September 17, 2019 • 39 mins
A super massive black hole broods at the center of our galaxy. In this Stuff to Blow Your Mind two-parter, Robert and Joe discuss just what that means -- and doesn’t mean -- for humanity, our solar system and our future.
Learn more about your ad-choices at https://www.iheartpodcastnetwork.com
See omnystudio.com/listener for privacy information.
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:03):
Welcome Stuff to Blow Your Mind, a production of I
Heart Radios How Stuff Works. Hey, you welcome to Stuff
to Blow your Mind. My name is Robert Lamb and
I'm Joe McCormick, and we're back with part two of
our exploration of Sagittarius, a star, the compact radio source,
(00:23):
the supermassive black hole we think at the center of
the Milky Way galaxy. Yeah, this is uh so, so,
as we mentioned in the last episode, we had what
three episodes we've done previously just on black holes in general,
and in these two episodes deal with supermassive black holes
more specifically. Uh and uh yeah, So if you're listening
to this episode, you do need to have at least
(00:45):
listened to the previous supermassive black hole episode. But I
think the supermassive black hole episodes are are are tailored
to stand on their own without necessarily having listened to
the previous black hole episodes. In either case, it is
recommended that you have seen either Walt Disney's The black
Hole or Event Horizon, so they have a proper basis
(01:07):
for all of our terrible jokes. Which one of those
two is more kid friendly? You think, Oh, blow. I
think it's the Disney movie, but the Disney movie is
also surprisingly dark. Like, uh, Anthony Perkins is eviscerated by
a killer robot um Like this is awful scene where
Maximilian the robots coming at him with the spinning blade
arm and he holds up like a giant dictionary to
(01:30):
block it, and he like cuts right through the dictionary
and uh and you know, apparently like just disembowels Anthony Perkins.
It cuts out the definition of in trails. Well you
don't see any in trails, but it's still pretty horrific.
There's some scary moments in it. But I loved it
as a kid. I really need to sit down and
watch it again. Now, speaking of a visceration, we're gonna
be talking about some somewhat violent events going on around
(01:52):
a black hole, or at least they presumed black hole today.
And one thing we promised you last time is that
we would answer a few questions every You've always wanted
to know about the supermassive black hole at the center
of the galaxy, but we're afraid to ask. And one
of the questions people most often ask about black holes.
If you're ready to jump right in robert Is. With
this big supermassive black hole at the center of the
(02:14):
Milky Way, will the rest of the Milky Way, including Earth,
one day gets sucked into this black hole? And I
was trying to find a good answer for this. I
think the short answer is no, or at least that's
not a given. All evidence indicates that, of course, the
Milky Way does have this supermassive black hole at its center.
The galaxy is sort of orbiting around it, or at
(02:36):
least roughly orbiting around it, But our Solar system is
in a stable orbit that is pretty far out. It's
something like light years away from the galactic center. And
black holes, even unbelievably giant black holes, still basically behave
like stars until you get really close to them. They're
not vacuum cleaners just sucking down the entire universe. You know.
(02:59):
They're objects traveling through space with a gravitational attraction that
is a product of their mass and your distance from them,
and like other objects, if you're far enough away, they're
gravitational attraction is negligible. So we've got no indication that
there is a risk of a black hole swallowing our
Solar system or the Earth or the rest of the
(03:20):
Milky Way. But of course, if anything as massive as
a black hole pass near our Solar system, I think,
I mean that that would be a problem. It might
not swallow our Solar System, but it's gravitational influence could
alter the orbits of the planets, which would be not good. Obviously,
life on Earth depends very heavily on us being where
we are relative to the Sun and other objects in
(03:42):
the Solar System staying where they are. You don't want
to say the orbits of comets and other objects like
that thrown out of whack, because then that can lead
to interplanetary bombardment. Yeah. I think the fact that a
black hole is an object is something that we do
have to come back to again and again because especially
with science fiction treatments, especially those especially the Disney black Hole.
(04:02):
So you know, there's this idea of like thinking of
it as a whirlpool it's a hungry, hungry hippo, yeah,
or thinking of it as a tunnel or just an
open like some of these you know, these analogies. They
they may be useful to a certain extent. It gives
us something to picture in our mind, but it kind
of drifts away from the idea that this is an object.
(04:24):
This is a highly dense thing, and now, of course
in the region really close to it, it doesn't behave
like most other objects too. But once once you get
farther away, I would say that the ways in which
it is unique become less relevant to you. Does that
make sense? Yes? Now, Um, you touched on some of this,
but but I was looking around like, Okay, what is
(04:45):
the scenario in which the supermassive black hole at the
center of our galaxy uh could conceivably destroy us? And
that there is one very strong possibility. So and we've
mentioned that our system is again in a stable orbit
around the galactic center. Um, we're not being pooled pulled
(05:07):
into Sagittarius M A star. But in four point five
billion years, the Milky Way galaxy will likely merge with
the Andromeda galaxy. And when this happens, all bets are off.
It's possible that everything gets pushed around, gets shuffled around,
and our solar system then could be gulped up or
(05:28):
just hideously disrupted by Sagittarius A star in the process. This,
according to Fabio Pacucci, b Hi Fellow at Harvard University
and Clay Fellow at the Smithsonian Astrophysical Observatory. He has
a wonderful ted Ed video about this. So if you
just go to if you go to YouTube and you
look up, just look up ted Ed in general, because
(05:49):
they're great educational short form videos to watch with the
entire family. We watch them all the time in my household.
But they have an extra excellent one about black holes
that Fabio is the contributor for. Yeah, now, when we
talk about the collision of galaxies, maybe someday we could
do a whole episode just on the upcoming collision between
the Milky Way and the Andromeda galaxy because yeah, so
(06:10):
they're on a collision course. Uh. On one hand, that
sounds like, okay, so that's just the end of everything, right, Actually,
I think not necessarily, because you have to remember, well,
you know there is a lot of space in between stars, right,
you know, there's there's a lot of space for things
to go by. But one of the big fears I
think is not necessarily that like Earth will smash directly
(06:32):
into a star from Andromeda or something. That the fear
is about gravitational disruption. Right, things moving past each other
in space can still have a perturbation effects on on stars,
on the planet's orbiting stars, on the objects and junk
in space all around stars. Well, none of that's good. Yeah,
I mean it's kind of like, and this is a
(06:52):
terrible analogy, I'm sure, but it's like, if two companies merge,
your your concern is not that, you know, if you're
an editor at one company and you emerge with another company,
you're not concerned that there's another editor over there that
you're just going to smack into so hard that you
both explode. No, you're worried about redundancies. You're worried about
reshuffling of titles and priorities, etcetera. Which you know, all
(07:16):
of that can be can can certainly be catastrophically disruptive
to your life. Um, but you're not worried about, you know,
like physically, you know, exploding or you know, melting into
them like Ron Silver and time coop. So I guess
that is possible. I mean, whenever things drift past each
other in space, there's always a potential for a collision.
It's just you know that that's not necessarily the thing
(07:38):
you should be worried about. I think the bigger thing
would be, Yeah, do you get thrown out of place?
You get thrown in? You getting thrown into the near
orbit or towards the black hole would obviously be bad
and and catastrophic in its own right for sure. Alright,
So the next big question that that you might be
wondering about. Could intelligent life forms live of and or
(08:00):
operate in orbit around a supermassive black hole, specifically our
supermassive black hole? Uh? You know, how would this factor
into a like a galactic civilization? Yeah? Or in the
in the galaxy center more generally, right, can you get
close to the galaxy center and have life there? This
seems debatable, right, Like, So there are some scientists who
(08:25):
think that just the way solar systems have a habitable
zone for planetary orbits, the galaxy as a whole has
some kind of habitable zone for star systems. Now in
star systems, of course, this habitable zone has temperature as
a primary variable, right, And this depends on the radiation
coming off of the parent star and how far away
(08:48):
that planet is from the star. So if your planet
is too close it's too hot to have liquid water,
you'd be something like mercury, or could be a hot
gas planet too far away, it's too cold to have
liquid water. You might be like Jupiter or Saturn, And
it's generally believed that liquid water is sort of a
prerequisite for life, or at least the kind of life
that we understand. Could it be the galaxies as a
(09:11):
whole have zones kind of like this where life is
statistically more likely to emerge, thrive, and survive than in
other zones of the galaxy. Some scientists have proposed this.
And if that is the case, what characterizes this zone? Uh?
