Thinking outside the 10-dimensional box

[@abhavishwakarma5035]

"The goal here is genuine understanding, not shock" You're the best.

[@Blaze6108]

1-dimensional array: a line 2-dimensional array: a square 3-dimensional array: a cube 4-dimensional array: death incarnate

[@slymey_]

4D=tesseract

[@kerseykerman7307]

@@MattacksRC You mean it has a bunch of cubes. Tesseracts are made up of cubes, not squares.

[@SimonPegasus]

@@kerseykerman7307 Not just a bunch, infinity ammount of cubes

[@skytrexz3714]

@@SimonPegasus yeah 2nd dimension is just 1st dimension with a lot more dots

[@237homer238]

ten grams to snifindor

[@thecrystalmemes5767]

It's nice how the video is over 20 minutes long but he doesn't put any midroll ads. Respect man, respect.

[@Jamberia]

he should get way more praise for that

[@ceff01]

ive reported you for having that stupid bitch picture

[@a.yashwanth]

I can see that picture in almost all comment sections. What what that picture?

[@villerger_27]

Watch out guys, josh thumperluck will report you for a profile picture. Maybe you should get one, it’s better than the lime green default.

[@ceff01]

@@villerger_27 your now reported !!!

[@ArxxWyvnClaw]

-Quality Content -Clear Information -Awesome Animation -No Ads -No BS I need more channels like this

[@portul566]

kzbin.info/door/KzJFdi57J53Vr_BkTfN3uQvideos

[@abaundwal]

Captain Disillusion

[@ArxxWyvnClaw]

Thanks guys, you're both a great help. I subbed to both channels. But I'm still looking for more channels :D

[@SoumilSahu]

@@ArxxWyvnClaw I don't mind ads though. The man is working his ass off to educate us for free. Least we can do is allow him to survive, even if it means watching a couple ads every video.

[@ionisator1]

@@ArxxWyvnClaw Numberphile?

[@arnaldo8681]

Hey, im leaving this message to say this video really helped me with my research in economics It has nothing to do with high dimensional spheres, but something about the investigative way you approached the problem made me remember about the way i used to approach mathematical problems when i was younger, and it gave me insight that might help me with a problem ive been stuck for more than 1 month There is something about this way of seeing math that is very powerful, and that frequently gets lost when we are too deep in more analytical and formal approaches. It is hard to define what exactly it is, but this channel's videos are very good at inspiring it

[@PasseScience]

Never forget that if someone sells you hyper-oranges in dim-87 by hyper-weight, you'll mainly pay for fruit skin.

[@user-bg6xh7vv7t]

i love this

[@ibieiniid4240]

22:04 he said the correct number of "one"s. now I'm impressed.

[@b.clarenc9517]

I counted them too :D

[@mathiasbrio2105]

i counted them

[@hanstheexplorer]

how many

[@xXMindSoulXx]

@hanstheexplorer 10

[@Sparkette]

7:59 Why imagine yourself as a bug on that small sphere? A human on a really, really big sphere works too, and you don't even have to imagine that.

[@cryies]

@Bruce U stupid bug

[@Brawler_1337]

Because the Earth is flat. Duh!

[@AnhThuNguyen-zz2hm]

*no*

[@felixroux]

You've definitely triggered a flat Earther... Oh wait, there's no way they understand maths in 4th grade or above.

[@elreyrey7537]

@@felixroux Maybe 3b1b should do an video on thinking in the third dimension for flat earthers

[@SSM24_]

That point about how far away the corners of the boxes are in higher dimensions is what really made this click intuitively for me. In higher dimensions, there's effectively more space for the outer spheres to fit into the corners of that outer bounding box, and they're located farther from the origin as a result. This leaves more space for that center sphere to take up while still being adjacent to the outer spheres. At no point, however, does the center sphere overtake the _corners_ of either of the boxes.

[@maddyschad6649]

YES, exactly!

[@RichConnerGMN]

lol hi

[@RonMar]

Those numerical sliders are like Braille for higher dimensions.

[@SamraiCast]

Ron Mar Best Comment

[@mlg-allallong5491]

this comment poke my all dimension at the same time....

