Thanks for these videos! I’m a 74y/o retired MD, with a lifelong love of math, physics, and esp. astrophysics, and never enough time or energy to study then being general college courses, until now. Your videos inspire and inform me❤❤

One of the few astronomy channels I watch on a daily basis Keep up the good work

If I had known that Astronomy classes were lectured the way you do in your episodes, I would have chosen astronomy as a career.. Beautiful work.

i love how the more we find out about deep space the more questions it raises and the more we realize how little we know

I'm going to have to watch this one a few times to let things sink in! Cheers Alex :)

Always felt like astronomy pages overhype stuff but this one feels just right. Love that it’s trustworthy too just absolutely amazing

One more interesting thing that you forgot to mention about Neutron Stars (which almost no one ever makes clear) is that they are almost pure neutrons - hence the name... but where did all the electrons and protons go that were in the star? Well once they get squeezed close enough to each other they combine and become more neutrons.

Speculation of alternative explanations are always good. We haven't made any real progress in cosmology for a long time, so we need all the speculation we can find and let the ideas compete with one another and compare them with observations.

Wow. Fabulous video. Probably one of the most mind stimulating productions I have seen. Dark energy is the pressure which expands our universe, so I assume that black holes are definitely connected. No one wants to say we may be living in the equilibrium of a gravastar. Amazing concepts.

Dear Alex, I do appreciate your show and the enormous amount of work that you put into each episode. There is one criticism of today’s dialogue when about 1/3rd the way through you talked about “Heat coming from the sun”. Heat is the progression of the vibration of molecules within gas, liquids or solids. The sun lives in a bath of vacuum and therefore heat cannot be emitted from the Sun’s surface. Radiation {eg Infrared EMR} can travel through a vacuum and in turn heats up gases, liquids and solids when it interacts with them on Earth. This is how heating of Earth happens but it is an indirect rather than a direct process. Cheers.

There has been so much new info coming out about black holes recently. It's a super exciting time to be intrested in this stuff. And From what I have heard other science channels say, James Webb is just getting started. the last year has been fine tuning it, and now we can get some very intresting data from it!

Alex, you are one of the most precious things in the Universe: An Educator. Thank you for all your work. 🙂

Fascinating!

This video is absolutely fantastic!

Awesome videos with great quality as always say 🌍🌟

Man that music at the beginning, the one with the bells, is haunting and beautiful

Thank you, Alex! 🌟

That is either a duck or an extremely dense object mimicking a duck. Everything's funnier when you replace it with a duck, especially a rubber duck wearing a top hat.

Love ASTRUM. For non-scientists; I’ve read it take a million years for a photon to radiate outward from the sun’s center til we see it. If there is some truth, please explain. Thanks. Tom. Poulsbo, Washington

Great video 💪

I don't know why but I was thinking that every information you said just in the first 30 seconds of the video took Millennia to be discovered and making an astrophisicis of just 100 years ago or less listening to this 30 seconds would completelly blow his mind...

Great video, very informative and much appreciated

Man.. glad you posted today. My phone malfunctioned and i lost multiple hours of work yesterday

A GRAVISTAR??? Ouch! I think you just bent my brain. Superb video Alex! 10/10!

I once saw a video about someone referring to this theorie, to suggest our universe is inside a black hole. With the edge of the observable universe being the event horizon. Matching the expansion. Pretty cool thought imo

I love your videos

Love the format but references would be nice

I'm leaning toward 1 more kind of star, the quark dwarf. (Not necessarily different externally from black hole, but different internally.) Only works if there is quark-degeneracy pressure, and probably only works with neutrons stars close to the neutron-degeneracy limit. Pre-quark neutron star vacuums up gas (interstellar medium) until second collapse. Then quark degeneracy takes over for interior. (An extension of _____'s book, "The Dragon's Egg", where a crustquake and collapse caused a size reduction.) If a collapse is gentle enough, and quark degeneracy exceeds neutron degeneracy, a quarkstar is possible. Still could be invisible, but not nigh-singularity. Just conjecture, though. While I've read of same-quark resistance to touching, I haven't read how close top and bottom quarks get in protons and neutrons.

