I remember the times when JWST was a program that was always being delayed and was taking more and more money and it wasn't clear when will it be finally launched. Nowadays we regularly hear about new discoveries made by JWST, which just shows how worth this program actually is
The thing that makes me angriest about Hubble and JWST is that they only built one. Why spend $10B on ONE JWST when you could have TEN JWSTs for maybe $20B?
I don't think that's the right way to think about it. The discoveries made by the JWST are going to feel more visceral than the lack of discoveries that would have been made by JWST's alternatives, even if the former is far less significant than the latter. I think that Daniel Kahneman has a good term for the difficulty of accounting for opportunity costs, but I don't remember what it is.
A lot of the issue as per normal with America and science is delays an due to congress canceling and interfering with stuff they have no idea about as they say "what return does this have to America" or "how can this beat the Russian's or China?" They are fine with spending untold trillions on military that often never works, is over budget in the billions or is just for their contractors to have work but want to enhance humanity as a whole? pfft
Translation: The explanation for why you are wrong exists… but is informing you, a random person in a UA-cam comment section, worth the lost opportunity cost required to look it up?…. No. No it’s not.
Dear whoever edits/does music for these, PLEASE make the outro quieter! I love listening to these before bed and the last 15 seconds are so much louder than the entire episode. THANK YOU! Sincerely, An overworked mom who just wants to peacefully learn and fall asleep to science
My sentiments, exactly, both the intro and outro are way too loud. I am constantly looking for videos that are interesting and boring at the same time to listen to while I'm asleep. There are some good ones if you like the subject matter, but this subject is ASMR gold.
@@jvcyt298 They said they would adjust it on my other comment on their most recent video! I liked the channel called “Astrum” for fall asleep space videos. He even has a “sleep space “ playlist on Spotify.
It seems louder, but I checked the audio in Audacity and the main part of the video is about 7.5 dB louder than the outro. In other words, the outro is less than half as loud. Tom Scott made a video a while back explaining how some sounds are perceived as being louder even when the actual amplitude is lower. But I agree it should be made a bit quieter, or perhaps the music could be changed to something more subtle.
I'm planning a social media campaign to cancel the early universe as it was. It didn't do anything for us as far as I'm concerned. The new early universe has to be cotton candy friendly! And the contemporary universe should grant me more luck in general. 😂👍
They did a video on Population III stars (the very first stars in the universe) that shows just how big those stars got because heavier elements weren't there to interfere: ua-cam.com/video/4pSUtWBiuB4/v-deo.html
I never considered that black holes do not need to be dense, but when you think about how the mass of a black hole scales with its surface area instead of the volume, it makes perfect sense.
Another way to think about it is that if all mass is assumed to be at the central, gravitational attraction goes down with the square of the distance to the center, while density goes down with the volume. So to get the same attraction, mass has to go up with the square of the distance, making density go down with the distance
@@thedeemonunless you are a black hole. Singularity has no radius, but still has a finite mass. The surface area of the event horizon, however, is in direct 1:1 correlation to the mass. As mass goes up the surface area increases. The event horizon doesn't have mass.
Likewise. It has been my favorite youtube subscription for years. I have watched every episode at least once, and all of it has been time well spent. I surprise my calc-based physics prof every week with the comprehensive trivia I've picked up from this series. The pauli exclusion principle was the most recent example. I love it when my professors are caught offgaurd like "hey, you aren't supposed to know about that yet" haha
@@Beanskiiii 2 types of space time viewers: 1) wow this is really cool, i learned so much from this, im definitely going to show this to my professor 2) i like the background music
Welcome back! It's always exciting to see a new episode of Space Time. This series is absolutely wonderful. Thanks for the whole Space Time team for the great work and for keeping this going. Space Time is one of the bright spots in the universe of online media.
100% i just wish we'd put more support into replacing the kepler space telescope because when vera rubin observatory goes online it would have been our best way to find earth sized planets in the habitable zone of potential candidates. right now its virtually impossible given our tools. rubin would look at huge swaths of space to find potential candidate stars to look at, and kepler2 would have the ability to get a good look. its sad that failures tend to shelf projects for EONS regardless of the potential science it can bring. the only reason we soldiered on with jwst was because of the fact that it was the spiritual successor to the amazing hubble telescope.
Love getting my PBS fix. Always good to see Matt dropping knowledge that I mostly don't understand but still explained in an excellent way and some stuff does stick. Very enjoyable!
So, if I understand it right, the Volume of the sphere delimited by the Schwarzchild Radius is proportional to the cube of the Mass. And that relationship implies a crazy different density range, since as the Mass grows, that Volume grows much, much quicker. That means that the physical process able to form a black hole doesn't necessarily need to be always the same, and that some volume range may not have a physical process that can make them (like in the current gap from 100 sun masses to 100.000 sun masses), or if it has existed, it needed different conditions from the ones in the current universe (I'm looking at you, Primordial Black Holes). Maybe the future universe will have conditions that will lead to the formation of black holes in completely different range from the current ones. Anyway, IMO, the current gap of observed black holes in that mass range is quite a neat indicator of a different physical process to form SMBH. I mean, not a single blackhole seen in that mass range in an entire visibile universe (until today) seems to me quite "suggestive".
@@NboOfficialAus Except there is, or really _was,_ a process to form them. The hypothetical but very well-supported Quasi-star, also known as a "Black Hole Star", is a supermassive star ranging from 1000 to 10000 solar masses, with a black hole for a core. These kinds of stars require highly dense molecular clouds and extremely low metalicities to form, conditions only found very early in the universe, and would only last for a few million years before they collapse inward on themselves and shed their outer layers, resulting in the formation of intermediate-mass black holes. The reason why they're either super-rare or non-existent _now_ is because most of them likely merged into the supermassive black holes that sit at the centers of most galaxies.
