The Black Hole Information Loss Problem is Unsolved. And Unsolvable.

[@mathewahrens4475]

Peanuts aren’t nuts???????

[@poo2uhaha]

They're legumes ;)

[@SabineHossenfelder]

No, technically, they're legumes. And cashews aren't nuts either. Not that it matters as long as you understand what's meant, but goes to show how imprecise accepted terminology can be.

[@derekfrost8991]

They're not peas either.. 🤣

[@rubenanthonymartinez7034]

That may be so, but both give me gas, as far as I'm concerned they're the same!

[@Bassotronics]

Black holes drive me nuts.

[@TheGodfatherjohn]

My name is John. You scared me. I was actually doing something else when you said that . It was an amazing experience.

[@bangers1962]

Exactly the same experience here. Had a flashback to being in school.

[@JonSebastianF]

@@bangers1962 Me too! I freaked out :O

[@fredburns6846]

Me two and i actually wasnt listening

[@andrewpriest9403]

@@JonSebastianF Do all the people stop and shout whenever you guys go out?

[@chocolatepiano7366]

@shashanka Mg Didn't he used to write for Scientific American?

[@GururajBN]

"If you try hard enough for ten to the power of five hundred and thirty years!" "vacuum cleaner does not clean vacuum!" "Of course, everyone likes their own solutions best!" Another set of Sabinesque statements. You are simply unbeatable when it comes to quips. By the way, what a "wow" dress.

[@Retro_Rich]

Vicky Gill could have designed that dress. Definitely a ten from Len.

[@kirkkohnen5050]

Sabinian.

[@williamcozart9166]

@@Retro_Rich who is Len?

[@ps200306]

@@williamcozart9166 , I imagine it's Len Goodman since that's a quip of his. On the dress thing, definitely the most coordinated outfit + background to date. I took it as an artist's impression of Sabine enhaloed by Hawking radiation.

[@josephjohnson3738]

Sabine always dresses in outfits that are quite grand. But her science, like most, is just gobbledegook. Pretend discoveries.

[@NyscanRohid]

"John, are you listening?" Ouch.

[@JeffNeelzebub]

I don't get the reference. Is she calling out someone in particular or is it just supposed to be a joke?

[@JeffNeelzebub]

@shashanka Mg Thanks!

[@ps200306]

@shashanka Mg , surely she's talking about John Preskill who was on the side of information preservation in the Thorne-Hawking-Preskill bet?

[@Bassotronics]

John aka The Report Of The Week

[@sageinit]

@@ps200306 no: twitter.com/skdh/status/1324340529593753601

[@geraldmerkowitz4360]

"Vacuum cleaners don't clean vacuum, dark energy is neither dark nor energy" This line is epic

[@zolniu]

English language is full of nonsensical names like that: "pineapple" is not apple nor does it grow on pines - can we just call it "ananas" like the rest of the world? :)

[@ZeHoSmusician]

No, it's not epic. In the expression "vacuum cleaner", the word 'vacuum' describes the process by which the machine cleans--by creating a vacuum (or at least a significantly large air pressure difference)... Therefore, by that logic, "dark energy" could indeed be energy that is described as 'dark'--and, arguably, it is (that's why the expression was coined). That being said, peanuts are indeed NOT nuts (so, a misleading name like 'pineapple').

[@BladeRunner-td8be]

There are hundreds of other things which are even worse. A certain political party in the U.S. has, for years, named Bills which describes the exact opposite of what its intent actually is. And it works, the people vote based solely on what they think is in the misnamed Bill based on the title. If it weren't so sad it would be hilarious. Cheers

[@sillymesilly]

Then they really need to name things accurate. Or invent a name based on action or property.

[@JB-ue6lf]

@@ZeHoSmusician Thank you!

[@rainerlanglotz3134]

Wolfgang Pauli was frequently called the "conscience of physics". Sabine represents this function in the 21. century. Chapeau!

[@fluentpiffle]

"Finally, if nothing can be truly asserted, even the following claim would be false,
 the claim that there is no true assertion." (Aristotle)

[@dzonybajlando9270]

My name is John, and i wasn't listening for a second. 3:57 at this moment, the coincidence got me a lil bit shocked 😮

[@askingEveryone]

I'm pretty sure that was directed at John Horgan (I figure they are pals): twitter.com/skdh/status/1324340529593753601

[@ps200306]

@@askingEveryone , I thought she meant John Preskill who was on the side of information preservation in the Thorne-Hawking-Preskill bet ... but your Twitter link looks persuasive.

[@poo2uhaha]

Razor sharp physics delivered in 11 satisfying minutes; this is why I subscribed :D

[@LS8eighteen]

Refuting other people's work is all she does these days. What is razorsharp about that? Has she published on black holes or the subject? No

[@Bambabah]

@@LS8eighteen She literally said it's for all practical purposes unsolvable.

[@rtfgx]

@@LS8eighteen yes she did. She says it in the video

[@AndrewBlucher]

@@LS8eighteen You seem to be confused. She is a University academic, and makes a few YT vids on the side as a public education service. As a trained physist I can tell you that there has been a problem at the heart of physics for the last 30 to 40 years. It's not that I left the field. It's lack of progress. Lack of progress in science is always a sign that you're going in the wrong direction. Sabine points out several philosophical issues with current work, such as preoccupation with math, pursuing approaches for which there are no evidence, and using scarce resources for those.

[@ragir]

@@LS8eighteen She says in the video she published several papers on the topic, should've watched till the end before getting that pitchfork out :P

[@markmartin2292]

You have the coolest wardrobe! Sort of Emma Peel as designed by a Soviet Constructivist with some Italian 1920s Futurism thrown in. Awesome.

[@SamA-qf2dy]

Just noticed the same thing leaving out Soviets and Italians.

[@ThomasJr]

Mark, you are gay. Am I rite?

[@BizVlogs]

It’s just stripes dude. You’re coming across as incredibly pretentious.

[@davidludwig3975]

I've always loved physics, but I could never handle the math. I love your videos because you really explain things in a way I can process. Thank you.

[@morty908]

This is one the best videos about science in general that I have ever seen. The distinction between doing science and doing math, resolving how there can be so many different 'resolutions' to science problems that don't actually resolve the problem, while simultaneously exposing how clickbait titles and the desire to churn out papers play a negative role in all this. This should be played in every science class everywhere. I think it can do nothing but reassure students that science has always been and always will be about experiment, not conjecture.

[@imagiro1]

I tried unmixing my dough. But before I finished, my kids came and ate the cake I didn't yet unbake. Then I noticed, that I don't have kids. Now I'm confused.

[@philjed5178]

i may have a unconventional but consistent approach to your problem: may it so be, that perhaps instead of your children - currently in a more virtually state of existence - you ate your cake? and therefore you first have to undigest it for all your other proposed experiments? so what ever you do DON'T FLUSH!