First of all, if the proponents of the idea of
a galactic hapitable zone are correct, the zone of the
(09:34):
galaxy most suitable for life would tend to be a
sort of wide ring around the center of the galaxy,
so not farther out in the galactic halo, not not
way out there, but also not deep in the middle
near the galactic center. Now, why would this region be
potentially better to live in than say, the galactic center. Uh?
(09:56):
Just the short and basic version of your main consideration
here would be first of all, conditions that give rise
to life, and then the conditions that can sustain life.
So to give rise to life, we assume you need
first of all, terrestrial planets with stable orbits, right, and
and this means solar systems with a moderate amount of
(10:16):
metal in them. If you've got a solar system that's
like mostly hydrogen and doesn't have much that looks like
it could turn into rocky terrain, that probably means you're
not going to have life forms at least as we
understand them. But this isn't the primary concern for our question. Uh.
A big one for our question would be conditions that
can sustain life, Like how often or how intensely would
(10:41):
a planet in a given region be subjected to outside
damaging influences. Examples of this could be radiation from violent
nearby phenomena their stars. Uh, you know, violent things going
on Obviously nearby supernova would be a huge problem. If
a star anywhere near I you goes supernova, it will
(11:02):
blast your planet and could potentially sterilize it. Uh. The
near passage of of other massive objects like stars or
black holes is a huge issue that could potentially disturb
planetary orbits or bring about a bombardment of terrestrial planets
by comets and other junk from space. So like, if
something passes through your Solar System, and it's really heavy.
(11:24):
It will disturb these commetary orbits and then suddenly, you know,
things that haven't been hitting your planet for a long
time suddenly are This even makes me think about the
Lisa Randall dark matter and the dinosaurs hypothesis. I can't
remember if we ever talked about that on the show,
but basically her idea was that, you know, it's possible that, uh,
some extinction events in Earth's history are correlated to Earth's
(11:48):
passage through a region of the galactic plane where dark
matter is concentrated, and the extra gravitational influence of that
dark matter along that plane, uh disturbs the orbits of
some objects in the Solar System and makes you know,
the Earth get bombarded by stuff or maybe influences. I
can't remember. I think it was mainly comments she was
(12:08):
talking about, but maybe it was also vulcanism. I didn't
actually read the book, but I remember reading articles about
it when it came out. It seemed interesting. Maybe we'll
have to come back and take a look at that someday. Yeah,
that sounds frightening. I don't know whether that theory is
widely believed to to you know, have credence or not.
But but generally, if something disturbs the gravitational field of
(12:28):
your of your star system, that can be really bad
for anything living there. Yes, and so there are a
lot of variables at play, but generally these kinds of
dangerous conditions, like being subjected to more intense or more
frequent radiation or radiation events, and more more frequent disturbances
of gravity by large objects, that's going to be more
(12:49):
likely in densely packed regions of a galaxy, like closer
to the galactic center. The higher the density of nearby
stars and other stuff, the more dangerous there are. And
a very crude analogy is you're more likely to have
some kind of auto accident or mishap on a busy
city street than on some empty country road. Right, Yeah,
they're just well there's you know, there's just more going
(13:10):
on there. But then again, I do want to say
it seems like a lot of the writing about galactic
habitable zones is subject to ongoing criticism and dispute. Uh,
it does seem clear that there are at least some
risks to life associated with moving closer to the galactic center.
But you know where exactly this habitable zone of a
galaxy would be if it in fact is true that
(13:33):
some regions of the galaxy or on average more habitable
than others. I think that's highly disputed. So this is
not settled science. Alright, We're gonna take a quick break.
When we come back, we have a little more information
about just how chaotic and destructive uh, the inner reaches
of the galaxy seem to be, and then we'll move
on to some other possibilities for uh, extraterrestrial activity in
(13:55):
the inner galaxy. All right, we're back, all right, So
we were just talking about this question of like, could you,
you know, could you tend to find life for intelligent
life forms in orbit around a central supermassive black hole
in our galaxy or in the galactic center more generally,
would you expect to see something like that? Would it
be a survivable region? And and it uh, it seems
(14:18):
like this is not fully settled, but we were discussing
some potential risks of living in the galactic center. Yes,
I was looking around for some more details on this,
and this brought me as questions like this often due
to Centauri Dreams, which is a wonderful space website and
I was reading a blog post by the writer Paul
Gilster of The Planetary Society, in which he looks to
(14:40):
the work of Sergey n Action at Leicester on the
idea that the doughnut shaped dust clouds obscuring half of
supermassive black holes might be the you know, the result
of crashes between planets and asteroids occurring at a thousand
kilometers per second speeds, pounding everything into micros copic dust.
(15:01):
So it's a realm of you know, of a violent
collision high radiation. But he points out that while those
planets are doomed, you know anything, actually any of the
planets actually in that region or potentially doomed, the resulting
dust blocks harmful radiation from all of this chaos from
reaching the rest of the galaxy, the host galaxy. That's interesting.
(15:21):
I mean, yeah, we were talking in the last episode
about how dust clouds obscure the galactic center from our
point of view, like it's harder to do astronomy looking
towards the galactic center. I mean, I would imagine that
brightness has something to do with it. But also, yeah,
the dust blocks our view and does significant dimming. It
causes many magnitudes of extinction to the sources coming from
that direction. But we do have methods of looking that
(15:43):
way now, and we can do astronomy focused on the
center of the galaxy, I think, you know, due to
stuff like looking at infrared and X rays. I was
also looking around, uh and found some writings on this
from Phil Plate of Bad Astronomy, always a great read
on space related topics, and he points out in some
galaxies called active galaxies, gas and dust fall into the
(16:05):
yawning black hole at the center of the galaxy, forming
a disc of material sometimes hundreds of light years across. Again,
this here is going to be a realm of high temperatures,
high radiation, and intense light that outshines the rest of
the galaxy, and that would mirror some of the phenomenon
we were talking about in the last episode, where yeah,
like you've got like this quasar or something super powerful
(16:25):
in the middle of the galaxy that just sort of
like you know, it sort of is the galaxy, right,
But fortunately, the Milky Way galaxy is not an active galaxy.
It's a quiescent galaxy, so it's not quite the cosmic
forge we find in other galaxies where you know, it's
just super intense. It is to a certain extent slumbering,
(16:46):
and we're able. I mean, I keep coming back to
the idea of their just being like an awful, all
powerful eldric deity the center of the cosmos, and we're
just lucky that it's that we're in a cosmos. It's
a little worn out and take in a lengthy slumber.
I think at the end of the last episode you Were,
You Were, you sort of fought against the idea of
thinking of black I know, I don't want to think
(17:09):
of a black hole as being you know, and this
has his off figure, but it's hard and it's hard
not to when we used to read things like this.
So I guess we've been looking at answers for mostly
like no, we're looking at the idea of the inner
galaxy is a place where you're probably not encountering um,
you know, planets where life is evolved. There. There are
(17:30):
a lot of risks in the galactic center because you know,
the things are more densely packed. There's probably more radiation risk,
probably more gravity disturbance risk. But at the same time
there are more stars. You might just get more chances
for things to evolve there. So it's it's like I
was saying, it's not settled science, but you can point
to some things going on there and say it looks
like there are are risky phenomena near the galactic center. Now, indeed,
(17:53):
if we are dealing with habitable zones and uh, you know,
uninhabitable zones of the galaxy, one thing to keep in
mind is that technology can potentially change things. Like just
look to our solar system. Yes, Earth is the like
it's it's the bowl of porridge. That's just right. But
we've discussed on the show plenty of times that you know,
(18:13):
there are plans, there are ideas and concepts where with
sufficient technology, humans could live on Mars, they could live
in the clouds of Venus. Even here on Earth we
have a neutrino observatory at the South Pole. You know,
we've got or at least yeah, deepen Antarctica. That's not
a place that's inhabitable by mammals. So you know, so
(18:36):
like we we have found technological ways of overcoming the
environmental limitations imposed by the universe. And you can see
that even without us leaving our host planet. So you know,
if you can build a research station on the South Pole,
where no mammal like us should be able to survive
if you can potentially build it. Oh, if you can
build an I. S. S. Yeah, and live out in space.
(18:58):
Yeah you can imagine. Okay, just extra appellate that up. However,
many orders of magnitude of whatever scale you're talking about
to our power to live beyond our original organic means. Yea.
So we have to come back to something we've discussed
in the show before, sort of a propose technological ladder
to um to godhood if you will. The Cardassie of
(19:18):
scale an old favorite. Yes, so you got you got.
