Does the Universe have Higher Dimensions? Part 1

[@hrperformance]

I can't get over the quality of these videos. Everytime I watch, I get filled with boundless excitement and motivation. Next week can't come soon enough!

[@ideliversoftontario4976]

Yes, she is a gifted teacher and a beautiful mind.

[@hans-joachimbierwirth4727]

It's the lowest you can find in the physics department. Loads of bullshit.

[@emmanueloluga9770]

@@hans-joachimbierwirth4727 what do you mean?

[@frankdimeglio8216]

@@hans-joachimbierwirth4727 You have to CLEARLY AND fully understand what E=mc2 means and represents ON BALANCE. We want to understand the dimensions in a seamless (or balanced) fashion in relation to gravity AND ELECTROMAGNETISM/energy (including what is E=mc2). Consider one AND three dimensional SPACE ON BALANCE. Consider what is the fourth dimension ON BALANCE. NOW, consider all of the following. Consider what is E=mc2. CLEARLY, you have to understand what is a TWO dimensional surface OR SPACE ON BALANCE. c squared CLEARLY represents BALANCED acceleration in conjunction WITH what is NECESSARILY a dimension of SPACE ON BALANCE. The stars AND PLANETS are POINTS in the night sky ON BALANCE, AND consider what is the speed of light (c) ON BALANCE. This CLEARLY AND NECESSARILY represents, INVOLVES, AND DESCRIBES what is possible/potential AND actual ON/IN BALANCE. Carefully consider what is THE EYE ON BALANCE. Great. Consider what is gravity AND E=mc2 ON BALANCE. By Frank DiMeglio

[@sergeydenisov15]

excitement is not knowledge. and science is not a drug, it is demanding thing and one has to pay - time & effort - for acquiring a new knowledge.

[@hesitantjaguar7897]

Ah yes, Saturdays are not complete without a good helping of knowledge from our friend Sabine

[@rog2224]

And this one has a cliffhanger.

[@paulotorres558]

Confirmed !!

[@beachbum77979]

And without the gobbledygook!

[@KibyNykraft]

@@beachbum77979 The whole idea of dimensionS of emptiness sounds pretty much like gobbeldygook to me.

[@KibyNykraft]

Unknown "dark"particles is of course another and more plausible question. At least. And there is no way of cheating out of special relativity and the continuous variable motion of all that exists *in* space. :)

[@RydarkVoyager]

I just loved it when Sabine starts quoting Dr. Kaluza in the original German (7:33). Certainly woke me up! LOL

[@matheuscarbonero8186]

It's so funny, she's speaking English in her own pace and then, out of nowhere, she just starts speaking crazily fast hahahahhaha it made me realize I wasn't paying enough attention

[@finanzkrise]

I have not noticed any difference in speed :o Im German tho

[@homeape.]

her german isnt really faster than her english

[@thorr18BEM]

I count 6 seconds for the German version and 7 for the English 😁 Depending on how I round off since this app's timestamp only showing to the nearest second. I think the German was faster! lol

[@SliceSupeRStaR]

Never in my life I would have thought that I'd be waiting in excitement for a physics episode but here I am! Thank you!

[@Yolo_Swagins]

Yes me naither, i wish that in elementary school we actualy hawe someone able to show us how anmazing physics is. I would definitely choose different path in my life.

[@mahikannakiham2477]

@@Yolo_Swagins But then you would inevitably have to study some "boring math" and may choose a different path yet another time.

[@MangySquirrel]

lol, same.

[@paperheartzz]

Some parts go over my head a little... and yet I still love to learn how physics expands our understanding of the universe!

[@antonystringfellow5152]

Never really took the idea of extra dimensions seriously until I watched this. I tried to keep an open mind to the possibility but this is first time I've felt there might actually be something to it. Very well (and clearly) explained! - Can't wait for next week's episode!

[@benoize]

Arrgggghhhh... what a cliffhanger! Can't wait for next week's episode. Great stuff!

[@kikodasneves1]

I absolutely love your sense of humor, so one of a kind. That “that guy again” bit always gets to me.