[@harriehausenman8623]

You gotta get unentangled quickly!

[@michaelskywalker3089]

You are confused because you conveniently forgot that you changed your mind while un-mixing the dough and reversed those actions far from the prying eyes of the observable universe.

[@heisag]

I found that the best way to umix dough is to heat it up for a little while, then let it cool until i can use my teeths to do some rough unmixing.

[@johnwilson4909]

I suggest listening to MacArthur Park sung by Donna Summer kzbin.info/www/bejne/fYipeYl4o7dqfZI

[@SAVVALEX]

As always, another common physics problem presented via a totally unique perspective that no one is talking about... Outstanding Sabine!

[@geraldmerkowitz4360]

PBS Space Time have a very interesting series of video on the subject, though Sabine's video already said it all.

[@fluentpiffle]

"Finally, if nothing can be truly asserted, even the following claim would be false,
 the claim that there is no true assertion." (Aristotle)

[@shelley-anneharrisberg7409]

"Physics is not mathematics. Physics is science" - pure gold. And learned that peanuts weren't nuts!

[@DJVARAO]

NNN

[@orlock20]

Science is a process while physics is the state of being.

[@davidwuhrer6704]

Mathematics is still science. If something isn't true in mathematics, it isn't true at all. Philosophy is applied mathematics: Anything can be expressed in mathematics, and then tested for consistency. Physics is another name for natural philosophy. It is a philosophy in which the final, and only, arbiter for truth is nature itself.

[@DJVARAO]

@@davidwuhrer6704 Nice play of words.

[@helicocktor]

Mathematics is a language we use to communicate with the universe to understand its laws.

[@lorenzo.bernacchioni]

"He's a decent guy" is Sabine's best compliment 😅

[@Thomas-gk42]

I love the "OR"s, wonderful explanation, thank you.

[@domainofscience]

This was great, thank you for you clear explanations.

[@sebastianclarke2441]

Hey great to see you here! A good bit of ammo for one of your upcoming vids, hey?

[@aniekanumoren6088]

@Arthur Dent dude she's German it's called an accent.

[@NeilCrouse99]

@Arthur Dent You are aware that her first language is not English? I think she's doing pretty damn good explaining quantum related subjects in another language,... It just feels like this might be a situation where "Don't sweat the small stuff" might be a classy way to go,.. No??

[@thechessmaster9291]

@Arthur Dent They are , but your dendrons also seem glued together , so now what to do ???? Seems like you are in a pickel now.... ;-)

[@thechessmaster9291]

@Arthur Dent Dear Arthur , I speak German , English , French , Italian , Spanish , Dutch , and studied Latin and Greek . Trust me .... , when YOU make a youtube video , i will be really impressed . Maybe she was born in some Kuhdorf im Arsch der Welt ? Who knows ? Who cares ? She is hilarious ( no offense Sabine) , and very Brave , but I am sure you missed that movie.... ;-)

[@mikesawyer1336]

I am listening -- Sabine, I really get so much out of your lectures. Every time you post a video like this I drop what I'm doing to listen to you. I have literally nothing to offer in return, and may never fully understand physics, but I am captivated.

[@talldarkhansome1]

I love how you keep the categories separate. Physics, math, and philosophy. It's good to know how unsolvable things can be without data and how the media (not the scientist) hypes the headlines. Looking forward to understanding how to think about Warp Drive theory as the most hyped problem in popular entertainment culture.

[@Lincoln_Bio]

Warp travel is easy, just fly toward a blue-shifted star, it'll be closer by the time you get there. And the faster you go, the slower time will pass while you travel. *Relative* faster than light travel is totally possible, the universe breaks the speed limit all the time. Relativity in an expanding universe is fun!

[@angelmendez-rivera351]

@@Lincoln_Bio That's not warp travel, this is time dilation. And that isn't how relativity works either. There doesn't exist a frame of reference in which any objects with nonzero mass travel at the speed of light or faster. Even if I travel to the Andromeda galaxy within a period of 5 years, the speed with respect to the frame of reference of the Earth is still less than 299 792 458 m/s, and it will always be measured as such for the 100 000 years that may pass on Earth while I do my trip.

[@Lincoln_Bio]

@@angelmendez-rivera351 I know it's not proper warp travel, I just mean space already warps itself, which is cool! If you look at redshifted light, the distance it has travelled has expanded by the time it reaches its destination, so its ultimate distance over time is indeed > c. It still travelled @ c in its own temporal reference frame. This is how the Universe can be expanding @ > c. c is only the speed limit in our everyday 4 dimensions, the Universe laughs at such things ;D

[@angelmendez-rivera351]

@@Lincoln_Bio No, that is not how that works. First, you have a very fundamental misunderstanding of how speed is defined. The expansion of the universe has no speed, because it is not a movement. The rate of the expansion of the universe is measured in SI units of 1/m^2, while speed is measured in SI units of m/s. Thus, it makes no sense to talk about the expansion of the universe being faster or slower than c: it makes no more sense than saying 5 °C is hotter than 15 kg. Second, space is not being expanded. Spacetime is being expanded. The redshift tells us information about how the metric of spacetime changes with respect to proper time, but the speed at which the light is traveling is not changed, because all of spacetime is expanding, not just space by itself. Therefore, nothing is traveling faster than light. Spacetime expanding is not a form of travel, and there is no speed associated to it, because the rate at which it happens is not a speed, but an inverse length squared. I suggest you read up some general relativity material if you want to continue having this conversation, because we will frankly get nowhere if you continue adhering to this fundamental misunderstanding of how speed works and what a frame of reference is.

[@Lincoln_Bio]

@@angelmendez-rivera351 Sorry, I do mean space-time is expanding, I was trying not to get too technical so I've probably not got myself across too well. Space-time is the everyday 4 dimensions I referred to. And yes expansion has a *rate*, not a *speed*, what I meant was how 2 points at opposite ends of the universe can appear to be moving apart at a relative speed > c if we do not account for that expansion. I think it helps to think of expansion as a 5th dimension, but that's just me. I'm not saying anyone's right or wrong & I appreciate the discussion :) I started trying to get into the maths of General Relativity but I got a bit stuck on Equivalence when I realised gravity is therefore negative kinetic energy, which seems important and requires further investigation. And the gravitational constant appears to just be a conversion between Newtons & kg, it all seems rather circular & we're accounting for mass and gravity over & over again in the maths. Physics infuriated me at school because Newtons are clearly an arbitrary measure of force, I much prefer the well defined kilogram. We can only calculate mass from weight, not the other way around, at least without a bunch of other variables like volume, density, chemical structure etc. So I'm going back to basic principles to see if I can come up with something better that uses measurable values in SI units. Not got a lot else on, I figured why not, Einstein came up with Relativity while he was bored at work right? ;D

[@Leon-kb5qs]

This is exactly how you democratise/popularise science! So many try, yet I haven't seen anyone doing it so well! I love how calm and detailed Sabine's explanations are, many science channels either are too superficial or go at lightspeed. Well done!