Basically you've got type one, Type two, and type three,
and you know, I've also seen people discuss the possibility
of the type four. But a Type four is so
far beyond where we are now it's almost not even
worth thinking about. Well, I'd say even like type three
is hard to imagine what that would look like. Uh,
you know, we've got more like science fiction that kind
(19:40):
of deals on the realm of one and two. Yeah,
so we're not even type ones yet. Time close. Yeah,
Type A Type one civilization, the cardassi of scale should
be capable of harnessing all the energy of their planet,
because basically that's what the scale is about. It's about,
you know, civilization's ability to to harness in yeah, to
(20:00):
take what's there in the universe and turn that into
the ability to do work. Now, of course that doesn't
necessarily mean work, like it's hard to do. That could
be you know, operating the video game systems of the
future or whatever to turn it into usable energy. Right. Yeah.
So so again we're not type one yet. If we
could harness all the power, all the energy of our planet,
(20:20):
we would be type one. The next step is is
a is a type two in which a civilization has
become masters of their own star, essentially solar solar system
level power. And then that type three, which is an
an enormous step. Then from from from step to tow
a step three civilization has the power of an entire
(20:43):
galaxy at its disposal. That's hard to imagine, it is,
It is very difficult to imagine it. It It gets so
difficult to imagine it's almost ridiculous to try and think
of what is beyond that, you know, uh, and and
so most of our contemplations deal with one, two and three.
Most deal with one and two. So level one and
two on the Kardaship scale would theoretically have access to
(21:04):
technology we refer to as a Dyson sphere, named for
theoretical physicist Freeman Dyson, and these are essentially means of
surrounding a power source and harvesting all of its energy.
There are different varieties of this. You don't need to
necessarily think of a hard sphere, um though I love
too because it should pops up in that episode of
(21:24):
Star Trek. But it could also be you know, more
like a dice in cloud. It could be you know,
satellites surrounding something and absorbing its energy. Um. So it's
maybe oversimplified, but the classic example would be just surrounding
the Sun with something like solar panels, so you get
all of the energy out of it. You can just
sort of like release the waste exhaust outside and and
(21:46):
use everything the sun can give you. Yeah, the still
suits of Dune are sort of like Dyson spheres for
human sweat, you know, for human moisture. Don't waste to drop.
So how does this tie into supermassive black hole old holes?
You might wonder, Well, I was reading a very interesting paper. Uh,
this is from a two thousand and eleven edition of
(22:06):
the Journal of the British Interplanetary Society. And this is
by an o U and you Ku titled Type three
Dicen sphere of highly advanced civilizations around a supermassive black hole.
Uh So, I'm gonna read a quick quote from this quote.
A society of a highly advanced civilization is supposed to
(22:27):
require a huge amount of energy to operate the social system.
As the gravitational energy released by the accretion of matter
into a supermassive black hole is huge, a system must
be developed to use this energy. In such a society,
the condition around a supermassive black hole at the center
of a of a galaxy would be more efficient both
(22:48):
in extracting energy and exhausting the waste energy for advanced
civilizations than those of a Dicen sphere. So basically they're arguing, like, hey,
like we've touched on before, there's a lot going on
on at the center of the galaxy. There's a lot
of energy at the center of the galaxy. Any sufficiently
advanced civilization would go where the energy is and presumably
(23:09):
have the technology to harness it right, extract that energy
and do something with it rather than letting it just
turn into radiation and in space. Yeah. So yeah. They
point out that a huge amount of radiation energy generates
in close vicinity to a supermassive black hole, and here,
you know, this accretion disc rotates around it, so the
potential energy of the accreting matter releases to form a
(23:31):
hot and dense disk. Sorry, I was just for a
moment trying to imagine what we would do with it,
and it would be like, I, let's load up, you know,
ten billion spaceships full of coal and take them to
the center of the galaxy and let the supermassive black
hole burn the coal and then we can use the
heat from the cold power. So yeah, that's our solution.
(23:55):
Uh yeah, that's not quite the system that that that
they're proposing. Here, this is what they add quote, radiation
from the accretion disk will be collected by a mirror
system as a type three dycen sphere. Waste material and
energy could be thrown off towards the central supermassive black hole,
and the supermassive black hole would be the final reservoir
for all the waste materials for any civilizations. Thus, the
(24:19):
most advanced civilizations would develop their activities using a supermassive
black hole efficiency, putting the power plants around the supermassive
black hole at the center of their home galaxy. Wow, well,
I mean that's pretty out there. Yeah, that that's interesting. Yeah.
So from here they lay out a power plant system
that amounts to a sort of Dyson's sphere or shell.
(24:41):
The energy from the power plants is then transferred by
electromagnetic waves the habitats of advanced civilizations, which would be
as imagining more sustainable, stable regions. And then these transmissions
would also serve would serve as a power grid, but
also as highways, four vessels, uh, you know, more or
(25:02):
less sailing them as if they were sailing, you know,
the solar wind. So putting power plants on a supermassive
black hole, well, well, not quite on, but close to.
And then they touched on that to uh you know,
basically asking asking answering the question how close would these
power plants be. Yeah, they say that considering Sagittarius a star,
(25:23):
that the closest you would be dealing with the closest distance,
the closest orbit would be six hundred r s. That's
a swords child radius, and uh, they say that the
proper area for the power plants and their model would
be around one hundred three to one hundred four r
s is um. Also basically just like a hundred of
(25:46):
the radius of the black hole region itself out And
that sounds frighteningly close. But then again, conceivably this would
be a civilization that assuming they're not entirely technological by
this point, you know, and they even have any kind
of like you know, a physical remainder in their their
their being and their culture. Again, it's difficult to imagine
(26:09):
some of these civilizations with him they could consist of.
But even if they were in some way organic, still like,
surely this would be the domain of robots that they
send out, sending the robots in to do the hard
work at the center and then being that energy back
to the centers of civilization. I feel so two ways
(26:29):
about this, because on one hand, it's like, I love
the idea of people trying to work out how CARDASHEV
level three power plants would work out would function. But
on the other hand, it's just like, we don't even
we're not even you know, level one yet, So you
you have to imagine that even if these authors are
totally on the right track, there's probably a lot of
(26:51):
details we haven't we haven't really faced yet and and
don't really know how to incorporate. But at the same time,
this is this is such a blessed project, trying to eagine.
All right, maybe like a billion years in the future,
what does what does the civilization do to get their power? Yeah?
I love I love papers like this. Now, now to
be clear again, this is all theoretical and it's something
(27:11):
the authors say we might look for, but there's no
evidence that something like this is actually going on anywhere
in the universe. Okay, So this is another example, as
has often been done before, where working out the details
of a potential uh Dyson sphere type project would be
mostly useful in the search for extraterrestrial life. Right, right,
(27:35):
What would be the signatures of this type of technology?
Do we look out into the universe and see anything
like that? Right? And and and Astronomers have observed objects
that could potentially be explained by dimming due to a
Dyson sphere. For instance, in two thousand and sixteen, scientists
observed a dimming of the star Epic to zero four
(27:56):
to seven eight, nine one six that was out of
keeping with a large planet, you know, passing between us.
And they presented a few possible explanations, but the last
of them was a dicense fhere, because there's always aliens,
should always be the last explanation we turned to, no
matter how exciting that explanation might be. But which of
(28:17):
their potential explanations made the headlines? Well, of course it's
the dicense fhere right. In fact, I think one of
the headlines I was looking at was researchers just found
a second dicense fhere star, What what happened to the
first one? That's brilliant? Well, I mean, like, like I said,
there have been at least a couple of cases where
people have seen something and they're like, we don't really
(28:38):
fully understand what it is, but here a list of
things it could be. And yeah, number three or four
or five is sometimes a dicense here. Yeah. Um, I
just like that. It sounds like it was assumed that
the first one they found actually is a license fhere,
and not just like there's an off chance that it
could be and that would be consistent with what we saw.
All right. On that note, We're gonna take one more break,
(28:59):
but when we come back, we have some more mysteries
to consider, not about uh, you know, hypothetical you know,
super advanced technological societies, but rather mysteries concerning the supermassive
black hole at the center of our galaxy. Thank all right,
we're back. Now it's time to talk about how our
own galaxy supermassive black hole, Sagittarius A star has been
(29:22):
showing some weird and mysterious behavior lately, just just in
the past few years or this year. Yeah, that's right.
