Black Holes: Crash Course Astronomy #33

[@michaelconstantind.l.mendo5485]

"The Universe is under no obligation to obey our preconceptions. " That's beautiful and terrifying at the same time.

[@Elrond_Hubbard_1]

I've got it. The only way to survive falling into a black hole is to be _made_ out of spaghetti, because if you already are spaghetti, how can you be spaghetified?

[@abdullahmohamed6276]

you will be streched more and more dude

[@MrInitialMan]

"The core of the star is about to go bye-bye." My FAVOURITE line in this series.

[@sohinidutta97]

MrInitialMan MINE TOO 😂😂😂😂

[@sid670]

If I had to fall in a black hole, I'd do it twice. Once looking directly at the black hole, and once looking out into space.

[@theallmemeingeye5927]

Looking into the black hole, wouldn't you see nothing? Because no light is escaping. So it would only be worth doing it once looking out.

[@sid670]

Matthew Spurrier In theory, if you (somehow) make it past event horizon, you would be able to see the beginning of time, due to the stretching of the space-time continuum. Looking out, you would see the end of the Universe, and looking in, you would see the beginning.

[@satanicmailbox]

+Sid Or you can just blow my mind

[@DodgimusPrime]

"As you hit the event horizon, all of time would pass." Me: "All of...?" "ALL OF IT."

[@TheFireflyGrave]

Black holes, The Event Horizon, and Spaghettification. Astronomers really know how to name stuff.

[@truboo4268]

+TheFireflyGrave They're much better at naming stuff than histories. Then again... Brown dwarfs...

[@josephfox9221]

+Bryan Cotto I dont know. economist have some neat names. the winter of discontent?

[@GeneralMonday]

+TheFireflyGrave We have observed these dark spots on the sun! Quickly, we need a name for them! ...Sun spots...?

[@flensdude]

+TheFireflyGrave Oh, Be A Fine Girl, Kiss Me.

[@dhartmahmed50]

+Bryan Cotto. Way to bring back old vids. I'm not kidding, that reminded me crazily

[@Filippirgos]

Today the history was made, the first picture of a black hole ever has been captured !

[@screamingtrees9619]

Yeehaw

[@callahans44]

It's not a picture of the black hole which is invisible. It's the silhouette.

[@Gilder-von-Schattenkreuz]

The bigger thing I wonder. Is how much Mass it Requires for a Black Hole to Start Fusing Iron and Basicly Explode. Its also somehow Strange to Assume Time Stops. Because most of the Gravitational Effect of Time does not really require an Explanation that would assume Time Stops. What Stops is the Progress of Energy. A Black Hole so Massive it can Curve Light. Will have a Similar Effect on all Energy. Meaning that any Energy Affected by it will be Pulled towards the Black Hole and Potentially Slowed down by the Pull of that Black Hole. But this does not Change my Concept of Time. Because Time is still Time. Time is from the get go a Man Made Scale and not something the Universe Cares about. And the Fact that we cannot Build a Clock that would be able to keep moving at an Undaunted Speed inside a Gravitational Pull like that is not Surprising to me.

[@brokenSnake]

It's not a picture of the black hole. That's a picture you can never see. It's a picture of the gases around a black hole before the event horizon

[@familydiaz6293]

vadermask//mass retaliation the hell, why you here then?

[@WhosFaulty]

new uploads from this series is my favourite time of the week

[@willpunch4food]

+WhosFaulty seriously. He's one of my favorite people to listen to explain things. I already know a lot of what he talks about (though by no means all of it), but I still look forward to the videos.

[@Jagdpilot]

+WhosFaulty And it's Friday night for me no less. That's like, favourite time of the week squared!

[@sabbyreloaded]

I felt so sad yesterday when there was no release. today was worth the wait. this is by far my most favorite channel on youtube

[@joshuahellauer2400]

Ok, the gig's up. We know you're Vsauce's brother.

[@turtleman583]

Joshua Hellauer lol

[@CaJoel]

They even have the same beards

[@huemanyeet5608]

Lol they r so similar

[@CenturionDobrius]

@@huemanyeet5608 and they are both infinitely annoying with those exaggerated facial gestures..

[@amvjaeger8967]

ikr

[@dorkmax7073]

Only 4 years after this video was released, a team was able to composite an image of Messier 87 and it's supermassive black hole. We are an incredible species

[@chibinyu1548]

"The universe is under no obligation to obey our preconceptions.." The best quote ever!

[@Connarthian]

Actually, I think that falling into a black hole is somewhat a romantic idea now. Falling in, I would see everything happen. All of the future. The price is life. That's frickin' deep man.

[@brysontheghostgaming9218]

Connor Peterson or you'd be blinded and ripped to bloody shreds.

[@callmeastaire5700]

If I could choose how to die, that'd be it.

[@thetimelords911]

+BrysontheGhost Gaming Well remember. If its a supermassive Blackhole, you would be fried first long before being ripped apart

[@jovetj]

What they never tell you is you'd be dead just from the gravity before you even got very close to a star or neutron star or black hole. Your body is just too fragile for such an environment.

[@sonicspeedctr]

With such gravity pulling on you, do you think you could even turn your head to see what is beside you? You wouldn't see all of time, just what you are allowed to see in front of you before you land or get fried.