[@christianstandridge1285]

I am so much reminded of my partner when I watch your videos. He’s a post-doc at the Max Planck Institut in Berlin. Thank you for your entertaining and informative videos!

[@vincentclark5739]

I like how the background goes well with your dress! The your lecture is amazing as usual

[@melm4251]

"physics is not mathematics" in 4 words you've summed up my problems with a good chunk of modern/speculative physics haha

[@Jolly_Rodger]

mel m Absolutely agree. Mathematics, which used to be one of the tools of Physics, now has become the Physics itself. The problem is that mathematics (been abstract itself) builds an abstract models of the Universe that could be very different from physical Universe.

[@maythesciencebewithyou]

I hope you don't see that as a a justification to believe in some crackpot hypothesis made by some armchair expert, like so many people seem to do. Also, that's not a problem of modern physics, that has been a problem for a long time. Theoretical physics has been way ahead of experimental physics for many many decades and has podered about subjects that's are practically impossile to test. At the end this is just some advanced philosophy and not real science. It's at least better than philosophical ideas that are not based on scientific knowledge. At least these people have some basis to what they are doing and not totally making up stuff.

[@dlevi67]

@@maythesciencebewithyou Well, I guess the problem is where does the "basis" end, how robust is it and if it is not testable how do I know that it's actually empirically true. I'm not sure I see that much of a difference between string theory and some philosophical speculation regarding the nature of consciousness (e.g. Bergson). Given a fairly simple premise, it's amazing where one can get extrapolating while suspending the requirement for experimental verification.

[@jwrosenbury]

"It's turtles all the way down." Science is so much easier and interesting when you leave off that pesky "observation" part. The only mistake these modern physics guys make is putting their work in the non-fiction section of the library.

[@alphagt62]

I agree, math is a valuable tool that can explain many things, but it is not reality. Logic doesn’t go out the window just because math says so. I can see no reason why Hawking radiation would end up with nothing? Would it not stop, once it reaches a point that it no longer weighs enough to be a black hole? Seems to me as soon as it lost enough weight, it would become a black hole remnant, or a neutron star or some such body. If it no longer weighed enough to be a black hole, why would it continue to act like a black hole? And the problem is, no black hole is old enough to have evaporated, so there is no way to observe it happening, we will have to wait a few trillion years to find the answer. Some things are beyond the capability of humans to know.

[@Semispecula]

The production quality is getting better and better. Thank you, Sabine. A lovely video as always.

[@johnhough4445]

"John ... are you listening?" Hit me with a jolt. In fact, I actually was; but as always with Sabine her words not only deliver information they trigger whole streams of thought and query. Her timing was perfect ... thank you, Ma'am~! And now (again, as always) for another viewing.

[@RogerLuedecke]

I really appreciated how you pointed out the problem with nomenclature. It was relatively recently that I came to understand how much of a hurdle that is to comprehension. I'd propose having a whole series of breaking down problematic nomenclature.

[@anon2761]

becoming my favourite channel to see with fresh upload - thanks Sabine!

[@facundomarino10]

I want Sabine to be my teacher and my mother. Excellent as always.

[@halporter9]

Well, I am 73 so for me an exceptionally bright, talented and (especially in a 15 yo video presentation I ran across) adorably cute. Label me avuncular.

[@Squbber]

Sabine coming out here lookin like she radiated out of a black hole. Iconic.

[@kevinmathewson4272]

Don't want to distract from the content of the video but yeah the outfit is fire.

[@isabelab6851]

As someone with limited science knowledge...but who loves science, I cannot thank you enough for your explanations that are approachable without the need for deep technical knowledge

[@ivocanevo]

I start a Sabine video expecting only contagious pessimism. But when it's over, I feel enlightened.

[@peteclark9]

Does Sabine design her own virtual sets? This is one is really something.

[@PinocchioGG]

yes, the dress is phenomenal and the matching background is definitely no coincidence

[@Retro_Rich]

Is the dress Doppler effect inspired? Reminds me of the BASF sponsored BMW M1 Procars.

[@danielpaulson8838]

I wonder what color her tennis shoes are?

[@TSBoncompte]

@@danielpaulson8838 there's always a foot guy

[@KonkyPlonky]

Amazing how she everytime manages to find a dress that matches the background.

[@saraeva]

"On Saturday, we'll be talking about warp drives." Woohoo... time to invest into Dilithium mining.

[@jwrosenbury]

I fear I no longer have a Spock Broker.

[@KeithRowley418]

@@jwrosenbury ooooohhh!!!!!!!!! ouch!!!

[@jcf20010]

@@jwrosenbury Booooooo...Hissssss........Booooooo......

[@KeithRowley418]

@@buddysnackit1758 OK so there is no such thing as negative energy, the power required is simply never going to be available and we require materials that cannot exist. But apart from that it sounds just fine!

[@angelmendez-rivera351]

@@KeithRowley418 That's like asking a person who was shot 5 bullets in their chest if they're fine or not, and they reply by saying "Well, I've been shot 5 times, and I'm going to die within the next 5 minutes from major organ damage and blood loss, but otherwise, I'm doing perfect! How about you?"

[@ZardoDhieldor]

This video is particularly aesthetically pleasing! And at 4:25 I had to think about brimstone butterflies.

[@dwaynesievers1397]

I love your content!! And, I must say, I think your outfit and background in this video are great! 👍🏻

[@Unknownprara]

Finally someone explaining science without bull***t. I hate those misleading names such as "Dark Energy", "God Particle", "Information loss" and etc. It took me a lot of time to understand that superposition principle is in reality just a mathematically effective model and not actually the phenomena itself. Dankeschön Sabine!

[@bobdinitto]

I absolutely love your pragmatism! And also your very direct way of elucidating your subject matter. It really helps those of us who are interested but uneducated in physics. Thank you.

[@alamagordoingordo3047]

Sabine, always the most clear and elegant (even not in the mathematical sense) on the scene.

[@raffaeledivora9517]

I refute this statement. Logics is the cleanest and most elegant form of mathemathics

[@alamagordoingordo3047]

@@raffaeledivora9517 Sei italiano?

[@raffaeledivora9517]

@@alamagordoingordo3047 Sì

[@alamagordoingordo3047]

@@raffaeledivora9517 Per matematica intendevo in senso lato, quindi anche la logica, in fondo tutta la matematica è logica, ce lo ha rivelato l'algebra booleana e l'informatica teorica.

