Hey Space Timers! Want to deep dive some Space Time and watch ALL the episodes referenced in this week's episode? Then check out our episode companion playlist: https://www.youtube.com/playlist?list=PLsPUh22kYmNAO4wmE0sua4zqcs0D7eqv7

That's a great idea! These videos are so massive in their undertaking that at least 5 other videos can be directly recommended, while those 5 will each lead down their own rabbit holes.

If we live in a blackhole, this is all moot.

Hey could anyone help me with something. The geometry around a blackhole just simply would not allow for this correct? The very space around a black hole falls INWARD toward the singularity. To get expansion the solution for that is a whitehole. Isn't it?

​@king_ Tesseractthere are many unknown forces around black holes. Atom nuclei we predicted many particles to explain the stability of nucleus , simmilar theory required to explain structure of black hole😢

If the new theory in the video is correct, then you can bet that black hole's dark enery is also responsible for the phenomenon we now ascribe to black matter.

"People love to imagine things that they don't understand are somehow connected to each other" Me, that's me, I'm people.

lol, I'm so happy for you 😊

I'm atheist and very skeptical in general

​@Mark Muller Just stay open-minded, fervent about finding the truth, and willing to accept it if you find it, even if it negates everything you may have previously believed.

@BackYardProphet You're contradicting yourself, being skeptical and atheist means not holding any kind of belief Edit: Your name explains everything I guess

@Mark Muller Yea, you'll probably grow out of that by the time you are 30 kiddo. I found it an awful lot easier to be an atheist in my 20s when I still thought I knew everything 😁👍🏻

Thanks for the shoutout Matt and co! Great to see some of the historical cosmological context covered 👍

Love your content Dr. Becky!

This is the YouTube space channel synergy I've been waiting for!!! 😃

Awesome channels, both Dr. Becky and Matt's PBS Space Time!!

Although I agree with being skeptical about a new observational experiment's conclusion. There are other observational experiments that had reached the same conclusion. Gravity = the spaceless and timeless vacuum energy state of matter!!! :)

Here's the link to Dr. Becky's video on that topic: https://youtu.be/3gg1OS435UE

I am but a very ignorant electrician , I have followed this channel for year , I get maybe 30-40% of what’s being discussed , but your presentation skills, you vibrant explanations , and your sheer intelligence makes every video a joy to consume , thanks for what you do

I remodel homes. Aka glorified handyman. I've been learning about astrophysics for decades and still I am unable to grasp most of it. I've always wanted to know the fundamental truth of reality.

Same here, long time follower of the channel with zero background in astrophysics: I love the subject so much that I keep watching although I constantly make almost nothing out of it 🥲

"the smarter your mind, the smarter your god"... 100% factual truth "ignorance is not a disease, but a state of mind"... also 100% factual truth I am over 60, and I can't stop educating myself, lol I know, I will continue learning daily - till the day I die....and that is a cig way into my great-grandmother's words "You live 100 years, you learn 100 years, yet you'll die an idiot". DO NOT stop learning!!!

@Francesco Segrè keep watching... it will come!

I love how respectful you are in criticizing others' work. It's a hard skill to acquire, and you set a great example.

He does it in such a way to where some people won't even notice. A beautiful skill to have.

It didn't strike me as criticism, but rather, a healthy degree of cautious scepticism. The grander the claim(s), the more it behoves the reader to remain cynical. And from what little my Neanderthal brain comprehended from this video, this paper's proposing some pretty massive claims (pun intended).

I feel the more time you spend trying to be productive and running into your own limits, the easier it can be to be humble critiquing others.

Because it's not critique.

He's just performing the script!

PBS Space Time is in my opinion, the best science show I have ever seen. It's hard to put into words how much I love your videos. Absolutely fantastic work.

Check out Sea, also Space is Ace

@Ryan Romero Will do, thanks for the tip

PBS Space Time, SEA and Anton Petrov are my top 3 space related channels. No sensationalized click bait, just straight up current scientific information. What a treat!

add cool words to the mix. dr kipping teaches at columbia and is a fantastic communicator with a way with words. him and SEA are my all time favorites.

Thanks everyone for great tips on channels, they're great!

"A black hole only knows about what falls into it" in my head became "The black hole knows what's inside it at all times. It knows this because it knows what isn't inside it."

Props to your motion design/VFX team. This might be some of their best work yet

Came here to say the same thing. Amazing visuals on this episode!

let’s just say everyone has their standards.

it's AI 🤣

​@HellXels no it does have that unique style, not AI

@Windows XP memes and stuff lol Prompt: Graphics in style of PBS spacetime AI: Gotcha fam

Thank you Matt! I was wondering if you and your show could cover "Quantised Inertia" theory at some point? A vehicle going to space to test the theory is going to space on a Falcon 9 soon, and I think more people would be interested to hear about it.