[@dougg1075]

My hope is some kid somewhere watches this type video and becomes inspired. How many Einstein’s have fallen through the cracks of poverty or abuse . Anyway this is a great service academic folks like Sabine is providing.

[@Bunny99s]

Right. Just like Ramanujan. We had some great minds that come out of the ordinary. Think of Pierre de Fermat who was a judge and did mathematics has a hobby. Our currently used public / private key algorithm RSA is based on the results of fermat's little theorem. At the time of it's discovery no one could think of any practical application. That's what a lot of people forget: Science is not done by individuals. Science always builds upon previous ideas and knowledge. Some claim that Einstein was a fraud because a lot of the equations he used in his theory of relativity were discovered by others before him. But that's completely pointless. Again, science build on top of pervious knowledge. Sometimes it just takes a great mind to connect the dots that were there for a long time. That doesn't make such an achievement any less great. The invention of the car is a result of the invention of the steam engine and the invention of the wheel. That doesn't make that invention any less amazing. Just the right input at the right time may lead to the next ground breaking discovery or insight. Many inventions and discoveries in the past were pure luck and by accident. Like penicillin, radioactivity, x-rays, vaseline, gunpowder, microwave oven and many other things.

[@garymathis1042]

How many Einstein's were lost from abortion?

[@luckyhiker3434]

I loved Sabine introduction when she said “in part one we will discuss things like Kalusa-Klein Theory and stuff like that.” - like I instantly was to know what she meant by “stuff like that.” Sabine is the greatest!

[@brendonwest-m1n]

Thank you Ms Hossenfelder. I am very grateful for your work.

[@brendonwest-m1n]

@Greg Jacques I would imagine it's hard to stop being at work when you do what she does!

[@brendonwest-m1n]

@Greg Jacques mmmmm..... So much mmmmmmmmm!!

[@brendonwest-m1n]

@Greg Jacques 😂🤣👍

[@nimo517]

To explain such a complicated subject takes so much more than just understanding it… explaining in detail is the proof of knowledge

[@AncientOfDays963]

Out of all the physics youtube channels, yours is the best and most refreshingly upfront and real. Btw please keep doing your music video as well they’re pretty cool Sabine!

[@BikerDash]

"Yes, that guy again." That just made my day! I'm really enjoying your videos. I feel I learn something new each time I watch one. There is true joy in that.

[@ideliversoftontario4976]

So clear explanation, just a pleasure to watch till the end. Thank you, professor.

[@synthetic144]

your content is so much better than dozens of documentaries... many thanks

[@stanlibuda96]

Your videos are just great. If some one had told me that one time the best part of my saturday afternoon would be watching a physics vid ...

[@das_it_mane]

This is the best video I've seen on extra dimensions. It actually makes sense instead of making it sound mystical.

[@DavidTJames-yq9dr]

It always amazes me that I comprehend all this when Sabine presents.

[@andrewmhurth9845]

Im totally lost

[@wulphstein]

You should talk about the properties of regular spacetime, the physics constants, the number of dimensions, and attempt to answer questions about what spacetime is made of.

[@andrewrivera4029]

Suns coming up and I’m having tea with my favorite physicist Sabine! Cheers!

[@CraniumCarl]

Not pretending I understand ANY of this but I just saw another video regarding Muon and their strange existence AND vibrations which makes me wonder if they're rolled up in their own rolled-up dimension - FASCINATING!

[@TM-vh1qg]

2:14 me watching this 4D structure in this 3D world on my 2D screen with my 1D brain.! Turns out I became Einstein.

[@rmehta54]

That guy again!

[@johnnisshansen]

Sound like 0D understanding

[@AurelienCarnoy]

At leats you are here, That is 0 dimension.

[@gsalien2292]

All while multi-tasking playing 6D chess!!!

[@simonmultiverse6349]

You use the numbers 1, 2, 3 and 4. Guess what? 1+2+3+4 = 10 and this is a 10-dimensional universe. I think of time as something different and special, since it does not describe space. Our universe is really 10+1 dimensions, not 11 dimensions.

