Is the Universe REALLY a Hologram?

[@LouisGedo]

Sabine..............I get the sense that you're very skeptical about the current model of String Theory

[@SabineHossenfelder]

That's one way to put it.

[@guest_informant]

I'd recommend reading her book, "Lost in Math" to get an idea of just how sceptical :-) I've nearly finished it, it's very good, and in a sane world it would be important even.

[@arctic_haze]

I see you have not read the "Lost in math" book by Sabine. You should.

[@LouisGedo]

@@arctic_haze Thanks for the recommendation......you're not the first to recommend that particular book of Sabine's. 👍 It's going on my shopping list.

[@arctic_haze]

@@LouisGedo To use the words of Maui: "You're welcome!" 😀

[@SwissPGO]

This really reminds me of my matura exam at the end of my atheneum (high school) in 1984. In belgium, you had to pass such an exam in order to do university studies. My topic was holograms, and I had made several myself to present during the exam. While waiting in the class to do my presentation, I wanted so show my treasure holograms to a girl sitting next to me. Moments before I was called to pass my exam, the envelope with the holograms fell... scattering the content to pieces. I ended up using the catastrophic event to demonstrate the difference between a thorn photograph and two shards of the hologram. My teachers were impressed by the demonstration. The girl that was sitting next to me also ended up becoming a professor. Thank you Sabine for reminding me of these events through your video's.

[@SeanCMonahan]

When people say that the entire scene is still encoded in a fragment of a hologram, I am imagining it's more like looking through a smaller piece of a window, right?

[@Guido_XL]

@@SeanCMonahan It is like the aperture of a lens. The scenery that a lens can capture does not depend on the size of the lens, but on its ability to view the scene as a cone of angles. When we look with our eyes, regardless whether we use a camera or a telescope or whatever, we use the cornea and lens of our eyes. They are small, and yet, we can see vast areas around us. That's because we capture the scenery as a set of angles. A hologram is not different in that respect. It captures the phase information that a normal vision with our eyes also captures, just before the image becomes a projection of intensities, losing that phase information in the process. We cannot reconstruct the original anymore, as the phase information is lost. The projection on our retina, or on a camera sensor, is the resultant flat image of the original object. A hologram not only stores the resultant intensities, but the amplitudes with the corresponding phase information of the light waves. This is like the actual optical image before it becomes projected on our retina or camera sensor. A hologram is like the original object, as far as the light waves that emanate from it, can carry information through the cone of perception that we allow for that capture.

[@raezor82]

This is the science equivalent of Guy falling off treadmill and doing push-ups.

[@SwissPGO]

@@SeanCMonahan exactly

[@SwissPGO]

@@raezor82 yep... but it allowed me (and others) to see that feature of holograms. I would never have had the courage to break them willingly: after all, I only had a few, with no easy option to recreate more.

[@DanEllis]

"So now that you know how real holograms work..." - whoa, let's not jump to conclusions!

[@velikovskysghost]

@Dan Ellis Darn straight! The day she makes a strawberry shortcake and sends it to my kitchen table is the day I'll consider this "electrified magnetic plasma" universe to be "holographic", she's letting her imagine run away with herself.

[@gworfish]

Haha, when she said that I also had forgotten that wasn't actually what the video was about lol

[@amyscott9496]

Lol I don’t know shite

[@patpowers9210]

Can I be said to "know anything"? Many Internet theorists would contest that statement!

[@phillustrator]

Now that you know how real holograms work, here's an introduction to the fake ones that String theorists hallucinated 😂

[@Mike_858]

In science channels in TV they always throw around that term ''Holographic Universe'' without much explanation, which left me puzzled. Thank you for clearing that up!

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@scene2much]

Even String Theorist Susskind (Stanford) has been fond of the term.

[@hyperduality2838]

@Kank OG Yin is dual to yang. There is a 4th law of thermodynamics once you accept that duality is real:- Syntropy (predictions, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Making predictions to track targets, goals & objectives is a syntropic process -- teleological. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Perceptions or measurements are converted into conceptions (ideas, notions) according to Kant in "The Critique of Pure Reason". Thinking is a syntropic process as your rational thoughts result in optimized predictions. Noumenal (rational, analytic) is dual to phenomenal (empirical, synthetic) -- Immanuel Kant. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Human culture = language or words (memes). Words are being generalized over time and you can study this using the internet, their meanings change over time. Genes are dual to memes!

[@hyperduality2838]

@Kank OG Points are dual to lines -- the principle of duality in projective geometry. You can watch the following videos about this, universal hyperbolic geometry:- kzbin.info/www/bejne/e6ezaYmqrs2tjtU Same is dual to different. You are the same person now but different compared to a few hours ago. The passage of time means that you are a different person but still the same. Personal identity or the self is a dual concept. Null homotopic implies contraction to s point, non null homotopic requires at least two points (duality) -- topology. The big bang is a Janus hole/point (two faces = duality) -- Julian Barbour physicist. Topological holes cannot be shrunk down to zero. Two points (singularities) define a line or space is dual. Up is dual to down, left is dual to right, in is dual to out -- space duality. Space is dual to time -- Einstein. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). There are patterns of duality hardwired into physics, mathematics & philosophy! Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Potential energy is dual to kinetic energy -- gravitational energy is dual. Electro is dual to magnetic -- electro-magnetic energy (light) is dual. Energy is duality, duality is energy. Null vectors or light rays are perpendicular to themselves from our perspective -- self duality. The concept of projection in mathematics & physics requires at least two points, an origin or projector and the screen, the observed is dual to the observer -- David Bohm. "Always two there are" -- Yoda.

[@KipIngram]

It sounds so very smart and intellectual. 🙂

[@darioinfini]

The way even science leaning media reports this information, it really sounds like they didn't understand it at all. Even I don't despite your explanation. But it's clear that when the media reports "scientists say the universe is a hologram", the impression they give is not at all what scientists are actually saying. Again, due to the extraordinary ignorance of journalists in reporting on anything. YOU are our journalist, and I'm grateful for you and others like you.