[@wyrdthabyrd542]

I love your dress Sabine!! What a wonderful scene cohesion. Thank you for producing one of my favorite (and highly recommended) science series!

[@leorivers7759]

Professor Hossenfelder, this essay really showcases your skills. From your explanation of irreversibly to distinguishing what math can and can not do from physics. I am not really properly educated but still, you explain to me what others leave in Mysteries - it is a pleasure to see you at work.

[@karllenasson]

"... Do not ask whether the math is right - because it probably is. ... Ask: what reason do we have to think that this particular piece of math correctly describes nature?" A very valid point, not limited to natural sciences: As an economist, I can more than relate to that statement ;-) But don't you dare ask your German professors how their super-fancy overcomplex economic models of this and that actually relate to reality (or if they do at all)...

[@WindsorMason]

Seems like people don't really know what a model is or how to judge one; they either accept it as true scientific reality or brush it off as nothing but math.

[@drdca8263]

I do think that some economic models, even if the assumptions they make about the rationality of the participants or the efficiency of a market or whatnot, are substantially too strong, and are therefore sufficiently far from accurate to not be useful when applied to actual people or actual markets (not saying this is the case of them, just saying even if it is), I think that some of them would still have substantial merit as a purely mathematical construction that just happens to be inspired by the idea of people and such. I guess by merit I mean like, aesthetic merit, and also as a potential tool for making other constructions in math with desirable properties (which could have applications later down the line). For example, the logical induction algorithm is based on ideas behind prediction markets, and I think it is very nice, despite the fact that I now think that prediction markets are probably in practice not quite as effective as I once thought (I mean, they still work to some degree, just, not as well as I hoped). Of course, how much public resources should be spent researching something on the basis of aesthetic merit, is presumably substantially less than if it were applicable in practice. Nevertheless, I personally would like for people to continue to do math that produces math results (by results I mean true conclusions. I only value the aesthetically nice math if the math is actually correct-as-math.) that mathematicians find aesthetically pleasing.

[@leovuyk]

No Hawking Black Hole, No Information Loss, NO Black Hole Evaporation?. Physics is not mathematics. Recently, S Hossenfelder ( Frankfurt university) published a video questioning the Hawking Black Hole information loss and evaporation. It says: Until now we did not observe the evaporation of Black Holes, so there is reason to speculate that there is NO evaporation and NO Information Loss as suggested by the general accepted.Hawking Black Hole model, but Black Hole Big Bangs. Other observations on black holes, does not suggest that black holes evaporate, such as central giant black holes inside galaxies. Physics with propeller shaped Fermions is not mathematics, if propeller shaped fermions (mass) do not enter the black hole but they are pushed away into discs of rotating matter and so called Fermi jets/ bubbles perpendicular to the disc plane around the black hole just like the shapes of galaxies. see: The Cyclic Undivided Raspberry Multiverse.

[@divvy1400yam600]

Re the efficacy of models see the approach to Covid. The first lockdown frequently didnt work so the solution has been to apply another lockdown based on the same modelling criteria. Nobody ever mentions how the Covid virus replicates. It seems to be assumed that if humans are isolated then the virus will die. Is that true ? Note the virus has allegedly been found in mink in Denmark. If the virus mutates easily then expect doubleplus unhappiness !!!

[@drdca8263]

@@divvy1400yam600 you appear to have responded to the wrong thread. Nothing in this thread was talking at all about ncov19.

[@MultiRRR123]

Sabine! Love your videos, greetings from México.

[@SabineHossenfelder]

Thanks! Greetings back to Mexico!

[@cremasca]

The ravage of platonism is the problem, the map is not the territory !

[@aclearlight]

Thank you for this liberating bit of clarity! As an experimentalist, I SO APPRECIATE your distinction between that which we call "science" and that which, for lack of relevant data, is still residing in the arena of "math" (which may or may not link up with data and become science one day). I am in the cautious camp who believe that math describes and regularizes our observable reality (even beautifully sometimes), but that this description never quite "is" the underlying reality. The map will never "be" the territory.

[@GreenAsJade]

"Physics is not mathematics, consistency is not sufficient". Wow, simple and gold!

[@jessedaas6365]

I think, this is a crucial piece about fundamental science that is almost never communicated: Ever single argument is based on assumptions. Always. This is why we need to test our theories. I have the feeling that nobody mentions this anymore because the moment they do, everyone will think less of it given that assumptions were involved. I remember I was deeply puzzled by "Where do I start with building my theory?" in high school. Now I know. Making assumptions, and recognizing that they are assumptions, is an incredibly powerful tool to make progress. I use this in my daily life almost every day - it works wonders. In my opinion this should be deeply ingrained in the educational system. As clearly and on as many levels as possible.

[@davidwuhrer6704]

_> Ever single argument is based on assumptions. Always._ _> This is why we need to test our theories._ That's just what you assume. Meanwhile, a theory is a hypothesis that has been tested and proven to make useful predictions.

[@jessedaas6365]

@@davidwuhrer6704 No. There are lots of theories - and many of which are incorrect. The part "proven to make useful predictions" only refers to the subset of theories that, we know, do describe nature. All established theories in this subset (e.g. general relativity, classical mechanics, quantum mechanics, electrodynamics, etc.) are all built up from assumptions (usually referred to as axioms or postulates). >That's just what you assume This is not an assumption, it is just the basis for how to formulate a theory - where else would you start? Of course, the assumptions for the established theories have been thoroughly tested, although not directly. One computes the consequences of these assumptions and compares these predictions to experiment.

[@davidwuhrer6704]

@@jessedaas6365 _> There are lots of theories - and many of which are incorrect._ You are thinking of hypotheses or conjectures. _> The part "proven to make useful predictions" only refers to the subset of theories that, we know, do describe nature._ That is the very definition of what a theory is. It is what separates theory from speculation. _> All established theories in this subset […] are all built up from assumptions (usually referred to as axioms or postulates)._ Now you are confusing physics with mathematics. _>>> Ever single argument is based on assumptions. Always._ _>> That's just what you assume_ _> This is not an assumption_ What kind of argument is that?

[@jessedaas6365]

@@davidwuhrer6704 This is just becoming terminology at this point. >You are thinking of hypotheses or conjectures. Well, isn't string theory, a theory? It's certainly not verified experimentally. So eventhough string theory has not been "proven to make useful predictions" it is among scientists always referred to as a theory. >Now you are confusing physics with mathematics. Although there is a clear distinction between physics and mathematics, in the end every theory of physics is also one of mathematics. For instance, quantum mechanics proper starts out with number of postulates and from that, and only that, all observable quantities can be computed. Of course, in practice, the assumptions you make are not formulated precisely. Still we work based on assumptions. >>> Ever single argument is based on assumptions. Always. >> That's just what you assume > This is not an assumption This is perfectly reasonable. It is *not* an assumption that 'every argument is based on an assumption'. This can be immediately read of from the *definition* of an argument. Again: How else do you start your argument?