[@bauagan]

are you rich yet? xD

[@williamromero-auila921]

Braille in a hyper-plane

[@johnchessant3012]

A mathematician and an engineer attend a talk given by a physicist about string theory. The mathematician is obviously enjoying himself, while the engineer is frustrated and lost, especially when the physicist starts talking about higher dimensions. Finally, the engineer asks the mathematician: "How can you possibly visualize something in 11-dimensional space!?" The mathematician replies: "Easy, first visualize it in n-dimensional space, then let n equal 11."

[@vivekthomas8]

John Chessant Get the fuck outta here, AND CLOSE THE DAMN DOOR ON THE WAY OUT!

[@leowong8777]

John Chessant That wasn't even a joke. It was just *straightforward*

[@dannydk6]

Lol

[@edvink8766]

This supposed "joke" seems like the embodiment of r/iamverysmart. I mean, there''s not even a real punch-line here.

[@Graknorke]

Edvin K It's a joke about mathematicians being detached from reality. It's like the spherical cow joke but without the buildup.

[@feynstein1004]

Thank you so much for explaining WHY it happens, not just that it does. I never imagined the answer would be so simple. The sides of the cube stay the same but the corners get farther and farther away because more dimensions are contributing to them.

[@bwcbiz]

I've typically use a couple of methods to visualize higher dimensions: 1) imagine variation over time, 2) variations of color across the spectrum. The sliders map more easily to the vectors used in analytic methods, and give a better feel for what actually happens at higher dimensions, so I'll definitely be adding this to my "toolkit".

[@nutronstar45]

3) adjusting the "w" slider

[@evanmeyer1496]

from now on i will only buy higher dimensional real estate seems more profitable currently

[@Blox117]

we will build a wall to keep the low dimensions out and make the high dimensions pay for it

[@pokemoncatch6727]

Blox117 yeah lets do it. Also is that a reference to Trump

[@Blox117]

@@pokemoncatch6727 yeah its a joke on his build a wall statements

[@JBB685]

you should check out what *some* people are doing in selling (or trying to sell) virtual real estate, like in VR worlds

[@LazyRare]

Jonathan Bryant VR worlds should be free, for humanity!

[@terner1234]

x: moves a little y: it's free real estate

[@realbignoob1886]

dynadude lol

[@pranamyabelvai7488]

AHAHHAA

[@squealer7235]

I can't understand what real estate means in the video.

[@sharqstep]

@@squealer7235 so basically it's like the point in space that you're supposed to conquer and they're mutually dependant on each other imagine a line segment where x+y=1. you (x) take some part of the land, so obviously the other part belong to (y) similarly, in the next (2nd) dimension, the curve is a circle defined by x² + y² = 1 so by the relation, as x moves a bit, the length y covers is termed as the "real estate" of your and vice versa

[@ramakrishnansubbaiyan3798]

No no no no....you wrongly knowledge I am indian i am the best of the rest world.i need 5 Nobel prizes Minimum.. X is a male..gender Y is female..gender This is Univesel formula Don't Changes knowledge. ..

[@ConspiracySundays]

*It's free real estate*

[@darioinfini]

Yeah but it's mathematical swamp land. You get what you pay for.

[@nemou4985]

It literally says it isn't free, though.

[@taureon_]

i was thinking of that meme XD

[@cordialmanx2334]

got beat to it

[@DehJarlorNoob]

Came to the comment section looking for this comment. I wasn't disappointed.

[@Wren4123]

I'm like "It's a weekend, take a break from math, enjoy life!" *Sees this video* "Eh, a life without math is no life at all."

[@NikitaMittcev]

Coordinate: *Is close to zero* 3B1B: *It's free real estate*

[@erikfauser2418]

thats funny

[@danegoodwin3057]

It blows my mind how brilliant some peoples' minds are

[@gruminatorII]

This is not even a glimpse of how brilliant people like Einstein really are. He invented General relativity, which describes the movement of objects in a 4 dimentsional space which is not even flat 4 dimentional space, but curved space, and it is the matter in that space that is responible for how the space curves, over 100 years ago when geometry in 4 dimentional space was not even knows...

[@MeganBoschen]

Philippe Durrell: 🤯

[@GASPERL1]

To be fair, Einstein did receive some help from mathematician Minkowski

[@hoennnoodle]

and to blow your mind even more, chances are the smartest people to have ever lived died without ever leaving a trace of their thoughts behind

[@tim_nj_devil176]

beepybeetle and unfortunately due to the internet, idiotic fucktards that believe the earth is flat, space is fake, etc. are forever enshrined

[@SoopaPop]

VISUALIZE HIGHER DIMENSIONS WITH THIS 1 WEIRD TRICK! STEM PROFESSIONALS HATE HIM!