[@kem8609]

I'm not even watching this for a class I just love astronomy and our school in Ohio doesn't provide the course :(

[@amandahathaway1136]

Same but I'm in Indiana and I am in elementary school.

[@kem8609]

+Lex Xander Oh what grade? 5th? If so that's really cool that your looking into astronomy at such a young age. Keep with it and study hard in school!

[@terry2788]

I live in Asia and they do cover a little bit. The material in this video is way harder than in my books though 😅 (Well maybe it depends on what grade your in)

[@lucariomaster2104]

Me too

[@sunnyexe2998]

I started astronomy when I was 3 and now I’m 8

[@ffggddss]

Phil: Thanks for the incredible ride! Just two things I might (or might not) add: 1. Tidal "spaghettification" is just as much about transverse compression as it is about longitudinal stretching. 2. An alternative, and perhaps even neater way to explain the inability of anything escaping from inside the event horizon, is that while outside it, the radial direction is spatial, inside it, the radial direction is time! And forward in time points toward the central singularity. So escaping from inside, is exactly the same as traveling backward in time!

[@Aziz-ev1ez]

Black holes are still brighter than my future

[@rexevan6714]

No.

[@irotimmex5508]

Poopflinger617 - 🤣🤣

[@cthedosboss5113]

thats because they shine in other ways ;)

[@blackhoundSSC]

Loooooool emo memes. Cheer up dude!

[@settratheimperishable4093]

@a ramdom astronomy star aww this is so wholesome it needs mire likes

[@akramzakriti9909]

finally black holes

[@braindeadbogan9272]

My thoughts exactly!

[@thefourshowflip]

I know right!!

[@nedocromil]

Please turn 2:34 into a poster. Thanks.

[@jaypatel5985]

Yesssss

[@BudgetBugout]

lol!

[@javiermatias-cabrera5267]

+nedocromil Shut up and take my money

[@thetradefloor]

+nedocromil justblackholethings

[@nedocromil]

Vor Tex Nice!

[@TheKingNappy]

black holes be scary bruh

[@emanuelrodriguez5244]

Throw Jay in the black hole

[@shadowhex9666]

+TheKingNappy I did not expect to find you in the comment section when I watched this. Though, to be fair, I don't really expect to find anyone I know in any comment section, so there's that

[@astrogecko1650]

Never knew you liked this stuff too Nappy!

[@hynjus001]

+TheKingNappy Once you go black, you never go back.

[@SharkClaw]

+TheKingNappy BOO!

[@luludrinkerofcoffee4035]

"What ever happens in a black hole, stays in a black hole" So what you're saying is that at a black hole's core, there's a cosmic Elvis impersonator ready to officiate your shotgun wedding in a drive-thru chapel. Gotcha, I'm sooooo going to ACE any astronomy exam.

[@bossfeild3523]

Irritable Jon Syndrome plus the phenomenon is already called “spaghettifiction” and scientists actually have a sense of humor

[@TheHelghast1138]

@Jon Dillon r/wooosh Switch to decaf and get some sunlight dude

[@TheHelghast1138]

Ha! That's awesome.

[@navagharkiran5769]

i wonder, where light is form of energy then where this energy goes

[@CrimsonDragon15]

There is absolutely nothing that I love more about Astronomy than learning about Black Holes. My favorite subject. By far the most complex and fascinating thing about the universe.

[@cholten99]

No love for PBS Space Time? Would have been the absolute ideal time to point people over there :-)

[@MD-pg1fh]

+David Durant You can do it now. Which you just did. It's an amazing channel. It takes you, the viewer, seriously, and trusts you even with complex matter. It takes some serious head-work to grasp it, but it's so worth it.

[@sd4dfg2]

I recommend that channel too, but it's not nearly as easy to take in. Well worth it though - I thought I knew black holes until their video showed me how wrong I was.

[@crashcourse]

+David Durant A bit complicated to do in the context of the episode, but we absolutely have tons of love for Space Time! Highly recommend it! :) kzbin.info -Nicole

[@grmasdfII]

+CrashCourse It may have been worth mentioning that Spaghettification is only one of several mutually exclusive theories.

[@jrrtt25]

+David Durant you deserve a round of applause. took the words right out of my mouth!

[@tarvingill1777]

I've watched this episode and the episode about the Sun about 50 times ... please never end this series .. and make sure Phil does all the shows.. he is incredible ☺ thanks

[@mercybellafiore3677]

"All of time would pass. ALL OF IT."

[@calinculianu]

+Roy Bellafire If that's true -- how the hell doesn't the black hole evaporate before you get there? Black holes evaporate in finite time due to Hawking Radiation. What gives?

[@bigoljoe1829]

+Calin Culianu He also said you'd be "fried" (I assume me mean burned up) by the infinitely blue shifting light. I see so many comments that seemed to have glossed over that bit. XD

[@tiffles3890]

+Roy Bellafire Letss assume for a moment tat the person is capable of surviving those conditions. Does that mean the person would have experienced all of time except because of hawking radiation, he does so only till the point the black hole itself is extinguished. And if the person can remain wholly intact through all of it, then basically what he has done is time travel? Because his own state is stuck in what he entered the black hole with, and yet time in the rest of universe has passed faster. You were all the while disconnected out of "universe time", watching it pass by in fast forward (or perhaps it was fast forward till you hit the event horizon and then it happened within a moment?). And then when the black hole goes poof, you are plugged right back into it. Conversely if someone managed to create a space with absolutely zero gravitational effect, then for a person in that space, time would speed up. The person would spend time till say a certain point in HIS future and yet when he is plugged back into the universe time (gravitation restored to normal), the universe is practically stuck in the same point of time which has now become a part of his past (but still the present for the universe). So in this case, he has effectively travelled back to the past (his past) by first travelling to the future and then rejoining a region of space stuck at the same past point of time. How is that for a mindfuck?

