Welcome back to Cosmos in a Pod,
space and astronomy series, of course.
Today we're gonna be diving deep into something
I think will leave you terrified,
but also like completely in awe.
Supermassive black holes, ready to go explore.
Always, always ready for a cosmic adventure.
What kind of mysteries are we uncovering today?
Well, we're not just talking about
your average black holes,
we're talking supermassive black holes,
the kind that are like millions,
even billions of times the mass of our sun.
Ah, yes, the cosmic heavyweights,
they're really something else.
Exactly, and here's the thing,
they're not just like passively sitting there
in the centers of galaxies,
they're actively shaping the galaxies they inhabit,
almost like cosmic architects.
Yeah, that's what's so fascinating, right?
Their influence stretches way beyond
just their immediate surroundings.
Now, before we get too far ahead of ourselves,
let's like take a step back, right?
For anyone who might not be totally up to speed,
can you break it down for us?
What makes a black hole supermassive?
Yeah, sure.
So you're probably familiar with the basic idea
of a black hole,
a place in space where gravity is so strong
that nothing, not even light, can escape.
A supermassive black hole takes that concept
and like, LLs it up to 11.
We're talking objects with masses
millions or even billions of times greater than our sun.
Wow, so that's a completely different scale.
Oh, absolutely, and all that mass
equals some serious gravitational pull,
the kind that dominates entire galaxies.
So it's not just about size,
it's the impact, the influence it has
on everything around it.
You got it.
Think of our solar system,
but instead of the sun in the middle,
you've got this supermassive black hole
dictating the movements of stars and gas clouds
over these incredible deptances.
Wow, that's, I mean, it's almost impossible to picture.
But how do these things even form?
I mean, where does all that mass come from
in the first place?
Well, that is one of the biggest questions
in, well, all of astrophysics.
We're talking about a cosmic mystery
shrouded in darkness, you know, pun intended.
One theory is that they formed directly
from like giant gas clouds that collapsed
way back in the early universe.
So they basically skip the whole star phase
and just go straight to black hole.
Boom, right to black hole status.
It's like, I don't know,
going from a grain of sand to a mountain
in a single step.
Another theory is they start out smaller,
you know, maybe leftovers from dead stars,
and then they just gradually grow
by pulling in stuff around them.
The cosmic vacuum cleaner's just sucking up
everything in their path.
I like that analogy.
And of course, we can't rule out the possibility
of mergers, smaller black holes colliding
and combining over, well, billions of years.
So a combination of things happening like forever.
It's a complex process,
a puzzle we're still piecing together,
but it's definitely one of the most fascinating
puzzles in astronomy.
I know we tend to think of black holes
as these like destructive forces,
but I've heard they actually play a pretty surprising role
in shaping galaxies, is that right?
It's true, they're a lot more
than just cosmic vacuum cleaners.
They actually act as regulators,
influencing the life cycle of stars within their galaxies.
So they're not just destroying things,
they're actually contributing to the creation of new stars.
That's the amazing part.
It's a delicate balance.
They can trigger star formation,
and they can suppress it.
It all depends on the circumstances.
It's like they have this like cosmic thermostat
fine tuning the conditions inside their galaxies.
Okay, now I'm really interested.
Tell me more about this cosmic thermostat.
How does it work?
Oh, one of the key processes is something called feedback.
When a supermassive black hole is like actively feeding,
pulling in huge amounts of gas and dust,
it releases this enormous amount of energy.
So it's like a cosmic engine,
with all that fuel creating this powerful output.
That's it, yeah.
And this energy comes out in different ways,
powerful jets of particles, intense radiation.
And this is what affects star formation.
Yeah, so picture it like this.
These jets, they can heat up
and even push away the very gas and dust
that would usually clump together to form new stars.
So basically the black hole's activity
can actually prevent star formation in some areas.
That's right.
It might seem counterintuitive,
but these forces, these destructive forces,
they play a vital role in regulating the pace
of star birth in a galaxy.