I want to see this channel break 2M subscribers this year!! 💫🙏

Quick note, betterhelp has done some shady stuff in the past, and I would recommend avoiding them in the future. Love the content here, keep it up!

Fantastic 🙏

Anything denser than a neutron star will still affect light the same way as a black hole. Or is there a type of particle that can escape?

i would like to know what is the definition of a star... if a neutron star is a star then a black hole should be a type of star as well

Very interesting, so, if we follow the naming convention for neutron stars, could a white dwarf then be called an electron star since it's balancing on the electron degeneracy pressure limit?

Every time another Astrum video comes out, I just gravitate to it. This is another excellently presented, mind expanding topic. Astrophysics is getting weirder by the " - - -day, week, month or even year - - -". Are gravistars the universal version of antigravity generators?

Yes. Expanding black stars which emit expanding dark energy / pushing force❤

I bet both my testicles that these stars do not exist or never have existed in our universe.

Thanks!

Your videos are my bed time stories

I’ve been trying to get some science coverage of the infrared star in dune 2 because for the life of me I don’t understand how that would work or if it’s even possible for light to sap the colour of things that way. Would love a video on the various questions about the giedi prime star.

Great content, commenting for the algorithm

The knowledge we get from physics is actual astonishing. I’ll wait for more information before commenting on this

Not even two minutes in and i already got an ad man

We have direct radio waves images (let's call them photos) of at least two black holes from the event horizon telescope though. So at least these two have to be real black holes?

A member of my astronomy club is an astrophysicist at New Mexico State University here in Las Cruces. He talked about it to me and a couple of other members and said some people just cannot say I do not know, they _have_ fill it in with something. I'm a retired bio/engineer and stayed out of it, we have our own dogmatists with the same problem. It's just funny to me now.

~ There shouldn't be any confusion about grav. blackholes, e.m. jet streams, or wormholes, because the balance of light energy & gravitational matter determines whether cosmic objects become strictly gravitational black holes, or e.m. jet streams (stars), & anything in between. Along with wormholes which are a equal density balance between both, as well as bound with their corresponding balanced & equilibrated strong & weak forces. ~ The blackhole/jetstream in the center of the Milky Way Galaxy is the e.m./grav. finite & mortal signature of our Milky Way Galaxy, which is also bound by it's correspective Strong & Weak Forces as well. ~ In conclusion: The balance & equilibrium of Strong & Weak Forces determine the color, shape, size, & spatial qualities of a grav. blackhole, e.m. jet stream, or a wormhole, in both space & time.

I Love "Exotic Stars" am i right fellas

What is the music playing around 3' ?

I'm curious how neutron degeneracy pressure is affected/counteracted by centrifugal force generated by the star's spin. If the star at the absolute minimal mass to be a neutron star and was spinning so fast that its surface was moving very quickly, let's say 50% the speed of light, would that reduce the neutron degeneracy pressure enough to "break" it out of being a neutron star?

I really hope we get more follow up on this. I think that this being a potential answer to dark energy is a very compelling proposal.

What is the track on the background in the beginning?

I think there's a lot to consider when talking about this, I also think we always look at the basic system we know to explain what we don't, EG: cold is the absence of heat, dark is the absence of light, vacuum is the absence of matter....... Or is it? is there more to this, and the base values are just not measurable in our 3dimensional plane. obviously this will offer so much more debate, and we really done have the space on here to do it? or do we?

"Wonky", he says! I love it. 😀

I'm not sure from this, it seems to say there are Back holes AND there are Gravastars. Both can look similar but have very different interiors? Of Gravastars form from collapsing stars and negative energy matter (never heard of that before more detail required), then how do black holes get created?