@@KrudlerTheHorse Existing theories being invalidated by new data doesn't just let you replace those theories with unfalsifiable bullshit. Alder's Razor (also humorously referred to as Newton's Flaming Laser Sword) comes into effect at that point - any scientific proposition made must have observable consequences and a formal demonstration that they are indeed the consequences of the proposition claimed. Or in simpler terms, the "vacuum" left behind by refuted theories can only be filled with another theory backed by direct observations. Saying "A Wizard Did It" is invalid unless you can somehow prove that, yes, a wizard did actually do it.
Great episode as always. I didn't see many references on the graphics so I'm presuming their being done specifically for Space Time now, in which case huge kudos to the folks doing that as they're top-level quality. The only thing missing is the comment responses - are they coming back?
@@franck3279 From his voice it sounds like he's on the tail end of or just recovered from a cold or the flu. Maybe if the team took a break over the holiday period and Matt got sick just after it could've delayed recording new episodes for a bit.
Excellent Video. Dr becky as a couples of video about those problems about black hole. PBS-ST fans should watch them too. Also, I want my black hole cotton candy now!
Click these videos as soon as i see them in my sub box. I was wondering if comment responses will return at some point in the future? I always found it interesting to see what people ask about certain topics and having such a great and knowledgeable presenter as matt answer them.
Oh boy, does the internet have treat for you... Go check out Dr. Becky. Her Oxford Doctorate is in SMBH research and she does weekly shows on a range of 'Space' and other Astrophysics topics, including SMBHs. (she gets shout-outs from Matt on this channel pretty often, as well.)
The merch segment for the hoodie should have gone something like this: "Now you can be warm as you fall into a super massive black hole if you don't like cold spaghetti"
Glad to see you back Matt and I hope you are feeling better now? You really have been pushing yourself a lot the last year or so, what with your professor work, your film, PBS Space Time, your own research and much, much travelling around the world. Please remember you are "made of meat" and overworking is not good for the health, believe me I found out the hard way and it made me seriously unwell. You are still a young man, take a break occasionally. Oh and congratulations on 3 MILLION SUBS! I remember when it was 1 then 2. Take that Malta and Pakistan!
Imagine if we made five of these and pointed them all in different directions at the same time how about 10 already sent that much money to Ukraine cancel few wars for the next few decades and we can build 100
Firstly, I absolutely love the channel and your content! Two scientific questions related to the visuals. 1. Why did you show high energy (gamma rays) on the left side and low energy (infra red) on the right? 2. @3:15 - @3:25 is this a scientifically accurate representation of a black hole from the observer's perspective? Keep on doing what you do, it's a breath of fresh air. ❤
1.) Left-right is used to signify progress or increase. Usually this is from low to high, so high frequencies are on the right.However in this case it is intended to show the progress of redshift, so the reverse is true.The most progressed, redshifted wavelengths are shown on the right. 2.) The rendering at 3:15 is artistic, but based on models and meant to show the temperature of the accretion disk (Red vs blue color) as well as waves in the disk as matter orbits. It is an artistic rendering of what is considered a good scientific model.
At 0:53 and ai is going to help so much in advancing in physics, it wont just help in therotical physics, but will also help in analyzing interstellar data and noticing all important stuff in it.
Could energies have been high enough in the pre-CMB era to produce supermassive kugelblitzes? That would provide earlier seeds for SMBHs despite energies in that era being too high to allow accretion.
The Schwarzschild density is really tricky to wrap your head around. I figured out the equation to calculate it when I was in high school. The higher the mass, the lower the Schwarzschild density. For something like a trillion solar masses, it only needs to be as dense as air and it'd automatically collapse into a black hole. Hey that gives me an idea. How much mass would correspond to a Schwarzschild density equal to the average density of matter in the universe? Huh. Doesn't this prove that the universe cannot have infinite mass and thus must be finite in size? Because if it were infinite, the Schwarzschild density would be zero and it'd just collapse into a black hole? Hmm 🤔
How would we even know we aren't inside a collapsed black hole? We can't look inside a black hole, that's why we're calling it black. The outside of the observable universe is also black, also by definition. This doesn't prove much though, there's many reasons we can't look at something. But infinite mass isn't even required for us to be in a black hole, just a higher mass than what would correspond to a Schwarzschild density equal to the average density of matter in the universe. Yet my understanding is that the Standard Model isn't compatible with this. Regardless, with our current understanding of black holes, it's not really scientific to theorize we are inside a black hole, since it implies that it cannot be proven, so you just have to believe it, if you wish. So, according to the standard model we aren't in a black hole, but we are also aware that the standard model isn't perfect, so we also can't rule it out. So the universe may be infinite in mass and we're in a black hole, or it may be finite and still be in a black hole, or the standard model is not wrong about this and we aren't in a black hole and indeed the mass is finite in size.
The density assumes that only gravity is acting however. If you factor something like expanding space then you can have a higher density. It also assumes that there's an 'outside' and center for the volume to collapse into; in an infinite universe of infinite mass there is no center and so no preferred point for all matter to collapse to.
The direct collapse proposal for SMBH's is the best suggestion yet on how those BH's grew so large so fast in the early universe. Most certainly not all of them were formed that way. The early universe was so chaotic and spatially not very large it is not hard to expect that in some densely packed areas mergers happened growing the BH's. There's one thing to remember though. Even if a BH has the density of Cotton Candy it is still a BH. Meaning that at some distance from the BH the gravity becomes so strong that it prevents light from escaping meaning if you get caught in that gravity there will be no soft landing waiting for you.
Why is there such a pronounced (even log large) gap @ 4:42? Could detector limitations contribute here? I would imagine it would be easier to detect black holes if they are close by, most of which I would guess are stellar; or supermassive via quasars. Is it possible the latter dominate at large distances in data because of instrumental limits? Thx!
Sadly no; w can detect supermassive and stellar mass black holes even at close range, and the masses don't scale with distance ,as we might expect if detection limits were the problem. The gap seems to be real and present even in our nearby universe.
