The Boundary Between Black Holes & Neutron Stars

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When we detected the very first gravitational wave, a new window was opened to the mysteries of the universe. We knew we’d see things previously thought impossible. And we just did - an object on the boundary between neutron stars and black holes, which promises to reveal the secrets of both.
Hosted by Matt O'Dowd
Written by Matt O'Dowd
Graphics by Leonardo Scholzer, Yago Ballarini, & Pedro Osinski
Directed by: Andrew Kornhaber
Camera Operator: Bahaar Gholipour
Executive Producers: Eric Brown & Andrew Kornhaber
Previous Episodes Referenced:
Ligo’s First Detection of Gravitational Waves: • LIGO's First Detection...
The Future of Gravitational Waves: • The Future of Gravitat...
How to build a black hole • How to Build a Black Hole
Strange Stars - • Strange Stars | Space ...
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[@rays5163]

8:47 I like how whoever made this animation thought it would be cool to have the pulsar hit me in the face instead of just spinning.

[@zanvure330]

Dude that is what a pulsar is, it gives radio pulses straight at us.

[@rubyred3580]

@@zanvure330 Obviously they know, they're just commenting on how the animation is uncomfortably bright

[@DrDeuteron]

@@rubyred3580 a guy named "ray" should be able to handle it.

[@FuSiionCraft]

@@zanvure330 no, thay just spin and emit energy at their poles Not necessarily ay us Wtf dude

[@DarthSagit]

@@FuSiionCraft We only see the pulsar pulsing because it’s directly pointed at the Earth

[@diegorodriguesdesouza7389]

"Billion-year-old secrets carried to us on ripples in spacetime" I need a tshirt with this.

[@braddixon3338]

you know, I think you have something there!

[@kkgt6591]

You can get it done from any N number of t shirt shops.

[@DrDeuteron]

but it violates relativity, as GW move on null geodesics, so the secret is 0 years old. Or a billion. Or 2 Billion. It's totally relative.

[@jannmutube]

...."The heavens declare the glory of God; and the firmament sheweth his handywork. 2 Day unto day uttereth speech, and night unto night sheweth knowledge". (Psalm 19:1-2)

[@PapaTanGh0stNI9htM4R3S0nMaInSt]

Relative breadcrumbs.

[@Krish-jm6ve]

If Matt says - "The calculations are horrendous". I just simply believe him 🤣🤣🤣

[@realzachfluke1]

Same lol. And the same goes for the first time I heard Matt say that General Relativity is _"you know...hard"_ hahahaha

[@jason4547]

This mind set is not uncommon amongst those like yourself, whom have simple / discernible minds.

[@realzachfluke1]

@Greg Jacqueslike unironically tho _sometimes_ lol

[@MrRenanwill]

That's because General Relativity requires the study of a discipline called Differential Geometry, a mathematical discipline, which most calculations are quite hard even for mathematicians. For physics, must be even harder, since it's usually not they specialization, at least not in a mathematical level as mathematicians have.

[@arthurmartin4616]

Agreed. It's just one of those things best left to professionals. :)

[@malectric]

It's great to have physicists prepared to share information and their ideas on KZbin like this. SO accessible to all. A big thanks.

[@Military_Archive]

Finally here is an episode I kind of understand

[@Yora21]

No Lorentz-Transformation required. :p

[@makismakiavelis5718]

I feel you bro

[@TheExoplanetsChannel]

Hehe

[@distitube]

True. I was waiting for the moment where I don't understand nothing more but that moment hasn't come :D

[@MannexX]

Haha I was thinking the same as the video progressed :-D

[@akashbhullar]

This video is one of those rare videos on this channel where your chances of understanding it are 25% instead of the usual 3-5%

[@ThatOneGuy-iv9sn]

Indeed

[@alchemist6819]

True at least for me I only understand a small part these videos still love watching them and hearing Matt.

[@carlosvigil1868]

I could understand it thanks to the pics and draws hehe

[@thomashan4963]

Couldn't agree more

[@InfamoussDBZ]

Personally I learn much much more at the Reel Truth Science Documentaries yt channel with Jim Al-Khaliki

[@sumdude132]

"the calculations are horrendous" I don't even want to imagine

[@ericvos620]

i once studied it a bit. The major culprit is just the simple sign change, which occur on short distances in the equations. It makes numerical approximations very very hard

[@fandomguy8025]

If the Nerds say it's horrendous, yeah.

[@sumdude132]

@@ericvos620 this is what I was looking for, thanks

[@sumdude132]

@@fandomguy8025 dislike

[@fandomguy8025]

@@sumdude132 What?

[@justincase9638]

Another fantastic episode. You make learning fun and I've been with you for so long that I now actually understand what you've been trying to tell me!