[@CollinBuckman]

+Roy Bellafire I think those would be some awesome last moments. Imagine the last thing you see before you die is all of time go by at once, and then you instantly get vaporized from it.

[@MoebiusPan]

+Calin Culianu My guess is that the black hole's spacetime warping only needs to be created to make time stop (and for you to experience all of time passing while you go through the event horizon). So inside that warping all of time passes instantly, even if the object that created it evaporates before that.

[@MrTmm97]

8:50 Einstein was right, he was right a lot….” I love it!

[@vanhouten64]

What astronomical phenomenae might exist that we have not yet detected or even hypothesized? There must be many such phenomenae.

[@A13-e3w]

هل تعلم انو كيلو البصل له نفس وزن كيلو الفجل. والله شكلك ما تعلم.

[@AbdullMohommedlol]

space is just so interesting and awesome

[@emoore29681]

Thank you, Phil, for uttering what is possibly the best thing I've heard all week: "It turns out, none! None more force! The core of the star is about to go bye-bye."

[@CuppaGi]

My favorite astronomical object. I need to know if you'll be covering the theory of White Holes.

[@ValleysOfRain]

+The Ramos Online Well, I'm not entirely certain that they would, because there is very little on that subject matter. It's purely theoretical, and even then, it's only a concept because Einstein's theories make allowance for it. Doesn't mean it actually exists. And as I said, it's only a thing to mention in passing. So little is known about them, there's nothing really to discuss.

[@cocoarecords]

+ValleysOfRain sweet thanks for the clarification

[@serioustable8659]

Now every time I eat spaghetti I will think of black holes

[@small_SHOT]

lmao 😂

[@jackknifer1]

So, essentially if you fell into a super massive black whole, you will be the last human to die in the universe? because you can reach the event horizon and still be alive at that point, on which all of time will pass very quickly. Is that right?

[@ScareSans]

i mean, if you somehow survive being stretched into an infinitly thin noodle, sure

[@bryceanderson9267]

nobody knows....it's all theory at this point....

[@JustRicky]

The study of Black Holes grabbed my attention in elementary... To think a person is actually time traveling(into the future) when they get near a Black Hole(because that person time is slowing down). Also, if a person curiosity is so strong they could sacrifice their life by falling into a Black Hole to possibly see the creation of our(or another) universe. I remember as a kid thinking if it was possible to make a camera-drone type device that can drop into a Black Hole and survive long enough to get to the Event Horizon. I hope something similar can be created in our life time...

[@shekharpandey5246]

Just Ricky! looks like that u r in preschool itis impossible to make such camera that will survive it and the information sent by the camera will not be able to get out as it will have to trabel faste than speed of light to get out. by the way i am in 5th classs.......

[@drts13]

the event horizon is the edge of the black hole. if the drone was sturdy enough it could get to the edge and still send information

[@astrohan_]

Shekhar Pandey pretty much you said was wrong so don't boast about your "knowledge"

[@intricateperson7878]

One of the reasons why this is impossible is that the camera will, like Plait said, undergo spaghettification so it won't retain the same properties as the original camera. Even if it was in a super massive black hole, the main reason it won't be able to detect ANYTHING whatsoever is that the light itself of whatever is inside won't be able to reach the camera, the reason being the escape velocity of a black hole is higher than the speed of light. How light works is that it is reflected in a way so that we can perceive it, while a black hole completely absorbs it so nothing can be visible from inside or outside. Furthermore, the nearest black hole is way too far away for us to reach it anytime, meaning at least millions of years if us or even the Earth for that matter is still around. Whatever happens in a black hole, stays in a black hole (except for hawking radiation but that's a different subject).

[@Alex-bw6yd]

Actually, the closer you get to the event horizon the stronger the effect on space-time it has. So hovering right above the event horizon time and space become essentially infinite. And so information trying to escape from that point would have to travel an infinite distance over an infinite amount of time. It would never be able to escape a warping of space-time like that. So you will never be able to receive information from inside or the very edge of the black hole, hence the reason it even has an edge.

[@Colinthecasualcook]

I nerded the fuck out when I saw this on my subscription list! SPAAAAAAACE!!!!!!

[@garethdean6382]

+Colin Sales Better buy a telescope. Wanna see me. Buy a telescope. Gonna be in space.

[@reckoneddead847]

+Colin Sales lol me too

[@Miranox2]

+Colin Sales I like spaghetti.

[@LazerLord10]

All of time would pass. *ALL OF IT!*

[@f4u1g2d9]

I can not believe that these "CrashCourse" postings have been going on for years and I did not know it. Since discovering them a few days ago, I've been watching a couple every day! This explanation regarding black hole gravity and "Escape velocity at the surface being equal to the speed of light" made a light go off in my head. Love this channel.

[@zamane1234]

"Bloop,gone."That was my favorite line

[@karlvega7931]

"Love is the one thing we're capable of perceiving that transcends dimensions of time and space" Anne Hathaway, you silly.