While I was watching this I took note of just how clean the camera footage is, and how well it's blended with the background and animations. Overall the visuals of videos on this channel are really well done, and I wish to voice appreciation of that.

Gliner's theory helps me to imagine why some black holes are larger than others, because if the singularity is theoretically infinitely dense, I find it hard to speculate why the diameter of any event horizon would vary in size from others.

This fact didn't pop in my brain as I study a lot about black holes.I think I have ans for that question So I will compare your fact with infinity, think you added 1 to infinity the ans is infinity but this Infinity is +1times grater than infinity. So the same thing goes to black holes even there are having infinity dense singularity the size of event horizon can differ. The size of event horizon normally doesn't affect singularity. I hope this might help you.

The event horizon boundary exists at the radius where the escape velocity around the singularity matches that of the speed of light. As I understand it, however big or small the singularity is, the diameter of the black sphere we see in space will depend solely on the mass. More mass = larger orbital radius where escape velocity is c.

"For complicated reasons due to general relativity being weird" is now my go-to excuse for basically anything 😂

"You've been late to work three times this month"

Since "dark energy" is merely a placeholder, it - of course - remains to be seen. But I think there are too many "known unknowns" (to say nothing of "unknown unknowns") to dismiss this out of hand. As always in science, more testing and exploration and creation of detection techniques are required. Science is the process of generating *questions* . The occasional _answer_ popping out is an anomaly; not the goal.

I've seen almost every of your videos, for past 6-7 years, each of them terrific quality. Never bias, always factual with passion and realnest. Awesome content! 😉😁

Agreed. Had to laugh at a guy in one of the comment replies above you saying all Matt does is make up "pure unadulterated nonsense", and hopes that people that understand science don't see it and that enough people that don't understand the science believe his "nonsense".

And what have you learned in 7 years?

I'd argue that PBS space time has a clear pro-reality bias.

@ProtMythic it's a bot

I've watched a number of decent videos on this topic. That said, I've come to expect PBS Space Time to provide the clearest explanations, and this episode did not disappoint. 🙏

I’m glad Matt wasn’t totally convinced of this paper’s claims, and neither was I. Of course, it’s nice to hear alternative takes from time to time, especially concerning things like

I really appreciate the detailed breakdown at the end! Great to see specific reasoning as to the strong and weak points of a result :)

Currently the places to hope for a real space craft engine capable of taking us into the cosmos are in a few places as I understand it. There is little to no hope in negative energy being a thing. What does a graviton look like is definitely going to answer some questions. Are there fundamental forces we haven't discovered yet is lastly also super important. Fact of the matter is, light speed is not fast enough. We need to understand energy better. I suppose we will eventually start blowing up anti-matter bombs to observe conditions no longer existent in our current state of the galaxy and unlikely to occur again. Maybe some answers will be observable we haven't considered in such high energy events we can collect every possible information off of.

Great video! This is a really intriguing idea, and one can see how people might wish it into existence. It's a novel take for sure, and it will be cool to see if the paper is dissected seriously by the community.

in the english language "black" equates to "dark"...that's good enough for me.

I love the phrasing “For complicated reasons due to relativity being weird…” 😂 So true! Wonderful video! I think I understood only 5% of it but it’s still wonderful! Great work!

5%! Look at Ms Big Brain here 😅

Damn, 5%?

Spacetime tomfoolery

My man understood regular matter and ignore dark matter and energy lol😂

You guys are getting percents?

The explanation of hawking radiation (2 virtual particles on either side of the event horizon are forever separated) may be part of the key to understanding the difference in the observed size of black holes vs their theoretical size due to accumulation of matter.

I’ve thought like this for a long time, I m glad to see that theoretical physicists have at least considered all this. It may be wrong but I’m glad curiosity allows all possibilities to smash up against evidence.

Been waiting for this one! Thank you Matt and team for another amazing video on a most fascinating subject! Visuals are insane btw, so well crafted.

I love this jab at quantum consciousness. It feels fitting for the topic. I have a hard time making sense of it and it was explained to me in detail for a class I’m taking for my degree.

I always look forward to the PBS Space Time video when a hot topic pops up in cosmology. I appreciate that the skepticism is expressed respectfully on this channel. And there should certainly be skepticism on these claims, but it is better to consider the possibility that the authors could be on to something rather than arrogantly dismiss them with a wave of the hand. This channel gets it right. Thanks for the continuing effort to help explain the topics to someone like me. I am a highly interested layperson, and the vast majority of other channels are either too basic for me, or far beyond anything I could understand without actually being a researcher in the field.