[@AnarchoAmericium]

Mass goes in, radiation comes out: We can't explain it.

[@DJVARAO]

Yes we can: E=mc^2

[@captain_context9991]

Mass goes in, nothing comes out. No radiation, no nothing.

[@DJVARAO]

@@captain_context9991 In fact it is called Hawking radiation...

[@captain_context9991]

@@DJVARAO Yeah but that doesnt come out of a black hole, does it. Thats the result of randomly spawning particles in free space. And by random chance, if one spawns near a black hole, it might fall in or it may go out and its paired twin falls in... Which IN THEORY causes the black hole to lose a tiny bit of mass. But nothing comes out of a black hole. Not even radiation.

[@DJVARAO]

@@captain_context9991 OK the come from the event horizon not from inside the center of the hole, true. But it is caused because of the hole.

[@derekfrost8991]

If you reverse an omelette, your chickens will be traumatized for life.. :)

[@chocolatepiano7366]

Could it be...you speak from experience?

[@michaeljones7465]

IK Pegasi B going supernova soon!!! Let's see what happens.

[@dlevi67]

@@michaeljones7465 "Soon" on astronomical timescales is rarely soon on human timescales. If it happens within the lifetime of anybody alive on Earth today I'd be surprised.

[@davidwuhrer6704]

Why would the chickens be traumatised? From their perspective, nothing would have happened yet anymore.

[@dlevi67]

@@davidwuhrer6704 Surely that depends on whether the reversal involves the subjective sense of time of the chicken as well, or just the particles of the egg!

[@Philomats]

I learn not only from the content of your lectures, but from the sound of your voice.

[@fernandogarajalde4066]

The title says it all: it is unsolvable. But I enjoy watching you explain it.

[@manucitomx]

Science without the gobelygoock - the reason I come here.

[@discogodfather22]

Just was watching Leonard Susskind on Keating's show. Over the years, I liked Lenny for many reasons, but lately I feel like I have come to loss respect for him. He basically inferred some pretty big insults against you Dr. Hossenfelder and Lee Smolin and others in that interview. This is the guy ultimately responsible for the extreme expenditure towards a dead end who just can't admit it. He seems like the most out of touch Boomer physicist ever. He even admonished Roger for his recent noble prize. Really a myopic man.

[@carlosruperto8705]

This is, by far, one of the best physics videos I have watched. You kept my attention throughout the entire video, something that is very hard for me to achieve. I am in my first year of an undergraduate physics degree and, of course, with that comes a great deal of naivety. Being the age that I am and the little I know about physics and math, I had come up with the conclusion that the Black Hole Information Loss problem was going to be the center focus of my career, which is a very naive thing to say. Even if I ever did come up with a mathematical solution to it, I'd essentially be wasting my time, and you made me realize that even in an extravagant field like cosmology, boudaries must be set and the universe cannot be treated like a math problem because it is science and science still requires the element of observation regardless what domain it is, and there is virtually no possibility of observation in this case. This was such a wonderful eye-opener and I am so surprised as to how I have not discovered your channel before... so, thank you.

[@Cosmalano]

Resolving this problem is meant to teach us more about quantum gravity. A consistent theory of quantum gravity is a feat. in itself, but regardless of that, what would actually be naïve would be to assume we won’t be able to test such a theory on Earth. That would be to assume we know the phenomenology of quantum gravity already. Don’t give up yet. There’s more to out there than we already know.

[@alistermatheson7472]

Yes Yes Yes as an observational scientist in chemistry I love your comments about science vrs maths. As usual you are inciteful and wonderful to us non-physicists but interested people.

[@filovirus1]

3:57 woke me from half asleep and I sat straight in my chair. looking forward to Saturday's warp drive lecture!

[@bernardmueller5676]

"You still need to go and test your theory against observations." That's how it is done in Chemistry.

[@IFearlessINinja]

That's true, but chemistry is also seriously lacking in progress over the past century. Not that this issue does not exist in "pure" physics, but the problem is not as old

[@CamQTR]

Awww! Baby universes! They're so cute!

[@MichaelDeHaven]

Sure, but they get big so fast.

[@JK_Vermont]

I heard this in Linda Belcher’s voice.

[@harriehausenman8623]

Just don't feed them after midnight and no water!!

[@tubebrocoli]

"A particular initial state will give you one and only one final state. The final state therefore tells you what the initial state was if you have the correct differential equation" This assertion is not valid. The correct precondition is that "Each particular initial state will give you a different, unique final state" to get to that conclusion.

[@jwrosenbury]

I can't swear to it, but I think that assumption is in the model for either General Relativity, or Quantum Mechanics. I've heard the two theories are incompatible, and this seems to be an example of that incompatibility. Unfortunately, to resolve this we need to be able to observe both models working at the same time. Small black holes seem like a good testbed for these observations, if we could only make/find them. But maybe we can find others? (Large quantum effects perhaps?) I do disagree with Dr. Hossenfelder that we absolutely can't determine which adjustments need to be made. It is possible some other effect could give a testable indication about how to modify the models. I suspect that would require both luck and a deeper understanding of the universe though. It's not likely this week, or this century.

[@tubebrocoli]

@@jwrosenbury It is for quantum mechanics, and not for general relativity, that's the whole crux of the Black Hole Information Loss problem. It's just she spoke the wrong premise in the video.

[@raffaeledivora9517]

Your statement is an immediate consequence of the one enounced in the video

[@tubebrocoli]

@@raffaeledivora9517 if you're talking about the statement I quoted in my comment, no it is not.

[@raffaeledivora9517]

@@tubebrocoli It does by Lioville's theorem: since the volume of the phase space is unchanging, if you start from N initial states and arrive to N final states and (assunption) each initial state gives only one final state, then those final states must all be unique and different from each other. If you suppose two final states are the same, you find the absurd that the two different initial states are in fact the same.

[@billymcnomates7764]

Ah waking up to a Sabine KZbin! Makes all of works problems seem so easy.

[@jppcasey]

You're are looking absolutely fantastic Sabine!

[@sipplix]

If aliens landed and said “Take me to your leader.”, I would take them to Sabine.👍

[@MrAlRats]

Why not Donald Trump though?

[@sipplix]

Donald who?

[@MrAlRats]

@@sipplix Joking aside, I would take the aliens to The Institute for Advanced Study, Princeton, USA. Though, if these aliens are bright enough to have got all the way here, they should know not to ask to be taken to our leader. No social animal has a single leader for the entire species.