[@MangySquirrel]

It's been said if you can make something complicated sound clear and simple, you have a true grasp of the subject.

[@DrDeuteron]

What amazes me is that tiny dimensions were proposed by a man named "Klein".

[@CAThompson]

gott dammit

[@arctic_haze]

I wonder whether Kaluza's surname is relevant. He was a Gernan scientist eho came from Silesia and had a Polish surname neaning "puddle". Do you see a connection?

[@LuisAldamiz]

@@arctic_haze - clean as a puddle?

[@deth3021]

That's how you know the ones running the simulation are just ducking with us.

[@rushunnhfernandes]

can you explain that statement to a non-german speaker

[@yt.personal.identification]

Sabine's words have gravity of their own. Bringing modern physics back to earth in a way it doesn't want, but needs.

[@flotspe]

Sabine: Space! me: The finale frontier! Sabine: The way we experience it has 3 dimensions me: *sad Star Trek noises*

[@lordkekz4]

That was exactly my reaction!

[@shockwave326]

extra dimensions and alt universe's make for great TV dont they? but sadly are NOT real,,,, so start the tears for the stupid theories ya thats the right thing to do

[@deth3021]

Surely with extra dimension, space wouldn't be the final frontier?

[@goartist]

@@deth3021 space entails 2 frontiers. inner and outer

[@deth3021]

@@goartist not classically. It also doesn t apply to the star trek reference. The closest relevant thing might be the inner frontiers edge. Inner frontier is typically used for spiritual reference.

[@EG-cs3wv]

This is not about physics, but I like a lot your smile in the videos miniatures in the presentation before click to watch the video, Sabine. About the videos, incredible content as always

[@donaldjacobson4184]

Thanks so much for the excellent explanation. Ich liebe Ihre Vorträge ❤️

[@vikramgupta2326]

This was the best overview providing the background on this topic I've seen. I'm glad the point about geometry of higher dimensions not be an easy given came up, and that it's fairly recent. I always wondered about that.

[@timthompson468]

Thanks. That was helpful. I got an “A” in introductory linear algebra, but it was not very satisfying because I can’t visualize the results. That explanation of the three extra dimensions to include three dimensional momentum along with the position was interesting. I’m taking the Great Courses Linear Algebra course to refresh my memory and take it a bit further. Looking forward to the next video.

[@dozer1642]

I really enjoy listening to you explain things that I thought I understood before.

[@frederico_mello]

Sabine i just had this dream today that me and my epidemiology professor were talking about some big book you wrote about the g2 muon ! it seems so real !! just wanted to share :p

[@SabineHossenfelder]

Well, I *am* writing on a book and last week I was *also* writing about the muon g-2, alas the g-2 isn't in the book. But it was pretty close to reality!

[@12jalbrandao]

@@SabineHossenfelder Lol, this guy is almost a prophet.

[@tim40gabby25]

@@12jalbrandao Almost a prophet, by strict definition, is not a prophet. Old uk duffer here, enjoying the ride :)

[@ollebo]

@@tim40gabby25 What if the almost-prophet had a few extra dimensions? ;)

[@O_Lee69]

@@SabineHossenfelder Hallo Sabine, ich würde mich auch sehr über ein statement von dir freuen. Als interessierter Laie habe ich folgende Fragezeichen: Die Abweichung zwischen Vorhersage und Messung ist sehr gering. Kann es a) ein Fehler in der Vorhersage sein? b) ein systematischer Fehler sein? (das Experiment wurde in derselben Anlage im Fermilab durchgeführt. Diese ist im Vergleich zum CERN winzig. Wurden eventuell auftretende Zentrifugalkräfte und/oder das Verhalten der Myonen bei relativistischen Effekten (träge Masse) unzureichend berücksichtigt? Schließlich ging es um das "Wackeln" der Myonen durch die Wechselwirkung mit virtuellen Teilchen. Außerdem stört mich, dass immer sofort nach einer "neuen" oder "5." Kraft gerufen wird. Kleiner scheint es nicht zu gehen. Das klingt für mich immer als Schrei nach mehr Forschungsgeldern. Vielen Dank.