I think the fact that the early universe did not have significant quantities of cotton candy (for all we know) may now be my favorite astrophysics fact of all time.
I remember when I watched this show years ago and I had no clue what you were talking about lol. Now I love learned a new language and it makes so much more sense. Thank you.
Studies on Betteridge's law have actually shown that "yes" is a more common answer. Both two studies on such headlines in scientific journals, and another that checked 26000 articles on news websites.
Can you make an episode on how astronomers locate known objects? More so how do they calculate depth of field/magnification. I mean how they report were they found an object for other scientist to observe
Very nice, thank you! I happen to know of the co-authors of the paper by Bogdan+23, and learned from him that in fact x-ray observations with Chandra were performed before even the launch of jwst! If I recall correctly you can find such interesting details in the data section of the paper. Impressive work on the paper and yours explanations, Matt.
Edit: x-ray observations were performed before the launch exactly because they though they will find something interesting in the JWST data which had already already scheduled
Another great space time release. Could you, in some future episode, explain how two black holes actually merge? Because there are some things that don't make sense at all. If the matter inside the BH really does collapse in to a "singularity" then how can it ever merge with another BH? Two points of zero size means zero surface area and thus should never be able to touch anything. Also space inside the event horizon would be infinity big and infinitely skewed so two small seed black holes should just spin around each other inside their common eventhorizon forever and ever never touching and generating gravitational waves with crazy frequencies. While that is not what LIGO detects.
Or is the idea of a singularity dead and perhaps we have a 3 kilometer event horizon inside the sun? This would kind of explain why larger stars don't necessarily shine brighter.
There are two important things to remember. The first is that we do not KNOW a singularity forms. That's what theory *says*, but w have not seen one. There are other theories such as Loop Quantum Gravity that avoid singularity formation. Secondly, to merge black holes only have to touch event horizons. What happens *under* those horizons won't affect the outside result. So it's quite possible the 'cores' of black holes don't merge, but they'd be seen to merge from the outside, which is all that LIGO can detect. The insides of black holes are a mystery to us.
@@garethdean6382 the event horizon is a limit of light, which can not escape, but gravitational waves should not be affected just as gravity isn't diminished as a star collapses in to a bh. Also my question was answered in the latest spacetime vid. 😅
Man, you're a saint. I was about to come here ask a question on black holes and I see you have this video on black holes! hahah So, I have this question. When black holes are feeding, they form an accretion disk around them, made of ionized plasma, if I'm not mistaken. This plasma rotates, generating a magnetic field that moves "upwards" (if that can be said) from the black hole. However, every diagram of a magnetic field that I know of has a south pole and a north pole, with the field running inside of the magnet from south to north, then out from north to south. (I'm no physicist, so something, probably most of the things, I said may be wrong). My question is, wouldn't that magnetic field inside the BH be running thru the BH itself, from "bottom" to "top", leaving on the other side? CAN it leave? If so, how, if not, does that then behave like a magnetic monopole?
Certain properties are "imprinted" on a black hole's surface. It's mass (gravity), spin and charge. These things don't need to 'escape' or 'pass through' the hole, but they can behave a bit strangely due to various spacetime effects. One of these effects is that a black hole will always behave like a perfect magnet, with a single field,two opposite poles and reflecting all of the magnetic flux that has fallen below the horizon. (This is worth an entire video by itself.) The field of the accretion disk is complex since its will tend to be electrically neutral on average and there will indeed be an complex interaction with the central hole as magnetic field lines are 'swallowed' by the hole and 'pinned' to it. The physics of this is poorly understood, it may be,for example, part of how black hole jets are formed and why they're so energetic.
Well, I'm coming to this too late for anyone to see my question, but just in case: Does anything else create reshift? Like, does gravitational lensing ever induce redshift?
I don't understand how the Eddington limit would apply to dark matter, as I'd assume the outward radiative pressure that limits the feeding rate of a black hole would only apply to normal matter? Do we assume that dark matter cannot be a feed stock for black holes?
While dark matter won't be expelled by radiation, it cannot emit radiation itself and collapse. This means that it won't tend to form accretion disks and feed black holes, severely limiting how much dark matter a hole can consume. Even moreso than with regular matter.
It was stated if the solar system had the density of cotton candy it could be black hole. What about if we scale up to the observable universe? What would the density need to be for it to be a black hole and how does that compare to the estimated density (with and without dark matter)? With the expansion of the universe, what did these calculations look like in the past and into the future?
Is there any correlation between the microwave background and that quasar. If the location of the quasar is in colder region in the CMB, will that definitely mean the collapsing massive black holes as it is rather early on in the life of the universe?
is it possible that the disk of matter falling in can become dense enough for that to become a backhole? it seems reasonable, but then maybe that requires a non spinning disk of material or just more matter than is generally around.
I feel like I might be missing some fundamental understanding with the detection of x-rays that are as old as this. Are the x-rays emitted at such a high energy that even over billions of years of red shift, they are still just x-rays?
The beginning is when light was used yes. But not exactly the way its described imo. Some chose to look at a light and distance it's trajectory as a start point. For some reason the lean went on that way. We might say light is a energy part that has to be involved. At least in making forming or arguing. Look carefully at a bulb designer. Before light , there is a must have control mechanism. Did it just happen? There must be something set to contain or maintain the light. Aas that bangin? Was it ?
I wish it was possible to go back in time to meet Albert Einstein just after he released his theory of special relativity just to tell him that, about one century later, we'd be looking at 'black holes' at the 'beginning of the universe' through 'gravitational lenses'. That'd certainly be overwhelming, even for such a genius
Does the Eddington limit constrain the rate an early black hole could grow by consuming dark matter? I wouldn't think the radiation pressure would slow the inflow of dark matter.
