What is a Black Hole? - Stephen Hawking's final theory

~ The black hole information paradox and Soft Hair ~
You can check out Google's Science Journal app at g.co/ScienceJou...
What does Stephen Hawking's last paper on black holes with soft hair say about the black hole information paradox?
If you liked this video check out these:
The Most MYSTERIOUS Object in the Universe • The Most MYSTERIOUS Ob...
Why is the universe flat? • Why is the universe flat?
physicsgirl.org/
/ thephysicsgirl
/ thephysicsgirl
/ thephysicsgirl
creator: dianna cowern
editing: dianna and eric birkemeier, and jabril ashe
animations: keegan larwin, kyle norby and dianna
research: sophia chen
writing: dianna cowern, sophia and dan walsh
script editing: dan abromowitz
Thanks to Andrew Strominger, Derek Muller and Kyle Kitzmiller!
Thanks to Matt Parker for the footage of the "flaming parabola of fire” - from Festival of the Spoken Nerd show "Just For Graphs” - fotsn.com/j4g - / standupmaths
Paper source: arxiv.org/abs/...

[@Patiboke]

You killed it again in the 'explain in layman's terms' department, with that paper on the globe.

[@MountainFisher]

Just learn how to navigate with a compass and sextant. Plotting courses have to be done on a Mercator chart to account for the curvature of the Earth. If you do not allow for that curvature say going from San Diego to Oahu, you'll hit Hawaii instead.😁 Mercator charts you can draw a straight line. Mariners have been using them since the 1500s. Just FYI in case you ever decide to buy a big sailboat.🤣

[@Sameoldfitup]

“Has it ever struck you that life is all memory, except for the one present moment that goes by you so quick you hardly catch it going?”― Tennessee Williams.

[@argir5849]

Yeah, quite often actually.

[@rgl8109]

#ACTUALITY

[@akhilnair1761]

I'm gonna have a headache trying to feel that

[@HalfdeadRider]

It doesn't come by you, you are always here just as the dinosaurs were. it's always the same as there is no time, other than the tools humans made such as clocks and watches.

[@mystic3549]

omgggggg!!

[@chuckofalltrades]

“Gravity is what happens when you walk straight on a non flat thing” what an absolutely incredible line.

[@RumbleLab]

That blackhole animation is sick! Would make a great lockscreen animation

[@LeukeGast]

@Astumed Just waiting for the hairy lock screen animation

[@Mikeztarp]

I was just about to write the same thing! It would make a great live wallpaper for something like Live Start Page, too (disclaimer: I am not affiliated with Live Start Page. It's just an addon I use.).

[@LeukeGast]

@@Mikeztarp That sounds great

[@SunShine-kd6td]

The matter is just spinning around the "hole" (they aren't really holes).

[@MicraHakkinen]

Shame it's slightly too late for one of Microsoft's recent Windows updates...

[@besmart]

Dianna, what kind of conditioner do black holes use

[@besmart]

Also welcome back!

[@harsh_t]

Hello! Your channel is great

[@Robert-Peterson]

The conditioning kind.

[@reddytoplay9188]

Ikr they have such great hair I also want to know

[@hamabrewer]

It's Okay To Be Smart Is It Okay To Be Smart?

[@davidvose2475]

When I studied physics at university, every single lecturer was male. So was nearly every student. I'm so happy that this is changing. My daughter has people like this young lady to inspire her.

[@GordyRogers19]

@Dodd Rougeau finally someone said what we are all thinking

[@dickcickle9555]

Men and women naturally gravitate to things , women more often like people men more often like systems. In societies where the most has been done to equalize outcomes this has been proven to be true time and time again. Why do you want force an agenda on your daughter or any other woman when they simply might not be attracted to science? What about that natural tendencies of women upset you so much you want to inspire them to change. How about let your daughter and women do what they want.

[@Plasmacat1]

@@GordyRogers19 no one but imbeciles think the Earth is flat.

[@altalio5383]

@Dodd Rougeau when we are on a plane, we are also flying fast af, how do we not fling to one side of the plane when we stand on the plane?

[@tazkrebbeks3391]

Funny. Back in the 70s all my science teachers were ladies. My father had passed when I was young. I was raised by my mother. My first boss was a lady. I never understood and still don't understand why society has such a hang up about women empowerment.

[@johnnysins4298]

Whose here after 10th April's first black hole picture

[@tribopower]

me

[@dovahkiin3379]

Well we all had the idea of coming back after the pics of the black hole is released to make fun of old theories

[@christiandeininger1790]

I am

[@beatriztorres4458]

lol, I was just about to say this.

[@lonewolf3239]

@@beatriztorres4458 👍

[@altrestrictionsclrd]

RIP to the man who studied, but never saw one himself. We all owe you Professor... Thanks Mr. Hawking, I hope you can now see it yourself from above.

[@radvilardian740]

Now in heavens they probably already discovered the black hole answer earlier than us.

[@jalpapatel456]

he IS the one we are seeing now...