NASA Schandra X ray Observatory has observed a mysterious daily
flares from Sagittarius A Star, and it leads us to,
you know, wonder what's going on? Um so. One theory
is that the dust cloud around it contains comments and
asteroids stripped away from other stars, and then when collisions occur,
(29:46):
it's sometimes sends one off into Sagittarius A Star. And
according to a NASA report from two thousand twelve, quote,
if the asteroid passes within about one million miles of
the black hole, roughly the distance between the Earth the Sun,
it would be torn to pieces by the tidal forces
from the black hole. So basically, you know, you're just
ripping apart a huge chunk of metal or rock in space, right,
(30:08):
and this produces a flare as the asteroid than as
the pieces of it consumed by the black hole. Comets
have been observed to impact our Sun with almost identical
frequency uh and with a resulting flare. You can even
get a really cool flare in astronomy just looking at
like Jupiter. Have you seen some of these when like
a comet goes into Jupiter. Yeah, amazing. Now there have
(30:31):
been other recent observations of of big flare ups right. Yeah.
In May nineteen, a sizeable flare was was observed by
a team using the CAT ten meter telescope, and this
was in the near infrared range. There they're also variable
blasts from Sagittarius a star, and other frequencies like the
X ray range. This was the brightest flare we've ever
(30:52):
observed in the infrared or near infrared. In fact, according
to the u c l A astronomer Twine Doe, who
was the lead researcher on these uh, these latest latest
radiation bursts are our telescopes only caught the tail end
of the flare. It was probably much brighter right before
we started looking at it. Yeah, as Phil Play reported
in Bad Astronomy, the flare was well over two thousand
(31:16):
times more luminous than the Sun in the infrared. Right.
But yeah, and and furthermore, the scientists judged it to
be basically a one and two thousand occurrence compared to
two past observed fluctuations. Right, so it's probably not just
a random fluctuation in the brightness of the radio source
there it is. It is a an event, right. So
(31:36):
this led researchers who think it might be tied to
a star known as S two, which regularly makes a
super close pass by the supermassive black hole. Uh, super close,
you know, in astronomical terms. But in doing so, it
drags a kind of wind of particles with it. Well,
I think the star puts out a stellar wind, just
like our sun does. Yeah, and and but then there
(31:58):
in their particles within that wind, And so it could
be that that wind of particles is crashing into the
black hole. Uh. They considered this, but they decided, well,
I don't I don't think this would be strong enough
thing to actually make that flare. So another possibility, though,
is that S two's pass disturbed clouds of gas and
caused them to fall into the black hole. It's also
(32:21):
possible that an unknown object known as G two on
a two hundred and sixty year orbit around the black
hole might have caused such a you know, in an
area of gas to fall into it. You know, it
moved close enough. In fact, it moved close enough that
you have G two itself were a dust cloud, as
some have thought it might be, it would have just
(32:43):
fallen in. But we don't know for sure exactly what
G two is, right, right, I thought it was maybe
gas or dust, but it didn't behave like that when
it went by the supermassive black holes. Right, there's at
least one idea that it could be a star. There
could be a star in the middle of a of
a cloud of of of of gas and or a particle, etcetera.
And the or it could be two stars that have
merged due to their you know, proximity to the black
(33:06):
hole and then blow they end up blowing off dust
in the process. Okay, So if there's a star within it,
that would explain like gravity holding it sort of together
when goes by the black hole. Yeah, there's something strong
inside it, or the flare could just be due to
an asteroid or come it stripped away from a star
system falling into the black hole. That's that's always a
possibility that's discussed as well. You know. One of the
(33:27):
sad things about trying to look at the center of
the galaxy is that sometimes the Sun gets in the way.
Like our our viewing window is limited because the Sun
passes between the Earth and Sagittarius at a you know,
a certain time each year. Also along the same lines
of mysteries dealing with Sagittarius a star, I was reading
an article from just a couple of days ago about
weird observations regarding what are called Fermi bubbles and Sagittarius
(33:51):
a star. This was on space dot com, authored by
the Ohio State astrophysicist Paul im Sutter. Uh So, Okay,
what you've got here are two giant bubbles of stuff
including hot gas and cosmic rays, and they're globbing onto
the middle of the galaxy, of the Milky Way galaxy.
And we can see these bubbles are emitting high frequency
(34:13):
radiation like gamma rays and X rays. They were discovered
in two thousand ten by researchers working with the Fermi
gamma ray space telescope, and they extend out vertically from
the flat axis of the galaxy to a distance of
roughly twenty five tho light years in each direction. So
if you're trying to picture this and you're picturing the
(34:34):
disc of the galaxy as a vinyl record, imagine a
balloon tied to the middle of the record, like the
hole in the middle of the record on each side,
and this will give you an idea. So, these huge
blobs of stuff are referred to as Fermi bubbles, But
what are they and how do they get there? Well?
An interesting development is that more recently, the Ice Cube
(34:54):
Neutrino Observatory and in Antarctica has observed high energy neutrinos
blasting directly from these bubbles, indicating that perhaps, in in
Sutter's words quote, some crazy sub atomic interactions are afoot.
He writes that the position of these bubbles right above
and below the center of the galaxy could point to
(35:15):
their origin, and that would be the supermassive black hole.
Of course, Sagittary essay star Now, like what could have happened,
that's not really known. He supposes maybe millions of years ago,
something significant fell into the black hole quote with the
infalling material heating up, twisting around in a complicated dance
of electric and magnetic forces, and managing to escape the
(35:37):
clutches of the event horizon before falling in. That material
energized beyond belief, raced away from the center of the galaxy,
riding on jets of particles accelerated to nearly a speed
of light as they fled to safety. These particles spread
and thinned out, but maintained their energetic state to the
present day. So maybe we've got these gigantic, almost galaxy
(36:00):
sized bubbles reaching out of the top and bottom in
the milky way that it looks very possibly like something
fell or almost fell into the black hole and created these.
So possibly a star got too close, was torn apart
and ejected by the gravitational forces, or maybe many of
the stars in the dense core of the galaxy all
(36:20):
went supernova around the same time. This created this highly
energetic stuff to get ejected out in these these polar
jets from the black hole. But anyway, it created these
bubbles that are full of all this high energy stuff
that's still ejecting neutrinos today, and you know, that's exactly
the kind of thing that would interest be very interesting
to uh type two civilization or a type three. Uh. Yeah, well,
(36:45):
I guess at this point we've we've come to the
end of the episode, uh, and come to the end
of this uh this two episode exploration of Sagittarius a
star and supermassive black holes in general. But obviously we'd
love to hear from everybody out there. Um. You know,
obviously nobody has personal experience with a supermassive black hole,
(37:06):
but we would love I'm always happy to hear from uh.
You know, some of our listeners are have read a
quite a lot of science fiction, and even they've read
science fiction that I have not read and you haven't read.
So I love to hear anytime, you know, someone's like, hey,
I actually I know a science fiction novel that or
a short story that deals with exactly that concept, and
here's their solution to it. Oh. But we also know
(37:28):
from past listener mail that we have listeners in astrobiology,
astronomy and astrophysics. If you've got something to add to
this topic, please get in touch absolutely uh. In the meantime,
you can find all the episodes of Stuff to Blow
Your Mind at stuff to Blow your Mind dot com.
You can find our other show, Invention and Invention Pod
dot com. Uh yeah. If you're looking for another episode
of per week from from the two of us, consider Invention.
(37:52):
Each each episode is a different invention and it you
know it is essentially an invention by invention exploration of
human techno history. Uh And if you want to support
either show, really the best thing you can do is
make sure you've subscribed, and wherever you get get our shows,
just make sure you leave a nice rating and a
review that really helps us out huge. Thanks as always
(38:13):
to our excellent audio producers, Maya Cole and Seth Nicholas Johnson.