[@NothingMaster]

Fermi used to say something like, give me enough parameters and I can fit an elephant to the data. Any two-bit physicist could come up with ideas using higher dimensions. Try working with a single dimension and see if you could envision a beautiful and elegant theory that could make sense of the physical world.

[@gregbrown5020]

Vacant stare is my default response to these lectures. Like a dog listening to owner's verbalizations.

[@bobh28630]

“The mind, once stretched by a new idea, never returns to its original dimensions.” ― Ralph Waldo Emerson An added benefit: the teacher is mesmerizing!

[@GeoffreyFeldmanMA]

Instead of allowing yourself the luxury of asserting a "vacant stare", allow yourself the enjoyment of thinking harder, listening again, follow up on the references. Otherwise it's a bit like someone who just watches sports and doesn't actually get any exercise simply because you don't think you will be a major league player.

[@gregbrown5020]

Feldman: not gleefully celebrating ignorance. Stating that clearly I'm not one of her intended audience. A furrowed brow and attitude adjustment is not going to change what is into what should be.

[@lamblyn]

Same. At least we're not under fluorescent light.

[@Earwaxfire909]

To summarize the last century of physics in a 10 min lecture. Wow.

[@amyers2141]

Another blockbuster of information, including 11 dimensions. Thank you, Sabine!

[@NiteshKumar-wv3if]

She is a wonderful teacher . Thank you Sabine for your honest and exact explanations with that sweet accent of yours.

[@ThioJoe]

I wonder what more than one dimension of time would be like, if such a thing was possible 🤔

[@slonslonimsky2013]

If we assume that the future is not set, that would mean there must be infinite number of branching time lines. We just sit on one of them in each particular moment. Some of those time lines may even intersect. That would mean, the past is not set either. Different versions of the past could equally fit to our current state. Indeed, we cannot reconstruct our past from our present to any possible precision. Some events are irrevocably lost. That is, there may be different interpretations of the past. So, our current time line is branching in the past too. But all those time lines together must live in a certain space. That would be a multi-dimentional time space, because you need not only to identify the position on a particular time line (i.e. our current 'present'), but also which time line it is (among lots of others). How many dimensions would be needed for that is unclear. Such a space would be quite complex thing. But it must definitely exist, at least theoretically.

[@jamesbloom2613]

Rolled up, of course

[@SpykerSpeed]

Your profile pic matches the emoji perfectly, lol.

[@ss01101]

@@slonslonimsky2013 Many Worlds Interpretation? String Theory?

[@VarroTigurius-u1f]

Slon has it correct. I like to imagine it like a book though.. imagine everything at this moment being a page of a book. Reading the book from beginning to end is the story of the universe. Change one page of the book and the story is different so it would be a different book. A book case would have every possible combination of books that told the possible stories of our universe with our laws of physics. Change our laws and you have a whole new universe of possibilities so it would have its own book case of possible books. The entire multiverse of universes would be an infinite library.

[@238assante]

great stuff. Those vids remind me of school when a teacher would explain , and i listened fascinated, nodding , understanding, it was all so clear. And after i'd just go back being clueless.

[@jamiegagnon6390]

Apparently some sneaky entity is wandering around rolling up dimensions just for giggles...

[@ldbarthel]

The Prince must roll up the katamari to grow bigger.... Na na na na na na na na na Na na na na na na.....

[@pedrolmlkzk]

Wouldnt be surprised

[@rustybolts8953]

Very sneaky operator. Like your sense of hummer. Nasal breathing and humming produces NO, I just found out..

[@sa.8208]

I imagine our 3D life's float in a subatomic 5D soup.. With time being a abstract 'Window pane for entities above us'' we basically amoeba from the perspective of the entities. the same way the strange subatomic quantum world is to us.. is what we are to the higher entities.. very possibly in scale / size / and importance. we are but long hyper dimensional time worms burrowing through the space they inhabit, fresh born baby's at one end, and a dusty corpse at the other... branching through time like a tree of sex and maternal instinct.. the mother.