The reason i love learning about the universe because there are so many question that are answered and unanswered. I do believe that we only know 0.1% of what the universe has to offer and there are def things that humans will never discover or find out because our brains cant comprehand it

Could possibly both versions of extremely dense objects exist in our universe? I am rather fantasising than speculating now, since I have no background in astrophysics: Could that be an explanation for the observed gap in the size of black holes, like: Stellar black holes are "real" black holes, whereas super massive black holes are of the even more exotic type?

Muy buen vídeo, enhorabuena! Puede ser que el gravastar sea la consecuencia de un agujero negro? La energía se contrae tanto en un agujero negro que la materia se polariza en forma de radiación y espacio-tiempo. Este espacio-tiempo se expandiría posteriormente en la siguiente capa en forma de energía oscura. Esta idea hace que el gravastar no sea necesario, pero sí existiera, debería ser consecuencia de un agujero negro

When I learned about the large explosions in space that are, seemingly, from nowhere.... and wondered if it could be a dark matter/energy star or maybe a star made of antimatter... going supernova. I don't know enough, however, to know just how ridiculous of an idea that is. 😂

An interesting vid idea, since you decided to talk about unrealistic stars, is different colors. I understand why we probably wouldn't be able to see them because blue/red shift, but could they exist? Like a green star for example. When you burn certain elements they can flare up in many colors, so could the same be true for a star that contains an ample amount of differing elements, or would it just cause problems or a collapse?

How wonderful is it to hover at the edge of knowledge

Wait, isn’t this similar to the Alcubierre metric and drive equations? What are the exact equations behind these gravity stars again?

Things get complicated when new things are introduced in the world of physics.

So they saying that they have separated a black light sun and a black hole, nice. Because I've wondered about that with some black holes giving off invisible light or gas but they are supposed to only absorb theoretically

Well, I would think that if a gravistar exerts no gravitational force no matter how close or far you are from it (maybe even touching it or sticking your finger in it), then it can't be a black hole, because black holes exert gravitational force.

Astrum : Dark Energy Me : Ah....My type of star....

Fascinating - I’ve heard of gravastars in the past but I didn’t know the slightest about them. If this is true, that they exert exactly zero gravitational pressure, is that *only* at its’ surface, and gravitational pressure exists perhaps further out from the surface of its’ radius? Meaning like any other star, an object would be drawn in by outlying waves of gravity exerted by the system, but *at the surface* the gravitational pressure equalizes? If so, one might think that it would create something that for all intents and purposes APPEARS to be a singularity - (no visible object PASSES the surface) when in actuality these objects become trapped within this “vacuum space”, where their motion is functionally neutralized? Maybe I’m confused by the mechanics at play here

I like this video for the layman. But man. Each sentence it feels deserves its own video

Enjoying Astrum Sleep Space but can never sleep as I’m left wanting more science. Please consider an audio book on astronomy/astrophysics A Walk Through the Universe with Alex McColgan