This is the first "dark energy is just..." theory that actually makes some sense. It's probably wrong, but it's not obviously wrong, that's always a good start in science. Einstein and his greatest blunder is a fascinating story, all the more so when it turned out he was so damn smart that he actually got it right, for the wrong reason.

would the time dilation beneath a black hole's event horizon prevent the matter inside from actually ever reaching singularity?

If dark matter is made of stuff, suppose it is an undiscovered particle for instance, is it possible for a black hole to absorb it into the event horizon? Would that change the mass of the black hole? Would it grow? Could this effect explain the very large rate at which supermassive black holes expand?

The only thing we know about dark matter is that it interacts gravitationally. Anything that does so becomes part of the black hole once it crosses the event horizon, and adds its mass/energy to it. There has been an argument that since dark matter doesn’t seem to participate in electromagnetism, it would have a hard time accreting efficiently, since unlike ordinary matter, it cannot loose velocity and any orbital angular momentum by blazing it away quasar like in an accretion disk.

@Richard Classey yeah, that makes sense. I wonder if it would be possible to measure how much dark matter falls into a black hole and if that could tell us something about it. That seems a little out there though.

Could black holes manifest as dark energy by pulling spacetime inwards? Pulling spacetime inwards towards centers of mass could have a similar effect (or similar appearance) to spreading the voids outward... stretching spacetime out in the center, rather than the empty/void space having negative density. Love the channel!

Just wrote this comment myself!

That's a neat idea for sure. But to me (a complete layperson on this stuff) that sounds like the empty space between galaxies is homogenous and unchanging, which would imply the amount of redshift of light from far away galaxies shouldn't be dependent on the distance it travels across space. In other words, galaxies far away from us (and of similar size) would have roughly equal redshifting no matter the distance - because only the space close to galaxies would cause redshifting. And as for larger galaxies with stronger black holes (which results in stronger pulling of spacetime), we would expect to see more redshifting for those larger galaxies. But again, I'm not an expert by a long shot and might be missing something.

@Danny DeWario if there is more distance to an object, then there more area being stretched by black holes between here and there. If every black hole is pulling space in (causing the light traveling through it to stretch) and there are more black holes stretching space between a more distant object than a nearer object, the redshift would correlate with distance.

I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

I always appreciate the detailed visuals. Keep up the good work!

It's always made the most sense to me thinking of black holes as tears in spacetime. The infinite mass and therefore gravity make a ton of sense in that scenario. That means they would be connected somewhere else. Possibly even not somewhere in our universe or maybe even dimension

Always nice to see Soviet scientists given the credit they deserve!

We couldnt have done it without Tsolikovsky

Very insightful and well argued/thought out, thanks matt!

I always thought a universe was inside of black holes. Dark matter was gravity pull of massive space objects around the black holes. Also, the expansion and the void energy are the absorbing of mas into black holes. But I'm just someone who enjoys learning such a thing, so their probably lot stuff I don't know that make this wrong. However, it would make a good story.

This paper sounds like a strong case of "having a conclusion before making the experiment" to me.

Yeah like which publication

"Come up with a theory that explains a thing, design experiments to test that theory, and record the results" are the basics of the scientific method, but another, just as important, part of the method is "rigorous adherence to honesty in your experiments and the willingness to accept when your theory is flawed."

@Derek Floyd But wait, the theory is "99.8%" non-flawed! Close enough for jazz, as they say. And cosmology evidently.

I had the same response. The idea that old galaxies should have smaller black holes seems weird. Assume a galaxy that does not accrete more mass. Over time it’s black hole should increase in size. Which would make “black holes grow faster than their galaxies”

Or just testing for correlation? It doesn't really say anything else as the space of explanations for that correlation (and all scientific explanations/theories-other-than-equations) is infinite, and we generally just use Occam's razor with no deductive logical basis to use it, sometimes more complicated explanations are the correct ones (though in the case of simplified models, it's more precise to formulate Occam's razor in terms of number of assumptions, and simplifying assumptions are assumptions)

If their claim, black hole growth is coupled with the expansion of the universe is true, then could they potentially figure out a way to calculate the vacuum energy density using this idea helping prove their theory? For example, by using Hawking’s equation for black hole entropy they could try to relate the vacuum energy density (VED) to a black holes surface area in the formula then rearrange the formula to come up with a new prediction of VED and see if this matches observed values.

Yes, I was wondering about Hawking Radiation.

I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

Absolutely. The distance between black holes is increasing from momentum, and being the strongest gravitational masses in the universe, by far, they pull everything along with them in their expansion. Next, you might find that the expansion of space between black holes might be faster than the expansion of the surrounding universe, because they don't pull everything in at the same rate as they are moving away.