[@sipplix]

Good point..😳

[@martinpopplewell8899]

The actual reality is that aliens take over consciousness as you advance your intelligence, as in you BECOME an "alien" little by little - which means we are already here and we are in fact YOUR leaders as we pass down information into your tiny view dimension of reality

[@robertlamantin5088]

"Vacuum cleaners don't clean vacuum" makes my day !

[@maxis2k]

"Physics is not mathamatics. Physics is science." Amen. And it's just like Archeologists who go around touting their theories as fact, with no way to prove it.

[@angelmendez-rivera351]

I'm going to bet a large amount of money on the claim that you actually know very little about how archaeology works and what are the methods and procedures used by archaeologists.

[@hans-joachimbierwirth4727]

@@angelmendez-rivera351 No reason to perform your ritual in my temple!

[@sarvar81]

Hello dear Sabine Hossenfelder, I love your name and you are such a great educator. Please except my true respect. Honestly, first of all, I don’t know how to start even but I have come up with this all, by myself, with my own understanding and studying the facts, over 2-3 years ago. That this world has initial beginning and will also have an end, in a sense that it is all repeated unlimited number of times and therefore the future and past is interconnected and we live one life over and over again. Therefore, we must Try to live hand-in-hand and be in unity, in brotherhood with everyone of our kind, Be compassionate to one another and this is the life we create for our one life that we have. Let’s do it all right. I believe we should be a smaller part of the mechanism including the universe we know it is just a part of the bigger mechanism because the true picture will be outside of our comprehension due to we are literally incapable of measuring that’s all what’s outside of our reach and eyesight and so we can’t be self-centered and think that everything derived from our standpoint. OK here we go, I think thanks the magnetism and other forces, all combined. As energy and the matter is the same thing, in larger scales it just changes its state to transforming into matter and energy and vise versa over the unimaginably long period of time. I believe the cycle of the matter is exponentially larger than the cycle of being in energy state. Therefore, when all the energy is concentrated in one place it explodes Giving birth to the same happenings that took place before us. It is all just a cycle that is really matters for us only time-wise. We should understand that time is nothing for the energy and it can exist forever and be there as is for good and there has never been a nothing other than vast combinations of energies floating around and fluctuating in its own unique way. The question is if all those energy clouds that are far enough from each other so as to not effect us radically are the same in size as ours? What can be their quantity? I think they are the same in size, although GOK )). To sum up, the universe as we know it will end up with black holes that will radiate into becoming energy from out layers of the black hole. Then after this cycle all there will be energy that will quickly find one another and concentrate onto a point where a new big-bang will occur with same you and me in it. Whatever is out there we won’t ever know you should admit it is unreachable so let’s do comparative analysis of what have been achieved so far to what have really been given to the society. Let’s work on our full potential! If you guys don’t know how let me tell you. Think deeper and even deeper a d always deeper. Then we will achieve all that can be achieved. Otherwise we are gonna fight over who believes what and never look in the mirror. That’s not all but thanks a lot for your attention and time. I would love to join the science community and discuss my views but I don’t know much about how it works because I’m new in the country. My goal is to achieve success in my business and help the poor people that deserve better life. Honestly, I didn’t take much time texting this. And I think I was able to describe my views. Thanks. This link is for the right reader only. gf.me/u/zkiyty

[@Verschlungen]

Pure gold -- a physicist who actually understands the difference between INFORMATION (at 3:55, just before 'John, are you listening?') and DATA (circa 10:33-10:35, thrice). That alone makes SB unique on the planet. And by thus demonstrating that "There is intelligent life on Earth," she may cause a passing ET to hesitate, and decide not to press the Big Red Button after all.

[@aidanclarke6106]

En rouge et noir, j'exilerai ma peur, J'irai plus haut que ces montagnes de douleur. En rouge et noir...

[@a_Minion_of_Soros]

Oui, baguette!

[@kirkkohnen5050]

I ask this most seriously: Are you welcomed in conferences and academic circles, or are your colleagues pissed off with you?

[@thechessmaster9291]

Hi Kirk , as this a retoric question , ( and from your Mind... ) i will not answer it . Those who are courageous enough to stand alone , and therefore have original thoughts , will make a difference ( in the end ) , the other "scientists' ... well ... they remind me of cows , ruminating and regurgitating .. ;-)

[@kyoung21b]

@@MicroClases_Ciencia Now all Sabine needs is a Nobel prize...

[@angelmendez-rivera351]

@Steven Strain Well, in all fairness, plenty of nonscientists do genuinely believe that the academic format is already polluted with junk and scientific research of dubious or no value. This may come from a place of ignorance, or from a place of philosophical radicalism, but this attitude is more common than not among nonscientists.

[@davidwuhrer6704]

This may be shocking, but some people not only don't mind being wrong, they even welcome being wrong because it means they have learned something. If you are always correct, you never learn anything, and thus remain ignorant. (Most people seem to prefer that, using agreement for agreement's sake as a cheap substitute for actual validation. Some even go so far that they don't care if they are right as long as everyone else is wrong.) Some of the people who keep looking for new ways of being wrong are scientists. They meet to learn from each other.

[@harriehausenman8623]

@@davidwuhrer6704 In some circles, "being wrong" is a wonderful thing and a certain 'school' of scientists actually go through great lengths of self-conditioning to get rid of this ol' bias.

[@tatjanagobold2810]

Vacuum cleaners don't clean the vacuum - omg why haven't I ever heard that? :D Great video!

[@Aurinkohirvi]

In my language it's directly translated: dust sucker. And computer in my language is: information machine. Yeah, I'm sure we have stupid words too, but those at least are somewhat accurate.

[@tatjanagobold2810]

@@Aurinkohirvi What is "your language"? Because dust sucker is also the literal translation in german, my mother tongue, for vacuum cleaner.

[@Aurinkohirvi]

@@tatjanagobold2810 Finnish.

[@Aurinkohirvi]

@@tatjanagobold2810 Is Tatjana a common name in Germany? Or do you have Russian family history?

[@tatjanagobold2810]

@@Aurinkohirvi I am from Austria where we also speak German and yes, I have Russian roots :) it is not a common name here, I think.

[@vacuousvoid]

My new favourite channel! Thanks Sabine!!

[@anameyoucantremember]

Gotta say, aside from the obvious applause regarding this excellent presentation, that that background-dress synergy was amazing! More of that!

[@kevincolwell2115]

THAT OUTFIT!!! 🙀💀❤️ SLAY!!

[@AntithesisDCLXVI]

Great dress/outfit! Really cool background, too. And they go very well together.

[@MrManerd]

I find myself trying to imagine what this person was like as a child.

[@AbcAbc-ii8zm]

Probably mean and trying to prove she is always right in vain

[@mssamsung7651]

As a child she was too cute 🤣😃

[@alexanderealley9992]

Fantastic explanation and thank you for giving the author of the article an objective evaluation.