[@bartsussygaming487]

It's so sad. He took that many years, but never got to see the picture

[@goduke3954]

From above? Lol dude was not religious by any means lmao

[@user-ki6id4vt8u]

@@goduke3954 His belief doesn't undermine or determine the truth out there. Both religion and science can be compatible but there is never one answer, otherwise that could open up Pandora's box and even a paradox maybe. Meanwhile, just as reality is reliant on our senses in the most straightforward manner, our views, and our deceptive consciousness is really all that matters since they lead us to our own answers. What we make of what we have, whether it's free will or atoms working together to make decisions, is what counts - at the end of the day, it's only been one day for all, so stop arguing about others' beliefs. People will always have their experiences, delusions and beliefs. Yours is just one, not enough to convince different perceptions of reality out there.

[@atree8648]

Dianna- "Not even a thank you note" rude! Me - 😂😂😂😂 I extremely love this type of craziness!

[@samiempapane5090]

I thought I was the only one who noticed

[@atree8648]

@@samiempapane5090 nope I m also here dude !😉

[@technicality]

Welcome back!

[@mustajab2088]

What did you charge?

[@isaacnewton7574]

6

[@mrdtlgamer9804]

Tq dued

[@fermp3690]

If you were my teacher in school I would probably have understood 90% more of what I was hearing in class. These are so well done.

[@HarmlessX]

Days of prep and animation to explain one topic for 10mins, we’d make no progress in school at that rate sadly

[@fermp3690]

True but most teachers these days have the benefit of being able to show something like this in class. If they don't have the resources themselves, hopefully they are looking for content like this to share with their students. But I can certainly see this being over the top for most teachers to be able to provide themselves ;-)

[@AlchemistOfNirnroot]

Technically, this material is waaaay beyond university, never mind school. Not trying to discourage curiosity ofc but this is more of a gentle approach to advanced topics.

[@Logarithm906]

lol, if she was my teacher at uni i've probably have understood 90% more than what i was lectured with and i studied physics there. Sometimes a well thought out explaination is all that's needed.

[@dingovory]

@@Logarithm906 Let's see if you'll feel the same when she introduces T H E M A T H

[@potawatomi100]

Outstanding video Dianna. As usual, you provided cogent thoughts, your delivery was engaging and your enthusiasm contagious. Love your work and I think you are outstanding in your field along with Derek, and the Green brothers.

[@gigglysamentz2021]

2:12 I love that photo of Einstein cuz I tell myself he wrote "LOL" on the blackboard :')

[@カラスKarasu]

"LOL, this is going to give them so many headaches..."

[@captainsnake8515]

I'm pretty sure that's a chart about how energy is conserved.

[@kalazakan]

@@captainsnake8515 buzzkill

[@Peanutdenver]

History repeats its self. Einstein also used "Yeet" or "Ya Yeet" quite a bit in his lectures.

[@JorgetePanete]

@@Peanutdenver itself*

[@masskonfuzion]

"Let's bring it back to black holes. See, they're inescapable." That joke was fantastic 🤣🥁

[@bettiebutcher5998]

masskonfuzion m

[@soba3409]

@@bettiebutcher5998 XD

[@wyatta7442]

Stephen has been a big influence to me, and a big inspiration too. I loved him and his work, and I'll always try to use his theories in any way I can. I love that people are finishing and publishing his infinished work, even in 2020

[@longerino]

wow, just wow.

[@MountainFisher]

Did you read his last book The Grand Design?

[@wyatta7442]

@@MountainFisher not yet, but I plan on reading it

[@MountainFisher]

@@wyatta7442 Don't waste your time. I was bummed out from reading it. He starts off talking about the "great questions like why are we here, etc" Then finishes it saying "those are questions for philosophy, but philosophy hasn't kept up with physics because philosophy is dead." A self stultifying philosophical statement. Like saying I am certain there are no certainties. Then he goes on to engage in philosophy throughout the book. To summarize his whole point he states," Because there is a law such as gravity, the Universe can and will create itself from nothing." The reason the Universe exists. There are three contradictions in his summary. First gravity is not nothing, it is something. Second the Law of gravity is a description and has no physical existence and cannot do anything. Third, to create itself the Universe would have to exist before it could create itself. Hawking really should have studied logic before making such pronouncements. A Universe from nothing creating itself is exactly what it sounds like.

[@ok_tim]

I now need a shirt that says, "I can't walk straight".

[@Sheamu5]

You see officer no one can walk straight, so I'm not intoxicated

[@antariksavvan]

Or "Nobody straight until somebody force them"

[@stinkleaf]

You can have it at Printful or sell it on any number of product services. That is after you design it.

[@JorgetePanete]

@@f3jay776 well, you'd be in a circumference, can we say straight is for eucledian geometries only?

[@ligh7foo7]

on the back of the shirt it reads I am walking towards the equator

[@braincraft]

4:13 what an extremely distinguished group of characters

[@jadegecko]

I only got a few of 'em!

[@fahadus]

Ahhhh... now I get it!

[@JamesHawkeYouTube]

yeah liars are distinguished right.

[@danielvandertorre7505]

braincraft look at what I posted .and tell me what you thing of what I say .

[@joeyouyang]

ooooo didn't catch that initially

[@tim1883]

Glad to finally hear someone say "density" instead of gravitational mass or critical mass. When talking to people not familiar with physics, I always put it that way.