[@victorbruant389]

A Neutron Hole or a Black Star?

[@amnesia071]

Lady's and gentlemen. The real question is over here.

[@b.griffin317]

Yes

[@roner61]

It needs a name obviously... i like Black Star. :-)

[@sheeniebeanie2597]

Victor Bruant yes.

[@_Killkor]

Umm... Star hole.

[@Vearru]

“It would be very difficult to get out of bed on the surface of a neutron star” Ah I see so that’s why it’s so hard for me to get up in the morning. I’ve temporarily had me and my bed quantum tunnel to the surface of a neutron star.

[@recklessroges]

Them sneaky neutron stars, playing hide-n-seek and one is under the bed.

[@sparecreeper1580]

Aurelia Gray so apparently my bed is always on a neutron star?

[@martin32074]

Maybe its just earth gravitational pull is too much for you.That could be the best excuse for been late at work.

[@Vearru]

Peace in the kitchen Hmm I don’t know I seem to get up pretty well when I accidentally sleep through my alarm and I get a call from my work. Perhaps the quantum tunnelling is only as my alarm goes off because earth’s gravity seems to be pretty easy for me to overcome.

[@adamwishneusky]

I’ve been having trouble getting up too. I thought it was my mental state due to the world being in fire but maybe it’s the world secretly being a neutron star 🤔

[@bskibinski]

This is an episode I'm comfortable sharing with some people that want to know more about physics, but are afraid of the math, and all the theories connecting to it. One of the best "quick" summaries with detailed information covering almost all the basics and not dumbing it down too much... This is kurzgesagt worthy stuff! Do a collaboration somehow! And don't get me wrong! I love the other episodes more that go into the nitty gritty of it, but I'm guessing this was one of the hardest episodes to make? Great visuals also, not even a mention of schwarzschild radius to keep it clean and understandable! And above all that, this discovery is really really exciting! Keep it going guys! My favorite channel for more in depth information without overloading with math!

[@mandr3w350]

Love your videos, have been watching them for years, specially to fall asleep(the more difficult ones). Thanks to you I've learnt a lot

[@dalvishlok]

Matt's hosting and information is amazing! But can we appreciate and emphasize on the music and animation in the video! It's cosmic.

[@mohnishlandge]

Absolutely man 💙

[@feralcatgirl]

i also just love his voice

[@sunnysideup8980]

@authorization batman you have access to all this content for free and you're bent out of shape by an ad or two? grow a pair

[@amnesia071]

When the gravitational wave hits just right *_WIGGLE_*

[@mvmlego1212]

The Nolan Diagram is a better political chart, IMO.

[@ericsilver9401]

@@mvmlego1212 no

[@mvmlego1212]

@@ericsilver9401 -- Why not, if you don't mind my asking? I like the Nolan chart because I think it correctly assesses that authoritarianism isn't a distinct political ideology; instead, authoritarian policies manifest in control over the economy (left-wing politics) or public order (right-wing politics).

[@the1exnay]

mvmlego1212 It's the same diagram, just mirrored

[@skydude221]

Wow I bet you support Bernie Sanders... Me too

[@tsuki-no-akuma]

I friggin love your little smile every time you end a video with the 'spacetime' line.

[@robertnolanclark267]

Thank you for making the difficult and complicated so easy to understand...I really enjoyed this one...thank you for the fine explanations and illustrations...

[@phoexer]

5:28 Say it ain't so, I have enough trouble getting out of bed at 1g.

[@josephsalomone]

But your avatar is Saitama

[@recklessroges]

I'm certain that someone's been turning the planets gravity up during the past few months. /s

[@phoexer]

@@josephsalomone you forget, Saitama is the patron saint of lazy. He would rather destroy a clock, and the floor its on, than get up.

[@josephsalomone]

@@phoexer Yeah, but gravity has nothing to do with it. Gravity could be 0.01g or 1000000000g, he'd still have the same trouble getting out of bed.

[@bobinthewest8559]

@@recklessroges... Not just the past few months... It has been gradually increasing over each of my 54 years.

[@graphixkillzzz]

instead of saying "the straw that broke the camel's back" we should now be saying "the atom that collapsed the neutron star." who's with me?! come on! who's with me? ...anyone? 👀🥺

[@samueloctober4797]

I am !

[@seionne85]

Yess 😂😂😂

[@DNToquer]

There are dozens of us!

[@thoughtsofapeer]

Don't worry, I'm sure it will grow! xD

[@YoJoof]

no need to change if it means the same but on a different scale like changing “it’s taking years or ages” to “it’s taking millennia”

[@pimpompoom93726]

Fascinating. I never thought I would live to see the discovery of Gravity waves-not only have I seen that, but the incredible events they signal. Amazing.