[@hugomajsoljaofficialchanne7880]

Karl Vega same is the feeling when you realise you got 5 missed calls from mom

[@caifancabr0n699]

That was such an awkward and stupid quote.

[@kunalchatterjee9221]

@@caifancabr0n699 Well, it was accurate from the movie's perspective, after crossing the event horizon he still manages to transcribe the quantum data to her daughter.

[@caifancabr0n699]

@@kunalchatterjee9221 probably accurate in the movie, but not in reality.

[@mhxybeats653]

Carlos Reyes well as she continued to described it, she pondered that the concept of love itself could be a relic of an higher dimension we cannot perceive. Hence why she was able to feel the attraction she had to Edmunds literally millions of light years away, knowing she would never see him again. It was built upon by the higher dimensional beings constructing time itself within a 3-dimensional space so Cooper could perceive it. It’s definitely a long shot but it’s cool to think about

[@sapphael.]

That's just freaking me out! The idea that as you fall in ALL OF TIME passes before your eyes...

[@BosonCollider]

+Eve Sav Yep. The real reason why you can't escape the inside of a black hole (assuming classical GR which is mind blowing enough) isn't just because you can't "get out fast enough", it is because you literally are in the infinite future, and from your perspective every event in the outside universe has essentially already happened, and you only need to move in space to get it in your past light cone. Getting out would be equivalent to traveling back in time.

[@that1valentian769]

Imagine the only way to see everything was to die in a black hole. That gets quite philosophical real fast.

[@Tytoalba777]

+That One Amiibo Hoarder The question is, is it worth it? I almost think I'd want to die being pushed into a black hole (as long as it's a super-massive black hole)

[@WayneJohnsonZastil]

+James A Clouder Would not have like millisecond to take in all that info before even enjoying it?

[@joelproko]

+Eve Sav Actually, it's a bit more complex, and not literally *all* of time. Watch PBS Space time's episode(s) where black holes are a topic (and the episode immediately afterwards, where questions are answered).

[@OniricChef]

Could you do an episode about wormholes (Einstein-Rosen bridges)? A lot of misconception around them. Especially a lot of people thinking that blackholes the "ends" of the wormholes. Example: create black hole, hop in, travel through its wormhole, out you go through a white hole.

[@andrew24601]

I hope Astronomy is the next course to be redone! There’s been a lot of science done in the past eight years. Black holes are now thought to be singularities (ringularities, really; singularities can’t spin), we have photos of Pluto, the JWST is looking into deep time… Lots has changed since this was published.

[@flickcentergaming680]

nothing can travel faster than the speed of light, except my new kitten on catnip.

[@TheZeyon]

Really intresting episode. Well done explaining one of the (if not The) most complex entities in the known universe.

[@cainfft008]

+TheZeyon I dunno, the Human brain is pretty complex too. lol

[@Imedge6]

+vormov Looking at the republican candidate I don't agree.

[@joelproko]

+Mat G Who says that's not an android with a mediocre AI? :P

[@Imedge6]

joelproko haha true

[@tedrastlin7972]

+vormov lol, you naive fool.

[@IlDeimos]

I have always found Black Holes to be very interesting. Not that I would like to be any where near one or anything. lol.

[@comewither]

I love Phil! I have seen him on some other specials on PBS and Discovery Channel and such, really like his explanations and these videos! I'm a freshman in college and I have an astronomy final today THANK YOU PHIL AND THANK YOU CRASH COURSE AND THANK YOU COFFEE

[@Scoutersigmachi]

0:41: "None more force!" Ah, science meets language. Phil, I love you.

[@johnsonguitarstudio]

It's almost certainly a reference to 'This is Spin̈al Tap': "There's something about this that's so black, it's like how much more black could this be? And the answer is none. None more black." --Nigel Tufnel

[@ch3rrie_bl0ssom]

0:51 Hey little man. Wanna stop waving at me. Thanks 😂

[@boqu8044]

Physics Teacher:How do you know all of this hard stuff? Me:THIS!!!!!

[@supernenechi]

I finally get it!!! It isn't just a weird way of measuring time that slows down at higher altitudes, no it's LITERALLY time itself! So even a normal mechanical clock would stop

[@insu_na]

For deeper info, watch PBS Space Time, which is another cool channel!

[@morningmadera]

+Haha 327 I disagree ... this video has only basic knowledge, while PBS is for advanced amateurs of physics.

[@garethdean6382]

+CeaoS Advanced amateurs?

[@MattiaBiggMattGentile]

+Gareth Dean Doesn't give you any formula or math, but messes with your mind more. In fact to watch the Black Holes video you must watch 4 earlier ones that explain some things and terms. So basically black holes take 5 videos in that channel to get explained, more in detail.

[@garethdean6382]

***** Aaah. Very true.

[@OnyxIdol]

+d3rrial Thanks mate, I guess I have my viewing schedule for the next weeks cut out ; )

[@nicktharme3908]

You could not fail to learn from Phil, the enthusiasm from an expert is just epic to watch. This guy needs a syndicated series, reminds me of the great James Burke! The view must be great, standing on the shoulders of Giants. I know I look up to you, keep on doing these!

[@WhyIsTheRumGone68]

Today, 10 April 2019, the first image of a black hole/event horizon was published.

[@westgogi]

It was quite cool, wasn’t it?