[@erich930]

6:32. As of April 10th, 2019, that statement is now FALSE! Excuse my ignorance. I have now updated the comment to say April instead of August!

[@advenco344]

*April

[@chalmerz99]

Go back to your tardis Doctor, you're false too as it's April

[@kris240376]

Actually, I believe her statement still holds as we didn't receive any photons from the black hole itself. We were able to observe the interactions of plasma with the black holes event horizon. We still don't know what happens beyond the event horizon.

[@chalmerz99]

@@kris240376 her statement was we dont have an image of one at all, we do, its radiowaves but itll do.

[@kris240376]

@@chalmerz99 Just being pedantic but technically, she is correct. According to this video, kzbin.info/www/bejne/fYPIZaBsarGDeJo, the fuzzy spot we are seeing in image is the shadow cast by the event horizon, not the black hole itself.

[@upandatom]

It's great to have you back. Your demonstration skills are to be envied (globe and paper thing)

[@cheesywiz9443]

up and atoms :O

[@Infinity2219]

Up and atom are you a flatard?

[@BlackHole-qw9qg]

You're better :p

[@11valiant]

Well, I tried globe and paper thing at home, and... it is interesting that if you roll your sheet of paper into a cilinder and place it on the globe, you WILL actually have a straight line, and it WILL be on the globe, and it will NOT intersect equator. It took me few minutes to understand what is wrong in this example... Try it also :)

[@mukulvdhiman]

@@11valiant The point was to walk in a straight line, not keep walking towards west. A cylinder's bottom is curved so obviously, it won't intersect. To follow the path taken by the cylinder, you'd have to correct your course every few meters to continue walking towards west.

[@pratimaramlall]

Thanks for these videos Physics Girl. I like your videos. They are very simple to understand. And I wasn't even particularly interested in math before. Thank you.

[@ScrapPalletMan]

Thanks for showing a straight line on a sphere. That was an amazing display of curved space.

[@liquidsonly]

However, If that paper is very (very) narrow it will follow the line of latitude, so there needs to be something else going on with that analogy. Paper width is clearly a factor here so what does that relate to?

[@ffffffflo_]

@@liquidsonly Wanna know this too. I'm not convinced on that analogy also.

[@392redienhcs]

@@liquidsonly Maybe not the paper width but the fact that latitude lines are not geodesics. The equatorial line is a geodesic, and so are the longitudinal lines, so if you start from any of those points and follow it horizontally or vertically, respectively, then your path will coincide with the edge of the paper. It's the analogy behind it that's cool. If you were walking very straight exactly due east from anywhere that's not the equator, and not specifically to any location, you may not be able to show your exact path when you're asked to show it on a globe.

[@mkilptrick]

The physics girl is such a great communicator of science information. Don't stop.

[@sethzink3458]

Thank you so much Physics Girl! For years I've had trouble wrapping my head around the concept of gravity as a force being able to effect intangible concepts, such as time. This vastly clears things up!

[@isaacthek]

This is actually an old theory proposed earlier by his collaborators. It's called the holographic principle. Gerard t'Hooft and Leonard susskind wrote about this.

[@tirthachakrabarti5912]

I am also trying to know (in fact for last few years since when Hawking proposed it) what's the difference...there must be some difference.

[@tirthachakrabarti5912]

@Michael Bishop As far as I remember, Black Hole Complementarity was the idea from 't Hooft. Susskind improved over it and they created the Holographic principle. But Hawking's theory uses a concept called 'Supertranslation'. I don't know what is that. It seems Hawking's theory has something new in it even if it looks same as 't Hooft-Susskind theory.

[@stuartschaffner9744]

@Maya , I have some further questions that you might be able to help with. First, almost all analyses I have seen assume almost-equilibrium conditions. If I understand correctly, the recent gravity-wave signals from merging black holes imply that most of this science works well in highly non-equilibrium situations as well. How does any information-containing hair in the two event horizons merge while losing only the amount of information carried away by the resulting gravity waves? Second, could this hair be more like fractal fuzz? I envision some division of position-momentum phase space into regions that mostly fall into the black hole versus ones that don't (at least down to Planck scale).

[@amanasci2481]

Thanks for returning and for again giving us a great video like this

[@HyperspaceQ]

*The Universe, the ultimate playground for never ending exploration! I love it!*

[@cliffp.8396]

Welcome back Diana you were missed, great video by the way.

[@ascetic3312]

*Dianna

[@custos3249]

New Physics Girl video? Alright, alright, alriiiight

[@user-xg6tv5hl6s]

Aaaaa o

[@chriskucera3776]

Custos u

[@Follower_of_The_Word]

I don’t know why this video came up on my recommended list but I’m glad it did! You are fascinating a Physics Girl and I enjoyed listening to you. I have’t met anyone that enthusiastic about physics since my college inter teacher! P.S. I work at Hanford and loved touring LIGO! Next time you’re in town I’ll arrange a tour of the infamous Manhattan Project era nuclear reactor here and you gotta check out the museum! Have fun!

[@sandylewis79]

Wow, the way you describe how gravity works is amazing. It’s so much clearer now. Thank you so much! Great video. Cool simulation too.