That innocent sounding phrase, "That may one day be detectable," pretty much kills of it. Nonetheless welcome a change from the more SF oriented episodes that we've had recently.

I've said this years ago on this channel, but I think dark energy is essentially just the part of gravity we haven't figured out yet. And if we can get the shape of black holes down (you know, get rid of the singularity in the math) then we may immediately get an answer as to what's causing dark energy. While this study has me far from convinced of their conclusions, I do like that they used that very idea to get here and I hope more do it.

I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

I've been binging on this and other channels to help me digest information about physics at which I'd otherwise shrug my shoulders. I sometimes find it easier to comprehend things when I don't get lost in the minutiae, and this sort of content helps me with that (I think). I still struggle with dark energy. My brain keeps telling me that black holes contain separate universes. We know mass and energy from our universe can pass the event horizon and theorize it becomes incorporated into the singularity. If there lies the possibility that our universe is nested within another, where our universe exists within a black hole in a parent universe, is it not possible that dark energy is fed into our universe as our parent universe feeds it matter and energy? Is it not possible that dark energy is the parent universe's matter and energy that fell across the event horizon following the instant our universe was created? Perhaps the mass and energy from our parent universe is not wholly compatible with our own universe, but continues to fall through and be present, regardless, contributing to our growing universe? Or perhaps that the information stripped from mass and energy falling into the black hole that cannot bear our universe's physical laws is damned to an existence at the threshold of the event horizon to be rejected back into the parent universe as Hawking Radiation or something along those lines? Would the feeding of mass and energy across the event horizon not lead to one or two inevitabilities: the universe that is being fed would have to expand in space and/or grow in density? But I'm also struggling to comprehend merging black holes if they, indeed, do contain separate universes within? If the universe within one black hole has different physical laws than another black hole with which it collides and merges, would the resulting merger produce a unified universe from the mix of the two physical environments or would the universes merge in such a way that the physical laws for each incorporated universe allow them to both simultaneously exist within the same space, only interacting through compatible physical laws? I'm in way over my head, but this stuff is so fascinating!

The unreliability of intuition is why we developed the scientific method. 😄 Just imagine the mess we'd have made of quantum physics without science, given its profound counterintuitiveness.

Matt links to a video by Dr. Becky, you should really check it out! If you like it, she also has good explanations on dark energy, etc in other videos. Re: multiverses, etc. Remember these are mathematical constructs created by following mathematical theory. A "universe" is a set of numerical values on one side of an = sign. Multiverse theory is the logical conclusion of following the math that was used to define that "universe". So most of your yes/no questions are answered "depends" - they depend upon the values used to formulate the original mathematical universe.

I really want to read your replies in full, but for sole reason whenever I try to "read more," I'm directed to this reply. 😢 Thanks for helping direct my curiosities, I can at least see that I should check Dr Becky's content.

Must have been a bug. Got to read the full contents after I replied. Thanks!

I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam, and black holes as factories of spacetime, turning matter into virtual quarks, because stars are said to fuse simple to more complex atoms, and denser stars are made of simpler elements, like neutron stars, it makes some sense to me that black holes make quarks stop being particles and go to be virtual particles. And gravitational waves, and matter that is converted into gravitational energy, contributing to the expansion of the universe. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

Ive been watching these vids for a while now, i appreciate Matts breakdown into simple terms on the subjects even if sometimes i dont fully understand them

Great video. With dark energy, I suspect it's a case of the theoreticians getting way ahead of the experimental data available. Or as Asimov would put it "Insufficient data for a meaningful answer".

I have speculated for years that dark energy is just another perception of black holes consuming space itself. If all black holes consume space, they cause a stretching of the spacetime between them and would be responsible for the primary red shift of measured galactic movements.

If you consider the 'rubber sheet' analogy, then it would make sense that if you have points on that sheet that are pulling in the sheet, then the points would increase in mass due to the 'sheet' they absorb and that the 'sheet' in-between would become stretched and give the impression of expansion. Over time, as the points increase in mass, they pull in more sheet, giving the impression that the expansion is happening faster. To someone living on the sheet, the difference between expansion and sheet removal would be very difficult to distinguish. And of course, if the sheet is being pulled in at a constant rate, it would also explain the rotational velocity discrepancy in galaxies, thus explaining dark matter.

Interesting and creative analogy! But, the black holes are not the only ones that are consuming the fabric of space-time, so to speak, also ordinalry mass object, like planets, stars, etc., are doing the same thing, just that the intensity or "speed" is order of magnitude lesser that of the black hole objects.