No,however the inability of dark matter to radiate energy sets up its own, actually lower limit on how much it can contribute. Dark matter shouldn't form accretion disks in the same way normal matter does. The same process that prevents it collapsing into the cores of galaxies keeps it away from black holes of any size.
Is the eddington limit calculated by looking at the disk around the black hole or does it take into account that matter may fall into a BH from all directions? I mean, we're talking about time where there may not even exist a disk because matter flows from all directions into the black hole, so maybe the eddington limit does not apply to the first SMBH. As far as I know, the eddington limit, so the radiation that "pushes away" all matter from the BH, can only occur in "ordered" discs while matter spirals closer and closer to the BH. Maybe in the early days of the universe there was no disc because matter fell in from all directions and collided with other matter, losing momentum and falling into the SMBH eventually.
No,it applies to omnidirectional collapse too,though slightly differently. Radiation still pushes outwards; not, say, only at a hole's equator. This is why 'quasistars' are considered possible, large masses of gas with a black hole at their center that last millions of years. Put differently a black hole is very small for its mass,its 'mouth' is tiny and only so much matter can fall through it. It takes time to drink a lake through a straw.
Regarding the theory of small seed and heavy seed, you mentioned that the only possible explanation is either the SMBHs started bigger than what is normal in today's universe, or that they grew faster? What if.. they did neither? Is it possible that the big bang wasn't the beginning of everything and those SMBHs were there from the "beginning"?
Maybe dumb question, but does the Gravitational lensing of distant light affect the redshift as well? If so do we account for it when use redshift to estimate a distant galaxy's age?
Yes, the lensed light takes a longer time to reach us.This means that we can sometimes do things like see a supernova happen several times over if it's light is lensed differently by intervening mass. Thankfully more distant objects need less extreme lensing to be seen so this effect is minor and easily accounted for.
Thank you very much for another interesting episode. I haven't thought about the problem of intermediate mass black holes in a long time. It's cool to see our knowledge progressing since I was a kid. All these years later, black holes are still as fascinating and mysterious as ever. God be with you out there, everybody. ✝️ :)
During that specific time period, what factors are impeding the merging of early black holes with other black holes? Is it plausible that the gap between black holes, and supermassive ones, represents the theoretical maximum size for traditionally unmerged black holes? Could it be that all black holes capable of transforming into supermassive ones have already had enough time to achieve this, meaning that those with nearby black holes available for merging have already completed the process?
It's possible.Current models suggest that black hole mergers simply take too long to close the gap, except under unusual conditions. This is one reason why it's still possible this new galaxy *is* unusual forming by just such a mechanism.
Questions: 1) Was the early universe plasma pre-gas pre-cosmic-wave-background one big SMBH ? This would entail that everything we currently can observe in the universe, was part of that original SMBH. 2) Could the 'Big Rip' hypothesis cause new 'Big Bangs' in the current SMBH somewhere in the future?
![Engine Black Holes [4K]](http://i.ytimg.com/vi/lLt9i1Z4Skw/mqdefault.jpg)
I remember the times when JWST was a program that was always being delayed and was taking more and more money and it wasn't clear when will it be finally launched. Nowadays we regularly hear about new discoveries made by JWST, which just shows how worth this program actually is
Science rocks
The thing that makes me angriest about Hubble and JWST is that they only built one. Why spend $10B on ONE JWST when you could have TEN JWSTs for maybe $20B?
I don't think that's the right way to think about it. The discoveries made by the JWST are going to feel more visceral than the lack of discoveries that would have been made by JWST's alternatives, even if the former is far less significant than the latter.
I think that Daniel Kahneman has a good term for the difficulty of accounting for opportunity costs, but I don't remember what it is.
A lot of the issue as per normal with America and science is delays an due to congress canceling and interfering with stuff they have no idea about as they say "what return does this have to America" or "how can this beat the Russian's or China?" They are fine with spending untold trillions on military that often never works, is over budget in the billions or is just for their contractors to have work but want to enhance humanity as a whole? pfft
Translation: The explanation for why you are wrong exists… but is informing you, a random person in a UA-cam comment section, worth the lost opportunity cost required to look it up?…. No. No it’s not.
Dear whoever edits/does music for these,
PLEASE make the outro quieter! I love listening to these before bed and the last 15 seconds are so much louder than the entire episode. THANK YOU!
Sincerely,
An overworked mom who just wants to peacefully learn and fall asleep to science
My sentiments, exactly, both the intro and outro are way too loud. I am constantly looking for videos that are interesting and boring at the same time to listen to while I'm asleep. There are some good ones if you like the subject matter, but this subject is ASMR gold.
@@jvcyt298 They said they would adjust it on my other comment on their most recent video! I liked the channel called “Astrum” for fall asleep space videos. He even has a “sleep space “ playlist on Spotify.
It seems louder, but I checked the audio in Audacity and the main part of the video is about 7.5 dB louder than the outro. In other words, the outro is less than half as loud. Tom Scott made a video a while back explaining how some sounds are perceived as being louder even when the actual amplitude is lower.
But I agree it should be made a bit quieter, or perhaps the music could be changed to something more subtle.
@@nameismetatoo4591 exactly. It might technically be half as loud, but the brash intense music makes it seem way louder.
I think it's the music itself that's off-putting.
I find the lack of cotton candy in the early universe vaguely disappointing.
Same.
You'd think they could budget for at least a little bit; but no, literally zero cotton candy.
I'm planning a social media campaign to cancel the early universe as it was. It didn't do anything for us as far as I'm concerned. The new early universe has to be cotton candy friendly! And the contemporary universe should grant me more luck in general. 😂👍
If we're in a multiverse, who's to say there isn't a universe full of cotton candy? 🤣
It has not been ruled out.
It sounds like the connection between heavy elements and gas cloud fragmentation needs its own episode.