[@justlisten82]

​@@sa.8208interesting way to think about it! Thanks for sharing.

[@cesarjom]

Excellent explanation and insights into topic of higher dimensions within physical theories. I'm hoping the second part has more details explaining how and why extra dimensions are needed in string theory and M-theory -- your style of presenting always adds another "dimension" to the understanding,

[@filipslavik9410]

Will you do a video on the results of the muon g-2 experiment?

[@SabineHossenfelder]

Not specifically, but I have one coming up on data anomalies in particle physics in general. It's tentatively planned for the last Saturday in April.

[@SabineHossenfelder]

I wrote about it here though, in case you are interested: www.scientificamerican.com/article/is-the-standard-model-of-physics-now-broken/

[@theoreticalphysicistzeinaq2753]

@@SabineHossenfelder I am 13 years old and I am taking Quantum physics college level and please can u make a video about Graviton boson and Quantum Gravity,,,,,,please!?

[@babublue69]

@@SabineHossenfelder summary of this articles... Nothing find out yet...

[@LaurenDove-x6x]

There are 18 dimensions. They are: 1. Length or distance 2. Breadth or area 3. Thickness or volume 4. Duration or time 5. Sex 6. Pressures 7. Potentials 8. Temperature 9. Ionisation 10. Crystallisation 11. Valence 12. Axial Rotation 13. Orbital Revolution 14. Mass 15. Color 16. Plane 17. Tone 18. Ecliptic The dimensions are not so much the issue. It is the dynamics of the electric wave that is not being understood. L. Dove Arbiter - Universal Law

[@davidw6936]

KZbin has extra dimensions. That’s where they keep the ads.

[@rodgermyles2871]

@Goth Vaush - Jedi Master Engineer No because it supports the rest of it!

[@charlesbromberick4247]

I marvel at how you can pull so many complicated things together and come up with a somewhat useful perspective - I guess that´s what being smart is all about. Thanks

[@Fregmazors]

A new video, awesome! This is such a great channel -- I finally get to understand some high level concepts without a lot of sensationalism and misleading BS. Just the facts. Thank you so much!

[@hanslepoeter5167]

Great lecture om an interesting subject. Thank you ...

[@michaelblacktree]

Looks like Sabine has been working on her presentation style. Keep up the good work! 👍

[@PilatesGuy1]

👍Agree. I earned Toastmasters Gold Level, which took years of work. These days Sabine seems like she has Toastmasters Diamond Plus. Simply exceptional presentation skills. Would actually be interested in how she did it.

[@bsadewitz]

Finally, a science communicator referred to these eleven dimensions and actually deigned to mention what they are! I'd always hear, "they're curled up" without the slightest elaboration. Yes, I know that I am not going to understand it, but I will not be injured by scaffolding, either.

[@vast634]

Kernel function in support vector machines use additions dimensions to solve problems. EG: use additional dimensions if the math does not work. It a cheap trick to make the math work, it does not mean there are additional dimensions in reality.

[@michaeljones7465]

@@vast634 Length, width, depth, duration, light, gravity, velocity & space-time. Now you know all the dimensions are real.

[@KeithCooper-Albuquerque]

Thanks Sabine for another great video, and also for what you do to a sweater!

[@GururajBN]

Great, lucid talk on a complex topic.👌 At 4.25 - “Yes. That guy” about Einstein! Only you can handle such a thing with elan!

[@blazeAkriti]

Hi Sabine, I love your videos ❤️please make a video on the muon G-2 experiment

[@SabineHossenfelder]

I wrote about this here: www.scientificamerican.com/article/is-the-standard-model-of-physics-now-broken/

[@Arziil]

“Physics is the most important thing because Love is the most important thing.” Thank u Sabine Hossenfelder

[@ricardlupus]

2:32: Arthur Cayley: the man who started posing as though he was talking on a mobile phone before even telephones were invented.

