love to hear from everybody out there. Um. You know,
Speaker 1: obviously nobody has personal experience with a supermassive black hole,
Speaker 1: but we would love I'm always happy to hear from uh.
Speaker 1: You know, some of our listeners are have read a
Speaker 1: quite a lot of science fiction, and even they've read
Speaker 1: science fiction that I have not read and you haven't read.
Speaker 1: So I love to hear anytime, you know, someone's like, hey,
Speaker 1: I actually I know a science fiction novel that or
Speaker 1: a short story that deals with exactly that concept, and
Speaker 1: here's their solution to it. Oh. But we also know
Speaker 1: from past listener mail that we have listeners in astrobiology,
Speaker 1: astronomy and astrophysics. If you've got something to add to
Speaker 1: this topic, please get in touch absolutely uh. In the meantime,
Speaker 1: you can find all the episodes of Stuff to Blow
Speaker 1: Your Mind at stuff to Blow your Mind dot com.
Speaker 1: You can find our other show, Invention and Invention Pod
Speaker 1: dot com. Uh yeah. If you're looking for another episode
Speaker 1: of per week from from the two of us, consider Invention.
Speaker 1: Each each episode is a different invention and it you
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Speaker 1: to our excellent audio producers, Maya Cole and Seth Nicholas Johnson.
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