They did a video on Population III stars (the very first stars in the universe) that shows just how big those stars got because heavier elements weren't there to interfere: ua-cam.com/video/4pSUtWBiuB4/v-deo.html
Space time rules, a big thank you to the whole team ❤😊
*hole team.
(Sorry, I couldn't resist the joke. 😬)
I never considered that black holes do not need to be dense, but when you think about how the mass of a black hole scales with its surface area instead of the volume, it makes perfect sense.
Another way to think about it is that if all mass is assumed to be at the central, gravitational attraction goes down with the square of the distance to the center, while density goes down with the volume. So to get the same attraction, mass has to go up with the square of the distance, making density go down with the distance
Mass is proportional to radius, not surface area
@thedeemon added context for others - this is only true for black holes
@@thedeemonunless you are a black hole. Singularity has no radius, but still has a finite mass. The surface area of the event horizon, however, is in direct 1:1 correlation to the mass. As mass goes up the surface area increases. The event horizon doesn't have mass.
@@thedeemonthe mass of a black hole scales with the surface area of the black hole, not its radius or volume
I look forward to new Space Time more than anything else on UA-cam
Likewise. It has been my favorite youtube subscription for years. I have watched every episode at least once, and all of it has been time well spent. I surprise my calc-based physics prof every week with the comprehensive trivia I've picked up from this series. The pauli exclusion principle was the most recent example. I love it when my professors are caught offgaurd like "hey, you aren't supposed to know about that yet" haha
The background music is the best I’ve heard ever
@@Beanskiiii 2 types of space time viewers:
1) wow this is really cool, i learned so much from this, im definitely going to show this to my professor
2) i like the background music
Really? That's lame. The only reason that I come to UA-cam is to get recommendations for financial advisors from the comments.
@@mvmlego1212 ha hahahaha
Welcome back! It's always exciting to see a new episode of Space Time.
This series is absolutely wonderful. Thanks for the whole Space Time team for the great work and for keeping this going. Space Time is one of the bright spots in the universe of online media.
Honestly, JWST already paid for itself multiple times. What a heck of an investment!
Yes. it is one of the greatest discovered tools in the early 21st century.
We must thank NASA and Dream America!
100% i just wish we'd put more support into replacing the kepler space telescope because when vera rubin observatory goes online it would have been our best way to find earth sized planets in the habitable zone of potential candidates. right now its virtually impossible given our tools. rubin would look at huge swaths of space to find potential candidate stars to look at, and kepler2 would have the ability to get a good look. its sad that failures tend to shelf projects for EONS regardless of the potential science it can bring. the only reason we soldiered on with jwst was because of the fact that it was the spiritual successor to the amazing hubble telescope.
Yup
What profit can you make out of an OBG - none!
@@davejones542 it's a discovery. Something might come out of it.
Love getting my PBS fix. Always good to see Matt dropping knowledge that I mostly don't understand but still explained in an excellent way and some stuff does stick. Very enjoyable!
The new intro explains the new profile pic
It is really good
So, if I understand it right, the Volume of the sphere delimited by the Schwarzchild Radius is proportional to the cube of the Mass. And that relationship implies a crazy different density range, since as the Mass grows, that Volume grows much, much quicker. That means that the physical process able to form a black hole doesn't necessarily need to be always the same, and that some volume range may not have a physical process that can make them (like in the current gap from 100 sun masses to 100.000 sun masses), or if it has existed, it needed different conditions from the ones in the current universe (I'm looking at you, Primordial Black Holes). Maybe the future universe will have conditions that will lead to the formation of black holes in completely different range from the current ones. Anyway, IMO, the current gap of observed black holes in that mass range is quite a neat indicator of a different physical process to form SMBH. I mean, not a single blackhole seen in that mass range in an entire visibile universe (until today) seems to me quite "suggestive".
No black holes in that range cause there's no process to form them in that range it's either smbs or stellar most likely
@@NboOfficialAus
Except there is, or really _was,_ a process to form them. The hypothetical but very well-supported Quasi-star, also known as a "Black Hole Star", is a supermassive star ranging from 1000 to 10000 solar masses, with a black hole for a core. These kinds of stars require highly dense molecular clouds and extremely low metalicities to form, conditions only found very early in the universe, and would only last for a few million years before they collapse inward on themselves and shed their outer layers, resulting in the formation of intermediate-mass black holes. The reason why they're either super-rare or non-existent _now_ is because most of them likely merged into the supermassive black holes that sit at the centers of most galaxies.
Remember all discussed is theoretical. From the theoretical Schwarzschild radius to black holes we know nothing and barely can test anything.
@@dragoscoco2173 yes, Schwarzchild solution is an ideal one, but that was interesting none the less.
@@KrudlerTheHorse
Existing theories being invalidated by new data doesn't just let you replace those theories with unfalsifiable bullshit. Alder's Razor (also humorously referred to as Newton's Flaming Laser Sword) comes into effect at that point - any scientific proposition made must have observable consequences and a formal demonstration that they are indeed the consequences of the proposition claimed. Or in simpler terms, the "vacuum" left behind by refuted theories can only be filled with another theory backed by direct observations. Saying "A Wizard Did It" is invalid unless you can somehow prove that, yes, a wizard did actually do it.
Great to have you back Matt, especially with such an exciting favorite topic! Thank you.
Great episode as always. I didn't see many references on the graphics so I'm presuming their being done specifically for Space Time now, in which case huge kudos to the folks doing that as they're top-level quality. The only thing missing is the comment responses - are they coming back?
New Space Time episode, drop everything!
Been wondering what had happened to you guys. Delighted you're back.
Recovering from the hollidays parties?
@@franck3279 From his voice it sounds like he's on the tail end of or just recovered from a cold or the flu. Maybe if the team took a break over the holiday period and Matt got sick just after it could've delayed recording new episodes for a bit.
Excellent Video. Dr becky as a couples of video about those problems about black hole. PBS-ST fans should watch them too. Also, I want my black hole cotton candy now!