[@alexandragrace8164]

After many years enjoying the show I have decided to become a Spacetime Patreon patron :) Go Matt go Simone go PBS!

[@tomareani512]

last time I was this early, the universe was still too hot for atoms to form...

[@fabriziodelcastillo189]

And the 4 fundamental forces of the universe were united

[@Attlanttizz]

Sup God :-)

[@ferdinandkraft857]

Yawn...

[@baldurk.1667]

There is the theory of a Blitzar: A Neutron Star massive enough to collapse to a Black Hole, but spinning too fast to do so. Has this been somehow ruled out?

[@elnure14]

Was thinking the same!

[@Yora21]

I believe every Type Ia supernova would be in such a state right before the neutron star collapses, at least for a small fraction of a second. (I was thinking a neutron star is the same thing as a white dwarf, which it really isn't. Silly me.)

[@eurasiandynasty9824]

It's just what I think that such fast spinning neutron star would leave significant trace in form of g-waves, and as such would be easy to recognise imho. So i supose that such setup has been ruled out.

[@markfreitas9202]

If it's part b of a binary Ab couldn't that be enough to rule it out?

[@Illure]

the neutron star would be inside the accretion disk. Could it have been increasing in size from just orbiting the black hole?

[@Bigandrewm]

Just a little thought experiment: as escape velocity increases with mass and becomes ridiculous in neutron stars, if light emitted by a neutron star is also red-shifted by the intense gravity well, and if the mass increases to such an extent that the red-shift is almost but not yet infinite (and therefore isn't truly a black hole) and the star doesn't collapse via overcoming neutron degeneracy pressure, the result might still look a lot like a black hole.

[@rogerjohnson2562]

light being red shifted by (travelling through) gravity instead of by traveling through an 'expanding universe'; I like it.

[@fdepontalba]

fascinating episode as usual, and love the "Firefly" T-shirt !

[@didgerich]

Love this show, so clear and informative

[@tristiancapozzi1194]

Could it be possible that a small 2.6 solar mass black hole could have been formed from two smaller neutron stars merging together sometime in the past? If so that would have required the original system to be a stable three star system, but assuming that is plausible, what other reasons could prevent that from being the case?

[@mercanerkan2891]

whenever I think of a idea like this which makes sense, I think that its probably not true because if it was scientist would have thougth of it

[@Jesin00]

@@mercanerkan2891 it's still worth asking why/how the idea was discarded, though.

[@w0ttheh3ll]

A a double merger like that is plausible, but unlikely. It does not require a stable three-star system. The problem is that for two compact objects to inspiral and merge within the lifetime of the universe, they have to start out in a stable orbit close together (the inspiral speeds up exponentially as the objects get closer and/or more massive). For this to happen twice in a single star system would be extraordinary. The paper (open access, DOI 10.3847/2041-8213/ab960f ) contains a couple of paragraphs discussing several scenarios where the low-mass object could itself be the remnant of a merger.

[@benjaminbeard3736]

​@@mercanerkan2891 I don't think the product of that merger would be massive enough to create a black hole. So much material is ejected from the system in a collision like that, it would likely not leave enough behind to collapse into a black hole.

[@MichaelClark-uw7ex]

@@benjaminbeard3736 I would think that depends on the masses of the merging neutron stars. If they were both near the threshold of becomeing a black hole, it seems quite possible the result would be a black hole even after the kilonova.

[@phutureproof]

Ill be honest here, I love the content this channel puts out, I like to think its good for my brain to try to comprehend these ideas and things we've discovered. I don't actually understand much, especially the math, but, it is some of the most interesting stuff going on! (IMO) Thanks for keeping up with the content even in the current climate.

[@sander_bouwhuis]

Wow, what a fantastic video! I am certainly going to be watching more 'episodes'! Thank you very much!

[@backpacker3421]

Wow, that Serenity teeshirt has seen some serious wear and tear! Very nice choice for this video as well with the concentric circles being suggestive of the phantom event horizon... Well done, sir.

[@pioneer_1148]

Shiny

[@JohnDlugosz]

Making a teensy black hole: Not directly from an exploding star. Start with a neutron star and add matter through accretion or merger with (say) brown dwarfs.

[@mikeciul8599]

Could it be a neutron star orbiting a black hole that has a lot of matter in its accretion disk? That seems like a logical place to find a lot of matter to add to a neutron star.

[@TheExoplanetsChannel]

:O

[@danilooliveira6580]

@@mikeciul8599 if that was the case we would see matter being ejected... probably

[@benjaminshropshire2900]

That was what I was thinking. But it still moots the question of how you get a neutron star to an all you can eat buffet for it to convert to a black hole, get that in orbit around another back hole, have little enough left over to not show up in EM and have them merge with all that in the time allowed since the big bang. And keep in mind, we have only been seeing these things for ~5 years, which suggests that anything we have seen already is probably reasonably common. All that said, I'd be interested in the real reason why that possibility isn't the leading proposed explanation.