[@lucasm4299]

SoopaPop Haha lol 😂😂

[@3blue1brown]

There was a very serious part of me that almost did that for the title :)

[@DjVortex-w]

The art of clickbaiting.

[@pe4o243]

use sum dank DMT and u'll see the world made out os Calabi-Yau manifolds

[@oceanliketeacher]

DIMENSION 6 WILL SHOCK YOU!!

[@X-Gen-001]

Ah so this is how Doctor Who's TARDIS is bigger on the inside than the outside.

[@SinHurr]

OH MY GOD IT WORKS

[@caidenkesler3945]

Time And Relative Dimensions I guess. Doesn’t specify 3 I guess, so it works

[@sonetagu1337]

Y'know, the classic non-euclidian space.

[@MonkOrMan]

Ohh yeah!

[@JoX1231]

mind = blown.

[@daksh8747]

I always get your videos until the halfway mark, after that it all goes over my head.

[@TimEnjoysGnocchis]

multiplying information ^^

[@99bits46]

i am at 16th minute mark and i am down to comment ^_^

[@mobob7989]

same

[@Acid113377]

same happens to me. after half way mark i have to often rewind and rewatch segments multiple times. i think thats ok with a information dense video like this. its tough being 100% alert for 27 minutes.

[@yamansanghavi]

I beg you; please make a series on tensors (contravariant & covariant) , curvature, manifolds etc. Thank you so much for what you are doing for us.

[@thorstambaugh1520]

If you truly want beauty please do a video on tessellation and matrice theory. The correlation is astonishing and sublime

[@Psyle_]

Yes differential geometry would be awesome with his clarity and animations Manifolds and their diffeomorphisms are very obscurely introduced at uni

[@tghuffine6277]

Dude, that would be so cool..!

[@justice576]

Now I understand why I suck at mixing/mastering. Its 10 dimensional circle math lol

[@mirmalchik]

except it's even better because you're not restricted to any surface, in any number of dimensions (wait that's not true, if you only have 10 free variables, you're restricted to some 10-D surface in 11-D space. but still neat)

[@MoonDystopia]

Thank you! This will come in handy next time I'm stacking my 8-dimensional oranges..

[@elperronimo]

This video helped me a lot on seeing Trump's 4d chess moves from a mile away.

[@zorgazorga7601]

But a mile is so small in 4 dimensions... =D

[@smacq6000]

This helped me a lot when looking through my 6-dimensional walls trying to find where my 9-dimensional pen is, lost it in the 6-dimensional wall

[@smacq6000]

This helped me a lot when looking through my 6-dimensional walls trying to find where my 9-dimensional pen is, lost it in the 6-dimensional wall

[@computercat8694]

8-dimensional oranges? Make sure to use the E8 lattice, it's the best!

[@johno9507]

How do you expect people to visualize a sphere in higher dimensions when flat earthers can't even visualize a sphere in three!? ;)

[@shiftl4]

earth is not a sphere :D

[@elijahheyrosa5398]

Hes not talking about earth being a sphere Hes talking about normal spheres like basket balls or soccerballs, basic stuff

[@chlorobyte_projects]

r/woooosh

[@takeyourdamnmeds]

fact:earth is an oblate spheroid

[@pluto8404]

We exist on the 2 dimensional surface of a black holes event horizon. 3rd dimension is just a hologram, illusion.

[@d.m.collins1501]

I wish I could like this video in more than one dimension, because it is the best video ever on helping (at least me) REALLY understand a lot more about how higher dimensions work. And I've watched loads of them. Matt's Numberphile video about "Strange Spheres in Higher Dimensions" was a good companion piece to help me get started, but this video completed the home run (to mix a few metaphors). I think you should make an updated version with few changes, republish it, and just call it "understanding higher dimensions." Because it does far more than explain just the 10th dimensional riddles. Whenever I get a new job, I'm becoming a Patron.

[@IgorDz]

27 minutes! I'm not watching it! ..Maybe just a couple of minutes out of curiosity ...*watched it all*

[@VVV.12345]

I've just watched 27 minutes?!?

[@albertovieira588]

the same here hahahaha

[@Handimedia]

and you think anybody cares that you do not watch it?

[@albertovieira588]

JAY CURVE and do you think we care about your opinion ?