Glad to see you back Matt
I appreciate this channel immensely
Click these videos as soon as i see them in my sub box. I was wondering if comment responses will return at some point in the future? I always found it interesting to see what people ask about certain topics and having such a great and knowledgeable presenter as matt answer them.
I love the change in music and video colouring.
I can't get enough of this channel, and black holes are definitely my favorite subject!
Oh boy, does the internet have treat for you...
Go check out Dr. Becky. Her Oxford Doctorate is in SMBH research and she does weekly shows on a range of 'Space' and other Astrophysics topics, including SMBHs. (she gets shout-outs from Matt on this channel pretty often, as well.)
The merch segment for the hoodie should have gone something like this: "Now you can be warm as you fall into a super massive black hole if you don't like cold spaghetti"
I used to eat cold spaghetti for breakfast.
Cold spaghetti is really good though but this was clever nonetheless
@AnimeMeetsReality thanks. I wasn't aware cold spaghetti was a thing lol I edited it to be more representative
I thought he said "wormed".. As is spaghettified
Glad to see you back Matt and I hope you are feeling better now? You really have been pushing yourself a lot the last year or so, what with your professor work, your film, PBS Space Time, your own research and much, much travelling around the world. Please remember you are "made of meat" and overworking is not good for the health, believe me I found out the hard way and it made me seriously unwell. You are still a young man, take a break occasionally.
Oh and congratulations on 3 MILLION SUBS! I remember when it was 1 then 2. Take that Malta and Pakistan!
JWST already proving its worth!
I read it as SJW Solve the Mystery 🤣
@@w415800like that would ever happen.
@@w415800like that would ever happen.
Such as disproving the Big Bang theory?
Imagine if we made five of these and pointed them all in different directions at the same time how about 10 already sent that much money to Ukraine cancel few wars for the next few decades and we can build 100
Awesome intro. Can never live without Spacetime. Keep up the great work!!
I love pbs spacetime!!!!
Firstly, I absolutely love the channel and your content! Two scientific questions related to the visuals.
1. Why did you show high energy (gamma rays) on the left side and low energy (infra red) on the right?
2. @3:15 - @3:25 is this a scientifically accurate representation of a black hole from the observer's perspective?
Keep on doing what you do, it's a breath of fresh air. ❤
1.) Left-right is used to signify progress or increase. Usually this is from low to high, so high frequencies are on the right.However in this case it is intended to show the progress of redshift, so the reverse is true.The most progressed, redshifted wavelengths are shown on the right.
2.) The rendering at 3:15 is artistic, but based on models and meant to show the temperature of the accretion disk (Red vs blue color) as well as waves in the disk as matter orbits. It is an artistic rendering of what is considered a good scientific model.
Thank you. You saved me from boredom again!
At 0:53 and ai is going to help so much in advancing in physics, it wont just help in therotical physics, but will also help in analyzing interstellar data and noticing all important stuff in it.
Its Space time now 🌌
Being a while since I seen PBS Space Time but I am glad they are back.
Could energies have been high enough in the pre-CMB era to produce supermassive kugelblitzes? That would provide earlier seeds for SMBHs despite energies in that era being too high to allow accretion.
Love the new intro. Looking forward to further discoveries by JWST, it seems to be one absolutely amazing tool :D
The Schwarzschild density is really tricky to wrap your head around. I figured out the equation to calculate it when I was in high school. The higher the mass, the lower the Schwarzschild density. For something like a trillion solar masses, it only needs to be as dense as air and it'd automatically collapse into a black hole. Hey that gives me an idea. How much mass would correspond to a Schwarzschild density equal to the average density of matter in the universe?
Huh. Doesn't this prove that the universe cannot have infinite mass and thus must be finite in size? Because if it were infinite, the Schwarzschild density would be zero and it'd just collapse into a black hole? Hmm 🤔
How would we even know we aren't inside a collapsed black hole? We can't look inside a black hole, that's why we're calling it black. The outside of the observable universe is also black, also by definition. This doesn't prove much though, there's many reasons we can't look at something. But infinite mass isn't even required for us to be in a black hole, just a higher mass than what would correspond to a Schwarzschild density equal to the average density of matter in the universe. Yet my understanding is that the Standard Model isn't compatible with this. Regardless, with our current understanding of black holes, it's not really scientific to theorize we are inside a black hole, since it implies that it cannot be proven, so you just have to believe it, if you wish. So, according to the standard model we aren't in a black hole, but we are also aware that the standard model isn't perfect, so we also can't rule it out. So the universe may be infinite in mass and we're in a black hole, or it may be finite and still be in a black hole, or the standard model is not wrong about this and we aren't in a black hole and indeed the mass is finite in size.
@@nydydn And if we are in a black hole wouldn't it be possible that other black holes merged with it producing these too massive SMBs?
The density assumes that only gravity is acting however. If you factor something like expanding space then you can have a higher density. It also assumes that there's an 'outside' and center for the volume to collapse into; in an infinite universe of infinite mass there is no center and so no preferred point for all matter to collapse to.
@@garethdean6382 Ah hidden assumptions. They always get you 😅
The direct collapse proposal for SMBH's is the best suggestion yet on how those BH's grew so large so fast in the early universe. Most certainly not all of them were formed that way. The early universe was so chaotic and spatially not very large it is not hard to expect that in some densely packed areas mergers happened growing the BH's. There's one thing to remember though. Even if a BH has the density of Cotton Candy it is still a BH. Meaning that at some distance from the BH the gravity becomes so strong that it prevents light from escaping meaning if you get caught in that gravity there will be no soft landing waiting for you.
Space time with a new intro 😮
Very nice new intro! Lovely work from the effects editor(s)
"In astronomy, where's there's one there's often many."
Except for life by the observed behavior of astronomers.
@@alicederyn Don't they have mirrors? 😯
I hope this whole conversation gets quoted in the show!