[@darioinfini]

@Kelvin Higgs She's a journalist in the sense of communicating scientific concepts from the labs to the public the way a proper journalist would if they had any knowledge or integrity. Of course I'm not discounting her science background and achievements. She's just one of those scientists that has crossover skill, following in a long line of teachers and public communicators. If it weren't for people like her the public would either be at the mercy of the ignorant media or have to pursue the sciences themselves.

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@Tom_Quixote]

@Kelvin Higgs There's no such thing as "the media". There are many different publications, with very different levels of quality. Don't expect to find anything worthwhile about string theory in the tabloid press.

[@Beastman5K]

@Kelvin Higgs Current corporate media is garbage and should be consumed critically if at all, yes, but journalism as a whole, and as an idea, is still worthwhile and needed, and should not be so maligned.

[@francescoroselli8162]

every time the press touches anything related to what I know best, it fails at represeting the argument properly, big time. so I assume now it is true for all other arguments.

[@sulijoo]

I'm starting to think that every time Sabine poses a question, the answer is either going to be: a) Yes, but it's more complicated than that and b)no of course not, don't be silly.😜

[@elgaro]

Clear, easy to follow, straight forward, anti-sugar coated explanations on every video. I like it

[@user-sb3wh3dd4v]

Dear Sabine, THANK YOU for the clearest explanations I've ever heard on these TWO subjects. I saw my first photographic hologram in 1964 at ITT technical institute, then again at the 1964 World's Fair and have been fascinated my them ever since. IN ALL THAT TIME, including ALL the books and videos I've seen, your explanation of 2D recording of 3D holographic imagery is the clearest and most concise. Likewise, I LOVE the way you explained the "holographic principle" so well and with no "Gobbledygook." Frankly, we have another term for "gobbledygook" here, and it's initials are B.S. Ever since hearing about string theory decades ago, I've always had the sense that, although beautiful, it doesn't quite agree with reality. Even with my limited math background, I see the hubris of Mathematicians who proclaim such absurd ideas as: "The Universe IS MATH", or that "GOD speaks to us in the language of math." Certainly, Mathematics is beautiful, powerful, flexible, dynamic. Math can HELP REVEAL nature's deepest secrets. Math can DESCRIBE and PREDICT Nature. But math is NOT Nature and Nature is NOT MATH. Which is why String theory and "the holographic universe" leaves me hanging... That all seems to be the hubris of mathematicians. Which reminds me of a JOKE: A famous mathematician DIES and goes to Heaven. Upon entering, he sees an Indian man feverishly working with complex physics formulas on a HUGE blackboard. The mathematician asked a nearby Angel, "Is that Srinivasa Ramanujan, the world's greatest mathematician?" The Angel replied, "Who HIM? Hell no! That's GOD. He just THINKS he's a mathematician!" ;-)

[@SabineHossenfelder]

Haha, I actually hadn't heard that joke before :)

[@dlevi67]

The idea of an Angel swearing 'Hell, no!' is quite interesting.

[@michael.forkert]

It is obvious that we are not living in a hologram. Try to stick a hologram in your pocket. You can’t even touch a hologram. Total BS.

[@thumper8684]

When Sabine says "String theorists think we do." I can taste the salt in the air.

[@aristideau5072]

you should watch that PBS Spacetime video where rips into Eric Weinstein. felt sorry for the guy. kzbin.info/www/bejne/eXvbZJqCoMqVf6M

[@Achrononmaster]

@@aristideau5072 What's funny about that video is Weinstein does not appreciate he is being schooled, and still thinks he is galaxy brained. His version of "Geometric Unity" has been debunked as just wrong on several points by Tim Nguyen for one.

[@ricktownend9144]

Many thanks for this - I'm a lot clearer on this issue now, though I may need to watch it again a few times...

[@robbirose7032]

Watch it again from a few different angles.

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@hyperduality2838]

@@robbirose7032 Perspective or different angles implies duality, see my other comment.

[@pursuitsoflife.6119]

Also watch a video about the same from PBS space-time!

[@u.s.a.citizen5590]

We need teachers in university like you. Students would learn much better.

[@davigosky]

I personally prefer to have them on KZbin and enjoy their explanations at home.

[@charleswest6372]

Yes. Pity they don't teach important things like this. Time to change the school curriculum.

[@jamielondon6436]

Dr. Hossenfelder (at the end): "Now you know exactly what that means …" Me: "Uhhhhhmmm …" ;-)

[@dougyates7218]

Me, too:)

[@SuperLol]

Sabine is the kind of aunt that we all wished to have in a family party when everyone is either gossiping or straight out boring.

[@CAThompson]

I want to go out and party with someone like her.

[@bob-ny6kn]

*step-aunt... iykwim

[@onehitpick9758]

I would love to argue with her about the meaning of cosmic microwave background radiation measurements, although she would just say, "I am not interested in your theory".

[@CraftyF0X]

Idk, it depends on your company. When I try to bust out a topic like this in the middle of the small talk ppl does not restrain themselves to communicate just how unimaginably boring abstract nerd they think I am. Avg seems at least 10 times more interested in the latest fashion trend or what is the actual celeb scandal than how the freakin universe works. I find it sad, then again the avg find me sad.

[@CAThompson]

I've had some interesting conversations with people I know about Superdeterminism, mostly to help pass time whilst working. I even had a short exchange with Sabine herself on the Backreaction blog. I would hope that if I ever get to speak with her in person I could find something worthwhile to say beyond the blurting of a daft fan.

[@atheistsince1210]

Thanks for the Ockhams Razor clarification I recently read Herzogs “On the Origin of Time: Stephen Hawking's Final Theory” and holographic universe is mentioned all Over the place Hawking was NOT a sting theorist neither am I after reading Smolins The Trouble With Physics. String theory was only a fast track to professorship tenure but it’s all bunk.