13:40 I'm failing to parse this sentence, can anyone help me please? ‘So far ... the radius of the black hole candidates we _see_ ... is at least approximately equal to their Schwarzschild radius: in some cases, that’s just a rough estimate, _but in others, we’ve calculated that radius to within 40 decimal places.’_ (emph. mine). If I read it as ‘the radius of the black hole candidates we _observe_ in some cases [the "others" in the original sentence] was calculated [based on these observations] to 40 decimals’, it becomes sheer nonsense: nothing has been ever measured to 40 _or more_ decimal accuracy (the 'calculation' implies other inputs, with their own uncertainties), and unlikely will in the next 200 years if at all. The most precise experimental measurement ever made has been the electron's gyromagnetic anomaly _g−2,_ calculated to 10 decimals from a measurement done to whopping 13 decimals. That's in the lab experiment, and all astrophysical observations I'm aware of are a far cry from these. 40, 30, 20, 10, 7 decimals spell nonsense in this context. Additionally, a high-precision measurement consistently yielding the _Schwarzschild_ radius, not Kerr (rotating), even if made to 3 decimals, not 40, would mean that these candidates, if really BHs, are (nearly) non-rotating. We know that newborn neutron stars spin like crazy, exactly what we expect from the law of angular momentum conservation, and there is no reason to believe that a collapse to a BH instead of a NS would not result in the high angular momentum of the BH. We know the Milky Way's SBMH approximate spin, too, and it's definitely non-zero beyond counting any sigmas, despite low accuracy/precision. More to this, GW signatures match rotating BH mergers, where certainty is high enough. None were _definitely_ non-spinning; there were only spinning and "maybe". I wouldn't have missed such a revolutionary discovery paper; it would turn our understanding of a lot of physics on its head, up to questioning the very angular momentum conservation validity. I obviously misreading the sentence, but I cannot understand in any other way, whichever linguistic contortions I try; it's pretty straightforward. Obviously, you can calculate an imaginary, theoretical case to an arbitrary precision, but the statement is clearly about calculations from observational data: 'the radius of the black hole candidates we _see_ ... we’ve calculated ... to within 40 decimal places'. Any help out there translating that for me, please?

I think it’s possible all of these celestial objects exist simultaneously. I think it’s possible objects like Grav-stars can exist, and I think that there could be a variety of different types of what we would consider to be black holes; both the traditional gravitational singularities, and these newer hypothesized “troves of dark energy”. I theorize that it’s due to the lack of precision and advancement with our instruments that makes it difficult to tell what is objectively true or not for certain

Great video 10/10

Electron degeneracy pressure. A new term for me but I love it, thank you

Idk, the way you described gravistars would make them seem quite rare, as you would need extraordinary circumstances to balance the gravity and pressure like that. By just the amount of dark energy there is supposed to be in the universe (it is supposed to comprise up to 70% of everything) I don't think it is plausible that gravistars would make up the bulk of dark energy. Maybe a small portion of it, but certainly not all of it.

I’ve always wanted to see a green star be discovered. I know it’s a very thing wavelength to achieve but I’m sure there has to be at least one in the universe

well... black holes do slowly emit radiation and over time diminish in size and weight and density. Last time i heard and checked we have proved hawking radiation but we havent actually detected it. so if every black hole is emitting a form of radiation that we know exists but we havent detected yet, is that not a form of dark energy?

I have often wondered if dark energy isn't some sort of pulling at the threads of spacetime. Like, what if instead of dark energy pushing at everything to cause it to expand, if instead spacetime was a threadbear sweater, with large sources of gravity pulling at the fabric, causing it to expand and stretch out, giving the appearance that things are being pushed farther away, when instead, space is just being pulled "thinner"

It's sad that there is so much light pollution that I have to remember the night sky from my childhood or drive 100 miles.

No credit for the Stellardrone music?

A plausible model of The Great Attractor(s)!

Now.. this may be stupid.. but what are the chances our universe is simply existing inside a developing Gravistar? It would explain the steady expansion rate, along with the tendency to vacuum. The curvature would also make sense. It is also maybe possible that the big bang was the infinity flipping from negative to positive? I don't like the idea, but it's a thought

I’ve been thinking that black holes are just exotic stars (sort of) for years and years, but humans don’t like things that have opposite effects and we can’t wrap our heads around things like this easily.

So the pressure values falls along a vertical asymptote through ever increasing magnitude negatives to a point of infinity or POI, where infinity and negative infinity are one and the same. The pressure then falls through the POI and down through lower magnitude positives. As a mathematician, I played around with replacing the x and y axes of the Cartesian grid with real projective lines. This replaces the infinite 2D plane with a torus. The outermost ring is y = 0. The central interior ring is y = POI The front most vertical ring is x = 0 The back most vertical ring is x = POI The graph of y = 1/x around x = 0 shows the behavior described above perfectly. While I just thought that this would be fun to play around with, going through a POI and wrapping around bridging positives and negatives was never a feature I thought could be part anything that truly exist. But it would be fascinating to be proven wrong about that.