[@ConspiracySmurf]

***GRAVITY*** No one anywhere has ever recreated water sticking to a spinning ball...ever...and the first thing you learned in science was The Scientific Method and that says "Thorough testing REQUIRES REPLICATION to VERIFY results." That means if you didn't recreate it, it isn't true, it's a failed theory EVEN if it's accepted by the masses. Earth is flat, stationary large plane of ice with some melted puddles where life has sprang up...brings to mind Darwin's Pond. As far as gravity and apples...why didn't the other apples on the tree fall at the same moment? Why didn't the apples in the rest of that orchard fall, too? Why didn't every apple on every tree in the world fall at the same time if gravity was the culprit? Did it zoom in on that one apple? Does it do that daily? Why are there even apples on trees or any fruit at all ever? How could there even be trees if a seedling had to battle the same force holding oceans to a spinning hurling through space ball? It makes no sense.It seems like when the apple ripens and gets to heavy for the stem to support it that it falls from it's own weight or a weak stem. It only happens to the one apple at a time. It can hold in the oceans but every morning you can see dew stuck to the underside of leaves...gravity doing nothing. And you claim gravity holds the moon in place and larger objects attract smaller ones but Earth hasn't attracted any other moons and nothing else on Earth has anything smaller sticking to it or orbiting it based on size or core attraction. Scientific Method says "Thorough testing REQUIRES REPLICATION to VERIFY results. You can also see dust in a sunbeam...not affected by gravity. They lied. Wake up and do some research instead of trying to prove the same stuff they have been trying to prove FOREVER and still have not done it. It's density and buoyancy, that's all. Gravity is a failed theory or it wouldn't still be called a theory, it's that simple. #ResearchFlatEarth

[@sandylewis79]

FFS

[@JeffVanRooy]

Conspiracy Theorists: Failing at math, science and common sense since they dropped out of high school because thinking is hard. They're so lol

[@PeterArnold1969]

So good to see you again, Dianna. you are the true essence of a communicator, taking the complex, and explaining it as easily as you can. Happy physics-ing, lovely lady.

[@julieenslow5915]

You are delightful! I had quit my interest in many sciences because those that could teach were so boring and unrelatable! Now at 68 I find renewed interest in physics, astrophysics and even chemistry. Chemistry failed me when a retired industrial chemist retired from industry and chose to try to teach high school chemistry. He had a PhD and simply could not get down to Chemistry 101 levels. After a few weeks, the students had quit listening, and he took to telling stories about his career to make it look like he was teaching and we were listening. He then graded us on a curve - I took top marks - which of course meant exactly nothing. Fail is fail is fail. Being the one that failed the least is still a complete fail!

[@kashansaleem9595]

Never been this early! Welcome back BTW

[@RetrogradeBeats]

Information paradox also known as finals

[@CanadianaJan]

Been a physics geek for several decades now, but I've never seen curvature due to gravity demoed using a sheet of paper on a globe before. Fantastic analogy!

[@crisdekker8223]

Cool that you're uploading again! One thing though on the equation you show at the 1:00 minute mark: the g you underline in that equation has very little to do with gravity, it is the metric tensor. Gravity (which you explained is actually the curvature of spacetime) is described by the Ricci tensor R, so you should underline the R (s) instead.

[@ashishgeorgeaby8404]

"we've never even seen a black hole" Not anymore!

[@jaypatil4047]

@S Li so why everyone saying we have first picture of black hole .

[@learnprog5350]

@@jaypatil4047 The same goes with atoms, that picture proves theories about black holes, but to get directly the photo of black hole is impossible , because light cant leave it.

[@lyaz0939]

@@jaypatil4047 they got a picture of the stuff around the black hole, that's all

[@jaypatil4047]

@@lyaz0939 black hole is the object that have strongest gravitational force right.

[@mr.perfect8746]

If you are in a room with no light do you see it? I know it seems like a trick question. What you "see" is nothing, but if you work on it you could measure the dark room, find the edges. That's sort of the case here.

[@MrPanama9red]

This bubbly 'Lil gal is great at explaining things by not making it boring! Love her!!

[@Sheptsh]

Informative, entertaining, and funny as usual. A great watch as ever.

[@abhineetsharma1561]

The video was didactic and informative. Can you please make a video on quantum computing and string entanglement. Also what are your thoughts on the recent news about "time reversal" using quantum computing.

[@hganeshniranjanrao8754]

that info and ur approach to the explanation of the subject in hand in simple terms was just mind-blowing for me ... I have read abt space-time fabric and space-time wrapping around celestial bodies with gravity ... but this was by far the simplest and analytical explanation ... when you explained with the space-time wrap analogy with latitude and equator ... I was speechless ... just fell in love with it

[@nikvolt8298]

Woot! The picture! I thought I was the only one that was excited by First M87 Event Horizon Telescope Results. III. Data Processing and Calibration

[@lostlatinlover]

The only energy that can escape the pull of a Black Hole is Physics Girl's Energy!!

[@RR-mp7hw]

That is corny, but she is corny.