[@aniksamiurrahman6365]

Sabin: "Now you know just exactly ...." Me: Yah! I forgot just exactly what I forgot. What am I called anyway?

[@mof2324]

Lmao!!!!!

[@ravensnflies8167]

i could listen/watch Sabine talk about this subject for hours.

[@robmorgan1214]

AdS/CFT works for superconductors but they are also 3d objects not 2d embedded in a 3d manifold. I think the key with understanding holographic principles is they represent a reduction in degrees of freedom in a mathematical/geometrical sense not necessarily a literal sense. This discussion represents a microcosm of "the trouble with physics". Namely it stems from a lack of nuanced understanding of analysis (Re and C), geometry, algebra, and topology and the physical origins of quasi mathematical concepts like probability and information theory. This toolkit is given to physicists and they're told how to employ it but the pedagogy is insufficient to build or discover new and better tools which is the very essence of what Newton, Euler, Gauss, Einstein, Boltzmann, Plank, and Feynman did and why they are so remarkable. So progress that requires new tools moves SLOWLY progress that requires us to apply new tools moves quick, it's the low hanging fruit of science. Hence the Cambrian explosion of technology in the 20th century.

[@hyperduality2838]

AdS is dual to CFT. Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@KipIngram]

I've started to think that one of the biggest problems with our approach to physics, at least in terms of how it's normally taught, is that we "pesume" four-dimensional spacetime as an a priori "container" and then try to shove all of the physics into it. I think Christian Baumgarten's paper, "How To (Un-) Quantum Mechanics," outlines a better approach. He begins by assuming only time and starts doing his math. Spatial dimensions "emerge" naturally from those mathematical consequences. In fact, it turns out that only certain values are allowed for the number of those spatial dimensions, and the smallest of those values is three. This winds up letting him draw connections between classical and quantum theory that are usually said to be impossible, and it offers a very good motivation for entanglement - some interactions "involve" the spatial dimensions, and those are limited to a maximum speed we can call c. But other interactions don't involve space at all, and there is consequently no speed limit at all on those. I think that's where quantum non-locality comes into the picture. I think the whole business of Einstein-Rosen bridges and so on is really just an attempt to force spacetime to "contain" these non-spatial relationships. It's interesting that we can do that, but it doesn't really feel like the right approach to me.

[@LowellBoggs]

Another great presentation! I always look forward to your videos.

[@scoreprinceton]

Yes it is - Is "knowing" what is a hologram? along with an explanation of the holographic principle, enough to understand we do not live in an "holographic universe"? We are immersed in a societal-universe that functions using the natural languages and we think it is "the reality" even though it is incorrect. Isn't the societal space-time and the sounds of languages bouncing off our ears and the sights bouncing off our visual cortex make us believe and accept the mind's thoughts as "real"? I am not arguing on behalf of the string theorists but instead pointing out the fallacy that scientific reasoning and logic are adequate to either "understand" our "universe" or the humanity's place in it.

[@NT4XT]

That purple fabric and cut is sohhh ON. Speaking of angles ♂️

[@echoromeo384]

It seems like some physicists have now entered the realm of philosophy and not science. Just like string theory and many-worlds. Sabine bringing some sense back into physics. Thank you ma'am.

[@RedRocket4000]

Result of being to far ahead of the actual research leaves one trying to come up with something new instead of doing nothing. But Relativity and many other things were done well in advance of the practical research so you can't say it has no value all the time.

[@caseytailfly]

I love that you both explain holography and how the holographic principle is not holography and now I somehow understand both better. It’s also crucial to understand the conceptual leaps and contortions that are being used to apply this theory to our universe. Thanks for that!

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@jwrosenbury]

It's nice that you are sponsored by Brilliant because you are.

[@robertlock5501]

oy vey

[@Luxalpa]

I lost 220 EUR on Brilliant because I forgot to cancel my subscription 1 year ago.

@@Luxalpa you lost your money by not using it.

[@riadhalrabeh3783]

Simply Brilliant. My by on the side comment is; regardless of the field of interest- string or not, it is always possible to map the volume of a sphere onto its surface- if the inside doesn't change with time. If it changes with time then this is solved by GR taking time as one of the coordinates. The surface of the 4D sphere then becomes a 3D sphere and that is perfectly possible.

[@simonhanson5990]

Thank you Sabine. I am gathering that physics and cosmology are brim full of deep insight and similarly of fairytales, and it is not always easy to tell which is which. I try to imagine sometimes what a 'science' of 500 years from now might look like, or five million years . . . we mustn't think for a moment that we are getting close to a complete understanding of things - but that doesn't stop me from loving the magical mystery tour . . .

[@xgalarion8659]

believe it or not physics is the grounded kid. Mathematics is it's unhinged brother

[@Fregmazors]

Finally a real explanation of this from someone who tells it the way it really is. Thank you!!! I never understood the concept of the holographic principle or where it comes from until now.

[@davidmaiolo]

i really do like your style. it seems any video of yours that I watch, I get the the entire jist of what you're trying to say by the end. You have to admit to yourself, most people struggle to understand these concepts themselves. Yet you find a way to master them and communicate them out to others so well. excellent work, Sabine!

[@scene2much]

I notice a few people reply with some confusion. I am also grateful for the fundamentals I learned in my Physics BA, that makes understanding Sabine less challenging. Without that, I'd miss the full flavor all those wicked understated 'insights.'

[@GreylanderTV]

Third difference: Optical Holograms actually encode information describing a 2D wave-front, not a 3D volume or equivalently, it encodes information about a 2D manifold _within_ a 3D volume. No information, for example, is encoded about object interiors. "Holographic" Principle encodes same information of an entire 3D volume. Also, isn't the "holographic" principle just a case of "solutions to differential equations are determined by the boundary conditions" plus "we found equations that describe the proposed physics purely in terms of the boundary state".?

