Deep Dive Into Primordial Black Holes

What are primordial black holes and how are they different from all the other kinds of black holes out there? How could we possibly detect them and what would it mean for Cosmology? Can primordial black holes be a solution for dark matter? Finding out the answers in this interview.
🟣 Guest: Jason Kristiano
jkristiano.github.io/
📜 Generating large primordial fluctuations in single-field inflation for PBH formation:
arxiv.org/abs/2211.03395
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00:00 Intro
02:27 Formation of primordial black holes
11:25 The impact on the Universe
15:45 How can we observe black holes
20:30 Constraints on dark matter solution
22:56 Research
35:11 Further observations
44:18 Current obsessions
51:49 Final thoughts
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[@lyledal]

"We need to see a gravitational wave with a wavelength the size of the observable universe?" "Yes." "That sounds hard." "Yes."

[@cykkm]

His enthusiasm is truly contagious!

[@JohnMuz1]

I need to move beer fridge closer to desk. /more likely to happen.

[@lyledal]

@@cykkm It really is!

[@notmyname327]

<a href="#" class="seekto" data-time="2285">38:05</a> Ooh I love his enthusiasm when he realized you went into a topic where some new physics are needed! Seeing someone passionate about what they do is inspiring.

[@qfman2]

I agree, but if black holes are dark matter, the universe would be blurry from the gravitational distortion. They also have a very strong interaction with normal matter.

[@AliHSyed]

Last time I was this early, primordial black holes had just formed

[@JohnMuz1]

From what though?

[@rwarren58]

Did you make it in time find a monopole?

[@AliHSyed]

@@rwarren58 missed it by a couple quadrillion Planck seconds

[@alleneverhart4141]

Wow, I get the feeling we are going to be hearing big things from Jason in the future. Fraser, thanks for giving us an early introduction to Jason!

[@shinkuujin40]

I feel like we should stop looking for dark matter and we'll suddenly find it, like when you lose your keys.

[@jblob5764]

Just pretend it doesnt exist and give it a month lol

[@swissbiggy]

Thank you very much Jason Kristiano and Fraser Cain for this excellent interview... We do not stop learning ❣✌

[@notmyname327]

Like you said at the beginning, much of this talk went over my head but I still really enjoyed it. I love that people are trying to find primordial black holes, seems like an impossible task (like much of science lol).

[@Kadath_Gaming]

This was fantastic 😊

[@gozattila9575]

Maybe i haven’t seen all vids, but this one is definetely remarkable, thanks a lot for all you efforts (watching from Hungary)

[@CloudPeopleRecords]

Thank you both, that was an epic interview!! Please keep Jason's contact close and have him back again.

[@JamesCairney]

This was rather good

[@annapaliarush7742]

I think this is my most favorite interview on a channel. And very interesting topic I always wanted to learn more about.

[@ricksspeedshop]

Great interview and super informative, thank you, sir!

[@brendanh8193]

"Can we observe primordial black holes?" I've wondered for a while why we didn't ask the reverse of this question: "Why do we not see black holes at all scales?" If quantum fluctuations created the distribution of matter, surely some significant portion of that was creating local densities that were black holes, depending on the stage of expansion. What stopped black holes forming during the big bang?

[@luketorkington8422]

About 30 years ago I joked to my mate that if black holes 'contain' information maybe walking through one, in a certain way could explain 'eureka' moments.

[@TheNemorosa]

Why is everyone on KZbin talking about "deep dives" these days? Thy're all at it. Nobody ever said this before about 5 years ago. Once you notice it, it can't be ignored and it grates.

[@HobieH3]

Automotive industry term used in problem solving, sometimes called "drill deep"

[@PhysicsPolice]

<a href="#" class="seekto" data-time="480">8:00</a> wow we did not need 5+ minutes to get there. That should have been a one-sentence answer. And it should have included a number: the amplitude of fluctuation needed to form a primordial black hole.

[@swissbiggy]

You are free to start your own channel if you do so much better... Don't hold back buddy ✌

[@davesatxify]

I enjoyed listening. I don't understand much more than I did beforehand however. Dr. Kristiano is clearly extremely intelligent and seems talented in the arcane science of his choice. Primordial black holes were caused by ripples in spacetime back when evverything was just starting to exxpand and finding them will take a nearly impossible detection of a grav wave the amplitude of the universe? His enthusiams shown through and I'm not denigrating him (at least not intentionally) but beyond than that synopsis I added above, I'm very confused. This is not normally the case for your videos..

[@Qrul]

I love these interviews.