[@bewildo]

FlingFlexer 11 minutes in came here to check the comments, f me right

[@arnavverma4557]

This is some gorgeous animation

[@Smokin438]

Glad at least someone appreciates how much went into all of that.

[@bwatspro]

The saying: "Think outside of box", got new dimension.

[@Jabrils]

Grant. youre a deity.

[@enebz3746]

Hi, Jabrils! You are one of my idols! Cool to see ur 25 like comment in a random comment section...

[@Nucleardoom]

@Danko Kapitan haha

[@twiggy_witch]

22:41 It says: "I may or may not have used an easy-to-compute but not-totally-accurate curve here, due to the surprising difficulty in computing the real proportion :)"

[@timlampers8610]

I really wonder how 20-dimensional beings will think about the 2/3D 'sphere packing' problem. "What do you mean that the inner circle is **smaller** than the outer circle in 2 dimenions?! That has to be impossible! This 2-Dimensional representation is just completely wrong! It has to be wrong!"

[@marekhudac8390]

20D beings would understand 2/3D efortlessly, just like us, 3D beings naturally understand 1/2D.

[@AldorEricsson]

Just wait till fractal beings with fractional number of dimensions join the talk...

[@thomasbeaumont3668]

Or imagine those 3 dimensional beings trying to understand 2 dimensional circles. They’ll be like “the square root of 2!? That can’t be possible it must be 1.8...”

[@shadowcween7890]

@@thomasbeaumont3668 Now wait a minute here-

[@souravzzz]

I just found out this channel and it is fantastic! Please keep making great videos!

[@MatthewSalathe]

U Wot M8 John Cena dun dun duuuuuuuuuun

[@itze_]

Just happened to me. I have an exam today! Now back to studying

[@CarlosMats]

This channel is goddamn brilliant. Love your visualizations.

[@jasonquidoz3452]

This man has solved the housing problem. Real estate agents hate him!

[@mushkamusic]

Your sliders there actually look like a stack of discs in a row to me with the graduations. Which actually really helps with visualising how points change for multidimensional spheres. Thanks!

[@milkwater1204]

This is how I visualise higher dimensions, too

[@jalfire]

It's pretty interesting that even though it is so hard to imagine the possibilities of universes in higher spacial dimensions, that the mathematics in those universes will always be the same with our's. It is nearly impossible to predict the properties of these universes, but the language of math will always be universal. Or you know, multiversal I guess...

[@peterpemrich6962]

@@realityversusfiction9960 what the hell are you talking about

[@goyonman9655]

@@peterpemrich6962 😂😂😂😂😂😂😂😂😂😂

[@guyfriedman295]

16:51 my brain started to shiver... I think that enough math for today...

[@box_inabox]

Hi, game designer here, I have been struggling to find a visual way to think about balancing the power of mechanics in games that have multiple contributing factors. After giving up on this problem, this video has got me going back to my white board. Higher dimensional game balancing coming soon to a steam library near you!

[@General12th]

Nice! It's good to remember that coordinate systems and geometric reasoning are good for more than just spatial dimensions. All sorts of properties are orthogonal to each other -- for example, temperature, pressure, and humidity, or health, attack, and cooldown rate -- and that means they can be described with this kind of logic.

[@EzaleaGraves]

Video games helped me understandable dimensionality because of exactly this. Seeing those hexagonal charts with 6 base stats on them (strength, dex, etc). Characters exist as points in a 6-dex space

[@Kabitu1]

As a computer science student, I've had to deal with some of the weirdnes of high-dimensional spaces up close, when using geometric methods to analyze high-dimensional data. The unit cube alone is so incredibly weird.. mainly because it has an exponential amount of corners. Meaning that if you slice off even a tiny region surrounding each corner (and they are all at east distance 1 apart, so these tiny regions don't overlap, and therefore add up directly), those tiny regions comprise nearly all the volume of the cube. You can sort of say that properties that can arise from the actions of single dimensions are common, while properties that only arise with the "agreement" of many dimensions is rare. It's even sort of hard to create a large high-dimensional volume, because all of the dimensions have to be large together, if even one of them is small, the volume is small. It also has it's good sides, it means when we do optimization problems, we rarely have to worry about local extrema, since they can only happen if all dimensions curve in the same direction, whih is difficult to arrange. I'm glad I live in 3 easy dimensions.