That's incredible.
Are there any other feedback mechanisms?
Like what else is going on?
Oh, there are.
Even when a black hole isn't actively feeding,
it can still exert a more subtle form of feedback.
Imagine like a gentle breeze compared to a hurricane.
This kind of feedback can gradually heat
the surrounding gas over very long periods,
preventing rapid star formation.
It leads to like a slower,
more gradual evolution of the galaxy.
So it's this constant give and take,
this interplay between the black hole
and everything around it,
shaping the galaxy over like billions of years.
Exactly, a dynamic dance that,
I mean, we're still trying to figure out all the steps,
and it's not just star formation.
Really?
What else is there?
What other rules do these black holes play
in shaping their galaxies?
Supermassive black holes.
They have this profound impact
on the entire structure of their host galaxies.
Their huge gravity, it pulls in stars,
it pulls in gas, creating this dense central bulges
that we see.
They even influence a galaxy shape,
whether it becomes a spiral like our own Milky Way
or an elliptical galaxy.
So they're like cosmic sculptors.
Shaping the distribution of matter
in a galaxy over vast periods.
I like that, yeah.
They're not passive observers,
they're active participants
in this grand evolution of galaxies.
Wow, this is like so fascinating.
It makes me wonder, are there any specific examples
of these supermassive black holes
that really show their power and their influence?
Oh, absolutely.
There are some real celebrity
supermassive black holes out there.
Okay, I love a good cosmic celebrity story.
Tell me more.
Well, right in our own cosmic backyard,
the center of the Milky Way,
there's Sagittarius A, a supermassive black hole,
about four million times the mass of our sun.
Hold on, so our own galaxy has one of these at its center.
It does, it's pretty quiet compared
to some of the others out there,
but still incredibly fascinating.
I mean, it's amazing and a little scary, isn't it?
What about some other famous examples?
Well, one that really captured everyone's attention
a while back is the supermassive black hole
in the galaxy M87.
Oh, right, that incredible image,
the first picture of a black hole shadow.
That's it.
That image gave us the first direct proof
of something that was once considered purely theoretical,
the event horizon, the point of no return.
It was such a powerful picture,
it really makes you think,
it's a reminder of just how mysterious
and powerful these objects really are.
Absolutely, and then there's TON 618.
This one's a true monster.
It's in a distant quasar,
and it weighs in at a staggering 66 billion solar masses.
66 billion, I mean, how is that even possible?
Makes our own Milky Way's black hole look tiny, doesn't it?
These examples are truly remarkable,
but it makes me wonder,
how do we study something we can't see?
I mean, they don't emit light,
so how do we even know they're there,
let alone learn anything about them?
Well, that's where things get really clever.
We can't see them directly,
but we can see how they affect things around them.
So it's like a cosmic detective story, looking for clues.
Exactly, one way is by studying the movement
of stars and gas clouds that are orbiting around them.
So we could literally see these objects
being like whipped around by the black hole's gravity.
Exactly, and we can also detect the radiation
that's emitted by all that superheated matter
spiraling into the black hole.
It's like listening to the black hole song,
you know, decoding its secrets
through the different frequencies of light.
And in recent years, we've got this amazing new tool,
gravitational waves.
Oh yeah, those ripples in space time that Einstein predicted.
Do those help us study supermassive black holes?
You bet they do.
Detecting gravitational waves from merging black holes
has opened up a whole new way of looking at the universe.
It lets us measure the masses and spins
of these black holes with incredible accuracy.
It's amazing to think that we can study these things
in so many different ways.
It's a real testament to human ingenuity.
Absolutely, and yet for everything we've learned,
there are still so many mysteries
surrounding these supermassive black holes.
Oh, I bet.
What are some of the big questions
that scientists are still trying to answer?
What are the puzzles they're working on?
Well, one of the biggest ones is,
how do these things grow so fast?
We see these incredibly massive black holes
in the very early universe,
and it just doesn't quite fit
with our models of black hole growth.