[@WhyIsTheRumGone68]

@@westgogi very. I was excited.

[@Aziraphale686]

I love how most of the questions Phil asks, he answers with "well you would die, but you would die in a very interesting way"

[@michaelrose93]

*"Someone deep inside the gravitational influence of an object, perceives time as ticking more slowly"* 8:32 < Untrue, they perceive time as moving as the very same rate; an outside observer would perceive their time moving sower.

[@game-r-age7157]

Thank you, these people don't understand perspective.

[@Dawkinsdude20]

space and time are the same? well, I wonder what dialga and palkia think about that..

[@StarboyXL9]

Colby Green They're reflections of each other, like 2 different avatars of the same transdimensional being/concept. Not that hard to graps

[@StarboyXL9]

*grasp

[@Dawkinsdude20]

Joel Gawne I don't think you quite got my joke

[@terry2788]

Believe it or not Pokélogic sucks 😂 I mean Nebbby, a Nebula Pokemon, turn into Lunala? A moon Pokemon?! (Makes sense when then into Solgaleo since its the sun Pokemon)

[@snoringmunchlax4295]

Is giratina a black hole then?

[@MorePower8679]

This is honestly one of the best and simplest videos about black holes out there. Simple in that it breaks things down to a point where most can understand it.

[@FewVidsJustComments]

7:25 "compaired to either black hole, a star still has substansial size, and when it gets close to either black hole, it can be distrupted via tides" CrashCourse Poems

[@cmmoe5680]

Thank you for the recap at the end of the video! It was a confusing subject so it helps to have it reiterated and summarised.

[@SciAntGaming]

After so many years I finally know why the 'Event Horizon' is called so, haha. Thanks CC man!

[@vijay1patil]

My son (6 yo) loved this video - ofcourse he was curious what's going on. But he loved the "spaghettification' concept.

[@morkryan8287]

Undoubtedly learnt more about black holes in 12 minutes than I ever thought possible. Just wish that they mentioned the gravitational lensing, Gargantua from Interstellar would've been perfect to showcase for this.

[@mashhud3290]

8 years, and people are still watching this series. Cool

[@mr.goodman354]

You want to know how scientist name things in space by banging their head on the keyboard

[@requiresethernet1019]

Scientists name things in space by giving them ridiculously simple names that describe exactly what they are

[@abloogywoogywoo]

So if light will infinitely red shift near a black hole's event horizon exceeding the speed of light... and light will infinitely red shift as the universe's expansion exceeds the speed of light... *Are we all inside a black hole?*

[@TomkoChannel]

This is probably the most reasonable way the universe was formed to me. It explains why the universe is expanding and because of the time shift why we think all of matter being made at the start of the black hole forming even though it is being pulled in over a time.

[@jakiasattar2084]

abloogywoogywoo 'y

[@poisinivyisepicandwasomexd7483]

abloogywoogywoo

[@DaReelSlimN80]

abloogywoogywoo yesss

[@ciao_fiv5118]

abloogywoogywoo so what you're saying is... the universe is a super SUPER massive black hole???!!! That'd be insane! And cool!

[@cainfft008]

I'm a bit confused by one one thing: Crash Course Astronomy says that a person falling into a black hole will see all of time pass by as they approach the final second of reaching the even horizon. PBS Space Time says that a person falling into a black hole will not see all of time pass by, only localized blue shifts (or something like that, I guess what I'm saying is that I dont understand this explanation). Can someone help me understand this? Seems like competing ideas. I know that black holes are by far, very mysterious and we have much to learn about them. I also know that scientists who study this stuff even have disputes about black hole properties. Is this one of those discrepancies? Help! I want to learn! (Also, I hope that this series never ends. I've enjoyed it so much and I hope there are many, many new episodes in the future.)

[@garethdean6382]

+vormov The difference is how simple things are. Here the simplest treatment is given; all of time. It's close enough to the truth. In reality when things start heading towards infinity there's usually some bug that pops up and ruins things. PBS Space Time is correct, there are two problems. First time seems to go faster and faster, eventually everything seems to happen at once so you can't 'see' a lot of it, it's a mess. Secondly the person is still falling, not standing still at the horizon so the incomming signals get warped by the black hole too.

[@cainfft008]

Gareth Dean Thank you, This helps a bit. I see now that Matt was trying to explain that, I guess I didn't understand his terminology or something. Because yeah, the black hole itself would warp any photons heading towards its center of gravity, correct?

[@garethdean6382]

vormov Yes. that's correct. Black holes affect everything the same, light, person and pony alike.

[@unvergebeneid]

+Gareth Dean What?! There was a MLP episode where one of them gets killed by a black hole? Geez, that's badass, maybe I'll have to watch this show after all.

[@garethdean6382]

Penny Lane MLP yes, but not FiM. The first series had some wonderful dark moments. Also PBS Spacetime is fond of putting ponies in space. They are banned from all petting zoos.

[@the_arch_astronomer]

This video is quite old, but at the time of me writing this comment (9th of April 2019) the first image of a black hole should appear tomorrow. CAN'T WAIT. PS: Phil I love this series and I love you for being an amazing person!!!

[@AbdullMohommedlol]

why is there always more than 50 dislikes for every one of you guys videos? you guys explain a lot of things very clearly, and really help me.

[@jr52990]

"Einstein was right, he was right a lot." True words my friend, true words.