[@christheswiss390]

The visualization at 7:40 REALLY made it clear. This is one of your best videos to date, imho!

[@InvisiRS]

I had a realisation during this video that really helped my understanding, so I wanted to share it. It involves thinking about the proportion of the n-dimensional cube's surface enclosed by the corner spheres. In 2D space, all of the surface of the square is enclosed by the corner circles. There is no way to draw a line from the origin through the square without touching one of the corner circles. When you move up to 3D space, you can already see this change. Focus on one square face of the cube. Notice the diamond shape that's not covered by any of the spheres. There's plenty of room to draw a line from the origin through the box without coming close to any of the spheres. In fact, it is this diamond shape that we filled in the 2D problem! Things get a bit harder in higher dimensions, but our 3D visualisation can still help in the 4D case. Visualise the solution to the 3D problem. Think about all the space inside of the cube that we filled with the inner sphere, there's actually quite a lot of it. Now, in the same way you can visualise the 2D problem as one of the faces of the 3D problem, think about this solution to the 3D problem as one of the faces of the 4D problem. You can actually see how there's quite a lot of space there that's not covered by the corner spheres! The visualisation breaks down after this point, but thinking inductively how each solution is a "face" of the problem one dimension higher, and how the space left over creates extra space for the next dimension to use was helpful for me.

[@Pyreshade]

Yeah, and this is because of how n-dimensional spaces increase in volume exponentially, so the space in between circles, spheres, hyperspheres, every proceeding sphere will do so as well!

[@ロズマリミルクシワル]

I think it's kind of cool that I was able to learn that the Pythagorean Theorem scales nicely with higher dimensions all on my own. I saw a line in 3D and was thinking "... I want to find the length of that.". I projected the line into 2D and found its length there. I brought back its Z data, armed with the knowledge of its length to X and Y and found it's length.

[@mattiasselin4955]

For those interested: Cubes in this setting would have the rule that at most one slider is not at the edges of the line (+-1).

[@aaronherman1056]

That doesn't seem right. Even just in three dimensions, the point (1, 0, 0) is on the surface of the 2x2 cube centered at the origin but there's more than one slider that's neither at 1 nor at -1. What you have are the edges of the cube rather than the surface.

[@iqdx]

As always so grateful for your creative work. After much reflection and reviewing of this video here are a few of my key takeaways. For problems in 2 and 3 dimensional spaces, finding solutions is greatly helped by our ability to move back and forth between analytical and geometrical expressions of the problem. For problems in higher dimensions we do not have access to this back and forth sharing of insights. Many if not most problems are formulated in these higher dimensions. This video provides an example of a counterintuitive insight that did not emerge at all in 2 or 3 dimensions. Namely: in higher dimensions the radius of the inner hypersphere, tangent to all N boundary defining unit hyperspheres whose centers are one unit from the origin as measured along any one of the N orthogonal axes is greater than the distance from the origin as measured along any single orthogonal axis to the surface of the N hypercube that encompasses all N unit hyperspheres. This is indeed counterintuitive. After grokking how you beautifully and skillfully led all of us to this insight, I was able to distil the following. To make the counterintuitive point, there is no need to introduce the growing inner hypersphere at all. Even in 2 and 3 dimensions the distance from the origin of any N dimension space to the center of any boundary defining unit sphere is always greater than one and grows as sqrt(N). So already for N=4, the distance from the origin to the center of any boundary unit hypersphere is greater than the distance along any one orthogonal axis from the origin to a surface of the hypercube that contains all N unit hyperspheres. The final grok (so far): the core insight is about the concept of distance. Not about radii, not about hyperspheres, not about boundary surfaces of all containing hypercubes. Distance from the origin to the centers of unit hyperspheres as you distribute them will always be significantly greater than the distance from the origin along an axis to any one of the containing hypersurfaces as you define them. Except in 2 or 3 dimensions. In yet another way: the N dimensional distance from the origin to any center of a unit hypersphere as you distribute them is always greater than the distance from the origin measured on an orthogonal axis to a hypersurface defined by your distribution of the centers of the unit hyperspheres. This is true for 2, 3 and higher dimensions. For the hypersurfaces containing all your unit hyperspheres, the distance from the origin measured along an orthogonal axis to any such hypersurface is always less than the distance from the origin to a center of a contained hypersphere except in 2 and 3 dimensions. Your videos are more accessible than my words. But my struggle to put the insights from you into these words deepens my ability to grasp what you offer. Thank you so much! Corrections and/or improvements to my text are most welcome!