If you would like to get in touch with us
with feedback on this episode or any other, to suggest
topic for the future, or just to say hello, you
can email us at contact. That's Stuff to Blow your
Mind dot com. Stuff to Blow Your Mind is a
(38:38):
production of iHeart Radio's How Stuff Works. For more podcasts
from my heart Radio, visit the iHeart Radio app, Apple Podcasts,
or wherever you listen to your favorite shows. The First
(39:01):
Times has Baby Attic
Welcome Stuff to Blow Your Mind, a production of I
Heart Radios How Stuff Works. Hey, you welcome to Stuff
to Blow your Mind. My name is Robert Lamb and
I'm Joe McCormick, and we're back with part two of
our exploration of Sagittarius, a star, the compact radio source,
(00:23):
the supermassive black hole we think at the center of
the Milky Way galaxy. Yeah, this is uh so, so,
as we mentioned in the last episode, we had what
three episodes we've done previously just on black holes in general,
and in these two episodes deal with supermassive black holes
more specifically. Uh and uh yeah, So if you're listening
to this episode, you do need to have at least
(00:45):
listened to the previous supermassive black hole episode. But I
think the supermassive black hole episodes are are are tailored
to stand on their own without necessarily having listened to
the previous black hole episodes. In either case, it is
recommended that you have seen either Walt Disney's The black
Hole or Event Horizon, so they have a proper basis
(01:07):
for all of our terrible jokes. Which one of those
two is more kid friendly? You think, Oh, blow. I
think it's the Disney movie, but the Disney movie is
also surprisingly dark. Like, uh, Anthony Perkins is eviscerated by
a killer robot um Like this is awful scene where
Maximilian the robots coming at him with the spinning blade
arm and he holds up like a giant dictionary to
(01:30):
block it, and he like cuts right through the dictionary
and uh and you know, apparently like just disembowels Anthony Perkins.
It cuts out the definition of in trails. Well you
don't see any in trails, but it's still pretty horrific.
There's some scary moments in it. But I loved it
as a kid. I really need to sit down and
watch it again. Now, speaking of a visceration, we're gonna
be talking about some somewhat violent events going on around
(01:52):
a black hole, or at least they presumed black hole today.
And one thing we promised you last time is that
we would answer a few questions every You've always wanted
to know about the supermassive black hole at the center
of the galaxy, but we're afraid to ask. And one
of the questions people most often ask about black holes.
If you're ready to jump right in robert Is. With
this big supermassive black hole at the center of the
(02:14):
Milky Way, will the rest of the Milky Way, including Earth,
one day gets sucked into this black hole? And I
was trying to find a good answer for this. I
think the short answer is no, or at least that's
not a given. All evidence indicates that, of course, the
Milky Way does have this supermassive black hole at its center.
The galaxy is sort of orbiting around it, or at
(02:36):
least roughly orbiting around it, But our Solar system is
in a stable orbit that is pretty far out. It's
something like light years away from the galactic center. And
black holes, even unbelievably giant black holes, still basically behave
like stars until you get really close to them. They're
not vacuum cleaners just sucking down the entire universe. You know.
(02:59):
They're objects traveling through space with a gravitational attraction that
is a product of their mass and your distance from them,
and like other objects, if you're far enough away, they're
gravitational attraction is negligible. So we've got no indication that
there is a risk of a black hole swallowing our
Solar system or the Earth or the rest of the
(03:20):
Milky Way. But of course, if anything as massive as
a black hole pass near our Solar system, I think,
I mean that that would be a problem. It might
not swallow our Solar System, but it's gravitational influence could
alter the orbits of the planets, which would be not good. Obviously,
life on Earth depends very heavily on us being where
we are relative to the Sun and other objects in
(03:42):
the Solar System staying where they are. You don't want
to say the orbits of comets and other objects like
that thrown out of whack, because then that can lead
to interplanetary bombardment. Yeah. I think the fact that a
black hole is an object is something that we do
have to come back to again and again because especially
with science fiction treatments, especially those especially the Disney black Hole.
(04:02):
So you know, there's this idea of like thinking of
it as a whirlpool it's a hungry, hungry hippo, yeah,
or thinking of it as a tunnel or just an
open like some of these you know, these analogies. They
they may be useful to a certain extent. It gives
us something to picture in our mind, but it kind
of drifts away from the idea that this is an object.
(04:24):
This is a highly dense thing, and now, of course
in the region really close to it, it doesn't behave
like most other objects too. But once once you get
farther away, I would say that the ways in which
it is unique become less relevant to you. Does that
make sense? Yes? Now, Um, you touched on some of this,
but but I was looking around like, Okay, what is
(04:45):
the scenario in which the supermassive black hole at the
center of our galaxy uh could conceivably destroy us? And
that there is one very strong possibility. So and we've
mentioned that our system is again in a stable orbit
around the galactic center. Um, we're not being pooled pulled
(05:07):
into Sagittarius M A star. But in four point five
billion years, the Milky Way galaxy will likely merge with
the Andromeda galaxy. And when this happens, all bets are off.
It's possible that everything gets pushed around, gets shuffled around,
and our solar system then could be gulped up or
(05:28):
just hideously disrupted by Sagittarius A star in the process. This,
according to Fabio Pacucci, b Hi Fellow at Harvard University
and Clay Fellow at the Smithsonian Astrophysical Observatory. He has
a wonderful ted Ed video about this. So if you
just go to if you go to YouTube and you
look up, just look up ted Ed in general, because
(05:49):
they're great educational short form videos to watch with the
entire family. We watch them all the time in my household.
But they have an extra excellent one about black holes
that Fabio is the contributor for. Yeah, now, when we
talk about the collision of galaxies, maybe someday we could
do a whole episode just on the upcoming collision between
the Milky Way and the Andromeda galaxy because yeah, so
(06:10):
they're on a collision course. Uh. On one hand, that
sounds like, okay, so that's just the end of everything, right, Actually,
I think not necessarily, because you have to remember, well,
you know there is a lot of space in between stars, right,
you know, there's there's a lot of space for things
to go by. But one of the big fears I
think is not necessarily that like Earth will smash directly
(06:32):
into a star from Andromeda or something. That the fear
is about gravitational disruption. Right, things moving past each other
in space can still have a perturbation effects on on stars,
on the planet's orbiting stars, on the objects and junk
in space all around stars. Well, none of that's good. Yeah,
I mean it's kind of like, and this is a
(06:52):
terrible analogy, I'm sure, but it's like, if two companies merge,
your your concern is not that, you know, if you're
an editor at one company and you emerge with another company,
you're not concerned that there's another editor over there that
you're just going to smack into so hard that you
both explode. No, you're worried about redundancies. You're worried about
reshuffling of titles and priorities, etcetera. Which you know, all
(07:16):
of that can be can can certainly be catastrophically disruptive
to your life. Um, but you're not worried about, you know,
like physically, you know, exploding or you know, melting into
them like Ron Silver and time coop. So I guess
that is possible. I mean, whenever things drift past each
other in space, there's always a potential for a collision.
It's just you know that that's not necessarily the thing
(07:38):
you should be worried about. I think the bigger thing
would be, Yeah, do you get thrown out of place?
You get thrown in? You getting thrown into the near
orbit or towards the black hole would obviously be bad
and and catastrophic in its own right for sure. Alright,
So the next big question that that you might be
wondering about. Could intelligent life forms live of and or
(08:00):
operate in orbit around a supermassive black hole, specifically our
supermassive black hole? Uh? You know, how would this factor
into a like a galactic civilization? Yeah? Or in the
in the galaxy center more generally, right, can you get
close to the galaxy center and have life there? This
seems debatable, right, Like, So there are some scientists who
(08:25):
think that just the way solar systems have a habitable
zone for planetary orbits, the galaxy as a whole has
some kind of habitable zone for star systems. Now in
star systems, of course, this habitable zone has temperature as
a primary variable, right, And this depends on the radiation
coming off of the parent star and how far away
(08:48):
that planet is from the star. So if your planet
is too close it's too hot to have liquid water,
you'd be something like mercury, or could be a hot
gas planet too far away, it's too cold to have
liquid water. You might be like Jupiter or Saturn, And
it's generally believed that liquid water is sort of a
prerequisite for life, or at least the kind of life
that we understand. Could it be the galaxies as a
(09:11):
whole have zones kind of like this where life is
statistically more likely to emerge, thrive, and survive than in
other zones of the galaxy. Some scientists have proposed this.
And if that is the case, what characterizes this zone? Uh?
First of all, if the proponents of the idea of
a galactic hapitable zone are correct, the zone of the
(09:34):
galaxy most suitable for life would tend to be a
sort of wide ring around the center of the galaxy,
so not farther out in the galactic halo, not not
way out there, but also not deep in the middle
near the galactic center. Now, why would this region be
potentially better to live in than say, the galactic center. Uh?
(09:56):
Just the short and basic version of your main consideration
here would be first of all, conditions that give rise
to life, and then the conditions that can sustain life.