[@TheKivifreak]

Learnt a lot, thanks

[@Aleksandr7364]

All quark centers of galaxies, which are mistakenly called black holes, are synthesized from strings in the Center of Our Universe. The very centers of galaxies synthesize stars, and stars synthesize planets. All modern astrophysics should be turned into waste paper))

[@HotelPapa100]

Is there a reasoning why supermassive black holes could not have collaped as primordial black holes right from the beginning?

[@sandervanderkrol4995]

Hi Frasier, what you think was more limiting for the development of life (as we know it): formation of earth-like planets or intensity of the early CBR?

[@michaellee6489]

I mean this in no disparaging way, but Homies' accent was too thick for me... I would definitely read his articles, though. Thank You, Jason and Fraser!!!

[@mckeeasdf]

That may explain VOIDS.

[@billionsandbillionsofstars]

You think voids could be primordial black holes merged together into galaxy cluster sizes? Because that would be too cool!

[@oskey5301]

What I can infer from this detailed numerical analysis is that primordial black holes may just very well be the missing mass originally attributed to 'dark matter' in the universe?

[@mauhey]

Let's think of a PBH small enough to be derived from a local fluctuation during at the beginning of the inflation process big enough not to have already evaporated. The size/mass is "easy" to predict with the help of online tools (i.e. Schwarzschild radius). So a mass of 10E-7 would give a BH size 0.3 mm that would be still around today but totally invisible (Note that this was also proposed as explanation for the still missing Planet 9) Question. Any idea of how this small entity with a moderate but present gravity would interact with matter in space. Just to be clear what would happen to a an asteroid (size, say, 100 m) whose route crossed this tiny but much massive BH? Sorry for the dumb question but I am just a molecular biologist lacking the tools to calculate the outcome

[@fritzelly7309]

If all these primordial black holes existed when the universe was "small" how come they didn't gobble up all the material before it had a chance to form anything else?

[@Spherical_Cow]

Because the universe was still rapidly expanding at that time. Black holes can only "gobble up" matter that gets really close to them; farther away, they act like just another massive object that matter can orbit around without ever falling in.

[@fritzelly7309]

@@Spherical_Cow So with nothing to grow with and with almost no mass they should have existed and ceased to exist in the blink of an eye relatively speaking. How could you ever hope to prove their existence? With no mass how could they have produced so much "dark matter". Seems very much clasping at straws to prove the existence of something else

[@Spherical_Cow]

​@@fritzelly7309I think the idea is that those primordial black holes would form from enlarged quantum fluctuations: at the end of inflation, the most extreme fluctuations enlarged to macroscopic sizes, would collapse in upon themselves and turn into black holes. These primordial black holes would run some gamut of sizes (i.e. masses) at which they are born; all but the really microscopic would still be around today.

[@tonywells6990]

The universe was expanding at almost the speed of light in the first fractions of a second after the big bang.

[@000fisherman]

I Loved this conversation, I will add this INFINITE CORRELATION!,,,, Just makes you think!!!!!

[@ddtt1398]

Primodial BHs would create dynamical friction, which is not observed

[@henrytjernlund]

I get that this is the fad now, but I watched String Therory come and go with the same amount of excitement.

[@Spherical_Cow]

Frazer, have you ever done an interview to address fhe "last parsec problem" of black hole mergers? I ask, because primordial black holes - unless they literally start out at a billion solar masses right away - still can't explain the existence of supermassive quasars so early in the universe (as recently revealed by the JWST), unless the problem of how they efficiently grow and merge is solved...

[@qpwodkgh2010]

We will find out in 3 to 5 years. We will have to build a special purpose telescope to confirm that these things exist.

[@ondrejpetyniak4582]

It was some L.Suskind lecture where he was describing how physics are trying watch the small/big scale to deduce if there is some structure and effects. Im completly amateur but once on a trip when i was thinking what are the scales known to us, i think universe, ultra massive black holes are one side. What would be on the other side? My thought was it would be most practical joke if the biggest scale is the same. Like the space time as we experience is just a noise propagating across field of plank scale black holes and all the foundational particles are some kind of Hawking radiation of these plank black holes. My feeling is by studying black holes small and big should be very beneficial for physics. The feeling was also somehow there is some foundational property of this field of holes and the remaining forces are some kind of excitation effect. Recently when some pop. science person was talking about negative matter thought occcured what if the field has charge and how our side makes curvage could the opposite straighten? Can the big bang be some inbalace until it evens out ? 😅

[@willivonen3886]

The real question here is what are the implications of quantum tunnel collapse and black holes in expansion and contraction of a universe.