[@nez14526]

Something in your explanation/insight (perhaps the 4th paragraph) made it very clear to me: Each time you add a dimension (and continue to say that a corner is at (1, 1, ..., 1)), you're moving the corner "further away" from the origin. But the sphere anchored there stays the same radius. No matter the number of dimensions, each sphere can always only extend "1" towards the origin from its corner, which is moving ever farther away.

[@dwinsemius]

Great stuff. The slider illustration is exactly what statisticians are using when they display higher dimensional data with a "parallel coordinates plot". They connect the coordinate dots with lines and one can then find clusters.

[@alfredinselberg7962]

Not just Statisticians. Please see "Parallel Coordinates: Visual Multidimensional Geometry" by A. Inselberg. Among others this book was also praised by Stephen Hawking. It is remarkable that it is not referenced.

[@battmarn]

I've been so confused about this for years and this is genuinely first time I've felt like i understood this. THANK YOU!

[@user-zd5pe7qh5n]

I have a simpler explanation for this: When the circles are replaced by spheres, and so on, the length between the edge of the inner circle and where the outer circles meet each other stay the same, regardless of dimensions. the volume on the other hand, is increasing with each dimension. Therefore, the space between the shapes grow slower than the volume of the shapes themselves as they enter higher dimensions.

[@andreamarino95]

I don't see what's your point!

[@zanti4132]

You can also visualize this, sort of, by first realizing that the long diagonal of the n-dimensional hypercube is increasing without bound. Now, the hypercube in n dimensions will have 2ⁿ long diagonals, and each diagonal will pass through exactly two of the hyperspheres. The radius of each hypersphere remains a constant equal to 1. So, any diagonal is getting longer and longer, with a fixed part of the diagonal inside two of the hyperspheres. The distance along the diagonal between these two hyperspheres has to be increasing without bound.

[@EjMacarus]

I am bias toward visuals so finding an established channel that really presents these ideas well is priceless. You are the reason I might actually get a degree. Thank you

[@flamingpi2245]

I mean, there are really no such things as people with different learning styles. The idea is unscientific, people benefit from a combination of all learning styles

[@boshgoria]

The dislikes are ppl who are jealous of the editing skills in this video From the people who can't say (1,1,1,1,1,1,1,1,1,1) as fast as this guy From the people who can't imagine a sphere bigger than the 4x4x4 box

[@hans_____]

I think the "real estate" metaphor made it more difficult for me. Now I have to figure out what exactly "real estate" is.

[@melocomanTV]

Real estate is the invariant, the constant set to one in this example, which governs the radius of the spheres. But he uses the metaphor inconsistently when talking about the inner radius

[@matthieudeloget8998]

It's cheap real estate 🙃

[@tiny_toilet]

Yeah, introducing this convoluted term just made things unnecessarily complicated.

[@philippelizotte3760]

Real estate is just a fancy term for land that you can buy.

[@Myrskylintu]

I feel the same. I kinda missed the whole video's point because of that

[@joshuasusanto6626]

22:42 *I may or may not have used an easy-to-compute but not-totally-accurate curve here due to the surprising difficulty in computing the real proportion :)

[@MadhumithaN]

Dude it’s sqrtx -1

[@prahas777]

I've been trying to wrap my head around higher dimensions for a while, and getting nowhere. This video is the first which has made a dent. Thank you so much!

[@fraserpye9667]

The reality is, 4 spacial dimensions don't actually exist. When he describes a "hypersphere" its actually fake, and non-sensical. Just like the number 3 can represent a range of things and be used for a bunch of things, a vector simply describes 4 independent "dimensions" where the dimensions are not necessarily spacial. Up to three dimensions sure your vectors can represent physical space, but after that they can only represent things like polynomials up to the fourth degree, solutions to the four dimensional equation like in the above video. These vectors aren't 4 dimensions spacially, its like saying a number is 1 dimensional. Numbers don't have spacial dimensions, neither to vectors

[@shaihulud4515]

IMHO by far the best YTvideo on this topic! It has mathematical proof, makes plausible assumptions, and comes up with an understandable way of explaining it's concepts. Congratulations to 3Blue1Brown - got yourself a new subscriber :)

[@gorkemvids4839]

Maybe we should keep every extra dimension constant and change 1 at a time and watch how x y z dimentions change. The pattern we'll see will be characteristic

[@caidenkesler3945]

If you do it with 4D, the 3D sphere will grow and shrink

[@jamesedward9306]

I've been struggling for a while with what all this math in higher dimensions really means. Watched a number of videos, and like many people I suppose, it starts unravel for me as soon as I get past 3-physical and 1-time dimension model. This is by far THE best video I've seen on this so far. In particular 3:00 to 4:00. That explanation on how to understand this stuff will always be burnt into my brain. Thank you Grant.