15:02 basically sounds like a load of hoopla then. They don't even know what to actually know by the sounds of it

Is a vacuum star Hoover or Electrolux?

black holes could be everywhere including where in this video, and be opposite of what we make of them. They could be dense enough that they "gravitate" to a larger dimension size than our own observation... like the view from inside an atom to the concept of a distant molecule. Attraction can be inside and out and beyond this even, getting larger and yet smaller infinitely. It boggles the mind to think bigger or smaller than we do right now, but it has to be possible, it's there even if it isn't. Gr8! Peace ☮💜

Hey Mr. Astrum, what would happen if a large asteroid hit the Moon? I was watching one of your videos on the Moon and all the pockmarks made me wonder what kind of chaos that would cause.

early Sunday morning here

My personal challengeable belief is that singularities only exist mathematically.

Since nobody actually studied a black hole, up close, any theory seems valid in this moment.

Is this the key to it all?

Here's something I've always figured to probably be way more plausible for black holes than most would reckon, which is... The fact that although they appear infinitely dense due to the fact that they are almost a true singularity, which would be infinitely dense and whatnot, They are not. In fact a rather interesting thing is... that black holes, if you could reach their surface safely without being ripped apart the moment you even got close to the event horizon in the slightest, would be immeasurable bright because of light's inability to escape. Which would also simultaneously make black holes the hottest objects in our universe because of the inability for light to radiate off like a star or stellar remnant. Furthermore, your retinas, would be fried on the spot the moment you even looked up out of the blackhole if they weren't fried the moment you saw the surface of the black hole. Furthermore, a theoretical star that has no real gravity that can be interacted with... although mathematically possible, I'd... reckon in terms of the real world, would be unlikely to ever see. Though on the other hand if we do encounter exotic stars. One such one that although would be more likely possible in an artificial format rather than natural... is a quantum energy star of sorts. A star whose existence is solely attached to quantum mechanics. And whose core would be a black hole potentially, that would also not only be fed by the star, but also feed the star too in the process. Relying on the potential unknowns of quantum mechanics to grow exponentially if not properly contained. Of course it'd be unlikely to see such a star, let alone one with a black hole at it's core in terms of natural ones.

If you crush neutrons into their subatomic particles (quarks) you end up with energy. If that energy had a negative charge at the core with a band further out where some neutrons might still hold their form or a combination of positively charged substances it sounds like a magnet. So what would cause the neutron (quark) star to have an opposite spin in different layers? the part I could see wrong in your video would be floating in such a star. The magnetic field would shred our atomic structure. Sorry, just thinking in place.

Interesting topic, but your charisma has all the captivating qualities of a house plant, which, I'm certain, would present it in more engaging manner, if given the opportunity. I could not watch it for more than 4 minutes without falling asleep

You seemed to define the first star you were talking about was our sun, but stated it would just take a few million years to use up all the Hydrogen but it will actually take about 5 Billion years, at which point it would start expanding as the balance of gravity vs outward pressure would cause the corona to expand to close to the obit size of Mars, so you need to either correct that or define its either another type of star or not our Sun at the very least, but it is rare for any star to just collapse into a Neutron star as it would still have a small nova as it blows off any lighter gas as it does its final period of rapid contraction, as it collapses into a neutron star or a dwarf star.

Dark energy - the invisible inflating unicorn.

This is the fundamental basis on which life exist

Okay this has really messed up my mind 😭

Okay, I've been handling the weird things in astronomy so far (I'm 77 yo), but here's my limit. You've finally gone "wonky" with "negative infinity".

Plot twist, The universe is contained inside of a gravistar

wow !