[@abrahamd2k]

When you said 'Spaghettification' I had a strong craving for spaghetti just then.

[@lucasbueling9147]

right before i die i want to fall into a black hole

[@slidysteven8002]

Li'l Heroes good luck with that lol

[@amrdx8845]

how kids think

[@thepunisher4507]

want to be spaghetti do you

[@bryceanderson9267]

you will, and go to the next world....

[@garytomas1757]

Oh the irony in that statement.

[@sheridansnyder6905]

This is my 3rd episode, and quite please with the Instructor descriptive analogies, example and info straight from the hip, I love his series!!! Will need to go back to lesson 1!!! Great Job! How I wish I had this kind of course when I was in Jr/Sr High school. I would then go on to College for a Medical career instead of Astronomy career.

[@brucefrizzell4221]

Thank you for the subtitles .

[@Eric06410]

You sir are almost Carl Sagan

[@karry299]

+Eric06410 Who is Carl Sagan ? I think i've heard of him...just a guy that rambles alot about space, but has never actually DONE anything of value, is that the guy ?

[@Eric06410]

+karry299 Ya, well, you know, ahh...that's just like, your opinion man.

[@travz21]

+karry299 You don't know that "alot" is actually two words. Congrats.

[@IstasPumaNevada]

+karry299 He was an astronomer and astrophysicist, among other things. But in a society where a few carrying out scientific advances for all are funded by those who aren't specialists (and in fact can tend to be apathetic and easily swayed), I would argue that the role of science popularizer that Sagan and Tyson and Plait perform is an integral part of progress.

[@SupremeStoops]

+karry299 Nope... you're totally off.

[@ruolbu]

Something I want to make sure I understand. What I was told as a child was, that a black hole combines all of its mass in a single point. After all we already agreed that no force in the universe can keep the core of a very large star from collapsing and it goes bye bye. So when it is said that a black hole grows with increasing size, we are primarily talking about the size of the space surrounding that former core matter that requires a higher escape velocity than the speed of light, yes? The actual size of whaterver matter is inside the black hole is probably unknown because we can't look inside. Do we have a concept for what state the matter inside the black hole could be in? Is it actually a single spot or can we maybe still apply the concept of having a radius to it?

[@ddjoray1042]

+ruolbu As I understand it, black holes have a volume of zero, therefore are infinitely dense (hence the infinitely downward spiraling gravity well image you often see associated with them), no matter what their mass is. The increase in mass accounts for an increase in the diameter of the event horizon. A black hole's singularity isn't a material object, it is simply a property of spacetime at a specific location, therefore the matter has no state of matter. If you know anything about 3D modelling, think of a black hole as a point in a 3D space that can hold metadata. The metadata is the mass, held as a generic object (not a string, integer, etc.).

[@garethdean6382]

+ruolbu The fact that our current theories predict infinities is good evidence they are incomplete. We've been here before (In the 1900s the 'ultraviolet catastrophe' predicted all warm objects must glow infinitely bright.) so it's likely that whatever is inside a black hole isn't infinite but does something weird that combines gravity and quantum mechanics. When we talk about the size of black holes, yes, we are usually talking about the 'event horizon'; a sphere of space that nothing can escape from.

[@tiffles3890]

+Idrialite I know of 3D modelling and that is one hell of a way to explain the concept that you are trying to convey. But I read somewhere that a lot of physicists argue that if something has exact zero volume, like what the math implies, then it effectively doesn't exist. If it doesn't exist it cannot exert gravity. So they say that there must be a limit at which the contraction stops even if it is minuscule.

[@garethdean6382]

Gaurab Chatterjee To me it seems rather like saying I can accelerate my car from 0-60 in 10 seconds so therefore I can accelerate it to the speed of light if I just step on the gas enough and nothing else intervenes. The math works out,but it ignores that quite a lot of things intervene. We get a singularity if a star core collapses and nothing else intervenes. I am confident that one day we will discover there *is* something else and it stops this zero volume kerfuffle.

[@UnknownXV]

Wait a second... if all of time went by in the universe, wouldn't that also mean the black hole itself would evaporate away due to hawking radiation, just as you were about to pass the event horizon? So falling into a gargantuan galaxy core black hole would essentially be a time machine to the end of time.

[@calinculianu]

+UnknownXV Yes, I'm confused by this as well. Black holes *DO* eventually evaporate. If all of time goes by as you approach the horizon -- doesn't that mean that as you approach the horizon that the black hole would evaporate before you got there because *all* of time would go by? I'm confused as hell.

[@UnknownXV]

Calin Culianu I mean, it should, right? As far as I know, black holes do evaporate through hawking radiation, though a giant one might take trillions of years. But so what? If all time passes by instantly, that's all of time. Or would it be all of time? Wouldn't it be all the time it takes for the black hole to evaporate away, at which point there is no more black hole and thus more more extreme spacetime distortion causing your time dialiation to occur in the first place?

[@flaviusclaudius7510]

+UnknownXV AFAIK, you only take an infinite amount of time if you're a massless particle trying to cross the event horizon. If you have mass, any object behind you would notice that the strength of gravity on a straight line connecting it and the singularity is stronger, deforming the event horizon. Note: I am not a cosmologist, I only did Honours in GR in undergrad, so please take this with a grain of salt. Also note that this doesn't take into account quantum mechanical effects, which are no doubt important at such a surface.