[@matheusbergamo240]

Which software do you use to make those incredible 2D animations? They're great!

[@mike4ty4]

He wrote his own, actually! He even has the source code posted here (he uses Python): github.com/3b1b/manim Though he does say this is not the most user-friendly software ...

[@Marf-yt]

So basically this is how the TARDIS is bigger on the inside.

[@misscrazygirl6963]

Master Marf oh yeah that makes sense now

[@shanewaters9402]

I haven't given any attention to math since grade 11 physics and I am 42 years old and just thought id say that watching this video it gave me an amazing amount of clarity to a topic I haven't addressed in over 20 years. that has to say something for putting things in to visual perspective.

[@jukokobarinko]

I used to imagine a 4d sphere as a continous collection of 3d spheres in some time perios, first a small sphere that appears at some time and at some point from a dot, grows up to the entire radius at the "middle time", then shrinks until it totally disappears at some moment. Every moment is that "3d slice" of a 4d space, where a 4d sphere is located. Sometimes I feel strange for thinking about such thinkgs, but hey, it's the reason I watch videos like this :D

[@caidenkesler3945]

And I’d guess the sphere grows and decreases at a sin rate

[@555artisan]

In fact, the thing you have been visualising, was the case of 4d sphere entering the 3d dimension space...for better understanding of what I mean, it's easier to step one dimension down and imagine of regular sphere (3d) going through sheet of paper (2d)...on paper surface, first it would appear as a dot and progress to grow until it's max radius...then getting smaller again :)

[@MB32904]

@@555artisan if you were a 2 dimensional being, it would look like a line growing then shrinking

[@fraserpye9667]

In math's your not supposed to relate things to reality, its a complete abstraction away from reality. Four dimensions should be thought of as four independent real numbers. Thats all it is. The hypersphere has no shape we can visualise, we are simply calculating distances based on what we know, except instead of 3 sliders we have 4. Its not actually modelling a 4 dimensional shape at all, thats a 3 dimensional application of 3 real numbers. This is mathematics not physics.

[@sethapex9670]

there are 2^n boundary N-spheres in N dimensional space. As n grows, each boundary sphere must take up exponentially less and less N dimensional space in a unit 1 N-cube which means the N-sphere which they bound must take up more and more space.

[@CosmiaNebula]

Also, if you are interested, think about what happens if you have infinitely many dimensions. You'll find that each point is a function, and end up with "gaussian processes" and "Hilbert spaces", where you think about the space of all "nice" functions as if it's just a high dimensional space of points.

[@DerNesor]

This reminds me when we calculated in physics that a high dimensional sphere has almost all of its volume on its infinitely thin surface , this blew my mind and so does this

[@petern.j.4121]

Wait, why?

[@p11111]

Visualize the 10D version by drawing the 3D version, but with the corner spheres tiny (and not touching) and the inner sphere huge and reaching outside the box. Then just declare that the corner spheres "touch" in 10D's. Although that last part is hard to visualize, it's easier than imagining a deformed inner sphere somehow poking outside of corner spheres that are actually touching in the model.

[@xanderbackus447]

That's how I envisioned it too

[@diogocruzdiniz3186]

I love the way you explain things. Instead of throwing math at us you explain the concept in a fun way. I hope you keep doing this!

[@nadiyayasmeen3928]

"The goal here is genuine understanding; not shock." Liked the video as soon as he said that.

[@theflaggeddragon9472]

This has always pissed me off that I can't visualize in higher dimensions when it's sooooo bloody tempting. But if you think about it, it's not that our brains haven't evolved to see in 4 dimensions or anything like that, it would be physically impossible to do it. You'd have to visualize infinitely many 3-D "slices" simultaneously to perceive anything 4-dimensional. I would give literally anything to be able to "see" in higher dimensions.