So it's like finding a fully grown oak tree
in a forest that's only a few years old.
Something's not adding up.
Right, and then there's the relationship
between supermassive black holes and dark matter.
I've heard of dark matter, this mysterious stuff
that makes up a huge part of the universe,
but how does it connect to black holes?
Well, we know that galaxies are surrounded
by these vast halos of dark matter,
and it's looking more and more likely
that there's this kind of dynamic interplay
between the dark matter and the supermassive black holes
at the centers of galaxies.
So they could be influencing each other,
like one affecting the other.
That's the idea.
Some theories suggest that dark matter
could even be fueling the growth of these black holes,
providing a steady stream of invisible food
for them to consume.
A hidden food source for these cosmic giants.
Exactly.
It's still early days in this research,
but it has the potential to change
how we understand both dark matter
and supermassive black holes.
This is just mind blowing.
It seems like every answer we find
just leads to more questions.
That's the fun part.
It's a constant journey of discovery.
Exactly.
Speaking of unanswered questions,
is there anything else about these supermassive black holes
that is still stumping the scientists?
One more big puzzle is the possible existence
of something called intermediate mass black holes.
And those are?
So we know about the stellar mass black holes, right?
The ones that are a few times heavier than our sun.
And we have the supermassive ones,
the ones that are millions or billions of times heavier.
But there seems to be this missing piece in the middle.
Like a missing link?
That's it.
We haven't found any solid evidence
of black holes with masses in between those two extremes,
the kind that would bridge that gap.
So it's like a cosmic treasure hunt then.
Exactly.
Maybe they're out there hiding in plain sight.
Or maybe there's something about how black holes form
that just prevents them from forming at that size.
It's a mystery.
And astronomers are still searching for the answer.
It's incredible to think about how much we still
don't know about these objects.
They really are like windows into the most extreme parts
of the universe.
And they push our understanding of physics to the limit,
that's for sure.
This has been an incredible journey so far.
We've covered so much from how supermassive black holes form
to their effects on galaxies and all the mysteries
surrounding them.
It's been a great discussion.
And we're just getting started.
That's right.
But we'll have to pick up where we left off next time.
Don't worry.
In our next deep dive, we'll be exploring even more
mind-blowing aspects of these amazing objects,
ready to jump back into those cosmic mysteries.
You bet.
Last time we were talking about those intermediate mass
black holes, the, you called them
the missing link in the black hole family tree.
Have there been any new discoveries, anything exciting
happening on that front?
Oh, yeah.
It's a really hot area of research right now.
Lots of tantalizing clues and possible candidates popping up.
Some astronomers think they might
have found evidence for these intermediate mass black holes
hiding out in the centers of really dense star clusters.
That makes sense, right?
I mean, star clusters have so many stars packed together.
Wouldn't that be like the perfect place for a black hole
to grow and feast?
Exactly, like a cosmic buffet table for hungry black holes.
And there's another interesting idea floating around.
Maybe these intermediate mass black holes,
they could be the seeds for the supermassive ones
we see in the hearts of galaxies.
So instead of starting from scratch,
these supermassive black holes could get a head start
if they begin as these intermediate mass black holes.
Exactly.
It's like giving them a boost up the cosmic ladder.
That's so cool.
It really paints a picture of this interconnected universe,
where all these different types of black holes
could be linked across time.
It's a humbling thought, for sure.
And it really highlights just how much we still
don't know about how the universe works.
Speaking of humbling, we were talking
before about the relationship between supermassive black
holes and dark matter.
I've always been fascinated by that.
Can you tell me more about that connection?
Of course.
So dark matter, it's one of the biggest mysteries in, well,
pretty much all of astrophysics.
It doesn't interact with light, so we can't see it.
But we know it's out there because
of its gravitational effects on the stuff we can see.
It's like this invisible scaffolding holding everything
together.
Great analogy.
And we think that galaxies are embedded
in these vast halos of dark matter.