Why is there such a pronounced (even log large) gap @ 4:42?
Could detector limitations contribute here? I would imagine it would be easier to detect black holes if they are close by, most of which I would guess are stellar; or supermassive via quasars. Is it possible the latter dominate at large distances in data because of instrumental limits?
Thx!
Sadly no; w can detect supermassive and stellar mass black holes even at close range, and the masses don't scale with distance ,as we might expect if detection limits were the problem. The gap seems to be real and present even in our nearby universe.
I think the fact that the early universe did not have significant quantities of cotton candy (for all we know) may now be my favorite astrophysics fact of all time.
I remember when I watched this show years ago and I had no clue what you were talking about lol. Now I love learned a new language and it makes so much more sense.
Thank you.
"No" - any headline that's a question can be answered with "no".
Studies on Betteridge's law have actually shown that "yes" is a more common answer. Both two studies on such headlines in scientific journals, and another that checked 26000 articles on news websites.
And in any headline starting with ’a study shows,,,’, the key word is ’a’.
Great video, very well explained as ever! Thanks for sharing! 🙂😎🤓
Thank you guys! You are one of THE best science shows out there!
Can you make an episode on how astronomers locate known objects? More so how do they calculate depth of field/magnification. I mean how they report were they found an object for other scientist to observe
Or you could Google for 2 seconds and answer your own questions
Love the new intro animation and not just because it doesn’t have an earth rotating the wrong way 😜
Very nice, thank you!
I happen to know of the co-authors of the paper by Bogdan+23, and learned from him that in fact x-ray observations with Chandra were performed before even the launch of jwst! If I recall correctly you can find such interesting details in the data section of the paper.
Impressive work on the paper and yours explanations, Matt.
Edit: x-ray observations were performed before the launch exactly because they though they will find something interesting in the JWST data which had already already scheduled
Magnifique new PBS Space Time opening!
Thanks for all you do, PBS Space Time. 🥰
Great video; I was hoping you would do one for this topic!
Another great space time release.
Could you, in some future episode, explain how two black holes actually merge? Because there are some things that don't make sense at all.
If the matter inside the BH really does collapse in to a "singularity" then how can it ever merge with another BH? Two points of zero size means zero surface area and thus should never be able to touch anything. Also space inside the event horizon would be infinity big and infinitely skewed so two small seed black holes should just spin around each other inside their common eventhorizon forever and ever never touching and generating gravitational waves with crazy frequencies. While that is not what LIGO detects.
Or is the idea of a singularity dead and perhaps we have a 3 kilometer event horizon inside the sun? This would kind of explain why larger stars don't necessarily shine brighter.
There are two important things to remember.
The first is that we do not KNOW a singularity forms. That's what theory *says*, but w have not seen one. There are other theories such as Loop Quantum Gravity that avoid singularity formation.
Secondly, to merge black holes only have to touch event horizons. What happens *under* those horizons won't affect the outside result. So it's quite possible the 'cores' of black holes don't merge, but they'd be seen to merge from the outside, which is all that LIGO can detect. The insides of black holes are a mystery to us.
@@garethdean6382 the event horizon is a limit of light, which can not escape, but gravitational waves should not be affected just as gravity isn't diminished as a star collapses in to a bh.
Also my question was answered in the latest spacetime vid. 😅
As soon as I heard about the accidental discovery idea, my first thought was Penzias and Wilson. It's such a great story.
an other Great video Dr.Matt, tks a lot! a video about GRB association with SuperNovae would also be amazing!
Just want to say that I love this show and everyone involved with making it!!!
Congrats to 3M subscribers, keep up your outstanding work!
thanks thanks thanks, really well broken down. really inspiring to stay appraised of the latest in space time ..
Whoa, new intro! Love it.
Cool video!! Blackholes are my favorite topic
Fantastic video, as always!
I dig the new intro and Logo,amazing video as alwais also thanks
Awesome new intro animation. And logo!
Outstanding episode, Matt and team!
Thanks you for another space time video.
so good, thanks for the update!
Good episode, I'm hoping for one of those deep theoretical topics soon.
1:48 does gravitation lensing shift the red shift?
@pbs space time can you do an episode explaining the physics behind IonQ photon entanglement por favor?
Oh nice, thanks for showing the cool data!
Another wonderful video
Thank you so much 🫶🏻
Sick I've wanted that black hole shirt for forever. Dibs.
Man, you're a saint. I was about to come here ask a question on black holes and I see you have this video on black holes! hahah
So, I have this question. When black holes are feeding, they form an accretion disk around them, made of ionized plasma, if I'm not mistaken. This plasma rotates, generating a magnetic field that moves "upwards" (if that can be said) from the black hole. However, every diagram of a magnetic field that I know of has a south pole and a north pole, with the field running inside of the magnet from south to north, then out from north to south. (I'm no physicist, so something, probably most of the things, I said may be wrong).
My question is, wouldn't that magnetic field inside the BH be running thru the BH itself, from "bottom" to "top", leaving on the other side? CAN it leave? If so, how, if not, does that then behave like a magnetic monopole?
Certain properties are "imprinted" on a black hole's surface. It's mass (gravity), spin and charge. These things don't need to 'escape' or 'pass through' the hole, but they can behave a bit strangely due to various spacetime effects. One of these effects is that a black hole will always behave like a perfect magnet, with a single field,two opposite poles and reflecting all of the magnetic flux that has fallen below the horizon. (This is worth an entire video by itself.)
The field of the accretion disk is complex since its will tend to be electrically neutral on average and there will indeed be an complex interaction with the central hole as magnetic field lines are 'swallowed' by the hole and 'pinned' to it. The physics of this is poorly understood, it may be,for example, part of how black hole jets are formed and why they're so energetic.
Well, I'm coming to this too late for anyone to see my question, but just in case: Does anything else create reshift? Like, does gravitational lensing ever induce redshift?