[@THEO-np1fv]

YO, the only informational channel i watch

[@abbasabbasli4590]

Let's bring it back to black holes See, they are inescapable

[@AnastaAnam28]

I laughed far to much at this joke

[@niranthbanks3595]

Amanda Gray You are not alone.

[@mael-strom9707]

Actually not true, black holes are needed for universes to re-exist ...'coz 2nd law of thermodynamics means all universes succumb to heat death.

[@silas6583]

Custom made black hole animation? Wicked. Keep it up.

[@jonoestreicner]

Ive watched every single one of your vids and i love your enthusiasm to the subject. I wonder who the script writer is, unless you do your own?

[@ayush612]

2:32 Flat Earthers be like: Hence proved the Earth is flat. Thank you. Bubye.

[@orsettomorbido]

LMAO

[@mael-strom9707]

All phenomena is bent ...no such thing as flat or straight. ...lol.

[@OrangeC7]

@Ummer Farooq ik man, it's just math! I don't get what all these round earthers are going on about.

[@yugesh99]

Same old words and cartoon as your proof, it's scary to wake up when you are enjoying your dream.

[@Zan219]

@Ummer Farooq a flat universe is still up for debate

[@chinmaytamhane]

Yessss..... finally a video after 4long months.....and first video of 2019😄😄😄😄

[@aresmars2003]

2:50 The line of constant latitude won't feel straight on a globe. The opposite is true. Walking a straight line will be a great circle path that will shift towards the equator, so your compass direction changes.

[@krisoutland1529]

It's like keeping a angle of direction and elevation in a plane. It cant be constant.

[@krisoutland1529]

@@Repurplecirculation right!!!

[@amanjotsingh7172]

Amazing video. Your videos always motivate me to study more physics🙂

[@mael-strom9707]

Unfortunately is still stuck in the Newtonian/Einstein closed system teachings.

[@paulthompson9668]

Your videos are great. Could you possibly do something like what Numberphile 2 does and have a Physics Girl 2 where you go into the math at a Physics 101 level?

[@PruthviRajKonu]

I like the way you visualise this physics of gravity and black holes. Completely understandable to anyone.

[@Abhishek-zo9jn]

I was thinking yesterday... what are you doing nowadays.... why no video... 😭

[@AnastaAnam28]

Ive actually gone and looked a few times, thinking i missed a notification!!

[@divyajeetsingh2620]

Samee mann

[@shalinshal76]

Same!

[@DennisSantos]

"That's a Physics Girl black hole!" LOL

[@fredflintstone9657]

I had a bad thought when she said that. Come to think of it, I have a lot of bad thoughts about her....😍

[@shethtejas104]

I like the way you think baddie ;)

[@doctorwatson1000]

@@fredflintstone9657 like could that hair possibly be short and curly?

[@fredflintstone9657]

@@doctorwatson1000 I wasn't gonna say, but....

I love you. Not in a creapy internet stalker way but the Midichlorians inside get al bouncy when you get excited. Gravity is my favorite physics phenomenon

[@krisray9]

Did you change your thumbnail after april 10 image??

[@RayRay-zt7bj]

I'm guessing that Diana had some good connections. Either that or she time traveled to the future to steal the photo and then back to March 8th to post the Event Horizon Telescope black hole image.

[@jacobapple1984]

@@RayRay-zt7bj or she just changed the image recently... However the time travel theory is just as likely so who knows?

[@davidespinoza102]

Bruh this woman changed the thumbnail BRUUH

[@mahditr5023]

It was so funny to read

[@ViralsexY2K98]

David Espinoza bruh

[@c.c.244]

no repeats

[@leonardirving3307]

Besides the education you provide in your videos..I just love the enthusiastic mannaer in which you do it !

[@orangesweetness]

Thank you for this video! I love and appreciate how you explain things so everyone can understand!

[@Area43-uBoot]

One of the most underrated channels on KZbin

[@noorjahannoorju1283]

Excellent class really good From India (kerala)💕

[@isi6402]

you can escape from blackhole if you are in event horizon with speed greater than light and travels time in back.

[@dehradooni007]

Yeah

[@LaithRogue]

I'm so glad youtube recommended me such a video! great video Diana, Much love ❤

[@alexanderm6862]

Thank you Dianna for all your videos, you send so much positive energy, even i can feel it thru the screen

[@stephenlangsl67]

Hmmm,...Physics Girl mentions Mathew McConaugughey and just then,He enters the room that She's in.

[@roy4173]

I feel myself getting a paper cut every time she straightens that sheet over the globe

[@DRiungi]

now i can't unthink it

[@davidmurphy1207]

The paper isn't at an extreme enough angle.

[@jerryp1970]

Dudette, you're awesome at these explanations, I really enjoy learning and sometimes relearning this " stuff" ! Plus it helps me explain some of the "stuff" I've been trying to explain to my friends!😂 thanks kiddo,

[@KnightSlasher]

But where does it lead to _nobody knows_

[@bertberw8653]

White holes

[@linyenchin6773]

Usually welfare...