[@gyozakeynsianism]

That seemed ... surprisingly understandable. SH really is good at explaining this stuff! That or I just don't understand at all lol ...

[@deluksic]

when it comes to optical holograms, it’s important to note that each piece of it only contains information for that perspective (viewpoint) so cutting the original sheet reduces contained information in a very obvious way.

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@RickDelmonico]

Hologram: N dimensions of information in N minus one dimensions. Monochrome, standard type. Full Spectrum, more information. Dynamic, closer to reality.

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@saimon174666]

Also optical holography stores only information about surface of an object, not it's inside.

[@schmetterling4477]

That's not a problem. One can easily make holograms of transparent objects.

[@mb-3faze]

2:28 I wonder how many viewers look at these wave diagrams and think that light actually goes up and down in space? Of course it doesn't : the Y-axis is some representation of energy, not distance.

[@jzapert]

"of course it doesn't" comes a haughty answer to a question nobody asked

[@arendellecitizen208]

isn't that the isolation of vectors in electric and magnetic fields?

[@arendellecitizen208]

they don't have physical length, but have direction

[@angrymeowngi]

My main problem with theories that argue "the math works...so reality must also" is that is not at all how it works. You can divide an odd number by an even number and get an answer that has a fraction, now that works for the math itself but to say that there fraction can also correspond to a person (existing as a fraction only) becomes a problem in semantics. Does the other fraction (a torso) that belongs to the whole person exist somewhere since the math works? Is a small person a half of a person? But surely, a person existing only as a headless body (say a 0.9 of a person and still presumed alive alive) is out of the question. I know this sounds like making a strawman (a 0.1 of a person maybe), but it makes more sense than a "theory" that is not liable to falsification and therefore should not be entertained as science.

[@RayWalker-pythonic]

I would love it if Sabine interviewed Leonard Susskind about this.

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@simesaid]

@@hyperduality2838 absolutely brilliant! Syntropy! Fabulous! Holons! Incredible! Just dynamite material, really, really great stuff! Encore, please..?!?!

[@simesaid]

@@hyperduality2838 ...different people? Crazy! Apples? Crazy! The 4th law? Crazy! Percepts? Crazy! Apples? Crazy! The internal soul? Crazy! Apples? Apples! Apple's, apple's, apple's!!!!!

[@simesaid]

@@hyperduality2838 ...Apples

[@hyperduality2838]

@@simesaid There is also a 5th law of thermodynamics:- Symmetry is dual to conservation -- the duality of Noether's theorem. The conservation of duality (energy) is the 5th law, energy is duality, duality is energy. Gravity is proof that duality is real, a falling apple converts potential energy into kinetic energy. It is front of everyone's eyes -- the force of gravity conserves duality!

[@juanmiranda-colon5207]

Thanks for demystifying and exposing the String holographic concept.

[@JohnMcConnellTheInevitable]

That was a wonderful explanation of ADS/CFT! Thank you!

[@hyperduality2838]

ADS is dual to CFT. Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@jeremyhofmann7034]

As Gem would say - this truly truly truly outrageous

[@Lagrange_Point_6]

Yup. Couldn't agree more with this. I do think these 'theories' make contributions in related areas (in particular when thinking about information entropy) but no, I cannot agree that the universe is a hologram. Almost seems silly on its face.

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@Lagrange_Point_6]

@@hyperduality2838 LOL

[@eottoe2001]

@Sabine Hossenfelder -- Ich bin so froh, dass sie sich die Zeit nehmen, dieses Video zu machen, Leute wie mich, die Wissenschaft lieben, aber nicht die Möglichkeit hatten, es gründlich zu studieren. Vielen Dank. (My German is not very good.)

[@benheideveld4617]

Dear Sabine. The recording of a hologram is three dimensional, because the photosensitive film has a thickness. The interference pattern is also three dimensional. Where light cancels the silver nitrate stays undeveloped and forms no silver nanoparticles in the transparent film (the matrix, the colloid). However where the interference is constructive, the electromagnetic field is intense and interferes quantized with the silver nitrate in the sensitive film, forming a pattern of silver nano particles wherever there was constructive interference of the object beam and the reference beam. After fixating the film, such that it does not contain unreacted silver ions anymore, only silver nanoparticles, we replace the film and turn on the reference beam. It illuminates the silver nanoparticles that all become emitters of coherent monochromatic light, which interferes exactly so, such that the object beam is recreated as if it were emanating from behind the sensitive film. When the hologram wat recorded by a divergent object beam and a divergent reference beam, we can get a virtual hologram IN FRONT OF the sensitive film shen a convergent reference beam is shone on the film (the hologram).

[@arctic_haze]

All physical object are 3D as they are held together by forces working in three dimensions. But the mathematical idea of a hologram is absolutely 2D: the third dimension is not used. By the way you are not criticizing Sabine who thinks the very idea is Quatsch (using the very good German term for nonsense).

[@dougaltolan3017]

@@arctic_haze "the mathematical idea" As with ALL of real life, it needs more than a basic mathematical idea.. The mathematical *idea* of a hologram is to consider a plane through which light passes, object one side, subject the other. If you recreate the light at that plane, phase and direction included then you have a hologram. We do not yet have ANY material that perform that task. So, as with everything real life is not an abstract theory and holograms are recorded and reproduce the mathematical ideas using *thick* film photographic materials.

[@arctic_haze]

@@dougaltolan3017 You apparently did not read my short comment to the end. Sabine thinks the Holographic Universe idea is a nonsense. It is the people who believe it who need the 2D hologram because their theory needs a boundary which has one dimension less than the Universe. Argue with them.