I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam, and black holes as factories of spacetime, turning matter into virtual quarks, because stars are said to fuse simple to more complex atoms, and denser stars are made of simpler elements, like neutron stars, it makes some sense to me that black holes make quarks stop being particles and go to be virtual particles. And gravitational waves, and matter that is converted into gravitational energy, contributing to the expansion of the universe. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

QUESTION: does that mean the energy of the vacuum is actually a false vacuum since that experiment that showed you can teleport energy using entanglement led to a lower energy value from the origin as a result of the transfer?

A question: many supermassive black holes we have seen are way too large considering the time they formed, especially those within a few hundred million years after the formation of the universe. We know that dark matter is affected gravitationally - could it be that black holes consume dark matter, along with regular matter, and gain mass that way?

Black holes always seemed terminal and detached. With this conjecture they become an active participant in reality. Look forward to more on this view.

i really love when Matt changes his cadence going into the ". . . Space Time" outro

This wasn't a good one for the outro

That's the one thing I hate about these videos.

Thats the one thing i get in these videos

Thank you for another informative and interesting episode!

We often see black holes depicted in 2D models as the singularity pulling down spacetime. Are there any good videos that discuss how black holes actually look in 3D? Like is the BH actually flat and the horizon could be on plane with our POV / seen at different angles? Or would it look more like an orb? Like if a BH is facing us where we are observing directly above the event horizon in the 2D model, how far does the singularity go down? Wouldn't it run into other things near it?

You can see the black hole in 3D in the movie Interstellar. There is a gif of how spacetime curves towards the inside of an object's center of gravity. You can imagine gravity as the concave curvature of a contracting vortex and dark energy as the convex curvature between galaxies.

A good way to think of this would be circulation in the body, but not arteries and veins, but instead both of those opposite the lymphatic system that balances pressure imbalances from the former with the rest of the body indirectly via an almost hidden medium of vessels. Likewise, as Black Holes concentrate matter, they might well be exerting opposite outward force in all directions, or possibly converting matter into space itself.

I like this «converting matter into space itself», black holes as spacetime factories, because stars are said to fuse simple to more complex atoms, and denser stars are made of simpler elements, like neutron stars, it makes some sense to me that black holes make quarks stop being particles and go to be virtual particles, such as are said to sprout and annihilate from quantum foam. I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

The thing that amazes me is that there is a answer to all our questions we have about the universe.

Would it be mathematically equivalent if everything in the universe would shrink at some rate over time, proportional including the strength of the force field? And time dilation included, this would just not be as dramatic for black holes so that they seem bigger to us over time? I feel like this could make sense if we flip the idea 180° once or twice.

Been looking forward to this video since the paper dropped. That was quick considering all the animation and editing, thanks spacetime!

thanks spacetime, for everything you do

Here is something I've been wondering: How differently would the stars looked like when the earth was formed? Have the expanding universes effect on the night sky be visible to the naked eye?

Thank you for this beautiful summary of the background. I find some analogy between this idea of equating DE to SMBHs, and OTOH a quip I came up with a dozen years back, in the form of the bold assertion that _Dark energy is ambient pollution from alien warp drives!_ -- with diverse motivations ranging from the humorous take on Fermi's Paradox; through an objection made to a subliminal perception (likely to be widely shared) that the focus on uncovering some Earth 2.0 that's expected of exoplanet research, was premised on a secret project to escape by relocating there (rather than address) a self-inflicted destiny of runaway greenhouse effect attributable in good part to vehicular emissions; to a more direct if vague analogy between _accelerating_ expansion and _runaway_ greenhouse effect; and, finally; to alluding to the idea that _the negative gravity (and negative self-gravity!?!) of the massive amounts of negative mass-energy postulated to enable FTL Alcubierre drives, leads to expect that in case of a leak or loss of confinement, the negative mass-energy would in fact race to mimic the uniform distribution and influence currently attributed to dark energy._

I'd concede however that the satire directed by this quip at the expectation of our relocation to some Earth 2.0, is at risk from Poe's Law. A picture emerges of a Universe polluted by the failures multiplied over eons, of desperate attempts of planetary civilizations to save themselves using unstable approximations to an Alcubierre drive...

I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

Brilliant, as always! What a joy to learn!!

Imagine if we in a couple of years actually figure out what dark energy is and it turns out to be embarrassingly obvious to have missed until then...

Best show on you tube for years straight. Keep it up Matt!

If ER=EPR, could that provide a mechanism for cosmological coupling to work and provide a solution to the even distribution? As in, all supermassive black holes are connected to each other via wormholes, which provides a way of ‘sharing information’ on large scales and smoothing out the distribution.

The question I have is whether the investigators are assuming that the exact same force that is pushing outward on black holes is also tunneling out to the space between galaxies to push them apart. If so, then wouldn't the force be used up in pushing outward on the black hole such that it cannot also be used in the space between galaxies?