So to give rise to life, we assume you need
first of all, terrestrial planets with stable orbits, right, and
and this means solar systems with a moderate amount of
(10:16):
metal in them. If you've got a solar system that's
like mostly hydrogen and doesn't have much that looks like
it could turn into rocky terrain, that probably means you're
not going to have life forms at least as we
understand them. But this isn't the primary concern for our question. Uh.
A big one for our question would be conditions that
can sustain life, Like how often or how intensely would
(10:41):
a planet in a given region be subjected to outside
damaging influences. Examples of this could be radiation from violent
nearby phenomena their stars. Uh, you know, violent things going
on Obviously nearby supernova would be a huge problem. If
a star anywhere near I you goes supernova, it will
(11:02):
blast your planet and could potentially sterilize it. Uh. The
near passage of of other massive objects like stars or
black holes is a huge issue that could potentially disturb
planetary orbits or bring about a bombardment of terrestrial planets
by comets and other junk from space. So like, if
something passes through your Solar System, and it's really heavy.
(11:24):
It will disturb these commetary orbits and then suddenly, you know,
things that haven't been hitting your planet for a long
time suddenly are This even makes me think about the
Lisa Randall dark matter and the dinosaurs hypothesis. I can't
remember if we ever talked about that on the show,
but basically her idea was that, you know, it's possible that, uh,
some extinction events in Earth's history are correlated to Earth's
(11:48):
passage through a region of the galactic plane where dark
matter is concentrated, and the extra gravitational influence of that
dark matter along that plane, uh disturbs the orbits of
some objects in the Solar System and makes you know,
the Earth get bombarded by stuff or maybe influences. I
can't remember. I think it was mainly comments she was
(12:08):
talking about, but maybe it was also vulcanism. I didn't
actually read the book, but I remember reading articles about
it when it came out. It seemed interesting. Maybe we'll
have to come back and take a look at that someday. Yeah,
that sounds frightening. I don't know whether that theory is
widely believed to to you know, have credence or not.
But but generally, if something disturbs the gravitational field of
(12:28):
your of your star system, that can be really bad
for anything living there. Yes, and so there are a
lot of variables at play, but generally these kinds of
dangerous conditions, like being subjected to more intense or more
frequent radiation or radiation events, and more more frequent disturbances
of gravity by large objects, that's going to be more
(12:49):
likely in densely packed regions of a galaxy, like closer
to the galactic center. The higher the density of nearby
stars and other stuff, the more dangerous there are. And
a very crude analogy is you're more likely to have
some kind of auto accident or mishap on a busy
city street than on some empty country road. Right, Yeah,
they're just well there's you know, there's just more going
(13:10):
on there. But then again, I do want to say
it seems like a lot of the writing about galactic
habitable zones is subject to ongoing criticism and dispute. Uh,
it does seem clear that there are at least some
risks to life associated with moving closer to the galactic center.
But you know where exactly this habitable zone of a
galaxy would be if it in fact is true that
(13:33):
some regions of the galaxy or on average more habitable
than others. I think that's highly disputed. So this is
not settled science. Alright, We're gonna take a quick break.
When we come back, we have a little more information
about just how chaotic and destructive uh, the inner reaches
of the galaxy seem to be, and then we'll move
on to some other possibilities for uh, extraterrestrial activity in
(13:55):
the inner galaxy. All right, we're back, all right, So
we were just talking about this question of like, could you,
you know, could you tend to find life for intelligent
life forms in orbit around a central supermassive black hole
in our galaxy or in the galactic center more generally,
would you expect to see something like that? Would it
be a survivable region? And and it uh, it seems
(14:18):
like this is not fully settled, but we were discussing
some potential risks of living in the galactic center. Yes,
I was looking around for some more details on this,
and this brought me as questions like this often due
to Centauri Dreams, which is a wonderful space website and
I was reading a blog post by the writer Paul
Gilster of The Planetary Society, in which he looks to
(14:40):
the work of Sergey n Action at Leicester on the
idea that the doughnut shaped dust clouds obscuring half of
supermassive black holes might be the you know, the result
of crashes between planets and asteroids occurring at a thousand
kilometers per second speeds, pounding everything into micros copic dust.
(15:01):
So it's a realm of you know, of a violent
collision high radiation. But he points out that while those
planets are doomed, you know anything, actually any of the
planets actually in that region or potentially doomed, the resulting
dust blocks harmful radiation from all of this chaos from
reaching the rest of the galaxy, the host galaxy. That's interesting.
(15:21):
I mean, yeah, we were talking in the last episode
about how dust clouds obscure the galactic center from our
point of view, like it's harder to do astronomy looking
towards the galactic center. I mean, I would imagine that
brightness has something to do with it. But also, yeah,
the dust blocks our view and does significant dimming. It
causes many magnitudes of extinction to the sources coming from
that direction. But we do have methods of looking that
(15:43):
way now, and we can do astronomy focused on the
center of the galaxy, I think, you know, due to
stuff like looking at infrared and X rays. I was
also looking around, uh and found some writings on this
from Phil Plate of Bad Astronomy, always a great read
on space related topics, and he points out in some
galaxies called active galaxies, gas and dust fall into the
(16:05):
yawning black hole at the center of the galaxy, forming
a disc of material sometimes hundreds of light years across. Again,
this here is going to be a realm of high temperatures,
high radiation, and intense light that outshines the rest of
the galaxy, and that would mirror some of the phenomenon
we were talking about in the last episode, where yeah,
like you've got like this quasar or something super powerful
(16:25):
in the middle of the galaxy that just sort of
like you know, it sort of is the galaxy, right,
But fortunately, the Milky Way galaxy is not an active galaxy.
It's a quiescent galaxy, so it's not quite the cosmic
forge we find in other galaxies where you know, it's
just super intense. It is to a certain extent slumbering,
(16:46):
and we're able. I mean, I keep coming back to
the idea of their just being like an awful, all
powerful eldric deity the center of the cosmos, and we're
just lucky that it's that we're in a cosmos. It's
a little worn out and take in a lengthy slumber.
I think at the end of the last episode you Were,
You Were, you sort of fought against the idea of
thinking of black I know, I don't want to think
(17:09):
of a black hole as being you know, and this
has his off figure, but it's hard and it's hard
not to when we used to read things like this.
So I guess we've been looking at answers for mostly
like no, we're looking at the idea of the inner
galaxy is a place where you're probably not encountering um,
you know, planets where life is evolved. There. There are
(17:30):
a lot of risks in the galactic center because you know,
the things are more densely packed. There's probably more radiation risk,
probably more gravity disturbance risk. But at the same time
there are more stars. You might just get more chances
for things to evolve there. So it's it's like I
was saying, it's not settled science, but you can point
to some things going on there and say it looks
like there are are risky phenomena near the galactic center. Now, indeed,
(17:53):
if we are dealing with habitable zones and uh, you know,
uninhabitable zones of the galaxy, one thing to keep in
mind is that technology can potentially change things. Like just
look to our solar system. Yes, Earth is the like
it's it's the bowl of porridge. That's just right. But
we've discussed on the show plenty of times that you know,
(18:13):
there are plans, there are ideas and concepts where with
sufficient technology, humans could live on Mars, they could live
in the clouds of Venus. Even here on Earth we
have a neutrino observatory at the South Pole. You know,
we've got or at least yeah, deepen Antarctica. That's not
a place that's inhabitable by mammals. So you know, so
(18:36):
like we we have found technological ways of overcoming the
environmental limitations imposed by the universe. And you can see
that even without us leaving our host planet. So you know,
if you can build a research station on the South Pole,
where no mammal like us should be able to survive
if you can potentially build it. Oh, if you can
build an I. S. S. Yeah, and live out in space.
(18:58):
Yeah you can imagine. Okay, just extra appellate that up. However,
many orders of magnitude of whatever scale you're talking about
to our power to live beyond our original organic means. Yea.
So we have to come back to something we've discussed
in the show before, sort of a propose technological ladder
to um to godhood if you will. The Cardassie of
(19:18):
scale an old favorite. Yes, so you got you got.
Basically you've got type one, Type two, and type three,
and you know, I've also seen people discuss the possibility
of the type four. But a Type four is so
far beyond where we are now it's almost not even
worth thinking about. Well, I'd say even like type three
is hard to imagine what that would look like. Uh,
you know, we've got more like science fiction that kind
(19:40):
of deals on the realm of one and two. Yeah,
so we're not even type ones yet. Time close. Yeah,
Type A Type one civilization, the cardassi of scale should
be capable of harnessing all the energy of their planet,
because basically that's what the scale is about. It's about,
you know, civilization's ability to to harness in yeah, to
(20:00):
take what's there in the universe and turn that into
the ability to do work. Now, of course that doesn't
necessarily mean work, like it's hard to do. That could
be you know, operating the video game systems of the
future or whatever to turn it into usable energy. Right. Yeah.