[@trumanhw]

​@@arctic_haze I apologize for the lack of parsimony; were I smarter or if I had more time ... I'd have made this shorter. :-) My goal is challenging apparent inferences you've made that... this threads comments argue with Sabine & You. (as best I'm able given the limits of my cognition and physics knowledge) ... It goes without saying that, because _I'm writing this_ that it's _my opinion_ ... I'm not calling anything a "fact." These are all just 'claims' ... claims which I'm articulating for you to criticize, reject or falsify... I say this only to explain why I'm not prefacing every single statement with ... "In my _humble_ opinion" ... 1. Ben is describing the physics / manufacturing process by which things we visually perceive as holograms are manufactured. Ben isn't CRITICIZING Sabine's statements about COSMOLOGY or The Universe ... but rather from an engineering standpoint. 2. You (Arctic) appear to have inferred some critique in Ben's comment of Sabine's explanation -- which I can't find. diesels condescension Then assuming that he therefore doesn't understand her opinion (which I think is the DEFAULT for almost all people who do not espouse to affirmatively believe in "STRING BS" ... as there's nothing either FALSIFIABLE nor USEFUL about any of their claims). _By the way -- thanks for the term 'Quatsch' ... though, I think puuuuuure bullshit works for us monoglots (re: String BS)..._ :) As a brief aside from a layperson ...? If all people are smart ... or all people are pretty -- doesn't that take away all descriptive (and more plausibly, vernacular ... or at least the subjectivity of humans and the scale of things we can see unaided..? If everything is definitionally 3D ... then, how do we describe graphene..? It's not 2D because each of the atoms in the carbon lattice is bound by atomic forces which include an electron cloud with depth ... so it too, is "3D" ..? Again, saying there's no such thing as "ugly" just limits our descriptive vocabulary without changing any facts... (unless I've misunderstood more than I realize). 3. Dougal (I think) is explaining the "necessary & sufficient" conditions for a "theoretic" hologram; not what HUMANS will consider to have satisfactorily EMULATED what we colloquially agree to call one ... or perceptually agree constitutes the use of the term -- but is challenging whether those things which Ben discusses the manufacturing of ... with the "physics definition." Dougal NEVER EVEN ADDRESSES your _2D vs 3D_ argument ... let alone, challenges SABINE'S PREMISE; I believe it's a response to BEN, alone; NOT YOU. 4. Arctic -- to which YOU appear offended that these REMARKS, all of which appear OBLIQUE to Sabine's premise or your arguments assuming Ben or Dougal's conversation ... to which you almost appear OFFENDED (to which I lolz ... if I'm correct !! Bc you've 'sniffed out some basis of which to pound on a desk without realizing people aren't even arguing with you) ... :-) There's nothing to be pissed about. ALL members of this thread are very smart (me excluded). The point though..? NONE OF YOU ARE ARGUING WITH EACH OTHER... :-) As a physics layperson who still loves following concepts (as best I can) who's envious I wasn't afforded a life conducive to pursue learning until I reached the limits of my ability to grasp the physics and its respective language (math) ... it's still very cool to read this comment thread in which all of you had interesting addendums to Sabine's discussion as they pertained to cosmology // the universe ... AS WELL AS ... the amusement I get out of seeing a smart person make the same mistakes I've made; reading a comment as though someone argued with me ... evoking a "counterargument" where no initial argument exists. :) ... which I'm sure you'd have recognized had you re-read your remarks in a week or so ... when you're in a different mood and didn't remember what evoked your response in the first place. :) Which -- I think is perhaps your intellectual admiration for (perhaps a fellow German..?) whom you respect ... Sabine. IF my remarks seem like their argumentative or condescending ... it's only because of my inability to write (and think) more clearly...as none whatsoever is intended.

[@peterbeale2]

I made some holograms in my physics lab classes 40 years ago. I still have the plates and view them occasionally! Love your work Sabine!

[@curiousuranus810]

Brilliant as usual, thank you.

[@nielsandersen6164]

Sabine, your video is absolutely brilliant (as always). Good thing that there aren’t more videos on your channel, or I would never unstick my face from the screen. Really, I’ve learned more about science from you than in high school, collage, and pretty much my entire adult life.

[@benjwils]

Dear Sabine, Is there any chance you could give your thoughts on the ideas about how a black hole preserves all of its information on its surface and any connections with the holographic principle?

[@edreusser4741]

I do get a quite skeptical note. Thanks for answering the questions I didn't know I had.

[@mrwideboy]

Hi Sabine , can you do a lecture on causal set theory.?

[@SabineHossenfelder]

Thanks for the suggestion, I will keep this in mind!

[@frun]

@@SabineHossenfelder We also would like to know how renormalization fits into the picture

[@vincentzevecke4578]

Have you talk about Yang-Miles and gap

[@grenda5]

this lady is a freakin genius, great video, thank you!

[@mina_rabbit]

This is sooo interesting! What if the universe expands because it needs to fit more information? Or the other way around, there can be more information thanks to the universe expanding? (+_+)?

[@SabineHossenfelder]

Yes, this is actually a very interesting question. I don't think anyone knows how to answer it. The problem is that we don't really have a sensible way to divide up the universe into bits of information.

[@asdfasdf71865]

"It is expanding to have less information." you meant? Maybe it handles the "parralell worlds" thing that way?

[@bobbyt9431]

Isn't this relationship shown in the surface area of black holes?

[@tarmaque]

What I find more interesting is this question was asked by a person with an anime character for an avatar and handle. o.O

[@alienzenx]

@@SabineHossenfelder Why do you need to divide it up into bits? The entropy tells you how many bits it contains, right?

[@TheKaylich]

Is it valid to imagine that the information of our universe is encoded on a "surface" with a thickness t, where 0 < t < planck lenght. So while not zero, there is a real limit?

[@schmetterling4477]

All of imagination is valid. We file imagination in the fiction section of the library. Would you like a copy of Harry Potter with that?