If local space time looks similar, does it look less similar on the edge of a large galaxy's space-time? Would dwarf galaxies at the edge of larger galaxies be affected differently than the ones closer in and could you glean anything interesting with that boundary region?

I heard from another video about this paper (Anton Petrov, I believe) that black holes “swallowing negative energy” is effectively the same thing as producing dark energy as we think of it now. Could you comment on how black holes eating space itself could lead to space expanding? Thanks for the awesome content!

I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

Congratulations on acknowledging Dr. Becky. Wish i could listen to both of you tear apart an astronomy topic sometime.

Wow The universe is big, complex and not understood. Good stuff. ❤

Black hole interiors are also coupled to healing pyramids, ancient aliens and the ghost of my dead cat. Crazy how nature does that!

Your cat too??!!

Ghost in the Cat!

I have had a silly idea in which I imagined electrons being remnants of blackholes... But thank you for sharing.

What I'm hearing is that dark energy and thus black holes are actually the friends we made along the way.

Very well put, and I also like the skepticism!

My brain was blown as usual. Thanks, Matt.

If two particles can become entangled by placing them very close to eachother, then is it possible that all of particles, under the immense gravity of a collapsing star, reconfigure into a wave function as seen in entanglement?

The entangled particles are said to in fact form a wormhole. The black hole would form a wormhole with a white hole from a big bang of the universe that it contained within.

Thank you for making a video on this. I have talked about this subject a few times, so its nice to see it being covered.

You should check out the video he suggested, Dr. Becky is just the best when it comes to black holes, and she gives them an even fairer review than Matt

It would make sense that if space is expanding in all directions from everywhere then massive objects would also expand.

Hi Matt I greatly appreciate your work. I was wondering if you can check out the new cosmology theories of Mohammad Ali Taheri around dark matter and dark energy and more and let us know about your thoughts Here is the name of the video 4- Dark Matter, Dark Energy & Space Viscosity - A Theory by Mohammad Ali Taheri There are more videos in that playlist they are very interesting Thank you

So if Dark Energy does turn out to be created by black holes would that mean its just a measure of how much spacetime has been stretched since the beginning of the universe by massive objects?

Maybe. I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

I think the universe is actually contracting, but doing so in such a way that from our perspective it appears inverted, much like the time/space reversal beyond the event horizon of a black hole. Has this possible explanation for an accelerating expansion ever been "mathed out" ?

I THEORIZED THIS in YOUTUBE comments many times! The paper should cite me 😂

Wouldn't the rate of expansion then depend on the local density of black holes? Then some regions of the universe will expand faster/slower than others.

On the largest scale matter as well as black holes should be equally distributed.

That was my exact question. That changes the shape of the universe making the visible horizon different in every direction. Meaning no more Hubble constant.

Not necessarily. Depends on the underlying physical mechanism by which the black holes convert mass/energy into space. If it's something like water pouring into a bathtub, then well, the water level rises uniformly even though the source is localized. This analogy is stronger than one might think - fluid dynamics equations are suspiciously similar to GR, both of which treat the subject matter as a continuous medium - even though we KNOW that water is NOT continuous medium, it's made of particles. Or better yet, imagine a tiny stream of water falling onto a kitchen table, slowly growing a pool.

@Emp Empischön Fair enough I didn't read the paper so I'm a bit unqualified to even ask a question. Yet this is the second video on this subject I've seen in as many days. I would love to explain dark energy this way, but it just seems way too hiding in plain sight to explain such a confusing and complex subject. So I guess I'm looking for that steel toed boot to kick it in the head. Thanks for your explanation it does make sense considering what is expanding is all part of the same single fabric.

@Emp Empischön I know that this is all conjecture but I like to imagine that space is an emergent property of mass / energy and that as it expands, it has to push against the surrounding spacetime, causing it to compress, causing what we call gravity. This expanding space still has to go somewhere and that's we observe at larger scales, i.e. cosmic inflation. What makes black holes unique is that the space is expanding faster than light can travel across it and any light that enters is basically red-shifted into oblivion.

Would attributing the mass of black holes to dark energy change the distribution of the masses in the pie chart (matter vs. dark matter vs. dark energy)?

This is The topic I have felt may explain what so many are looking for. Great discussion and If anyone is able to crack this problem I wouldn’t be surprised if DE Is coupled to galaxies and black holes. But this problem is the size of the universe so there’s that. Good luck. I’ll be watching.

If the new theory in the video is correct, then you can bet that black hole's dark enery is also responsible for the phenomenon we now ascribe to black matter.

Wouldn't it be funny if after all the work and math put into trying to understand dark energy and the expansion of the universe, we ended up realising that the universe is actually staying the same size but all the stuff inside it is just getting smaller so it looks further apart.