[@ikoukas]

I thought of that too but for some reason the "standard candles" are explosions that happen because a neutron star slowly gobbles matter from an orbiting star. For some reason they explode and don't turn into black holes, just shed the extra mass (I think)

[@georgehugh3455]

I'm thankful science is working very hard to provide Matt with his weekly content

[@elrondhubbard7059]

_"Jiminy, you're _*_LATE_*_ "_ _"I'm sorry, I moved to this new place that's on the surface of a neutron star and I'm struggling to get up in the morning"_

[@martingraham3990]

Haha ha Elrond Hubbard is the greatest handle! Nice mug too.

[@DanjasLP]

Sometimes I wonder if some alien species would actually be amazed by our theoretical knowledge of the universe if they are a more practical species.

[@rogerjohnson2562]

more likely cause humor, not amazement

[@judethaddeus9856]

Of course they would, just because a species if more advanced does not mean they have no interest in a lower-life form.. humans are highly intelligent yet we still have ppl who study insects for a living…

[@76rjackson]

I wonder about that, too. Only I tend to think that they would consider we are still woefully primitive in our understanding of the universe. Think of what a modern astrophysicist could teach Galileo. He had just started to unravel the false beliefs the church and Aristotle had had us laboring under for millennia. We were stuck in a blind alley contriving crystal spheres and epicycles to explain what we saw in the sky every night. Is dark matter our version of epicycles? We might labor with that theory for a century and the deeper we get down the rabbit hole, the harder it gets to back out.

[@DanjasLP]

@@76rjackson There is so much chaos in science right now. Dark matter, dark energy, is the universe really expanding faster than light, etc.. And it feels like every day we make a new discovery that throws yet another wrench into the pile. Not even considering the insanity that is quantum physics xD

[@cdurkinz]

@@DanjasLP More like _especially_ considering the insanity that is quantum physics xD

[@caruzo9631]

“fits inside a SMALL CITY!” *shows NYC

[@Yora21]

New York is a very dense city. And as you can see, the neutron star is much smaller than New York.

[@WeatherManToBe]

NYC is tiny.

[@caruzo9631]

Area of NYC: 740 square-km Area of my City: 190 square-km THAT‘S a „small city“ NYC is a Metropolis

[@lohphat]

City boundaries are usually much smaller than their larger metropolitan area. LA and SF are tiny postage stamps compared with their surrounding metro areas.

[@josephsalomone]

@@Yora21 Ah, so NYC is actually a black hole. Got it!

[@danielbaldoni6725]

The phantom event horizon is a great way to better understand black holes. Great video!

[@someguy3766]

Just when we think we know everything, we find there's still a LOT more to learn. Cool stuff.

[@Arcterion]

14:40 -- ... Man, I bet that would've been a sight to behold.

[@Silverwind87]

Neutron Star: The pressure here is immense. Black Hole: All the cool kids are black holes. Neutron Star: ALL the cool kids, you say?

[@Dmullins81]

I'm sorry... This looks like such a witty little joke; and yet here I have been feeling like imbecile for the last 1/2 hour for not "getting it"...- 🙄

[@healtheworld2059]

Epic! Exactly what I imagined or hoped to hear about couple of years ago... Grandiose!!

[@t1world767]

Thankyou sir. For your infomations. So.. I really impresed by this video. So good 👍

[@baronvonteuchter1412]

I watch loads of physics channels and this is the first time I’ve ever understood the difference between a black hole and a neutron star. Thanks! 😂

[@brendanBJJ]

I’ve been watching these videos since I was 13 and I always wanted to do something with my passion for physics as a kid but here I am, 18 years old about to major in finance and minor in computer science...wish I would’ve taken another route but I was a kid who never did my homework so there’s no options for me in that field. Oh well. Thanks for everything you’ve taught us!

[@BrillouinBoi]

It’s never too late to pursue physics! I know plenty of people in my PhD program who pursued other careers for a while and then crossed over.

[@wayneBranson]

Excellent presentation!! Thank you!!

[@vkm9156]

This is the video I was waiting for a long time

[@captainpuffinpuffinson4769]

That is one shiny shirt, one of the best in the Verse I would bet It would be a shame if a collision of two black holes would *stretch* it

[@TheExoplanetsChannel]

Oh

[@devilslamp7306]

I bet nobody's going to take the sky from _him._

[@sujimtangerines]

Came looking though the comments for someone to point out his shirt!!

[@electricatom2]

it also depends on how fast neutron star spins, if it spins really fast then it can be a little more massive because kinetic energy would keep it from becoming black hole, if u stop it from spinning it would collapse

[@idcgaming518]

Nice to see that we have a lot of new information on both neutron stars and black holes. That should help us in the future.