[@UnknownXV]

Natasha Taylor So time dilation doesn't occur if you have mass?

[@flaviusclaudius7510]

The time dilation does occur, yes, but infinite time doesn't pass because you don't get infinitesimally close to the event horizon before being consumed by it (relative to an observer at infinity).

[@avischiffmann6220]

Great overview!

[@sharpie3824]

"The Core Of The Star Is About To Go Bye-Bye" i don't know why I'm laughing so hard at that 😂

[@michaelo.1320]

The tides come in, the tides go out. How can you explain that

[@IstasPumaNevada]

+Michael Andrew The earth is spinning relative to our sun and moon. The ocean's tides are an effect of gravitational tidal forces from those two bodies (mainly the moon).

[@michaelo.1320]

That was a Bill O'Reilly joke. You'll see what mean if you look it up. I'm not a fucking idiot.

[@channelx7761]

If humans came from dust, why is there still dust?

[@IstasPumaNevada]

***** Strangely my previous response seems to have disappeared, so I'll repeat: Poe's Law strikes again.

[@gormitishipper5760]

"what happens in a black hole stays in a black hole" I didn't know black holes were Vegas, lol

[@Altrue]

"From your point of view, time would pass very quickly, ALL OF IT". Not really though, it would at worst only pass for the duration of the lifespan of the black hole that will eventually dissapear due to Hawking radiation wouldn't it?

[@infiniteblue895]

Altrue19 late response but if the hole it's hu bongo then that snazz will last a long time

[@tdogjenkins5349]

Sure but would you live to know the difference?

[@lehuy7306]

Altrue19 wouldnt the universe have ended by then?

[@rollingkneebar3534]

Gary Tran There wouldn’t be anything substantial to see. The only objects that will possibly outlive black holes will be black dwarfs cooled from white dwarfs.

[@tdogjenkins5349]

Maybe dark energy will last longer...

[@KillerIceStorm]

I'm not impressed by black holes, but I am impressed by how well this host explained this video. It was a really good job by him.

[@apostalote]

Your enthusiasm is infectious.

[@jovandukmedziev3214]

Who's here after the first black hole picture was revealed?

[@Nexthespookster]

JovanRockNRoll :p me

[@afrojacks4462]

Can you cover white holes or is that just a pseudoscience.

[@kinghasturFFFF00]

+Afro Jacks AFAIK it's just pseudoscience

[@bccollective388]

There's one on scishow space

[@nemo-zl1vm]

+Afro Jacks It's mathematically possible, but practically impossible. Still, it's a big universe....

[@dafiltafish]

+Afro Jacks It is a warzone between math and physics. I like to side with the physicists because they are usually right, BUT then that damn bastard Murphy pops up saying that because the math does support the existence of white holes, you cannot say they don't exist. Best course of action is to look up at the sky until you see something interesting.

[@joelproko]

+dafiltafish Thing is, math also doesn't care in which direction time flows. So a white hole is just a black hole seen by someone going backwards in time.

[@davidfeng6120]

Great video!

[@HarveyMeadowlark]

Man I shouldn’t have started this video so early in the morning, it’s to early in the day to have your mind blown like this

[@pamelasimon9842]

Ms. Simon's Earth Science Class (8th-9th grade) Hi, my name is Christopher Johnson. Our class has watched all of your videos on Crash Course Astronomy start to finish. There is some amazing content in all of the videos, but I decided to write a note on this video because, personally, it is one of my favorites. In fact, my friend Rochelle and I are doing a 4-H presentation on black holes and the misconceptions concerning them. We’re also using a couple of your other videos, to gather information. I have learned a lot about black holes from your video and I have used many different sources to find out more. Here is some of the stuff I learned from this video and what I thought about it: Black holes are some of the least known objects in the Universe along with dark matter. Also, black holes are seen as black because their gravity is so strong past the event horizon that even light can’t escape. That’s pretty incredible and also explains why it is called the event horizon. We need light to understand the Universe, and if there is no light, then we can’t tell distance, size, or really anything about what we’re looking at or the events going on inside it. Thus, the event horizon. Another interesting thing that I didn’t know before this video was that black holes don’t actually suck up everything around them. They have the exact same gravitational force as a star of the same size. Gravity is only different if you get closer to the black hole, where it increases exponentially. However, whether you are that close to a black hole or a star, you’re dead anyways. That’s about most of the These are some of the fantastic things I learned from the video. Thank you, Phil Plait, this video has been very helpful, and Don’t Forget to Be Awesome.

[@ekuliyo]

Here's a dark thought: what if there were living beings...even civilizations...orbiting that star that got torn apart?

[@salvadortorres7449]

Luke 😢

[@V1kram]

@Irritable Jon Syndrome I know it's a little late but, Luke isn't talking about Supernova, they're talking about the BlackHole ripping apart that Star like a piece of cake at 7:25.

[@lkeaboy]

Jesus Christ! you're right!

[@AlekSchultz]

If a black hole has the same mass, and therefore the same gravitational pull, as a star then why can light escape the star but not the black hole? Does it have to do with how dense the black hole is?

[@xXsolar99Xx]

+Alek Schultz (Pretzel Optician) It does. Because a black hole is a lot smaller than a star of the same mass, you can get a lot closer to its center without actually touching it, which means the gravity gets ridiculously strong.