[@CaliforniaBushman]

If the First Black Holes were formed in the first 1×10^-32 second from the largest of Spacetime Fluctuations, then the seeds of Galactic Cores were present when the Universe was Softball Sized. Giving us galaxies during the Dark Ages?

[@cykkm]

Not really, BHs don't expand with space, unless physics works differently at the energy scales seen back then - you're talking about inflation, don't you? If BHs had blown up during the inflation proportionally, that would amount to their huge increase in mass-energy. I've never seen models where the inflaton field would exchange energy with spacetime piecemeal until its final off-the-cliff decay, which ended the inflation. Inflation physics has a lot of problems, tho, it's far from being settled. We didn't get galaxies during the Dark Age by the definition of the Dark Age: it's the period with no light in the Universe, and galaxies are quite bright things. The farthest found galaxy at z=14 already shows spectra of metals, so it should consist of Pop II stars. There's no evidence of galaxies harking back to the reionisation epoch.

[@Spherical_Cow]

​@@cykkmI don't think it's possible for a black hole to form _during_ inflation, in the first place - so it makes little sense to discuss a black hole getting 'inflated' by the inflation. Rather, I think the idea is that extreme fluctuations get inflated, and then the moment inflation stops, those extreme fluctuations (blown up to macroscopic sizes) then go ahead and collapse into black holes.

[@dougirvin2413]

Wow Fraser, loved your interview with Dr. Kristiano. My question is, doesn't his whole theory come down to the assertion the initial cosmic inflation was NOT uniform? If that were true wouldn't JWST see way further in some directions than in others? Which I'm given to understand that it doesn't...right?

[@Spherical_Cow]

No, the inflation was uniform. What was not uniform, is the quantum vacuum being inflated: random subatomic-scale quantum fluctuations in it, driven by the Uncertainty Principle, were frozen in place by being blown out to enormous scales almost instantaneously, in the process of inflation. These fluctuations would have run the gamut of scales, topologies, spatial frequencies, and amplitudes - and a hypothesis talked about in this interview is that some of those fluctuations might've been extreme enough in amplitude, and pumped up by inflation to just a large enough (but not too large) size that, the moment inflation ended, they almost instantly crumpled in upon themselves and turned into black holes.

[@roqua]

<a href="#" class="seekto" data-time="666">11:06</a> What word is he going for here that sounds like "sit" or "seat"? Edit: I think Frasier helps us out at <a href="#" class="seekto" data-time="910">15:10</a> (ish) in clarifying "seed" and "seeds"

[@estraume]

What if planet 9 is not a planet but a primordial black hole with the mass and orbit of the theoretical planet 9?

[@billionsandbillionsofstars]

That's exactly what some astronomers have proposed. I'm one of the citizen scientists working on finding the illusive planet 9 on Zooniverse.

[@Midg-td3ty]

Question wouldnt this work: Lets say we would detect a few planets through wobbling a red dwarf. The mass of earth+ for example And this system would be just in the right view so we could also see the planets covering their host star. We would see several planets covering their host star and throwing a shadow thus we would be able to tell their radius. But one of the planets would not show up. However the wobbling was unmistakingly there. Culdnt one of the options bea primordial blackhole orbiting the star ? As they would need to be common wouldnt we detect many of those "invisible" planets. Do we have candidates already ? Because if they would be that frequent those invisible planets would be common too.

[@Spherical_Cow]

Unlikely, because planets tend to form inside the same accretion disk that forms the star. That's why they all orbit in the same direction (that the star also rotates in), and are confined to a narrow near-planar disk. By contrast, a primordial black hole would be free-floating through the galaxy, and would have to be somehow captured into an orbit around some star, before it could begin to 'imitate' a planet. Not only that, but for us to detect it via the periodic Doppler shift induced in the 'wobbling' star, a planet (or small black hole) would have to orbit very close to the star. Frankly, such an orbital capture is much less likely than the reverse: planets going 'rogue' by getting ejected via complex multi-body interactions within the planetary system.

[@zeljkoradojkovic6159]

Do we see the effects of dark matter on local scale, ie, on orbits wirhin our (or some other) solar system?

[@TagiukGold]

Last time I was this early, 1500 people had beat me here.

[@user-op3zf6if9i]

Next time he tells us he found wave with wavelength LARGER than the observable universe, from the multiverse.

[@lilkitty1977]

Could supermassive black holes just be an evolution of primordial ones? Have seen that JWST has been seeing galaxies very early, could this be a mechanic for that to happen? Also did your guest say that galaxies evolved before stars!