[@tmfd9476]

The thing that I find amazing is the guy that makes the incredibly fine instruments to detect these variables.

[@Crackhonos]

Fun theory: strange matter forms only in heaviest neutron stars. Black holes are protection mechanism so that strange matter is unable to escape and covert all barionic matter in the universe

[@FattyGetsFitty]

@Karen Shahgeldyan That would mean there would be a god, which I reject wholeheartedly.

[@ozzya9977]

@@FattyGetsFitty or the universe couldn't exist without such a system, so by chance this is the way this universe has to be by the pure fact that it exists.

[@FattyGetsFitty]

@@ozzya9977 that’s the anthropomorphic principle.

[@talathion369]

osama ahmad and that brings us back to the strong anthropic principle

[@SpookyRipples9]

Anyway all the matter is going to fall inside black holes at the end of time.

[@jimmorris5328]

How does the shape of the event horizons of two black holes evolve during a merger? Is there a point when spheres are no longer round or assume an hourglass shape at the moment they "touch"?

[@alterego3734]

Yes

[@mynameismatt2010]

No, the matter inside the black hole exists in a singularity which is unchanged by the universe outside the event horizon. The event horizon itself is just the point around the singularity where the escape velocity is equal to the speed of light, so it isn’t effected by the other black hole either. Once the two event horizons touch there’s a brief moment of a figure 8 orientation as the two singularities merge virtually instantly.

[@LecherousLizard]

@@mynameismatt2010 There is no need for singularity (which itself is a point, i.e. infinitely small), if a sphere is enough to do the trick.

[@mynameismatt2010]

@@LecherousLizard Not really sure what you mean. The sphere is the event horizon, which derives its radius by the mass of the black hole it forms around and won't be changed by proximity to another black hole, not the black hole itself, which is mathematically considered to be a point.

[@LecherousLizard]

@@mynameismatt2010 The event horizon is a sphere inside of which the gravity is too strong for the light to "escape". The "black hole" itself would most likely also be a sphere, because the mathematical model does not account for such an extreme entity. Remember, all the equations we have are APPROXIMATIONS. Trying to explain black holes using Einstein's theory of general relativity is like trying to explain relativity with Newton's law of universal gravity. Or in other words, black holes are simply outside the margin of error for Einstein's theory, which is why you get results like infinity or zero. First of all what is being ignored are properties of light. Speed of light is constant for a given medium (i.e. in water light propagates ~30% slower), so you cannot "trap" light with gravity (this is also why the entire "acceleration of universe" theory is fundamentally flawed). What happens then? Well, light has two properties, speed and wavelength. Since speed is dependant entirely on the medium, then gravity can only affect wavelength. How does it happen? As light moves away from a source of gravity it has "work", i.e. lose energy. That work decreases wavelength until it reaches levels that are either indistinguishable from background noise or too minute to measure in the first place, thus giving an illusion of being "unable to escape". Same thing happens with the cosmological horizon. As light travels toward us, it has to work against sources of gravity that pull it back, thus creating redshift, which mistakenly is used as a proof for the expansion of the universe theory.

[@DouchMonkey431]

Thats was a really cool visualization! Especially when you see the smaller body. Let's just say I think it was kind of mind bending.

[@NeorecnamorceN]

Keep on Rollin!

[@xytras6451]

Is that a Firefly shirt? Nice, nice.

[@pioneer_1148]

Shiny

[@36gih]

I admire how you kept on going even during this pandemic. Love this channel

[@HannesSwanepoel]

That was the most amazing simulation of a black hole merger ever!

[@katczar]

You rule man! Thank you so much!

[@MoritzvonSchweinitz]

Neutron Stars are awesome! Obligatory reminder that relatively mundane things like Silver or Gold (and most of the elements > Ru (44) ) were made in Neutron Star collisions! I think it's incredible that we can readily touch stuff that was part of such a weird thing like a Neutron Star.

[@JROD082384]

They are also made with just normal supernova events…

[@1adamgriffin1]

It seems the zone of collapsed stars between 2.1 and 5 solar masses is a bit of a grey area. I'm going to call them 'grey holes''

[@PrimatoFortunato]

Weasel holes

[@AnEvolvingApe]

@@PrimatoFortunato call them "brown holes" and it'll catch on quicker.

[@bizzaremonkey756]

@@AnEvolvingApe hehe brown hole like a butthole?

[@jasonwebb1882]

LIGO is about 45 minutes away from where I live and it was a really great treat to visit with my kids. If you ever get a chance, go and take a look. When we went it was open to the public on the first or 2nd Saturday of the month. Pay attention to the speed limit that are posted. I was very impressed on everything that they had out for kids to learn stuff. Anyway take it easy.