[@ILMTitan]

+Alek Schultz (Pretzel Optician) Black holes are much more dense than a star, and therefore are much smaller than an equivalent mass star. The two objects only have the same gravitational pull above the surface of the star, and light can easily escape from an object orbiting the back hole at the distance of the stars radius. Once you get below the surface of the star, however, the gravitational forces begin to decrease, while the gravitational forces of the black hole would continue to increase until you hit the event horizon.

[@MoTown-qd8fl]

+Alek Schultz (Pretzel Optician) Those 2 guys said it best. I'm just here to thank you for helping our pretzel population see properly again.

[@AlekSchultz]

MoTown2112 You're welcome. It's a grueling job, but sometimes you have to do what you have to do to help the community.

[@sorlag110]

+Alek Schultz (Pretzel Optician) Black holes aren't particularly dense, but I guess that depends how you define dense. The supermassive black hole in the center of the Milky Way has about the same density as water. Light can't escape because the escape velocity at the event horizon is equal to the speed of light. It has to do with how space time after the event horizon is curved so glaringly much, there is no out-direction anymore - every direction points inwards.

[@seymournerds342]

Aren't we all galaxies drifting in and out pass the earth. Our form maybe beautiful but deep inside there's a massive black hole within us.

[@alaskalife4035]

This is very informal! That last fact was very bizarre! What if someone could fall through a black hole and live to tell the tale? So many possible discoveries!!!

[@fastfutures]

Ugh I love this show, it was the...tinder to my burning fire of passion for astronomy (sorry, I couldn't think of a better analogy, I've just been watching CC Astronomy since I was 11, and WOW, do I still repeatedly watch this show just to go back to my nostalgia-driven roots)

[@navagharkiran5769]

star: I the one who created energy and light , and have right to destroy in the form of blackhole

[@OctopusWilson]

So why does spaghettification occur instead of you just getting torn in half?

[@TheByQQ]

Because, like the video said at least 2 times, the force of gravity decreases with distance gradually, you do not cross some kind of magical gravity line where you go from 0G to ∞G in a fraction of a second.

[@Masoudy91]

Would be nice if you awesome guys could put the numbers as text on the screen, and maybe high light important points as you go? :)

[@Linkfan450]

What I love about them is that there are many flying around the universe at insane speeds.

[@stevebrindle1724]

Love these crash course video's. Rewatch them and always pick up new knowledge!

[@demondik]

How do black holes avoid violating the 2nd law of thermodynamics?

[@manawa3832]

energy doesn disappear from the universe in a black hole. the black and everything inside is sill in the universe. white holes apparently do violate laws of entropy and for that reason the universe annihilates them the very moment they pop in.

[@demondik]

Dingo Egret A black hole is not considered to be made of any known state of matter. They're simply looked at as a region of space that has curved to the degree nothing can escape it. If energy that enters the black hole can never escape it, that means it has been taken away from observable spacetime and thus violates the 2nd law of thermodynamics. It is forever cutoff from the universe is it not? White holes are completely theoretical at this point. No evidence whatsoever to suggest they could exist.

[@manawa3832]

Mr. Lowery theres good bit of mathematics that suggest white holes have every right to exist. black holes are a collection of events. all events within a black hole are part of the black hole/are the black hole. the black hole is in the universe. no information is lost. the number of states the universe can be in has not decreased/increased and the black hole has merely churned out some entropy. thats is all

[@demondik]

Dingo Egret mathematical concepts are not evidence of anything. There is circumstantial evidence for the existence of black holes from observation of gravitational influence from a body that can't be seen. Science has taken this circumstantial evidence and all the math suggesting black holes exist and has pretty much claimed they are real. No circumstantial evidence even exists for white holes. Many mathematical concepts have predicted many things not yet observed. Like gravitational waves. I don't think LIGO detected any such waves. No real proof in what I looked at. Thus could have happened from any disturbance large enough to influence the earth. After all we are talking about a misalignment of laser light by less than the width of a proton! C'mon, that's total BS. Something to help justify the decades spent and the billions spent on a fruitless project. But I digress, reality is, black holes and white holes are nothing more than mathematical concepts and one has circumstantial evidence to suggest it might be real.

[@pjmichalik5939]

To explain how black holes do not violate the 2nd law of thermodynamics you need to invoke the principle of Hawking Radiation. Hawking Radiation actually causes the mass of a black hole to decrease in contrast to the previously widely accepted idea that the area of the event horizon, and thus the mass of a black hole, is always increasing. If the mass of a black hole decreases, the entropy of the black hole must also decrease. In order to not violate the 2nd law of thermodynamics, the entropy of the Hawking radiation would have to be larger than the entropy lost by the black hole itself. Only problem with this theory is the fact that it is has not been directly observed yet, but it is still a bold idea!

[@SuperTux20]

"If I kill you, you're taking the Universe with you." --Black hole

[@j-theorythequantummechanic6025]

I love quantum mechanics! And relatively theory! Special and General!

[@Shrekfromthehitmovieshrek]

j-theory the quantum mechanic I just don't like Newtonian physics

[@Nexthespookster]

j-theory the quantum mechanic same

[@Sophie-dt3ck]

When he said that time would pass by entirely, my mind was blown. Wow indeed. I already knew how black holes worked in principle and how it twists space-time. But that last bit, good lord! I just burst out with a big WHAT.

[@princejayhillable]

Yay we find one finally!!!!!!!!!!!