[@marc_frank]

@Marnige no need to make an opinion out of it

[@YTANDY100]

@@marc_frank um , i think id want a ladder ti climb down because the bottom may be a bit hard :-)

[@marc_frank]

@@YTANDY100 lol

[@bakamitai4723]

(3:00)The videos on my side bars are Hottest Himalayan Salt Lamp Ever By:King of Random History of the entire world, i guess By:bill wurtz And lastly Memes about black hole

[@Ranstone]

Mine: "How to become an executioner"- Today I found out. "Thunderturn Pt4" -OffTheRanch "Is Earth actually flat"- Vsauce. Close enough. XD

[@manjedfredson]

Great way to explain complex issues ..... thanks!!!

[@SahilP2648]

Ok so I wanted to add a couple of things. First of all, remember that I am no astrophysicist and secondly, I have no references, so take it as you may will. A black hole is also called an invisible singularity. Singularity why? Cause it is one object that breaks the laws of physics (or doesn't, we just don't know it yet). Light cannot come out of a black hole, not because of gravity (photons do not have mass), but because of the curvature of space-time itself. Think of it like a bottomless well which once you start falling inside, you will fall forever. Now what happens in reality is that any object nearing the event horizon, start going forward in time (yes that is relativity for you), for the observer, it seems like the object is slowing down (even though the gravity is increasing with decreasing distance). This is because any matter in the universe exhibits gravity based on its density, the higher the density, the higher the gravitational attraction. Now why is this important? Cause these large celestial bodies actually curve space time in a way such that the rate of flow of time decreases the closer you are to a body with high gravitation. So for example, the Sun which has higher density than the Earth, experiences a decrease in flow of time relative to Earth. A black hole is an entity where the space time curvature is so much that because of this property, the rate of flow of time reduces exponentially as you move towards the event horizon. That is why objects falling into the black hole (while you can see them) will seem like they are falling indefinitely. Now at the event horizon, these objects that fall in, from the observer's point of view, the objects get stuck in time forever. So when you consider light, its not because of gravity that the light cannot come out of the event horizon, but its literally because for us, the light or whatever object that has fallen inside the black hole are literally frozen in time. Thus, the objects form a layer on the outskirts of the black hole (which we cannot see) but are present in a squished sort of way, thus preserving the theory that information cannot be lost. Now for the objects that fall in (they are no longer objects anymore but destroyed into elementary particles like atoms or quarks), we don't know what happens from their point of view, cause from their point of view, time flows regularly and at the same time they are inside the event horizon. Black holes grow in size the more matter they consume and this can be observed. There is one theory that states that as black holes grow in size, they will ultimately merge into one huge black hole, which can form another universe inside it. Black holes are the only objects in the universe that defy laws of physics. That is why I think that if this universe is a simulation, that is probably a bug in the code of this simulation.

[@taileenalvarez1626]

Wow found this really interesting

[@SahilP2648]

@@taileenalvarez1626 thanks! If you haven't already, you should check out Kurzgesagt. Their videos are some of the best videos on YT, if you like science that is.

[@gigglysamentz2021]

Spoiler alert: the hairs on black holes aren't straight fur that make them look like cute fluff balls, but they're stuck to the event horizon, making them look more like sweaty...uhm...

[@AnastaAnam28]

Dying 🤣🤣🤣

[@niy._.]

What? I did not get it?

[@Howtard]

@@niy._. TESTES.

[@anpdm1]

@@niy._. Curly afro hair or infinite Fibonacci spirals...some only experience it when their testicles get sweaty.

[@victorcarneiro559]

It's just incredible how you can make accessible some very hard concepts. It's just great.

[@IroAppe]

So I have a question to the Black Hole Information Paradox. Why does a black hole "destroy" all the information? Just because we can't see beyond the event horizon? I mean the matter falling in there is still there, or not? It might be very cramped together and all, but then the information is just transformed, but still there. Only not accessible to us. Or is there a fundamental problem of us not being able to access it, even if it is there, just not accessible?

[@ObjectsInMotion]

It wasn’t mentioned in the video, but basically we know no black hole is stable. They will all evaporate, leaving nothing behind. But since nothing can escape, what happens to the information when the black hole dies? That’s the paradox. Basically one answer is that “hair” makes evaporation uneven and that’s where the information goes.

[@JonDraine]

I like to think I that a black hole is the other side of a new Big Bang. Its gathering up information and materials to eject out and form a new universe. Recycling in an epic scale.

[@IWTACoaching]

An enquiring mind wants to how physics girls thumbnail picture of a black hole for this video posted a month ago is identical to the actual picture of a black hole released in the past 24 hours??? Proof of time travel!?!?

[@zahra-bs2pz]

IWTACoaching I’m shook

[@Ninnepinne01]

Omg i thought the same thing wtf

[@louisfoley6955]

Ikr??

[@bolarastaburas3855]

Possibly she changed it when the picture came out.

[@almarma]

@@bolarastaburas3855 I guess you're right. The thumbnail is just an image the creator can add later to the video and it doesn't need to be part of the video itself, so it's quite possible she updated it today to get more views or to celebrate the news about it (or both) :)

[@mattkim4289]

Your manner of describing things so we'll that laymen can understand these concepts alongside your exceptionally placed humor is pretty awesome. Not to mention being quite pretty you surely are able to pass along science to those who wouldn't typically be drawn to such. Awesome work!