[@Roguescienceguy]

I am pretty sure he meant galactic clouds who then start producing stars when they condense enough. Let's not forget that the formation of one star and it's subsequent stellar wind causes other stars to form too. So technically he is not wrong, but he could have been a bit more clearer😅

[@420Khatz]

Among the first for once!🙌🏻

[@zdzislawmeglicki2262]

All supermassive black holes are primordial. The galaxies formed around them. Their spiraling shape is basically a dynamic residue of a whirlpool.

[@kenmccarty6229]

JWST hints at this but does not prove it...at least not yet. But the question is whether there are smaller primordial black holes and is there a preferred size? Whole ranges of sizes for primordial black holes have been statistically ruled out as significant as an explanation for dark matter. But other ranges of sized primordial black holes are still possible. But if these exist, then an explanation of why the preferred size is required.

[@zdzislawmeglicki2262]

@@kenmccarty6229 That's just my educated hunch, but I agree, the hints are there, proofs not yet. Even so, a proof in astrophysics is generally very hard to construct. Astrophysics is not mathematics, it's not even physics… You can't carry out a decisive experiment. You depend on the current observation snapshot of the universe. The Big Bang itself is hidden behind the veil of the CMB. If we can detect and measure the gravitational wave background, this will help a lot.

[@Biblicalprofessor]

The person speaking may be comprehensible in his native language, As performed here it came across as Something a native english speaking Citizen with training in physics would find As gibberish. Thanks for the attempt

[@000fisherman]

If i was the dot that exploded inthe big bang and i was crrelated to it, then the bigger the expansion, then the bigger the correlation. Hence the expansion of the universe, Also means tiny black holes get bigger , but baby holes form all the time!!!! JUST A THOUGHT PROVE ME WRONG!!!!!

[@jklappenbach]

Primordial black holes, if they do exist, could be the basic stuff of dark matter.

[@simonrae3048]

uuuuuh.Gonna watch a Clash video...That's after 20 seconds

[@Biblicalprofessor]

<a href="#" class="seekto" data-time="1027">17:07</a> <a href="#" class="seekto" data-time="1031">17:11</a>

[@willivonen3886]

This has severe implications for quantum tunneling. The answer to that question is the formulation of what I have already said.

[@000fisherman]

Jason Kristiano , If i was the dot that exploded inthe big bang and i was crrelated to it, then the bigger the expansion, then the bigger the correlation. Hence the expansion of the universe, Also means tiny black holes get bigger , but baby holes form all the time!!!! JUST A THOUGHT PROVE ME WRONG!!!!!

[@tonywells6990]

The size of a black hole depends on its mass. The size is not affected by the rapid expansion of space.

[@melangellatc1718]

My BA/History will be totally LOST in this video...

[@zanelittlegray]

Anyone here have enough physics to answer my [probably ignorant] question of "why dark matter - why not dark energy?" Is dark energy still a legitimate thing to research?

[@rudyj8948]

Dark matter and dark energy come from the study of two very different phenomena: Dark Matter is a hypothetical explanation for a list of strange observations, essentially our predictions about certain astronomical systems (such as galaxies and super cluster) are incorrect in a way that suggests there's another type of matter out there that doesn't interact with the electromagnetic fields, here it is a "dark" matter. Dark energy comes from the realization that the universe is expanding at an *accelerated* rate. So the idea goes that there has to be some sort of energy which is causing this acceleration, but since we don't have any other evidence towards what must be causing it, it is again a "dark" energy Both are very valid fields to research these days

[@420Khatz]

Well, we can tell something is amiss that we can't explain, as the universe is expanding, and it seems to be expanding very evenly thruout the entire universe. That means something unknown that we can't explain is definitely going on, hence "dark energy". p.s. never worry about having an "ignorant" question- any question is valid, and the only thing having a question says about you, is that you are a curious person who seeks to be informed- and that makes you cool af in my book.

[@zanelittlegray]

@@420Khatz Thanks, I appreciate the good words, and thank you for supplying a good answer!

[@zanelittlegray]

@@rudyj8948 Thanks, I'll tell my supervisor at work here, as we were having a conversation about it that neither of us has a clue about - haha!

[@JungleJargon]

Give up on invisible dark matter. The amount of gravity is what changes the rate of causation. No matter can ever make or direct itself. No energy can ever make or direct itself. This means that everything comes from a greater and greater source. You can’t charge your phone with an equal or lesser amount of power. Every physical thing exists by a greater physical thing except there cannot be an infinite regress of greater and greater physical things. At some point there has to be a non physical source that is infinite ♾️ in power and potential.

[@jackd42o]

You're ctushing it Fraser!

[@420Khatz]

>ctushing >cthulhu

[@AliHSyed]

First!!!!