[@cipaisone]

Your consistency with Saturday’s videos is incredible. Thanks a lot :)

[@einsteindrieu]

Albert E would have Loved to Hear your Sabine Stuff.🧡

[@hans-joachimbierwirth4727]

He would not.

[@einsteindrieu]

@@buddysnackit1758 why not ?

[@wishusknight3009]

@@einsteindrieu Einstein didn't subscribe to quantum mechanics.

[@einsteindrieu]

@@wishusknight3009 Yes I know. He didn't know where Time and small gravity comes from.

[@wishusknight3009]

@@buddysnackit1758 So if you are smarter than all the physicists in the world, publish a paper and win the nobel prize.

[@robertschlesinger1342]

Very interesting and worthwhile video.

[@heisag]

Are the dimensions relative to each observer, or are they universal?

[@SabineHossenfelder]

Very good question! I wish I'd thought about this when I made the video. The short answer is that they're universal. The number of dimensions is not an observer dependent-statement.

[@0MoTheG]

Plz explain the question.

[@ifonlyiwassaner]

@@0MoTheG Think of it this way: time is not universal, it is relative to the observers, that's why two people can experience times differently depending on their frame of reference. If time is relative what about the other proposed dimensions? That's what heisag is cleverly asking 😉

[@swissmix1]

@@SabineHossenfelder their size?

[@wilsonubi3922]

You speak intelligently. I'm subscribing to this channel ASAP.

[@lmahesh26]

Never clicked on a video faster

[@lionharpmusic]

What does it mean that we need to explain "why we normally don't get lost in it?" How is "getting lost" (in a higher dimensional space) a problem of physics/geometry?

[@achecase]

So many possibilities and so many questions, I cry a little that I will live not long enough to learn the truths.

[@CAThompson]

We're all a bit less confused now, at least.

[@chuckadams4400]

Relax. When you die, you get to see ALL the Truths.

[@CAThompson]

@@chuckadams4400 Or nothing. Maybe that's the Truth? ;)

[@CAThompson]

@Schlomo Baconberg No thanks, I don't think I'd have much fun there. At least I know I'll have fun as well as learn a bit more over here first. :)

[@zualapips1638]

@Schlomo Baconberg What do you mean?

[@antondichtl6557]

The simple fact: there are exactly 42 dimensions. But seriously: Thank you so much for your work!

[@connecticutaggie]

Recently I had been pondering - Could there be a connection between the three observable spatial dimensions and the three generations of particles in the Standard Model? Ex: Could it be that generation 1 particles only vibrate on a single plane. were generation 2 particles vibrate on 2, etc? Just a weird thought and I was interested if it had ever been pursued before.

[@Nibsipipsi]

There are some problems with that. Firstly, a single dimension can't hold a plane. A plane is a space that requires more than one dimension. Secondly, if a particle vibrated in only one dimension, it means it would be static in all other dimensions. So if all generation 1 particles would only vary in the "x" dimension, but not the "y" or "z" dimensions, that means that all electrons would only be found on a single line in the "x" direction, which clearly isn't the case. Finally, the number "3" really isn't that special. So the fact that there are three spatial dimensions and also three generations of fermions, really is no reason to assume that it's anything more than coincidence.

[@terrylandess6072]

I had previously made a comment about the reality of 'other' dimensions and this video has helped explain to me what these actually mean. I find the concepts of Harmonics particularly interesting as I can get my head around that and understand the universe has it's 'own' frequency.

[@IanGrams]

I knew the names but never the history or details of Kaluza Klein Theory. Thank you for making such an easy to understand introduction to it. I look forward to part 2! Do you think you'd ever make a video on your PhD thesis? It was the first time I'd ever heard of the concept of black hole relics and I'd really like to hear more about it.

[@ninadesianti9587]

Thank you for the short lecture! Very clear explanation as always!

Such cliffhanger at the end!

[@dr.OgataSerizawa]

.....always a pleasure to catch your show, doc! Thanks!

[@vernturnquist6729]

Ribbed sweater and liking your hair Sabine ❤️😍

[@andrewc2252]

I love your videos Sabine, along with Space-Time.