So so again we're not type one yet. If we
could harness all the power, all the energy of our planet,
(20:20):
we would be type one. The next step is is
a is a type two in which a civilization has
become masters of their own star, essentially solar solar system
level power. And then that type three, which is an
an enormous step. Then from from from step to tow
a step three civilization has the power of an entire
(20:43):
galaxy at its disposal. That's hard to imagine, it is,
It is very difficult to imagine it. It It gets so
difficult to imagine it's almost ridiculous to try and think
of what is beyond that, you know, uh, and and
so most of our contemplations deal with one, two and three.
Most deal with one and two. So level one and
two on the Kardaship scale would theoretically have access to
(21:04):
technology we refer to as a Dyson sphere, named for
theoretical physicist Freeman Dyson, and these are essentially means of
surrounding a power source and harvesting all of its energy.
There are different varieties of this. You don't need to
necessarily think of a hard sphere, um though I love
too because it should pops up in that episode of
(21:24):
Star Trek. But it could also be you know, more
like a dice in cloud. It could be you know,
satellites surrounding something and absorbing its energy. Um. So it's
maybe oversimplified, but the classic example would be just surrounding
the Sun with something like solar panels, so you get
all of the energy out of it. You can just
sort of like release the waste exhaust outside and and
(21:46):
use everything the sun can give you. Yeah, the still
suits of Dune are sort of like Dyson spheres for
human sweat, you know, for human moisture. Don't waste to drop.
So how does this tie into supermassive black hole old holes?
You might wonder, Well, I was reading a very interesting paper. Uh,
this is from a two thousand and eleven edition of
(22:06):
the Journal of the British Interplanetary Society. And this is
by an o U and you Ku titled Type three
Dicen sphere of highly advanced civilizations around a supermassive black hole.
Uh So, I'm gonna read a quick quote from this quote.
A society of a highly advanced civilization is supposed to
(22:27):
require a huge amount of energy to operate the social system.
As the gravitational energy released by the accretion of matter
into a supermassive black hole is huge, a system must
be developed to use this energy. In such a society,
the condition around a supermassive black hole at the center
of a of a galaxy would be more efficient both
(22:48):
in extracting energy and exhausting the waste energy for advanced
civilizations than those of a Dicen sphere. So basically they're arguing, like, hey,
like we've touched on before, there's a lot going on
on at the center of the galaxy. There's a lot
of energy at the center of the galaxy. Any sufficiently
advanced civilization would go where the energy is and presumably
(23:09):
have the technology to harness it right, extract that energy
and do something with it rather than letting it just
turn into radiation and in space. Yeah. So yeah. They
point out that a huge amount of radiation energy generates
in close vicinity to a supermassive black hole, and here,
you know, this accretion disc rotates around it, so the
potential energy of the accreting matter releases to form a
(23:31):
hot and dense disk. Sorry, I was just for a
moment trying to imagine what we would do with it,
and it would be like, I, let's load up, you know,
ten billion spaceships full of coal and take them to
the center of the galaxy and let the supermassive black
hole burn the coal and then we can use the
heat from the cold power. So yeah, that's our solution.
(23:55):
Uh yeah, that's not quite the system that that that
they're proposing. Here, this is what they add quote, radiation
from the accretion disk will be collected by a mirror
system as a type three dycen sphere. Waste material and
energy could be thrown off towards the central supermassive black hole,
and the supermassive black hole would be the final reservoir
for all the waste materials for any civilizations. Thus, the
(24:19):
most advanced civilizations would develop their activities using a supermassive
black hole efficiency, putting the power plants around the supermassive
black hole at the center of their home galaxy. Wow, well,
I mean that's pretty out there. Yeah, that that's interesting. Yeah.
So from here they lay out a power plant system
that amounts to a sort of Dyson's sphere or shell.
(24:41):
The energy from the power plants is then transferred by
electromagnetic waves the habitats of advanced civilizations, which would be
as imagining more sustainable, stable regions. And then these transmissions
would also serve would serve as a power grid, but
also as highways, four vessels, uh, you know, more or
(25:02):
less sailing them as if they were sailing, you know,
the solar wind. So putting power plants on a supermassive
black hole, well, well, not quite on, but close to.
And then they touched on that to uh you know,
basically asking asking answering the question how close would these
power plants be. Yeah, they say that considering Sagittarius a star,
(25:23):
that the closest you would be dealing with the closest distance,
the closest orbit would be six hundred r s. That's
a swords child radius, and uh, they say that the
proper area for the power plants and their model would
be around one hundred three to one hundred four r
s is um. Also basically just like a hundred of
(25:46):
the radius of the black hole region itself out And
that sounds frighteningly close. But then again, conceivably this would
be a civilization that assuming they're not entirely technological by
this point, you know, and they even have any kind
of like you know, a physical remainder in their their
their being and their culture. Again, it's difficult to imagine
(26:09):
some of these civilizations with him they could consist of.
But even if they were in some way organic, still like,
surely this would be the domain of robots that they
send out, sending the robots in to do the hard
work at the center and then being that energy back
to the centers of civilization. I feel so two ways
(26:29):
about this, because on one hand, it's like, I love
the idea of people trying to work out how CARDASHEV
level three power plants would work out would function. But
on the other hand, it's just like, we don't even
we're not even you know, level one yet, So you
you have to imagine that even if these authors are
totally on the right track, there's probably a lot of
(26:51):
details we haven't we haven't really faced yet and and
don't really know how to incorporate. But at the same time,
this is this is such a blessed project, trying to eagine.
All right, maybe like a billion years in the future,
what does what does the civilization do to get their power? Yeah?
I love I love papers like this. Now, now to
be clear again, this is all theoretical and it's something
(27:11):
the authors say we might look for, but there's no
evidence that something like this is actually going on anywhere
in the universe. Okay, So this is another example, as
has often been done before, where working out the details
of a potential uh Dyson sphere type project would be
mostly useful in the search for extraterrestrial life. Right, right,
(27:35):
What would be the signatures of this type of technology?
Do we look out into the universe and see anything
like that? Right? And and and Astronomers have observed objects
that could potentially be explained by dimming due to a
Dyson sphere. For instance, in two thousand and sixteen, scientists
observed a dimming of the star Epic to zero four
(27:56):
to seven eight, nine one six that was out of
keeping with a large planet, you know, passing between us.
And they presented a few possible explanations, but the last
of them was a dicense fhere, because there's always aliens,
should always be the last explanation we turned to, no
matter how exciting that explanation might be. But which of
(28:17):
their potential explanations made the headlines? Well, of course it's
the dicense fhere right. In fact, I think one of
the headlines I was looking at was researchers just found
a second dicense fhere star, What what happened to the
first one? That's brilliant? Well, I mean, like, like I said,
there have been at least a couple of cases where
people have seen something and they're like, we don't really
(28:38):
fully understand what it is, but here a list of
things it could be. And yeah, number three or four
or five is sometimes a dicense here. Yeah. Um, I
just like that. It sounds like it was assumed that
the first one they found actually is a license fhere,
and not just like there's an off chance that it
could be and that would be consistent with what we saw.
All right. On that note, We're gonna take one more break,
(28:59):
but when we come back, we have some more mysteries
to consider, not about uh, you know, hypothetical you know,
super advanced technological societies, but rather mysteries concerning the supermassive
black hole at the center of our galaxy. Thank all right,
we're back. Now it's time to talk about how our
own galaxy supermassive black hole, Sagittarius A star has been
(29:22):
showing some weird and mysterious behavior lately, just just in
the past few years or this year. Yeah, that's right.
NASA Schandra X ray Observatory has observed a mysterious daily
flares from Sagittarius A Star, and it leads us to,
you know, wonder what's going on? Um so. One theory
is that the dust cloud around it contains comments and
asteroids stripped away from other stars, and then when collisions occur,
(29:46):
it's sometimes sends one off into Sagittarius A Star. And
according to a NASA report from two thousand twelve, quote,
if the asteroid passes within about one million miles of
the black hole, roughly the distance between the Earth the Sun,
it would be torn to pieces by the tidal forces
from the black hole. So basically, you know, you're just
ripping apart a huge chunk of metal or rock in space, right,
(30:08):
and this produces a flare as the asteroid than as
the pieces of it consumed by the black hole. Comets
have been observed to impact our Sun with almost identical
frequency uh and with a resulting flare. You can even
get a really cool flare in astronomy just looking at
like Jupiter. Have you seen some of these when like
a comet goes into Jupiter. Yeah, amazing. Now there have
(30:31):
been other recent observations of of big flare ups right. Yeah.