[@jogolock1190]

Fantastic stuff, love watching this, will never understand it, but then again does it matter.

[@Vasharan]

Object between neutron star and black hole: _Exists_ . Protomolecule Makers: Hey, it's free real estate.

[@irfansyahril8511]

Maneo: splat

[@simbaonsteroids8836]

Hey let’s do something to increase the number of virtual particles popping in and out it existence, no way that could go wrong.

[@mrbuttocks6772]

@@simbaonsteroids8836 Big Bang 2: ELECTRIC BOOGALOO!

[@embyrr922]

“There’s a weirdly too small black hole.” *me chanting* direct collapse direct collapse direct collapse direct collapse

[@jaredgarbo3679]

What's direct collapse?

[@RsbidNoodle]

@@jaredgarbo3679 the opposite of an indirect collapse!

[@albertjackinson]

All of this is very, very exciting.

[@atmikes1]

always amazing content ! thanks!

[@danieljrea]

4:38 how could a neutron star get ripped apart by a black hole without a electromagnetic signal? Something that dense I assumed must become extremely unstable in such an event

[@fromlostdays863]

Watching this video now, same question. Did you ever figure it out?

[@soundsoflife9549]

the pictorials are not representative.

[@rogerjohnson2562]

em doesnt escape a black hole, something that dense would quickly pass through the event horizon

[@Nomadmandude]

Because Neutron Stars and Black holes are the most stable objects in the universe. Absolutely not easily disturbed. They orbit the gravity well and then combine their gravity wells. A black hole and a neutron star is still made out of mass.

[@logandarklighter]

Love the shirt. You can’t stop the signal. ;D

[@sujimtangerines]

Only 2 comments about his shirt so far... Not enough Firefly fans!!!

[@wantflappywing1355]

Fellow science nerds, I think this video is amazing greatly appreciated! Keep up the great work and get PBS space time to 5mil!

[@kumarchaitanya3171]

You guys are the best. You do some very good work.

[@c90sf]

Matt, apart from the great content as always, tell us whose visual art work (painting) is in the background. This gold foiled one...

[@popejbryant]

I believe he already answered previously that it was his sister's work

[@WylliamJudd]

It's his wife's!

[@goldenwarrior1186]

^

[@hunterwilson817]

It's his girlfriend's. Or partner if he uses this term.

[@bartekraglewski2697]

It's his girfriend's ;) There was a Q&A episode on that ;)

[@skyfever111]

me: opens a new window to the universe me: closes window

[@themysteriousuniverse2364]

kzbin.info/door/JQ__TswfwtS0khhCPO7TjQ

[@mikeyoung9810]

I just realized today that I hadn't seen a new video in a long time. It took me awhile to remember the name of the channel (by looking through 300 subs) to find it. Although I am subscribed I haven't seen it pop up in recent memory. Glad I refound it.

[@benmcreynolds8581]

So facinating!

[@FogelTheVogel]

So with the gap between biggest Neutron Star and smallest Black Hole, what happens if you add just less than 1 solar mass to an upper limit Neutron Star? Wouldn't that make it a Black Hole under this limit? Neutrons Stars can turn into Black Holes by gaining more mass, so shouldn't this regularly form a Black Hole smaller than 5 solar masses? They don't just magically gain enough mass to jump the gap do they?

[@Pouly__]

I guess when neutron stars are born some mass gets ejected as said in the video. So an actual neutron star would weigh max 2 .6 solar mass. But the star that made it may be3 solar mass. Disclaimer i am not a physicist

[@w0ttheh3ll]

Yes, of course this works in principle. The point is that astronomers don't expect actual neutron stars to gain that much mass.

[@BunnyOfThunder]

It would be great to see an episode about what exactly happens when the outer layers of the star "bounce" off the core and create a supernova. Is it purely the kinetic energy that causes such a splash? Do the leading waves of the outer star undergo sudden and explosive additional fusion when they land? Just curious what this process is.

[@johnclifford4185]

kzbin.info/www/bejne/j6WQhHWKbNOBnLc&ab_channel=ButWhy%3F This vid explains it pretty well.

[@AgreeableCorgi]

As I understand, when the outer layers of the star bounce to the core it fuses elements beyond iron.

[@frankcrawford416]

This was fascinating.

[@bobinthewest8559]

It always amazes me, as we go through these transitions from being totally unable to detect some thing or another... to "seeing them every week". The advancements of the past decade alone... of better telescopes, of new types of telescopes... of devising newer and better methods to obtain ever more accurate measurements of the mass, heat, light and molecular composition of objects over vast distances, etc... continually improves our understanding of those few things that we know... while simultaneously increases our awareness of how much we have yet to learn. These are exciting times. I may "check out" before our most incredible advances are realized... but, for anyone being born today... I believe their lifetime will witness some of the most dramatic changes to humanity, the world and the universe.