[@fred8174]

Please comment on the 4 new particles discovered by the LHC, last week.

[@ralos5930]

they're not particles mate, they are names given to things that are effecting other things. They only get names because we get stuck. And these 4 new particles are math theories, ie the math requires them as they create the alibi it requires. there is no such thing as a 'particle' there are no little balls racing around, it's all electrostatics and the fuzz created around the nucleus is charge potential only created by electrostatics itself.

[@KipIngram]

3:52 - Actually you can go further. You can pile all of the positions and momenta for N particles into a 6*N dimensional space, so the entire configuration of N particles is represented by a single vector. That's really what "phase space" is for a multi-particle system.

[@Luxalpa]

My Physics teacher was also named Kaluza and I just noticed that his face looks kind of similar to Theodor's...

[@alamagordoingordo3047]

Always clear and dense of informations.

[@georgesos]

Waiting for a "muon" video soon :)

[@JakeEpooh]

Man, Professor Hossenfelder is so good at this! Almost she doth convince me to study physics.

[@isntitabeautifulday1648]

She's gonna destroy string theory so hard next week.

[@wkgmathguy218]

I'm quite looking forward to that.

[@isntitabeautifulday1648]

@Goth Vaush - Jedi Master Engineer If it's a trial by combat, strings aren't gonna cut it.

[@luizguilhermediascatulio9997]

Thank you Sabine, your clear way of speaking help me to understand, even if english is not my mother language. Your scientific way of thinking help me to understand the world without biases, i admire your job. Hello from Brazil!

[@Wolf462]

It’s hard to focus on the physics with that lovely sweater.

[@LordMekenshi]

This has to be one of the best explanations of why 11 dimensions I have seen.

[@traderalex655]

Sabine is a gift to science communication.

[@antoniomaglione4101]

Compliments for the video. The best explanation I've seen why we need extra dimensions to explain all the necessary aspects in physics. Thank you.

[@nalathekitten3594]

Thankyou Sabine. I love your explanation more than anything.

[@rationalsceptic7634]

Sabine is lovely,funny and brilliant...she makes Physics fun and accessible...I love her German accent,too,tcx

[@MrWildbill]

Ahhhh a cliffhanger, love it. I am just a fascinated lay person and have been following string theory for about 10 years on that level, you know KZbin videos and a few books. In the last couple years I went from pretty much a solid believer in string theory (it just makes so much intuitive sense) but have to admit that support or belief as been waning so I can't wait for part two to see where you fall in this discussion.

[@jurgenriedl7347]

As a physizist I questioned myself, whether we live in dimensions at all. In my dreams my mind constructs a complete new world, and this is just thought, but forgotten by me, except the rare ocassions I became concious I'm dreaming, then I can go through walls or over water, and I know it is a invention of my mind.

[@icebox3678]

Excelent video, Sabine. Thanks, love your work.

[@jthrush]

@0:17 Actually we do know why there are only 3 extended spatial dimensions, and it's very simple: stable orbits are not possible in higher dimensions, so you could not have atoms or planetary systems as we know them.

[@lucidmoses]

We can easily understand that 2D creatures in a 3D universe would not be able to directly detect the third dimension. Yet many think that we are not in a 4D universe because we 3D creatures can not see the fourth dimension. It seems reasonable that IF it’s a 4D universe we could indirectly detect it. Spooky action at a distance seems a lot like a 4D->3D version of the single 3D pencil going through a 2D world twice by bending the 2D world. Sure they still can’t see the third dimension or know there world is bent but that can infer the third dimension by moving one of the circles the pencil makes and seeing how it deforms the other.