So these halos, it's like invisible cocoons
surrounding the galaxy.
Yeah, exactly.
And here's where things get really interesting.
There's this growing suspicion that these dark matter halos
could be playing a big role in how supermassive black holes
form and grow.
I'm all ears.
How could something we can't see be influencing something
as powerful as a black hole?
OK, so one possibility is that these dark matter particles,
as they bump into each other, they lose energy
and start to spiral inwards towards the center
of the galaxy.
And then what happens?
What happens when they get close to the black hole
at the center?
Well, as they get closer and closer to the black hole,
they can get so packed together that they form something
called a dark matter spike.
A dark matter spike?
I've never heard of that.
What is it?
Imagine a huge concentration of dark matter
just surrounding the black hole, like a dense invisible cloud.
So it's like a hidden food source for the black hole.
You got it.
This concentrated dark matter could
be getting devoured by the black hole,
helping it grow over, well, billions and billions of years.
So these supermassive black holes
could be growing not just by eating stars and gas,
but also by feeding on this invisible dark matter.
That's one of the leading theories.
And it really shows you how interconnected everything is,
right?
Something we can't even see could
be having a huge impact on these powerful objects.
It's like a hidden web, a cosmic dance between the visible
and the invisible.
Love that.
And it really emphasizes how much more there is out there
to discover and understand.
This is all so mind blowing.
It makes you realize that we're really just getting started.
And for all the amazing things we've
learned about these black holes, there's
still so much we don't know.
Absolutely.
And that's what makes it so exciting, wouldn't you say?
Every new discovery just opens up
a whole new world of questions and possibilities.
Speaking of new discoveries, I've
been hearing a lot about this thing called the Event Horizon
Telescope.
Can you tell me a bit about that and what
it's doing to help us learn more about supermassive black holes?
Oh, the Event Horizon Telescope, or EHT,
that's one of the most ambitious projects in, well,
maybe all of science.
It's not just one telescope.
It's this whole global network of radio telescopes
that are all working together.
Ooh, that sounds incredible.
Why go to all that trouble to build this worldwide network
of telescopes?
It all comes down to resolution.
It's about seeing the fine details.
By combining the signals from all these different telescopes
across the globe, the EHT can see things
in incredible detail, the kind of detail
you need to peer right into the heart of a galaxy
and see the regions around a supermassive black hole.
It's like having a cosmic zoom lens, right?
Seeing things that would be impossible to see otherwise.
Exactly.
And remember, a few years back, the EHT
captured that amazing image of the supermassive black hole
at the center of the galaxy, M87.
Oh, yeah, the first picture of a black hole shadow.
That was a huge deal, wasn't it?
It was a real turning point.
It gave us the first direct visual proof
that black holes and their event horizons,
the point of no return, actually exist.
We went from theory to, well, to actually seeing it.
A real testament to human ingenuity and collaboration.
And I'm sure the EHT has even more exciting observations
planned for the future.
Oh, absolutely.
The EHT is constantly getting upgraded and refined.
And astronomers are using it to look
at other supermassive black holes in even greater detail.
So we can expect even more incredible images and insights
into these mind-boggling objects.
You bet.
The EHT is going to revolutionize our understanding
of black holes, that's for sure.
This is all so exciting.
It feels like we're living in a golden age of black hole
research with new discoveries being made all the time.
And it's not just about black holes themselves, right?
By studying them, we're pushing the limits of physics,
testing our theories about gravity,
and getting a better grasp of, well, the basic laws that
govern the entire universe.
It's this constant search for knowledge driven by our,
I don't know, our need to understand the universe.
Exactly.
That's what drives us to invent these incredible technologies,
to build bigger and better telescopes,
and to work together to solve these cosmic mysteries.
This has been such an incredible journey so far.
But I know we're not done yet.
We still have so much more to explore.
That's right.
Hang on tight, because in our next installment,
we're going to go even deeper into the mysteries
of these supermassive black holes.