[@luiscabarique666]

Awesome explanation! I started my physics career fascinated by black holes, only to come to the same conclusion: physics is not math; theory without experimental backup is useless as a model of reality!

[@at0mly]

Ooh the outfit even matches the background!

[@SabineHossenfelder]

Well, it was supposed to. But upon export the colors didn't come out to be the same. Quite annoying. I eventually gave up on trying to match them. Clearly something about the video compression that I don't understand.

[@jhwheuer]

@@SabineHossenfelder try to export a frame and see what the distance between the reds is. Then shift the background by that...

[@dengudomlige8644]

@@SabineHossenfelder You are clearly human, still a beautiful outfit!

[@SabineHossenfelder]

@@jhwheuer I tried this a few times. And it did improve the mismatch, but in the end it still wouldn't quite come out right. Yes, I should hire someone to do that stuff.

[@leyasep5919]

@@SabineHossenfelder be prepared to half of the commenters flooding you with requests :-) That would give you more time to focus on your content however. You raise very interesting and important issues and I don't know how to fight the hype machine of the eyeballs-hungry media. Science is not entertainment and, as I often say (lately even more often with all the COVID stuff), "the audience of a sports match does not get to decide the outcome or who wins or how". It's not even a democratic process where a self-appointed group gets to decide what is true.

[@renato360a]

when you see that dress and that background you realize the KZbinr was definitely able to hire a team for production and editing. Congratulations to Sabine!! Much success moving forward!

[@Mavrik9000]

Why does graphic art that matches a garment imply a team?

[@renato360a]

@@Mavrik9000 because KZbin is very time consuming even without doing fancy editing and costume design. We also know Sabine has a primary job and one very draining: academic. We see people with primary jobs hustling on KZbin everyday but it is also known that hiring at least one editor is common place even for small KZbinrs and that move increases content quality a lot.

[@annaclarafenyo8185]

Or it means someone finds her convenient for pushing their anti-science agenda.

[@renato360a]

@@annaclarafenyo8185 WOAH! Okay, somebody clearly doesn't like Sabine's tone.

[@annaclarafenyo8185]

@@renato360a I don't like her ignorance. Her tone is fine.

[@Argrouk]

"Physics is not maths" Thank you, thank you, thank you! I've been saying this for years, that physicists need to spend less time in math class and more on observations etc. Not all things that math can "prove" are true.

[@vikramgupta2326]

I appreciate the main point that this video concluded with, and a good general reminder... consistency of the math is not the ultimate nirvana. As an engineer, it made me think that the increasing vector of theory to practice goes math-science-engineering. The only comment I had issue with is physicists will not agree in 100 years on this. That may well be correct...but the last 100 years have shown us it is impossible to say with confidence what we will know in 100 years.

[@amihartz]

5:09 glad you included this part because this is what always confused me about all the videos on this subject! nobody ever explains that

[@leyasep5919]

10:04 "Physics is not math." Yes. Math is the language physics use to model things : to describe and predict stuff. And the model is just a model : it is not an explanation or a "proof", and it is as weak as all its assumptions and the data we feed it.

[@renato360a]

a model is a proof alright, and an explanation. It's just not a proof of something concrete and tangible and pertaining to physical reality.

[@mikesawyer1336]

You better be careful Sabine is going to whoop you!

[@samnieves8158]

it just uses math to be a logically consistent argument... like everyone else she's critiquing, use what you want, and discard the rest to your best profit

[@leyasep5919]

@@renato360a a model is not a proof. A model is a model, that people use to prove or predict stuff...

[@renato360a]

@@leyasep5919 I was being vague with words. Being technically precise: a model is not a mathematical proof, nor it is a proof of a scientific theory. It's a mathematical construct, and as such you can prove (provable) valid statements about it or using it. So in this sense, what I meant to say is that people do use models to provide proofs for mathematical statements. And this in turn can be used as evidence for claims about physical reality. Models are misused, but also very powerful in skilled hands. It's just that at first I thought your wording was too strong, but on second reading maybe it wasn't.

[@dennisbohner6876]

That is a knock out outfit! I have a question that I'm putting up in multiple places and anyone can chip in an answer. Since the BH is only linked at the Event Horizon to the greater Universe, does the expansion of the Universe directly affect that 'surface'? Is there an expansion of the BH? Does it radiate more or less?

[@ChrisHoppe-wordmeme]

1. Explains physics better than I even understand. 2. Makes jokes in English better than I can in German. 3. Wears outfits better than I have even seen before on KZbin. 4. Rekt. 🤯

[@MichaelOZimmermannJCDECS]

CUDOS, Sabine!

[@MAl-xz7lc]

THANKS FOR BRINGING HEALTHY balance in SCIENCE 👈 🤓 🙏🏽🙏🏽🙏🏽

[@guy936]

Love the passage about irreversibility and quantum mechanics: "it's the same if you burn paper... or. if. you. die" 3:00 Goldie

[@JK_Vermont]

🔥 I love your savage takedowns of theoretical physics navel-gazing. 🔥

[@ThomasJr]

she's very anti-establishment. Confusion is all we don't need

[@ДаниилРабинович-б9п]

what if we create small blackholes that evaporate on sub-second timeframe, using a particle accelerator? could we have some data then?

[@biblebot3947]

The universe is a much better particle accelerator but we don’t see any black holes in space

[@trucid2]

We don't have a nearly large enough particle accelerator.

[@mostevil1082]

@@biblebot3947 Sure we do, they're a bit far away for most useful measurements though.

[@ДаниилРабинович-б9п]

@@biblebot3947 how would you go about detecting the fact that a black hole formed for a second in space?

[@ДаниилРабинович-б9п]

@@trucid2 that is true, we would need an enormous one for this

[@markpats290]

Hi Sabina, another great Vid. Can you give a shot at explaining Rogers Penrose big bang rebirth in an upcoming video. Thank you!

[@KeithRowley418]

Yes - I'd like that too. Penrose is my very favorite scientist!

[@bozo5632]

Penrose explains it well enough already.

[@KeithRowley418]

@@bozo5632 Yes he does, but an opinion from a respected scientist like Sabine would be interesting.

[@bozo5632]

@@KeithRowley418 He mentioned that he contacted her(?) and she replied disapprovingly.

[@KeithRowley418]

@@epajarjestys9981 Thank you very much.

[@99Michaelthom]

I'm glad you mentioned peanuts aren't nuts. I've been fighting this false information my entire life. I have a treenut allergy, and people often think that means peanuts when I have no reaction to peanuts because THEY'RE NOT NUTS. I love peanuts because I can eat them without going to the ER. However a hazelnut will kill me in a few minutes.