So glad you plugged Dr. Becky's channel. She has a great explanation.

Agreed! 💯%

Yeah, she actually studies the black holes in galactic centers and their evolution and she pretty much ripped this paper apart. Essentially, the authors ignored a lot of research from the past 20 years where we now better understand how the black holes in galactic centers grow, not just thru absorbing gas and stars but also via black hole mergers as larger galaxies swallow smaller ones and their central black holes.

idk I actually like this idea. I'm excited to see how much of it will be deemed plausible in the future.

Thank you very much for doing the "What If Black Holes ARE Dark Energy?" video, this was something I had explicitly requested on the Discord back when that idea was published.

For me I think it’s fair to imagine the same amount we know about black holes equals roughly the same amount we know about dark energy. Great team to push new ideas. They must align with the old rules but new discoveries make new rules. For me it’s the elephant in the room that black holes are what keep our sun orbiting around the Milky Way, keeps the earth spinning and set to motion the weather even.

Excellent as always. Fascinating topic.

Very good sir, thanks for wonderfull journey into my imagination. You guys are inspiring 🙏

My thought is that black holes don't contain an actual physical singularity, just a virtual one infinitely far into future. Due to the colossal time dilation it takes literally forever for the singularity to form, by which time the BH will have already undergone Hawking evaporation. Has this been considered?

That's interesting, no idea what the implications would be, or if it's testable at all.

No, it's not considered as your idea is inconsistent with relativity.

It's a chicken and the egg kind of thing.

Yes this scenario is considered in loop quantum gravity. "Loosely speaking, the full phenomenon is analogous to the bouncing of a ball. A ball falls to the ground, bounces, and then moves up. The upward motion after the bounce is the time-reversed version of the falling ball. Similarly, a black hole “bounces” and emerges as its time-reversed version—a white hole. Collapsing matter does not disappear at the center: it bounces up through the white hole. Energy and information that fell into the black hole emerge from the white hole. The configuration where the compression is maximal, which separates the black hole from the white hole, is called a “Planck star.” Because of the huge time distortion allowed by relativity, the time for the process to happen can be short (microseconds) when measured from inside the hole but long (billions of years) when measured from the outside. Black holes might be bouncing stars seen in extreme slow motion"

You should do a refresher into the archives of our own favorite space time channel! But just for the sake of your question, pretty much every respected astro/physiciscist / researchers do *not* believe that the singularity in a blackhole is a real, it's widely recognized that the singularity comes about because our current laws of physics are missing some key component(s) needed to properly describe blackholes. Think of it like a computer program that has a bug caused by faulty code, which makes it divide by zero, and so it spits out an answer that is impossible to reconcile and Call of Duty crashes. The singularity in blackholes just suggests our math is wrong, and I don't know of any non crackpot scientist who believes otherwise!

The idea that black holes are dark energy raised a question in my mind about dark matter: If it is five times more prevalent than ordinary matter and seams only to interact with gravity, are there very dense areas of dark matter i. e. dark matter "stars" or even "galaxies"? Obviously we can't observe them directly, but shouldn't they be visible via gravity lensing?

i'd love to review the data pools that lead you guys to the conclusions you reached

My theory for the "cosmological coupling" is in relation to how stars produce protection their solar systems. SMBHs produce a similar protection which surrounds the mass of the galaxy itself which is why it doesn't expand with the rest of the universe and would fall in like with dark energy holding galaxies together.

I kinda like this idea, it involves the things we see in the cosmos. Intuitively I don’t like strings (they can’t predict anything), multidementions we cannot see or detect. As far as the theory forcing one to conclude that blackholes should be distributed evenly around the universe the lambda CDM model has always assumed that on sufficiently large scales the universe is both homogeneous and isotopic should then not be a problem applying it to this new theory. P.S. and there are structures in the universe that seem to refute this assumption.

If black holes are a whirlpool of spacetime itself, it makes sense in an intuitive way to think of dark energy as the "drainage flow" of spacetime in all directions towards the only other black hole like event horizon that isn't local: the cosmological event horizon.

The part of me that wants it to be true because of how neat of a solution it would be says "maybe it's the universe trying to remain topologically homogeneous?" But the desirable answer is often not the real answer.

In the end the universe is going to do what it is going to do even if we think it shouldn't be able to do it.

Which made me think of Matt's topic last year about primordial microscopic black holes with planck size. What if they are the even distribution?

​@Paul Michael Freedmanthat's what I thought when he told about need for BH to be evenly distributed. But what about Hawking radiation, it should cause BH to shrink.

@Oskar Skalski But how big must a BH be to grow more from universe expansion than shrink from hawking radiation? Where would be the equilibrium?