[@paradox...]

3:51 *rude!*

[@jjd1799]

Have you ever thought that the human eyes imitate, black holes in regards to light. Lights is forever bleeding in and never escaping out?

[@JasonWW2000]

But it does escape. You can take a picture of the back of your eye.

[@kenniengland]

But we literally see by light bouncing off our eyes lol

[@harrysvensson2610]

3:15 this is very similar to 64/16 = 4 You just cross out the 6's and get 4/1 = 4 You get the correct answer but with weird/illogical reasoning. Showing that the earth is round -> you get a curve on paper is more or less just a coincidence, it shouldn't be used as an argument or a way to explain anything really.

[@roadrules3671]

When i was a kid; my aspiration was to work for NASA. But then i found out you had to be really good at mathematics. Today; i drive an ice cream truck for Jack & Jill.

[@Souravkumar-zq9ip]

And what happens to the information when a blackHole evaporates.

[@nafrost2787]

There are two main ideas. One the black hole creates a parallel universe that the information goes to. Two there is some mechanism that causes the information to be imprinted on the Hawking radiation.

[@JorgetePanete]

you forgot the question mark blackHole? that'sWrong

[@danilooliveira6580]

because as far as I know that is exactly what sparked the idea of blackholes erasing information, not the singularity. because if blackholes were eternal you could say that if you reversed time all the information would leave the singularity to its original forms. the problem is that when a blackholes evaporates, the information containing inside the blackhole is not imprinted on the hawking radiation, meaning the information that was supposed locked inside the singularity is gone. so if you reverse time, the hawking radiation would create a blackhole, but it would have no information of what it would spew later.

[@chinito77]

All matter pulled into a black whole converts into dark matter which pours into an alternate dimension. Our current expansion is the result of another dimension's previous information and the black holes present in our reality pour data back into another dimension. Think of it as an almost never ending loop.

[@crawlinginfilm9683]

What if one lump of information lands “splotch” exactly on top of (the imprint of) a previous lump of (some other) information? Wouldn’t that make a mess out of both lumps?

[@tonywilliams7104]

Thanks Nature, Stephen Hawking and you.... Physics Girl... good science is all about investigating and being fascinated.

[@esntlaman3433]

I missed that 'happy physicsing'

[@GlassTopRX7]

How is that any different than Leonard Susskind and Gerard 't Hooft, holographic principle?

[@garethdean6382]

The holographic principle is broad it says it may be possible to encode all information about a 3D space in 2D. This theory provides an actual mechanism by which this can be done. Plus it relates to a few other things like Hawking radiation and how it might remove information from a black hole.

[@schokoladenjunge1]

@@garethdean6382 somehow i knew I would see you somewhere here, on the most interesting question around

[@GlassTopRX7]

It'n not may be possible it is possible that's not disputed. The holographic principle doesn't require that kind of modification in the first place to be viable. The black hole evaporation fits nicely due to quantum effects but I fail to see anything this adds to that. At least not as out lined here, this is all info that is 3 decades old.@@garethdean6382

[@floyd3276]

@Michael Bishop just like Bekenstein which was never mentioned in his documentary. If it were not for Bekensteins work Hawking never would have come up with Hawking radiation.

[@garethdean6382]

You've got to pay attention to what has and has not been proven. We're pretty sure black holes emit Hawking radiation, that's not proven but seems very likely. It's been proven that if they do AND they preserve information then the holographic principle must be true , an HP-type mechanism must be at work. What was NOT shown however is HOW the HP worked in this case to store information. If it was then you could link to a paper that provided that mechanism and proved the math worked out. Hawking (and co) has developed a specific mechanism of HP-type that could explain how black holes preserve information. He built on earlier work.

[@jacktribble5253]

I always suspected we were a little warped... Great animation, by the way.

[@SIDEKICKONYOUTUBE]

its 2019 is this still what we think of black holes ?

[@despitefallacy478]

Kind of in a fractal geometry type of way it would explain how our universe could be infinite

[@jasminehguerra6459]

tell me more!

[@debashishroul3875]

Good explanation

[@Creepyseven]

"What does he mean?" - I think it would have been cool if you had given a shout out to the main author of the paper. Hawking was "only" a co-author after all. Working with a famous scientist shouldn't result in having your name erased because you put them as a co-author.

[@RocketDragons]

Per the paper itself, there is no main author. There are four co-authors, listed in alphabetical order of surname. A video title is only so long, why not use the name that will get the most attention for the research?

[@itzalex9216]

the 450 dislikes are from flat earthers

[@1971sls]

Don't forget the inner earthers!

[@rubetornabene8543]

And Muslims

[@najamalam4486]

@@rubetornabene8543 and catholics, orthodox, protestants and jews

[@nevermind6209]

People who don't buy into this nonsense.

[@hardbiker2k3]

@@nevermind6209 Those people are called Idiots

[@DougE.phresh]

excellent discussion AND excellent hair you earned yourself a like

[@francoislemoan126]

I have a question. Does that mean that the more objects the black hole absorbs the bigger it's event horizon gets?