[@rippenburn]

I can't remember how many videos I have watched to try and understand why holograms work and this is the first that explained it. Thanks!

[@martinbennett2228]

Thank you, I had guessed that those who might claim that we are living in hologram were claiming that everything can be expressed as a wave form. The last time I saw something like this it was from someone who said that the mathematical constructs of reality make space for free will! Needless to say, no mathematics were provided.

[@luizeduardoalvesdesouzabri2125]

It isn't a complete day without some truths delivered by Sabine

[@pedro3005]

To clarify, the idea that the maximum amount of information in a region scales as the surface area of that region and not its volume is known as the Bekenstein bound, and there are more fundamental reasons to believe in it than just the holographic principle. It's not even a strictly string theory thing, and LQG also has it. Basically, if you stuff too much information into a region of space, it collapses into a black hole, and then who knows what happens, but probably that information is hanging around the horizon somehow.

[@Hspryd]

First 4D projected commentator

[@CAThompson]

Is anyone actually truly cool enough to invent Sabine though?

[@paytonlee9836]

Amazing explenation. Waaay better than others I've seen

[@soilsenasuil]

Could you have a episode on the study of holonomy and its application to quantum mechanics and general relativity? Thank you!

[@rickgoranowski9428]

Such as does Thomas Young “double slit” (1801) determination of constructive/destructive interference constitute a hologram arguing against de Broglie/Bell Labs’ (1924) wave-particle duality?

[@hyperduality2838]

Homology is dual to co-homology. Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@rickgoranowski9428]

@@hyperduality2838 The necessity for Schrodinger complexity (shut up and calculate) knocks down double-slit holographic interference cohomologizing wave-particle duality but maybe Young's waiving Newton's corpuscular version of light sheds some on string theory. But is a wave function such as a star reducing to a point in space via BH collapse in supernova contradicting Einschtein "the moon is still there even if I'm not looking at it" especially because a BH is invisible?

[@hyperduality2838]

@@rickgoranowski9428 Thesis is dual to anti-thesis creates converging thesis or synthesis -- the time independent Hegelian dialectic. Hegel's cat:- Alive (thesis, being) is dual to not alive (anti-thesis, non being) -- Schrodinger's or Plato's cat. Being is dual to non-being creates becoming -- Plato. Schrodinger's cat is based upon the Hegelian dialectic and Hegel pinched it from Plato who pinched it from Socrates -- the dialectic method of argument.

[@drdca8263]

@@rickgoranowski9428top level comment was talking about *holonomy* which is an entirely different topic that what you started talking about. Holonomy isn’t holography. Holonomy is about things changing as a result of something going around in a loop while changing as little as possible at each part of the path. For example, if you have an arrow on a globe, starting at the South Pole, and (while never turning the arrow in place relative to its current location on the sphere), move it 90 degrees north (still pointing north) so that it is on the equator, then move it 90 degrees west (but still pointing north), and then move it 90 degrees south (again without rotating the arrow), ending up back at the South Pole, but now rotated 90 degrees from where it started. (The same also happens with smaller loops, but with a smaller change in angle.) That, and things analogous to it, is what holonomy is.

[@factsheet4930]

How I like to think about gravity is that it reduces the spacial dimensions. what I mean by that is for example on earth we don't really experience full 3D, as it is difficult to move in the Z direction (mostly upwards from earth) but it's easy to move in both the X and Y direction, so it's like gravity reduced the dimension of space to something between 3D and 2D. A black hole is then the extreme of that, where space is completely 2D, you cannot fall inwards and can't escape upwards from it, but presumably still able to move freely on its surface(if you are somehow still alive!)

[@mrvzhao]

It's amazing and frustrating at the same time that so much weirdness and confusion in physics are just products of bad analogies - I hope they were not manufactured intentionally.

[@Taricus]

They aren't. Usually it's because a popular science writer for a website or something misunderstands something a scientist says and then tries to write about it. I double majored in physics and mathematics for my bachelor degree and there were so many things that I thought were going to be cool to learn about and it ended up just being something normal that people online hyped up--either on a youtube video or an article somewhere. Not that there aren't cool things, but then half the time people never write about them in news articles or just pick out cool quotes from the scientist to make it sound like sci-fi. But the scientists themselves aren't trying to make bad analogies.

[@Taricus]

My concentration was in astronomy and astrophysics, before I went into biostatistics for my master's degree. There are a ton of times that I read some article written online.. like say when they took a picture of a black hole and the author starts trying to say something cool about it to make it interesting and I'm like, "That's not what that means, but whatever....." It just makes you get more picky about where you get science news from. Generally, if they don't put a link to the scientific paper itself that they are basing their article on, I take it with a grain of salt.

[@robertschlesinger1342]

Interesting and worthwhile video.

[@RaumBances]

Thank you for the explanation. I think the holographic universe theory is built out of convenience and therefore too abstract to be taken seriously. I suppose you can make just about any mathematical model work if you simply insert what works rather than what is. That is what they did with 3 major aspects of our universe.

[@mrsbethaniesmith]

Yep that's what they did

[@jtinalexandria]

Great explanation of holograms. The only thing I would take exception to is that string theorists don't "say the universe is a hologram". They only say it *could* be a hologram based on the holographic principle.

[@ivan-Croatian]

Imagine having a mom as smart and pretty as Sabine. I'd never stop talking to her. Imagine all the things you could learn from her.

[@vigilantejesus9010]

Sounds like something Norman Bates would say.

[@CAThompson]

Hossenfelder is pretty cool. My mum is pretty cool, gotta say. Props to her.

[@12jalbrandao]

LoL! Freud might have something to say about your thoughts on Sabine!

[@gentlyschannel4193]

I've imagined several situations I could be in with Mrs hossenfelder while she talks physics to me.. being my mother was never one of them!

[@jasonroku4219]

You are appreciated. The world is a better place with you in it.