[@nil981]

Primordial black holes likely dont exist. Physics tells us that such tiny black holes would evaporate very quickly due to hawking radiation or via the schwinger effect.

[@johnvanderpol2]

We are the leftovers. The leftovers that didn't collapse into primordial black holes. We formed galaxies but didn't become stars, or we're the stars that went supernova 2 to 3 times. We didn't end up in the sun but found our place on a planet.

[@jonathanrossroberts]

Wish you guys didn't do the flashing of the words on the screen. Makes my stomach churn and unfortunately cant watch anymore.

[@willivonen3886]

In conjunction with this question we can postulate the universe expands and contracts. What the universe floats through is not a one-way Street.

[@davidhess6593]

AKA "Dark Matter".

[@sulljoh1]

Imagine if pay grade correlated with knowledge 😂

[@nostalgiaarcadefuture]

To the people complaining about his accent. ​​ ummmm... This entire interview was in English... And was incredibly easy to understand and I only speak english. Anybody who had any issue with understanding this interview needs to not hide thier scientific ignorance behind the cloak of claiming you couldn't understand him speaking. Just admit you are not as smart as you think, and accept it. Because there was not one moment I had any issue in understanding this man and what he was explaining. In fact he taught me a lot and made me think about things in a way that made me a much smarter human. And he did that in what I assume is his second language. I could barely do that in my only language so good on him. Complaining about his speaking is just being a bigot, an idiot, and a racist. Just FYI. (side thought) how cool is it to live during the time when humans were so varied and able to communicate in such a large quantity of different languages and dialects, and had so many different cultures and appearances? In 100,000 years people will look back on this time with envy and wonder, as the golden age of human culture. Because I that time we will all look the same and speak sesame language and have the same culture. There will be no color or differences. All these languages will be ancient and dead. Appreciate the time you live and go experience these different humans because quadrillion of humans after you will envy you and wonder how amazing it must have been.

[@MikeKisil]

I may have caught on but echoing through me out .sorry it's me .

[@willivonen3886]

In forwarding the question from The Big bang we forget to ask before the Big bang what was it floating through

[@GadZookz]

For those of us who feel more comfortable floating around the inner harbour of the Newtonian Universe this is a very big leap indeed. What would Einstein think about it? 🤔

[@Roguescienceguy]

Yeah, I am not levels enough of asian wunderkind to grasp everything he says either, Fraser 😅

[@henrytjernlund]

I dont believe it.

[@Biblicalprofessor]

The non english speaking person needs a good translator To make this a formal conversation

[@cnote2627]

I couldn't finish the video, I had to concentrate on dissecting his English just to understand each word that it just felt like reciting a bunch of words instead of actually composing a sentence.. if this guy has a PhD then Frazier you need to go take the test and get yours

[@JamesCairney]

I could understand him fine, and Im Scottish, so not someone who grew up around people who annunciate appropriately.

[@neddea]

Do you realize that you can investigate and write your PhD in languages other than English? Please understand why what you just said is quite inconsiderate. Speaking a language that is not your mother tongue, especially about very complex topics that are already hard to try to explain in your language, is a difficult task.

[@420Khatz]

@@neddeapopped into the comments section to express that exact sentiment, and articulated my thoughts far better than I could have- and I didn't have any trouble understanding him either!

[@PhysicsPolice]

@cnote2627 Don’t be rude and bigoted. His lack of speaking fluency in English is no indication of his intelligence.

[@PhysicsPolice]

@@neddea Understanding primordial black hole formation is a challenge, too. And we expect Fraser to have guests on who do that well. It’s okay to have a standard of quality for the presentation as well as the content. On this channel, presentation is in English. It’s not too much to ask that Fraser have on guests who can speak clearly in English. Let’s be careful not to belittle commenters for sharing their experience. Let’s belittle them for their bigotry, instead.

[@vincentcleaver1925]

This guy is not up to doing interviews, in English or I suspect in Japanese

[@Ken-rq9xr]

In a universe filled with strings why are you looking for a partical. 😮✌️🦜🤓🖖😽

[@420Khatz]

particle*

[@Ken-rq9xr]

@@420Khatz thanks disslecsia so bad spell check is helpless.

[@billionsandbillionsofstars]

Everything is made of particles, even strings.

[@Ken-rq9xr]

@@billionsandbillionsofstars do you mean once observed strings snap into particles. Or is there a particle as yet unobservable that makes up the strings. 🤓😽🦜🖖

[@billionsandbillionsofstars]

@@Ken-rq9xr I think if I’m correct, it’s point particles that have snapped into strings. I could be wrong though. String theory is a bit weird. I do wonder though, if quantum entanglement could be via strings?