We'll be talking about their bizarre properties,
their influence on galaxies, and all the mind-boggling
possibilities they hold for understanding
the universe around us.
All right, back for more cosmic adventures.
You've really painted a mind-blowing picture
of how powerful these supermassive black holes are,
not just in their immediate area,
but shaping entire galaxies.
It's amazing.
And we're just getting warmed up.
Trust me, there's still so much more
to learn about these enigmatic objects.
Well, let's dive in.
You were saying before that studying black holes
can really push the limits of physics, right?
Can you tell me more about that?
How are they challenging our current understanding
of the universe?
Well, one of the most fundamental ways
is through their extreme gravity, right?
I mean, we're talking regions of space where gravity is so
strong that it actually warps spacetime itself.
Spacetime.
I've heard that term before.
But can you give me a quick refresher?
Sure.
Think of spacetime as the fabric of the universe, OK?
It's this four-dimensional concept
that combines the three dimensions of space
with the dimension of time.
So instead of thinking of space and time separately,
we're combining them into this unified fabric.
That's it.
And massive objects, like stars and planets,
they create a kind of like a dent in this fabric
that causes other objects to move towards them, which
is what we experience as gravity.
So gravity is like a warp in the fabric of spacetime.
Exactly.
And black holes, well, they take this warping
to a whole other level.
Their gravity is so intense that it
creates this bottomless pit in spacetime,
a singularity where nothing can escape.
Whoa, it's like a cosmic rip in the fabric of reality.
You could say that.
And this extreme warping of spacetime,
it has huge implications for how we understand physics.
Like it challenges our ideas about cause and effect.
Events that happen inside a black hole, well,
they might be forever disconnected
from the rest of the universe.
I mean, it's mind-boggling.
It's like these black holes are rewriting
the rules of the universe.
They're definitely making us rethink things.
And they're also really putting Einstein's theory
of general relativity to the test.
But hasn't Einstein's theory been pretty successful so far?
Oh, incredibly successful.
It's predicted tons of phenomena with amazing accuracy.
But black holes, they represent some
of the most extreme conditions in the universe.
And we're not entirely sure if general relativity holds up
perfectly in those situations.
So black holes could be showing us
like cracks in Einstein's masterpiece.
It's a possibility.
There might be some small differences
from general relativity in those super strong
gravitational fields near black holes.
And if we can find those differences, well,
it could lead us to a whole new, more complete theory
of gravity.
That would be like a game changer.
It would be huge.
It would change how we understand how the universe works
at a fundamental level.
So these black holes are like cosmic laboratories,
letting us explore the boundaries of physics.
That's a great way to think about it.
And they're also making us ask some really big philosophical
questions about the nature of reality,
about information, and about the limits of what
we can even know.
It's fascinating that something that seems so destructive
could also teach us so much.
That's the thing about black holes, isn't it?
They're both terrifying and awesome at the same time.
They inspire both fear and wonder.
And I think that's what makes them so captivating to so
many people, right?
They're just so mysterious and powerful.
They really grab your imagination.
Couldn't agree more.
And as we continue to study them,
I'm sure they'll keep challenging us, inspiring us,
and amazing us for a long, long time.
This whole deep dive has been incredible.
I feel like I've learned so much about supermassive black holes,
how they form, how they affect galaxies,
the mysteries we're still trying to solve,
and how they're pushing the boundaries of physics
and our whole understanding of the universe.
It's been a fantastic journey.
And it's been great exploring these cosmic wonders with you.
I hope our listeners are feeling just as inspired and fascinated
as we are.
I'm sure they are.
And if you want to keep exploring the universe with us,
be sure to follow Cosmos in a pod on your favorite podcast
app.
And don't forget to check out our YouTube channel
for even more mind-blowing space content.
We've got stunning visuals, animations,
all sorts of stuff that will really
bring these concepts to life.
That's it for today, folks.
Until next time, keep looking up and keep
those cosmic questions coming.