[@qtmeet]

"Reality is an illusion, the universe is a hologram, buy gold, bye"

[@CAThompson]

May as well go back to bed. It might be a hologram, but it's comfy.

[@alext5497]

Crypto will be more practice than hold when inflation hits.

[@WestOfEarth]

It's nice to know my confusion about the Holographic Principle is actually due to an inaccuracy of the metaphor. And as a bonus, I have rudimentary understanding of what Anti-de Sitter space is now.

[@Wolf462]

I approve this purple sweater! Lovely!

[@gilessmedley619]

. . . and her longer hair 🥰

[@JesusMartinez-mk6fc]

Another excellent video from Sabine. One of the few videos on the subject that clears up that aura of mystification surrounding the holographic principle by breaking down its key properties. A very good explanation also of where the similarities between photographic holography and the holographic principal begin and end.

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@Carhill]

Are there really a stack of turtles, or is it just one turtle with an infinity mirror?

[@zenshade2000]

"Turtles, all the way down!"

[@frun]

It's a turtle that turtles all the way down

[@tarmaque]

"The turtle _moves!"_ Terry Pratchett: _Small Gods_ (1992)

[@eljcd]

Well, actually.... You would need two mirrors, opposite each other.

[@andsalomoni]

Why not a stack of pies?

[@tedsolaris2801]

Clear and simple explained 👍

[@highfive7689]

For hologram universe to exist should there be a real universe from which it is spawned?

[@SenhorAlien]

Nuh OBS: not a scientist

[@frun]

No, it is just a single universe admitting 2 descriptions by means of holography

[@richardkerner5817]

Excellent talk. The only little thing that is missing is the exact definition of the adjective "REALLY".

[@jimmyzhao9748]

I've seen a hologram of a microscope, and you could actually look through the eyepiece and see the object on the slide. Very cool.

[@jorgepeterbarton]

Next is making a hologram of a hologram?

[@tristanwegner]

I love the very clear explanations with a well argued personal perspective on top. Having understood optical holograms in University, I of course assumed that the "one piece contains information about the whole object" would of course also apply in the holographic principle. It is in the name after all! (Holo meaning whole in Greek). If this does not hold for the Universe theory, than the name is not just confusing, but even wrong!

[@rc5989]

Ooooh! I want that Star Wars hologram!

[@wilhelmw3455]

And I want a Star Trek holodeck !!!

[@edwardlulofs444]

That was the best explanation of Anti de Sitter space that I have heard. I started my PhD work in the 1980s. I wanted to study these various theories. But I had to do other work. Now, 45 years later, I'm glad that I didn't work on them. Weird is OK if it works. But they just seem to be pointlessly weird now. I'm going to continue to work on Causal Fermion Systems. It is mathematically complicated, but the physics is straight forward without any of these unbelievable ideas.

[@hyperduality2838]

Hyperbolic geometry is dual to spherical or elliptic geometry. Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@mugin11223344]

String theory, believes in many things but has proven none of them.

[@rhianimal19]

Doesn't stop most of the world from being religious whackjobs though, does it?

[@jeremymiller9582]

Great! Your videos always make my day. Also, yours are the only videos I sit through the ads on; don’t know if it works that way, but I want to make sure you get your support, if I can.

[@THX..1138]

Hologram?...I'm gonna go with hydrogen, helium, oxygen and a sprinkling of other stuff.

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@JanBruunAndersen]

A small Danish 🇩🇰 company, Realfiction Holdings, is actually selling exhibition displays that shows moving holographic/3D video. And the company is currently developing a technology, called Project ECHO, that can be used to create 3D video on a flat, 2D device like a traditional TV at reasonable prices.

[@vinniehuish3987]

Has this ever been done before?

[@dewiz9596]

So, String Theorists like working with a universe that has a negative cosmological constant because “it’s easier”. Reminds me of the story of the guy looking for his car keys under a lamppost because the light was better there

[@kapoioBCS]

In physics you always start doing calculations where you can in order to get insights about the mathematical and physical structure, and then you try to apply your insights in order to make a more generalized model.

[@estranhokonsta]

The story about the lost keys is a good metaphor for all of science, not only string theorists. It shows the fragility of science and how important it is to have a sincere attitude to be able to do good science. It also shows how easy it is to abuse it, like so many do.

[@ObjectsInMotion]

If it were currently possible to do what string theorist are trying to do in our universe, they would have done so already and the problem would be solved. It's not just that working out these types of problems are harder in our universe, it's that no one's figured out how to yet.

[@gustavoturm]

This sound like a "betrayal" but in physics, they do this all the time. The point is to be able to predict things with the easier model you can find.

[@bobaldo2339]

Reminds me of the Iraq invasion & occupation.

[@LampDX]

i think about this video from time to time. As an engineer, my mind always jumps to analysis through degrees of freedom… from your description, we would need an expression describing the conformal boundary’s shape in order to fully recover the N+1-dimensional information, right? Alternatively, some expression to convert the intensity of your N-dimensional measurement to “depth.” in that sense the principle seems rather obvious, the same way we need to understand a heatmap is projected vertically from a flat plane in order to extrapolate a “true” 3D surface from the heatmap. it feels like cheating a dimension out, but in reality we are relying on an assumption that is not always true (the surface is flat and projects isometrically). Is it really that simple? either way excellent video, very clear. I appreciated the clarity with which you delineated your opinion from the theory, and the humor you used to do so!

[@curiodyssey3867]

My school shut down because of covid, thereforr we all had to be taught online. I got a vr set which makes it so real, but I got in some serious trouble and had to go see the holographic principal.

[@Miss__Understands]

Good that you pointed out these distinctions in the analogy, but it doesnt invalidate string theory or ads/cft.

[@karmabeast]

At least in the United States, the market for holograms is absolutely huge. I recommend checking out some Hatsune Miku concerts (of which there are plenty of recordings on KZbin) to see how we do it in the States.