[@thebenmiller]

Something I’ve been curious about... would there ever be a gravitational wave strong enough for humans to detect without instruments? Could there be one strong enough that it might be dangerous to us? How would we experience a super strong gravitational wave like that and how strong can gravitational waves practically be?

[@fortuna19]

When you consider the fact that the 2015 G wave contained more power than all the stars in the *observable universe* combined, it seems far fetched that we could harness that much power!

[@garethdean6382]

The question would be 'how?' Nothing prevents such waves from existing, but to have that much power reach Earth would require a massive merger quite close to us, in the same way that a supernova needs to be quite close to be seen with the naked eye. If there was a wave powerful enough to be dangerous, whatever made it would be far, FAR more dangerous to us Such a wave disrupts smaller and smaller things as it grows in power. Initially it would just warm the Earth a little, like tidal forces do. With increasing power this would tend to cause Earthquakes and eruptions. With a staggering power things like roads and buildings would be affected. But to make that we'd probably need two black holes inside our solar system making that the least of our problems.

[@marcpeterson1092]

"Sadly destroying the solar system in the process. OK" Moving on. We regret any inconvenience.

[@cherrydragon3120]

Galactic Post office: we're sorry for the inconvenience of destroying your local solar system and thereby all 7,8 Billion organisms you called fellow humans. Also we compensate the loss of any of these so called friends and family. Please leave your Galactic adress at Astroid-4413269 in the Jupiter astroid belt and we'll contact you in a couple centuries about a decent compensation. Our humble apologies for you inconvenience.

[@tehlaser]

Space Time: Greatest Hits

[@Shotgunz999]

honestly, these animations are unbelievable, so fkin good i swear to god.

[@ongbonga9025]

From Ozzy Man to PBS Spacetime. What a great evening this is turning out to be.

[@ongbonga9025]

@Cool Breeze Always Ozzy first.

[@jayknight139]

What's Ozzy man?

[@ongbonga9025]

@@jayknight139 The greatest channel on youtube.

[@b.griffin317]

In terms of angle how accurate is LIGO and its sister observatories? Within 1 square degree, 1 square arc minute etc.?

[@moredetonation3755]

3

[@darthtace]

It to be appears 60 square degrees, source: www.ligo.caltech.edu/news/ligo20170927

[@b.griffin317]

Gee, kinda imprecise. 😬

[@michaelsommers2356]

@@b.griffin317 What do you expect? The detectors are just a few million meters apart, while the event occurred over a billion light years away.

[@dickJohnsonpeter]

They are interesting in concept but worthless for their intended purposes.

[@Psalm1101]

Finally a science video good stuff im listening lov neutron stars

[@abysmalasabysmal]

I became a Patron because I love this Channel. It's the best on KZbin

[@royanders945]

In the 'creating black holes' episode you said a neutron star becomes a black hole around 3 solar masses. But here you said black holes can't be below 5 solar masses. So what exactly happens to the mass of a ~2.6 solar mass neutron star if you keep feeding it matter? Will it create a 3 solar mass black hole or a 3 solar mass neutron star?

[@garethdean6382]

There's a slight difference. If you take an existing neutron star and ass mass to it, at some point it will calmly collapse into a black hole. We don't know exactly what this limit is but the the 'Tolman-Oppenheimer-Volkoff limit' is generally held to be around 2.1 solar masses. But a supernova is not calm, it's a collapsing star. A core that is too heavy wil just be crushed by the star's outer layers and turn into a black hole, gaining more mass as it swallows the star. Our models indicate the lightest holes that should form this way are 5 solar masses.

[@royanders945]

@@garethdean6382 thanks, although that doesn't really answer my question. Your answer is what I was questioning. If you do keep adding mass to a Neutron star, over time it would become a black hole. If it becomes a black hole over 2.1 solar masses then a black hole can be less than 5 solar masses. If not, what does a Neutron star become if you keep adding mass to it so that it's mass reaches between 2.1 and 5 solar masses? If it does become a black hole then a 2.6 solar mass black hole shouldn't be very suprising.

[@garethdean6382]

Sorry, I think my answer got cut off. You're correct that a neutron star gaining mass should form a 'light' black hole. Currently the only issue we have is if such a process is common and can stop with a light enough hole. For example, we see lots of black holes feeding off of companion stars. These may have once been neutron stars, but feeding on a star is likely to provide many sun's worth of mass rather than cutting out below the 5-sun limit. We haven't seen any light holes feeding, which would be evidence for neutron stars being able to gain mass this way without gaining too much to be indistinguishable from the regular kind of hole.