I don't understand how the Eddington limit would apply to dark matter, as I'd assume the outward radiative pressure that limits the feeding rate of a black hole would only apply to normal matter? Do we assume that dark matter cannot be a feed stock for black holes?
While dark matter won't be expelled by radiation, it cannot emit radiation itself and collapse. This means that it won't tend to form accretion disks and feed black holes, severely limiting how much dark matter a hole can consume. Even moreso than with regular matter.
It was stated if the solar system had the density of cotton candy it could be black hole. What about if we scale up to the observable universe? What would the density need to be for it to be a black hole and how does that compare to the estimated density (with and without dark matter)? With the expansion of the universe, what did these calculations look like in the past and into the future?
Is there any correlation between the microwave background and that quasar. If the location of the quasar is in colder region in the CMB, will that definitely mean the collapsing massive black holes as it is rather early on in the life of the universe?
Are the methods used in determining UHZ1's redshift reliable enough though?
is it possible that the disk of matter falling in can become dense enough for that to become a backhole? it seems reasonable, but then maybe that requires a non spinning disk of material or just more matter than is generally around.
Anyone notice their new intro! Great update ST Team
That "spacetime" verbal finale was spectacular! How many take did that require?
I feel like I might be missing some fundamental understanding with the detection of x-rays that are as old as this. Are the x-rays emitted at such a high energy that even over billions of years of red shift, they are still just x-rays?
I'm guessing CMB is not high resolution enough or not applicable to be useful for the issue?
2:35 . . . Yea for Chandra (AXAF) !! 🤩
"The Really Exciting Moment Came . . . "
X-rays @ Chandra = Gamma Rays @ Source !!!
The beginning is when light was used yes. But not exactly the way its described imo. Some chose to look at a light and distance it's trajectory as a start point. For some reason the lean went on that way. We might say light is a energy part that has to be involved. At least in making forming or arguing. Look carefully at a bulb designer. Before light , there is a must have control mechanism. Did it just happen? There must be something set to contain or maintain the light. Aas that bangin? Was it ?
I wish it was possible to go back in time to meet Albert Einstein just after he released his theory of special relativity just to tell him that, about one century later, we'd be looking at 'black holes' at the 'beginning of the universe' through 'gravitational lenses'. That'd certainly be overwhelming, even for such a genius
Does the Eddington limit constrain the rate an early black hole could grow by consuming dark matter? I wouldn't think the radiation pressure would slow the inflow of dark matter.
No,however the inability of dark matter to radiate energy sets up its own, actually lower limit on how much it can contribute. Dark matter shouldn't form accretion disks in the same way normal matter does. The same process that prevents it collapsing into the cores of galaxies keeps it away from black holes of any size.
12:16 the acronym OBG reminded me about OMC. How bizarre...
What does this new information mean for the theory of a blackhole core star?
❤another beautiful and helpful lecture
The sight of one of those Heavy Seed supermassive black hole formations must have been something to behold!
Thanks for talking slower. I can actually process what's being said before I'm already behind the next thing being said. Big improvement!
Is the eddington limit calculated by looking at the disk around the black hole or does it take into account that matter may fall into a BH from all directions? I mean, we're talking about time where there may not even exist a disk because matter flows from all directions into the black hole, so maybe the eddington limit does not apply to the first SMBH.
As far as I know, the eddington limit, so the radiation that "pushes away" all matter from the BH, can only occur in "ordered" discs while matter spirals closer and closer to the BH. Maybe in the early days of the universe there was no disc because matter fell in from all directions and collided with other matter, losing momentum and falling into the SMBH eventually.
No,it applies to omnidirectional collapse too,though slightly differently. Radiation still pushes outwards; not, say, only at a hole's equator. This is why 'quasistars' are considered possible, large masses of gas with a black hole at their center that last millions of years. Put differently a black hole is very small for its mass,its 'mouth' is tiny and only so much matter can fall through it. It takes time to drink a lake through a straw.
Regarding the theory of small seed and heavy seed, you mentioned that the only possible explanation is either the SMBHs started bigger than what is normal in today's universe, or that they grew faster? What if.. they did neither? Is it possible that the big bang wasn't the beginning of everything and those SMBHs were there from the "beginning"?
Maybe dumb question, but does the Gravitational lensing of distant light affect the redshift as well? If so do we account for it when use redshift to estimate a distant galaxy's age?
Yes, the lensed light takes a longer time to reach us.This means that we can sometimes do things like see a supernova happen several times over if it's light is lensed differently by intervening mass. Thankfully more distant objects need less extreme lensing to be seen so this effect is minor and easily accounted for.
Thank you very much for another interesting episode. I haven't thought about the problem of intermediate mass black holes in a long time. It's cool to see our knowledge progressing since I was a kid. All these years later, black holes are still as fascinating and mysterious as ever.
God be with you out there, everybody. ✝️ :)
During that specific time period, what factors are impeding the merging of early black holes with other black holes? Is it plausible that the gap between black holes, and supermassive ones, represents the theoretical maximum size for traditionally unmerged black holes?
Could it be that all black holes capable of transforming into supermassive ones have already had enough time to achieve this, meaning that those with nearby black holes available for merging have already completed the process?
It's possible.Current models suggest that black hole mergers simply take too long to close the gap, except under unusual conditions. This is one reason why it's still possible this new galaxy *is* unusual forming by just such a mechanism.
There’s a solar-system size serving of cotton candy at the state fair this year
I LIKE WHAT YOU'VE DONE WITH THE PLACE.
Questions:
1) Was the early universe plasma pre-gas pre-cosmic-wave-background one big SMBH ? This would entail that everything we currently can observe in the universe, was part of that original SMBH.
2) Could the 'Big Rip' hypothesis cause new 'Big Bangs' in the current SMBH somewhere in the future?
Thanks to Matt and the team for another great episode! By the way, no background music on this one