In May nineteen, a sizeable flare was was observed by
a team using the CAT ten meter telescope, and this
was in the near infrared range. There they're also variable
blasts from Sagittarius a star, and other frequencies like the
X ray range. This was the brightest flare we've ever
(30:52):
observed in the infrared or near infrared. In fact, according
to the u c l A astronomer Twine Doe, who
was the lead researcher on these uh, these latest latest
radiation bursts are our telescopes only caught the tail end
of the flare. It was probably much brighter right before
we started looking at it. Yeah, as Phil Play reported
in Bad Astronomy, the flare was well over two thousand
(31:16):
times more luminous than the Sun in the infrared. Right.
But yeah, and and furthermore, the scientists judged it to
be basically a one and two thousand occurrence compared to
two past observed fluctuations. Right, so it's probably not just
a random fluctuation in the brightness of the radio source
there it is. It is a an event, right. So
(31:36):
this led researchers who think it might be tied to
a star known as S two, which regularly makes a
super close pass by the supermassive black hole. Uh, super close,
you know, in astronomical terms. But in doing so, it
drags a kind of wind of particles with it. Well,
I think the star puts out a stellar wind, just
like our sun does. Yeah, and and but then there
(31:58):
in their particles within that wind, And so it could
be that that wind of particles is crashing into the
black hole. Uh. They considered this, but they decided, well,
I don't I don't think this would be strong enough
thing to actually make that flare. So another possibility, though,
is that S two's pass disturbed clouds of gas and
caused them to fall into the black hole. It's also
(32:21):
possible that an unknown object known as G two on
a two hundred and sixty year orbit around the black
hole might have caused such a you know, in an
area of gas to fall into it. You know, it
moved close enough. In fact, it moved close enough that
you have G two itself were a dust cloud, as
some have thought it might be, it would have just
(32:43):
fallen in. But we don't know for sure exactly what
G two is, right, right, I thought it was maybe
gas or dust, but it didn't behave like that when
it went by the supermassive black holes. Right, there's at
least one idea that it could be a star. There
could be a star in the middle of a of
a cloud of of of of gas and or a particle, etcetera.
And the or it could be two stars that have
merged due to their you know, proximity to the black
(33:06):
hole and then blow they end up blowing off dust
in the process. Okay, So if there's a star within it,
that would explain like gravity holding it sort of together
when goes by the black hole. Yeah, there's something strong
inside it, or the flare could just be due to
an asteroid or come it stripped away from a star
system falling into the black hole. That's that's always a
possibility that's discussed as well. You know. One of the
(33:27):
sad things about trying to look at the center of
the galaxy is that sometimes the Sun gets in the way.
Like our our viewing window is limited because the Sun
passes between the Earth and Sagittarius at a you know,
a certain time each year. Also along the same lines
of mysteries dealing with Sagittarius a star, I was reading
an article from just a couple of days ago about
weird observations regarding what are called Fermi bubbles and Sagittarius
(33:51):
a star. This was on space dot com, authored by
the Ohio State astrophysicist Paul im Sutter. Uh So, Okay,
what you've got here are two giant bubbles of stuff
including hot gas and cosmic rays, and they're globbing onto
the middle of the galaxy, of the Milky Way galaxy.
And we can see these bubbles are emitting high frequency
(34:13):
radiation like gamma rays and X rays. They were discovered
in two thousand ten by researchers working with the Fermi
gamma ray space telescope, and they extend out vertically from
the flat axis of the galaxy to a distance of
roughly twenty five tho light years in each direction. So
if you're trying to picture this and you're picturing the
(34:34):
disc of the galaxy as a vinyl record, imagine a
balloon tied to the middle of the record, like the
hole in the middle of the record on each side,
and this will give you an idea. So, these huge
blobs of stuff are referred to as Fermi bubbles, But
what are they and how do they get there? Well?
An interesting development is that more recently, the Ice Cube
(34:54):
Neutrino Observatory and in Antarctica has observed high energy neutrinos
blasting directly from these bubbles, indicating that perhaps, in in
Sutter's words quote, some crazy sub atomic interactions are afoot.
He writes that the position of these bubbles right above
and below the center of the galaxy could point to
(35:15):
their origin, and that would be the supermassive black hole.
Of course, Sagittary essay star Now, like what could have happened,
that's not really known. He supposes maybe millions of years ago,
something significant fell into the black hole quote with the
infalling material heating up, twisting around in a complicated dance
of electric and magnetic forces, and managing to escape the
(35:37):
clutches of the event horizon before falling in. That material
energized beyond belief, raced away from the center of the galaxy,
riding on jets of particles accelerated to nearly a speed
of light as they fled to safety. These particles spread
and thinned out, but maintained their energetic state to the
present day. So maybe we've got these gigantic, almost galaxy
(36:00):
sized bubbles reaching out of the top and bottom in
the milky way that it looks very possibly like something
fell or almost fell into the black hole and created these.
So possibly a star got too close, was torn apart
and ejected by the gravitational forces, or maybe many of
the stars in the dense core of the galaxy all
(36:20):
went supernova around the same time. This created this highly
energetic stuff to get ejected out in these these polar
jets from the black hole. But anyway, it created these
bubbles that are full of all this high energy stuff
that's still ejecting neutrinos today, and you know, that's exactly
the kind of thing that would interest be very interesting
to uh type two civilization or a type three. Uh. Yeah, well,
(36:45):
I guess at this point we've we've come to the
end of the episode, uh, and come to the end
of this uh this two episode exploration of Sagittarius a
star and supermassive black holes in general. But obviously we'd
love to hear from everybody out there. Um. You know,
obviously nobody has personal experience with a supermassive black hole,
(37:06):
but we would love I'm always happy to hear from uh.
You know, some of our listeners are have read a
quite a lot of science fiction, and even they've read
science fiction that I have not read and you haven't read.
So I love to hear anytime, you know, someone's like, hey,
I actually I know a science fiction novel that or
a short story that deals with exactly that concept, and
here's their solution to it. Oh. But we also know
(37:28):
from past listener mail that we have listeners in astrobiology,
astronomy and astrophysics. If you've got something to add to
this topic, please get in touch absolutely uh. In the meantime,
you can find all the episodes of Stuff to Blow
Your Mind at stuff to Blow your Mind dot com.
You can find our other show, Invention and Invention Pod
dot com. Uh yeah. If you're looking for another episode
of per week from from the two of us, consider Invention.
(37:52):
Each each episode is a different invention and it you
know it is essentially an invention by invention exploration of
human techno history. Uh And if you want to support
either show, really the best thing you can do is
make sure you've subscribed, and wherever you get get our shows,
just make sure you leave a nice rating and a
review that really helps us out huge. Thanks as always
(38:13):
to our excellent audio producers, Maya Cole and Seth Nicholas Johnson.
If you would like to get in touch with us
with feedback on this episode or any other, to suggest
topic for the future, or just to say hello, you
can email us at contact. That's Stuff to Blow your
Mind dot com. Stuff to Blow Your Mind is a
(38:38):
production of iHeart Radio's How Stuff Works. For more podcasts
from my heart Radio, visit the iHeart Radio app, Apple Podcasts,
or wherever you listen to your favorite shows. The First
(39:01):
Times has Baby Attic
Stuff To Blow Your Mind News
Hosts And Creators
Robert Lamb
Joe McCormick
Popular Podcasts
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
24/7 News: The Latest
The latest news in 4 minutes updated every hour, every day.
Crime Junkie
Does hearing about a true crime case always leave you scouring the internet for the truth behind the story? Dive into your next mystery with Crime Junkie. Every Monday, join your host Ashley Flowers as she unravels all the details of infamous and underreported true crime cases with her best friend Brit Prawat. From cold cases to missing persons and heroes in our community who seek justice, Crime Junkie is your destination for theories and stories you won’t hear anywhere else. Whether you're a seasoned true crime enthusiast or new to the genre, you'll find yourself on the edge of your seat awaiting a new episode every Monday. If you can never get enough true crime... Congratulations, you’ve found your people. Follow to join a community of Crime Junkies! Crime Junkie is presented by audiochuck Media Company.