[@twstf8905]

The so-called _"Phantom Event Horizon, "_ that he's talking about is NOT the same thing as what's known in Astronomy as; _"Chandrasekhar's Limit."_ (NASA's premier X-Ray Observatory was named the; _"Chandra X-ray Observatory,"_ in honor of the late Indian-American Nobel laureate, Subrahmanyan Chandrasekhar.) The; _(Chandrasekhar Limit,)_ is; _(now accepted to be,)_ approximately 1.4 times the mass of the Sun; _"Any White Dwarf with less than this mass will stay a White Dwarf forever, while a Star that exceeds this mass is destined to end its life in that most violent of explosions: a Supernova."_ _(This is dealing with a specific kind of Astronomical object, in particular.)_ _(I realize nobody asked lol I'm just sayin', if anybody tries equating the two, they're not talking about the same phenomena. 😇✌)_

[@danieljackson4511]

I always learn something new on a video of PBS Space Time. Thats worth a big fat Like!

[@janfoustka3780]

I LOVE his Firefly T-shirt!!! Great!!!

[@spheresong]

My immediate thoughts for an undersized black hole: primordial black holes should be able to exist on size scales even smaller than the sun. A very old black hole might shed enough mass through radiation to drop below our expected mass. Very very small black holes are supposed to arise through quantum interactions all the time. Normally they wink out more or less immediately because their mass is so small but that doesn't say it's impossible for them to find enough mass in their local neighbourhood to cross the boundary between exponential decay and exponential growth.

[@Mp57navy]

The Firefly T-shirt give credibility.

[@antimattv]

I really like this guy. Definitely thumbs up.

[@channel-ug9gt]

This guy is getting better and better. Nice.

[@FattyGetsFitty]

Has to be a neutron star spinning at relativistic speeds lmao. Only reason it ain’t a black hole is due to the angular momentum.

[@comradenb1261]

Glad you know more than the scientists studying it that show a low level of confidence in any particular solution at the moment

[@josephcarcasole6039]

I was thinking the same thing; a neutron star with very high spin rate.

[@TheJMBon]

@@josephcarcasole6039 Conservation of angular momentum would indicate that a black hole spins much faster that a neutron star ever could.

[@VytenisR1]

they need to build a third one and triangulate the location lol

[@Yora21]

They have a third one. It's in Italy.

[@michaelsommers2356]

The Earth is small, the event was a long, long ways away, and there is always measurement error, so there is a limit to how precisely the event can be located.

[@KuK137]

@@michaelsommers2356 Put one on the Moon. Or maybe one of the Earth-Sun Lagrange points. There, done.

[@bjarnivalur6330]

@@KuK137 I mean, there are plans to put a massive one into orbit.

[@chadbusch8541]

Zoom in! Enhance!!!

[@sanjuansteve]

I agree that black holes are spheres of mass more dense than neutron stars and it always surprises me how many people have very different ideas of what they are. Great video.

[@osoraun9362]

Is bend 8 years for searching this question so damn long of any other website can not answer and finally I found this video from three days!

[@kaziaftab9797]

Let's assume we take a Neutron Star, isolate it from any external interference (any matter falling into it) for an 'x' duration of time. Now my question is, will the Neutron star stay the same over that 'x' duration or will it decay over time like a white dwarf or will it slowly but surely turn into a black hole eventually in the end. Note: 'x' here is just a variable used to describe the unknown amount of time (unknown to me at least) 😅. (asking because google breaks down when I ask it such question's 😅🤣.)

[@rogerjohnson2562]

it cools off

[@DharmaDerelict]

I’ve watched this a couple of times and I still don’t see why the object couldn’t have just been a neutron star that started out on the bigger side (like say 2 solar masses) then just picked up some mass as it travels through space (say the .6 solar masses) until it became a small black hole. 🤷‍♂️

[@EconAtheist]

I can't find this channel's relevant episode OTTOMH, but IIRC the explanation has to do with quantum effects and how formation of supermassive objects is quite different if slowly adding on mass over a period of time vs. collisions between massive objects. /stuff like the nuclear force and the pauli exclusion principle make for counter-intuitive occurrences on the macro level

[@Dmullins81]

Yeah... I was gonna say something along those lines. But what makes sense to me is that in the actual explosion and collapse of the "giant" star, the tremendous force induced by it's "super duper weight" of the whole star is what "punches a hole" in spacetime itself, thus, creating the black hole... (Hope that makes some sense..?!?) ~~ ¯\_(ツ)_/¯

[@xxguitarman23xx]

Allo' Matt, watch your show daily and learning so much. For a new episode, I would like to learn about star classification and if there is any limit to black hole size vs age and my very favourite MAGNETAR cool science there...

[@yolanankaine6063]

This channel always reminds of why I love physics.