[@mina_rabbit]

Ohh! Are they different than the ones performed in Eastern Asia?

[@karmabeast]

@@mina_rabbit i've no idea, but im guessing it's the same thing. I just inferred (possibly incorrectly) that Sabine didn't know about the huge blowout spectacles of modern hologram concerts

[@andsalomoni]

Watched one. I can't believe that there are people who go to those "concerts"...

[@HxTurtle]

the way you managed to pull off the pronunciation of, "depth" is remarkable, IMHO. (stemming from someone with just the exact same accent 😅)

[@kadourimdou43]

Have you any thoughts on Carlo Rovelli’s idea, regarding Quantum Relational theory.

[@vikramgupta2326]

The slight smile at the beginning and end of the video are good improvements to Sabine's presentation style.

[@ecMathGeek]

"The math looks nice. So let's just assume it's true." - String Theorists

[@jzapert]

C'mon why it gotta like that

[@edithseichter4857]

Einsteins and Diracs method

[@RAFMnBgaming]

Ah, "elegant" programmers.

[@SmartassEyebrows]

@Alpha Omega I see you are pretty harsh on the "many worlds hypothesis" folks.

[@robertsullivan4773]

I was and am a fan of Dr Richard Feyman. He wasn't a fan of String Theory either.

[@richardlong3745]

I was confused about this before this discussion and now I'm even more confused because my brain isn't sufficient enough to process this type of information thank goodness we have people like you that can.

[@Handelsbilanzdefizit]

After I dropped out of university, I made such holograms and tried to sell them. I'm a lousy businessman :-(

[@zmeta8]

Penrose proposed that universe could reboot big bangs after its final expansion by forgetting scales. Would you like to comment?

[@tubehepa]

FWIW, according to some Vedic texts, the universe, after Shiva has destroyed it, is created "from ~ memory" (smRti,~smriti), *yathaa puurvam akalpayat* (as it was before, or stuff?)...

[@cuddlebuff]

I've been studying this for years.... But your videos have basically brought everything together. 20 years of reading... And now... This finally makes sense to me... It brings me so much joy and grounding. To have peace in this science, which is weird but I'm okay with it.

[@clmasse]

What is the conformal boundary of an anti de Sitter space?

[@animax2422]

It was a simulation all along...

[@tarmaque]

Agatha approves.

[@chrisr7809]

I expected to open the video and Sabine would spend 10 mins saying different "NO" is various different ways. And I would have still watched.

[@billrock6734]

Only surprised that the holodeck of the Enterprise doen't have a hologram of Sabine in it..

[@CAThompson]

I imagine an iteration of her as a sassy space-station AI.

[@tarmaque]

@@CAThompson I want her voice and accent to replace the digital assistant on my phone.

[@Thomas-gk42]

Clear, structured and adorable

[@patrickfle9172]

Stringtheory: Alice in Math-Wonderland

[@entyropy3262]

A business strategy to call it Theory, while not being even close to one, to lure the pocket money out of the scientific community and prevent to let go a lot Mathematicians unemployed, so they can prevent to have to learn something of use instead.

[@patrickfle9172]

@@entyropy3262 well, rather stamp money, if to compare it to the LHC... but yes, that money should not be drained off physics departments. Let the math faculties pay for it until they come up with something serious (if...)

[@AndPennyThought]

This video really helped me get the holographic principle a bit better.

[@hyperduality2838]

Parts are dual to wholes -- Holons. Constructive interference is dual to destructive interference -- photons are dual. Electro is dual to magnetic -- Maxwell's equations. Positive charge is dual to negative charge -- electric fields. North poles are dual to south poles -- magnetic fields. Electro-magnetic energy or photons are dual. Convergence (syntropy) is dual to divergence (entropy). Syntropy (prediction, projection) is dual to increasing entropy -- the 4th law of thermodynamics! Biological cells are parts of organs but also wholes within themselves -- cells are dual. Same is dual to different:- You are the same person now but different compared to a few hours ago, the passage of time means that you are a different person but still the same. Personal identity or the self is dual. The future is dual to past -- time duality, you predict the future (syntropy) and remember the past. Absolute time (Galileo) is dual to relative time (Einstein) -- time duality. Mind (the internal soul, syntropy) is dual to matter (the external soul, entropy) -- Descartes. Concepts are dual to percepts -- the mind duality of Immanuel Kant. Positive curvature is dual to negative curvature -- Gauss, Riemann geometry. Curvature or gravitation is dual, gravitational energy is dual. Gravitation is equivalent or dual to acceleration -- Einstein's happiest thought, the principle of equivalence (duality). Gravitation is dual to acceleration -- Einstein. Energy is dual to mass -- Einstein. Dark energy is dual to dark matter. Time dilation is dual to length contraction -- Einstein, special relativity. Space is dual to time -- Einstein. Potential energy is dual to kinetic energy. Apples fall to the ground because they are conserving duality. Action is dual to reaction -- Sir Isaac Newton. "Always two there are" -- Yoda. Duality (The Force) creates reality!

[@burghdewd]

We are a hologram in a simulated universe in one of the many worlds. See how ridiculous this can get?

[@nsfeliz7825]

made of 100 dimensional strings......yes it keeps getting more .....ridiculous.

[@monad_tcp]

its not actually that ridiculous when you consider recursion can model the entirety of mathematics

[@zenshade2000]

I know, right? But then you look at the Hawking-Beckenstein Black Hole Entropy formula, which is proven beyond reasonable doubt and shows that the information in any given volume of space depends only on the surface area of the boundary of that space (and not at all on the volume), and you begin to realize just how ridiculous the truth can actually be.

[@brothermine2292]

Don't forget the branes and the eternal inflation.

[@CAThompson]

Like, who observeving this simulated hologram multiverse wants to know about me sitting at a table in my pyjamas half the day talking nonsense to my cat and commenting on random stuff on the internet?