[@levgtz7814]

Really appreciate your talk. Cleaver, fresh and honest explanation. Keep this up! Thnx.

[@KougaJ7]

I like how Sabine puts emotion into physics.

[@eugeneswanson7508]

Sabine is ver cynical, cold and ruthless, compare her presentation with Don Lincoln and u will be shocked!

[@AndrewBlucher]

Yes, I refuse to watch his unscientific waffle.

[@carlosgaspar8447]

"we do not have a theory of quantum gravity so we can't write papers about it".

[@leyasep5919]

hold my beer :-P

[@Wyrmser]

I don't know why there is even a search for trying to figure out quantum gravity. Gravity isn't a force, it's the effect of mass on space/time, according to relativity.. Unlike the "real" forces there doesn't need to be a force carrier for gravity.. right? I'm not a physicist, but I think they'll never find a graviton.

[@mostevil1082]

Quick, ram a god in there!

[@gammarayneutrino8413]

@@Wyrmser By quantum gravity we just mean unifying GR and quantum physics. Graviton is just one of the possibilities.

[@Wyrmser]

@@gammarayneutrino8413 why? Why bother trying to unify GR, which is an understanding of the curvature of space/time, and equations that allow us to make calculations/predictions, with quantum theory, which explains particle interaction/wave collapse? I understand that physicist really really want a simple theory, GUT, or a theory of everything... ,but what will that actually accomplish?

[@expchrist]

Wow... this video was EXACTLY what I was thinking when I saw that article. This was good, well worth my time. BTW I think I lean toward the "superluminal" method of getting information out of the black hole. Thank you very much for this video.

[@mgsxx]

This channel is a goldmine! Thank you Sabine!

[@scythefencer]

Cool dress!

[@alvaroballon7133]

Excellent, I was planning on starting an entire youtube channel just to debunk this. Now I dont have to :D

[@SabineHossenfelder]

Well, there is more to say about this than my short clip, so please don't feel discouraged!

[@alexanderkohler6439]

@@SabineHossenfelder I am wondering, whether the black hole information loss problem really is a "real" problem. In fact, assuming that the Hawing radiation effect was describing nature, I have a hard time to think of a consistent way of how black holes could possibly form and grow in the first place. Let us assume there already is a black hole. Could it "really" grow by the process of an additional object falling into it? I doubt it. General relativity alone tells us that it takes a _finite_ amount of the additional object's proper time to actually reach the existing black hole's event horizon from the outside, cross it and eventually fall into its singularity. However, it takes an _infinite_ amount of time from the perspective of an outside stationary observer, for the falling additional object to even reach the existing black hole's event horizon. The outside observer will see the falling additional object approach the event horizon but never actually cross it. Now, let us add the Hawking radiation effect to this process by assuming that its underlying assumptions are correct in describing nature. Hawking radiation tells us, that any black hole will evaporate in a _finite_ amount of time from the perspective of an outside observer. As a consequence, the falling additional object should now _definitely_ never cross the existing black hole's event horizon and thus never reach its interior and singularity, irrespective of which observer you choose. From the perspective of the outside observer, the existing black hole is evaporating in _finite_ time and thus gone long before the falling additional object may have crossed its event horizon in the needed _infinite_ time. Consequently, the existing black hole must also be gone in the perspective of the falling additional object before it could have reached its event horizon. In summary, I don't see how additional objects could ultimately, i.e. "really", fall into an existing black hole in the presence of the Hawking radiation effect. They could certainly still get very close to the event horizon, thereby effectively increasing the apparent mass, apparent Schwarzschild radius and apparent gravitational pull of that black hole for almost all short-term practical purposes, but they would ultimately never "really" cross it before the existing black hole ceased its existence due to evaporation. Consequently, there should be no black hole information loss problem either. If an additional object never ultimately/"really" falls into an existing black hole, I don't see that any "information" about that additional object gets lost in the first place. The "information" about that additional object was always there (outside the event horizon) and stays always there (outside the event horizon) without being gulped and hence lost by the existing black hole's event horizon. If I am correct that, in the presence of the Hawking radiation process, existing black holes cannot "really" grow and that there is consequently no black hole information loss problem for additional objects falling towards the existing black hole, what about black holes coming into existence? I suspect that in the presence of the Hawking radiation effect black holes could not come "really" into existence either. There might be existing real black holes, but these generally would need to have been around since the start of the universe in order to avoid the information loss problem. If they were around since the start of the universe, the "missing" information about their creation was never there respectively already missing at the start of the universe, hence no loss of information later on. There is probably one somewhat improbable possibility left for creating AND growing real black holes in the presence of the Hawking radiation effect. However, it would generate no information loss problem either. The process for creating and growing real black holes could be a process reverse to that of the Hawking radiation effect. One would have to concentrate thermal black body radiation with a temperature precisely matching that of the black hole's current size.

[@MicrophoneHell-ec3bm]

It seems like there is a lot of religion in the scientific community i.e. people believing in things that can never be observed and/or demonstrated to be true.

[@Tom_Quixote]

The problem is not that they can't demonstrate it to be true, beecause the maths work, but that nobody can demonstrate it to be false.

[@tsexostsexos6778]

Nope,they just wait for more and extra preciese data...this is the biggest problem of physics for the last century,technological we are far behind than the theories...Still today we test theories and models that comes 40-50 years ago

[@g.v.3493]

As someone who is studying Loop Quantum Gravity and who subscribes to the de Broglie-Bohm interpretation of Quantum Mechanics, I often take issue with your videos. I also love your videos and often play them multiple times. You have single handedly made me interested in physics again! Danke schön! (You and Goethe are my two favorite Germans, although Wernher von Braun was my hero growing up.)

[@AmbivalentInfluence]

A perspective on black holes. I found your comment that you were modelling a black hole as a superfluid most encouraging, it fits my belief perfectly. I offer this thought in the hope that it may be useful, a possible explanation of what is. The outermost boundary is the accretion disk, that region of space where matter is deconstructed into spacetime and EM. The EM (everything quantum, including information) is stripped from the matter and then ejected at the poles in jets. The remainder (spacetime) is accepted into the black hole. The skin of the black hole is most likely a BEC which surrounds a spinning ball of liquid spacetime. It is liquid because the temperature within the black hole is less than 0K. It is possible that a black hole has a structure containing thermoclines and, in the larger ones, a solid colder core. This core, even though solid, is far short of the density/coldness required to form a singularity (we know this because black holes have diameters). Black holes can evaporate but all that it produces is gaseous spacetime. If this is the case, creating a black hole would require the creation of a region of 'vacuum' below 0K, a region where particles can not exist because spacetime is not warm enough to support them. As I understand it, a BEC experiment did get close to this limit (state change boundary value) and the experiment appeared to 'melt', I would say condense. I hope that you find this thought interesting.