[@tribudeuno]

In the book, The Craft of Musical Composition by Paul Hindemith, he starts the book in discussing how to use the overtone series to construct a musical scale. In that chapter, he speaks about how although you can build such a scale, there is a small amount of vibrations that you cannot use chromatically or diatonically, and historically these vibrations were for centuries hidden in the interval between C and C sharp. This hiding of these vibrations made it so that those using a keyboard could not modulate - that is to say, change keys - into distant keys. That is why very ancient music tends to sound very simplistic. If I remember correctly, these extra vibrations were referred to as "the comma". Johann Sebastian Bach is considered a dissonant composer - although he resolved his dissonances - in that he got around this problem of the comma by means of what he called "well tempering", that is to say, distributing these vibrations throughout the chromatic scale. After Papa Bach, equal temperament where all of the tones of the chromatic scale were given intervals of equal distance between the tones, which kind of solved the problem... But I say "kind of", in that there was something lost by doing this equal temperament. There is in music today something called "enharmonic equivalents", which is the result of equal temperament. That if you can imagine a keyboard with its black keys, each of the black keys has two different names, i.e. C sharp and D flat are two names for the same note. And what name you call it would differ depending on what key you are playing in. I'm trying to keep this simple for the non-musicians. Back in the day of "hiding the comma", there were no enharmonic equivalents. C sharp and D flat were two entirely different notes, two entirely different frequencies. This cause a far more dramatic shift emotionally when modulating or changing keys. But when western music went to equal temperament, this dramatic shift was lost. Beethoven tried to compensate for this by increasing from the 40 member symphony orchestra of Mozart, to the 65 member orchestra, which included for the first time the most powerful acoustic instrument there is, the Trombone. This essentially made what Mozart called fortissimo and what Beethoven called fortissimo like the difference between Elvis Presley and Led Zeppelin... So you are probably wondering what the heck does this all have to do with Physics. The problem with "the comma" only came about as a result of the keyboard, i.e. clavier, harpsichord, piano forte. Human beings singing and playing violins and related instruments never had ANY problem with the comma. That is because human consciousness automatically makes the compensation for the comma, without even thinking about it. I have this sneaking suspicion that if the majority of scientists ceased to suffer from their condition of "rectal-cranial inversion" - mainly brought about by science being mixed with the profit motive - and seriously studied consciousness and its influence on reality, they would come to realize that the missing link between General Relativity and Quantum Mechanics would be Consciousness, which is without thinking about it, blending those two great truths to give us the reality we experience...

[@ChaineYTXF]

Brilliant presentation, as always. Thank you

[@jamescarnevale3312]

Dr. Hossenfelder, Early in my engineering career, I had deep exposure and need for vector and matrix methods, focusing only on outcomes not geometric visualization. I appreciated your clear description and graphics of vectors. Warm regards.

[@LQhristian]

Lovely summary!!

[@lopezb]

Fascinating. Thank you Sabine!

[@nonhumanhumanist2149]

This explanation is more digestable for my brane. Lieben Dank für Ihre ausgezeichnete Videos :-)

[@dr.michaellittle5611]

Ooh. This was a real mind-stretcher. Excellent video and looking forward to the rest of the story. Thank you.

[@DallasMay]

Thinking about time as a dimension and why it is we can only travel in one direction through time, I once thought to myself, "how do we know we only travel in one direction?" If we actually oscillated in time, constantly moving back and forth, how would we know? Our brains would be oscillating with time, and lose and restore information as we went back and forth. What if we were constantly being pushed and pulled through time as space is warped and stretched by gravitational waves from every star and planet and event in space? Could we interact with our past selves? If you think of an electron passing through space, if it oscillated back and forth with time, then the electron could intact with and "push" it's previous version of itself, causing a slight change in momentum, which would alter the future state, which would alter the future state's reaction to the change in time. Send that electron through a "double slit", as it oscillates through time, getting stretched and pulled while on gravitational waves, the future positions of the electron would affect the past positions and ultimately affect which slit the electron passed through and at what angle it passed through. It would ultimately "diffract" off its past and future selfs and ultimately appear to be a diffraction grading on the detector. And any attempt the "observer" tried to make to observe the state of the electron would alter the path of the electron such tht it could no longer interact with it's past self, thus "collapsing the waveform".

[@harrkev]

The answer to three dimensions is: stable orbits are only possible in three spatial dimensions. Anthropic principle.