Black holes warp space time. They could be emitting energy backwards through time (from our frame of reference) fueling the big bang causing an accelerating expansion.

Great idea. I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam, and black holes as factories of spacetime, turning matter into virtual quarks, because stars are said to fuse simple to more complex atoms, and denser stars are made of simpler elements, like neutron stars, it makes some sense to me that black holes make quarks stop being particles and go to be virtual particles. And gravitational waves, and matter that is converted into gravitational energy, contributing to the expansion of the universe. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

If the 'quantity' spacetime was finite, and if black holes consumed spacetime (not just matter), then it might make sense that black holes were literally dark energy: as they take in space time, it would decrease the overall amount of it, and since we know spacetime can stretch, it would accelerate the distance between objects as more and more of it entered the black holes. Total guess

This sounds like a neat idea, that may, or may not be evidenced later. It doesn't sound likely to me given the need for most black holes to not be in galaxies. The only black hole I know about is in a galaxy.

Strangely; I have been saying that black holes were the source of dark energy for a couple of years now - but my reasons/mechanisms are nothing like what was suggested in the Farrah paper. The Farrah paper has had one benefit for me personally; I can now say that black holes are the source of dark energy without the entire village turning out with burning brands and pitchforks. My speculation suggests that black hole entropy/information is stored by a new dark field coincident with the event horizons of black holes. Dark energy is the consequence of a repulsive force between these fields and to match the equation of state of dark energy this force does not fall off significantly with distance. Black hole entropy/information scales as the square of the black hole mass which would have an interesting effect on those three little moving green bars in the graphic towards the end of the presentation. One other consequence of this speculation is that dark matter ends up as being the 1 bit Planck mass black hole (No; it doesn't necessarily evaporate in 10^-40s - check out the limits of applicability of the Hawking mechanism - he did). Amongst other effects you end up with a new small repulsive force between the central supermassive black holes of galaxies and the dark matter halo (and also a lesser repulsive effect within the halo). This has implications for galactic bulges and the (general) correlation between the size of the SMBH and the galactic bulge. I'm interested in views and am also completely open to being shown the error of my ways - this is not a career move, I'm just having fun. If you are interested you can start here with the summary and follow the link(s) to more detailed stuff:- https://www.quora.com/profile/Gary-Duggan-22/Dark-Matter-And-Dark-Energy-A-Physical-Basis-For-The-Dark-Fluid-Concept-The-1-Bit-Planck-Mass-Black-Hole-Some-One Happy to chat.

I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam, and black holes as factories of spacetime, turning matter into virtual quarks, because stars are said to fuse simple to more complex atoms, and denser stars are made of simpler elements, like neutron stars, it makes some sense to me that black holes make quarks stop being particles and go to be virtual particles. And gravitational waves, and matter that is converted into gravitational energy, contributing to the expansion of the universe. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

I've thought of a similar situation. If our Universe is indeed 'inside' a Black Hole in a parent universe, the rate at which that Black Hole consumes matter determines the strength of Dark Energy and the rate of expansion of our Universe. A Black Hole that is consuming almost nothing would mean that the universe inside it would have a very slow expansion, while one that is feasting on a star would have a much faster expansion. I guess I'm implying that the Hubble 'Constant' is not constant, but depends on the amount of matter falling into our 'parent' Black Hole.

The hubble constant is already not constant. It's really the "hubble parameter". It is only constant across space(as far as we can tell), not time because the expansion rate changes with density.

Regarding the reformulation of the Friedman equations they presented to accomodate the non-local influence of black holes, I wondered whether it could indicate a way to link this whole thing (gravity and stuff) to quantum mechanics, which is indeed non-local

Wondering the same thing, if Susskinds “ER=EPR” (entanglement & gravity) relation could somehow be connected.

GR is also "non-local", the thing is, we're limited by not being "pure energy", just look at the frame of reference of a photon (basically everything everywhere with "no time nor space").

I often envision black holes tugging at the fabric of spacetime and spacetime like auxetic quantum foam, and black holes as factories of spacetime, turning matter into virtual quarks, because stars are said to fuse simple to more complex atoms, and denser stars are made of simpler elements, like neutron stars, it makes some sense to me that black holes make quarks stop being particles and go to be virtual particles. And gravitational waves, and matter that is converted into gravitational energy, contributing to the expansion of the universe. Look up a video titled "Auxetic Foam Research at HPMI" to see what an auxetic foam sample looks like. If the connection of black holes with dark energy is verified, the warp drive would have to be revised. Dark energy is said to be basically antigravity. It's something important for interstellar travel in reasonable time.

Could this relate to the accumulation of information over time and spooky action at a distance in a unified universe?

I think this only makes sense if black holes are copies of our universe