[@JasonWW2000]

Yeah. As it's mass goes up its gravitational pull increases which means the event horizon extends outward. At least it makes sense to me.

[@paulvinova]

You changed the thumbnail? That, or either you had the black hole picture for over 1 month ;)

[@octobias6705]

she changed it

[@chandnakumar4161]

What you do is an absolutely wonderful job and the best part of all your videos apart from questioning science itself is enjoying your witty puns ! Thank you so much ♥️😭 Lots of love from India

[@victor9]

What does information mean in this context?

[@cakeisamadeupdrug6134]

That's a really good video concept in itself. Most people do not have enough of an understanding of Information Theory for QM and GE to make sense when it comes up there.

[@plateoshrimp9685]

I can't totally explain this, because I don't fully understand it myself, but it's information on the quantum level that is being referred to. The quantum state of a particle at a given time should always be related to it's state at all other times because quantum field theory works both forwards and backwards in time. The destruction of information refers to the breaking of this connection. In other words, putting the particle into a state from which it's state at other times could not possibly be determined. It breaks quantum field theory. Or something like that. This is as close as I can get to understanding what is meant by this. I only offer this explanation because the video sort of makes you think she's talking about information on a macro level, and that's not it, Matthew McConaughey most certainly can be destroyed.

[@davidwuhrer6704]

Bits and bytes. Or nits and energy per temperature. Same thing really.

[@Ranstone]

Stuff is made of molecules, molecules are made of atoms, atoms made of protons, nutrons and electrons, those are made of quarks, and quarks are held together and function off of gluons (Debatable). Gluons are energy, so they're indevisible, but are _supposedly_ made of just energy information. By information, we mean "Yes there's energy hear, no there's no energy there" ect. kinda like binary code. (01001100 01101001 01101011 01100101 00100000 01110100 01101000 01101001 01110011 00101110) Very theoretical, but whatever makes up the base of everything, what defines all the yes and no's of the universe is essentially information. _Note: I missed a few steps in what is made of what for brevity's sake._

[@apeflac]

3:01 "no matter what the videos in the side bar may tell you" LOL I can feel the pain and frustration as an educator on KZbin

[@ThePinkus]

Thumbs up for the illustration of the point that gravity, as described by GR, is not a force. There's a lot of fixation even among physicists on gravity as a force, hence as a (fundamental) field theory. On the matter of what BH's are, first of all they are certain solutions to GR equations, which yield certain consequences such as that there's an event horizon from which nothing escapes. We somehow get the picture that things fall in and are "lost" to us, or rather the BH (its properties) is all that is left as physically accessible to us. In a sense what is accessible includes the proximity of its event horizon, though properly this is still the "outside universe" (relative to the BH). But is the "sink hole" the right picture? When things fall into the BH, when they reach its event horizon? For any reference system of the outside universe, not at any finite time: it takes an infinite amount of time for something to be seen as falling in. The picture that is given and objective to the outside universe is that of energy-matter accumulating on this side of the event horizon. This "seeing" that we are talking about is not simply appearances, they are objective relations under general-relativistic laws. When we determine a distribution of energy-matter to put into the GR equations, it is in the very same sense as we are now speaking of "seeing". We started by saying that BH's are certain solutions to GR equations, but these solutions, via the equations, corresponds to energy matter distributions. Proper theoretical BH solutions have infinite density at the singularity inside the event horizon. You can get to that by considering a fixed energy-mass and progressively reduce the volume it occupies. But this is not a physical process, it is an analytical path through a set of solutions of GR. At some point we get an event horizon, and the consideration that this has the property that nothing falls in renders the analysis we were following suspect, at least in view of describing physical BH's. We do know that the solution for an energy-matter distribution outside of the event horizon is not the same as that of an infinite density at the singularity. Furthermore if no energy-matter is inside the event horizon, we would not have a well defined solution inside of it (where there is no energy-matter, GR doesn't have a unique solution). Einstein though that these multiple solutions would represent the same physics, I think this scenario suggests the possibility that simply geometrodynamics is not defined where it is not well defined: there is no inside. And this latter point makes physical sense to the outside universe for the very fact that it sees nothing getting in. A physical black hole might not be described by the traditional proper theoretical BH solution, with an inside and a singularity, rather by a solution considering that energy-matter is accumulated on this side of the event horizon. Then, the picture is not that of a sink-hole, but that of a geometrodynamical cavitation: what is cavitating due to high energy-matter density is the very geometry of spacetime. And we probably shouldn't think that there is an inside (well defined to the outside universe), we have no reason to think that the geometry of spacetime is embedded in any other extension, curvature is intrinsic, and in the cavitation scenario it does not extends to the other side of the horizon. The benefits of this scenario are: - it fits the idea (it is based on it) that it takes an infinite amount of time to "see" anything fall into a BH, more precisely, to this universe nothing falls into the event horizon, rather it accumulates on this side of it, - there is no singularity, - there is no information loss, - makes sense of the result that BH entropy is a function of the area rather than the volume. The cons: I don't know if it is right. :P

[@lewribaedi5997]

"No matter what any of those videos on the sidebar may tell you" Up next: Vsauce - Is Earth Actually Flat?