[@hanniffydinn6019]

The Flagged Dragon it's easy! Take some LSD ! That is leave your body via OBE , NDE ! Many have. I have.

[@Roxor128]

There's a VR game on Steam called 4D Toys which lets you interact with 4D versions of children's toys by selecting a 3D slice. It can be played with more conventional input and output devices, but I haven't tried it out in either form.

[@Squideey]

Hallucinogenics just trick you into thinking you've had a profound experience. Colorful shapes and brain-fucking isn't going to shed light on any real truths in the universe.

[@garryiglesias4074]

+Hanniffy Dinn - Nothing about "higher dimension" with LSD... Alternate state of consciousness doesn't "open" any dimension... It can swap perceptions, it can do "post effects" on your 2D projected image, nothing about ">3 D" view... Or you're getting too poetic here, and words have no more meaning anymore, which would mean that you are actually high on LSD or other deceptive drug... :)

[@redsalmon9966]

You'll need a four-dimensional creature to take you out of this 3D world, like in the Flatland.

[@randykayser4145]

Hey Grant, another great video. Your quote at 24:42 is such a wonderful encapsulation of how it feels to do research in modern geometry, and I will definitely whip that one out in a future elevator pitch to laypeople! By the end of this video, I think that you plausibly demonstrated how people can use clever frameworks to parse high dimensional information and extract understanding, even without an honest image of the setting at hand. However, that calls back to an earlier point you made, about how our physical reality has possibly limited our ability to do geometry in higher dimensions. Perhaps reassuringly, I believe this to be false. In fact, there is an extreme meta-mathematical non-linearity in how the complexity of certain geometric problems grows with dimension. For example, consider the classification of smooth surfaces. This was written down non-rigorously in the 1860s, and rigorously proven in the early 1920s. Every surface is uniquely realized as some number of tori and copies of RP2 glued together. However, the classification of smooth 3-manifolds is a substantially more complicated program and is still incomplete in a couple ways. Instead of gluing just two fundamental units, the torus and RP2, there are now 2 countably infinite families of basic building blocks (aptly named prime manifolds) and also one more prime. Both of the countable families have lingering questions, with one family having substantial work remaining. Finally, in 4 dimensions, the problem becomes categorically harder still, with the new phenomenon of uncountable families of exotic 4-manifolds. I believe most experts today would consider a smooth classification theorem to be either literally impossible, or impossible for humanity to write down, in the sense that the statement of the classification would be prohibitively large from the perspective of data storage (much less proving it!). Even restricting to similar questions in more tractable settings has provided many famous, brilliant mathematicians (Chern, Donaldson, Cheeger, Witten, etc) decades of fruitful research. * The upshot here is that geometry in large dimensions is difficult in an essential, platonic sense. As you add dimensions, the problem grows in complexity in a way that is incredibly resistant to inductive logic. Honestly, there might be an anthropic argument that if intelligent life exists, it cannot be high dimensional, as evolutionary pressure would have difficulty developing a brain that was capable of synthesizing so much raw data as to interact meaningfully with the geometry of n>=4 spatial dimensions. *People familiar with the story may object that I asked about smooth classification, instead of topological, but the divergence of these questions in larger dimensions only underscores the way that low dimensional geometry occupies a degenerate simplicity. There are other similar stories across mathematics - the classification of algebraic singularities, rationality in bi-rational geometry, etc.

[@BrainSlugs83]

I'm not super great at math, and this was very intuitive for me, and easy to understand. Thank you for creating and sharing this. :)

[@jacobgirard7175]

Michael Jensen mayhe you are good at math and just don't know it because this was really hard for me to pay attention to.

[@scottgoodson8295]

Have you read Matt Parker's book "Things to Make and Do on the 4th Dimension"? It mentions this and he also is a mathematics youtuber [StandUpMaths (you probably know his channel already)].

[@wedusk]

Scott Goodson I have and it's a ton of fun!

[@vampyricon7026]

+

[@muizzsiddique]

Who wouldn't know of the great Parker Square?

[@ragnkja]

I first heard of this in that book. It turns out that spheres are a lot spikier than we tend to think they are.

[@xenontesla122]

Nillie Isn't it that the cubes are spiky? If we say that "spikyness" is how much the distance from the center of the object varies, an n-dimensional sphere would be the least spiky object. The cubes, on the other hand, have verticies that get farther from the origin as the dimension increases while the center of each face stays at a fixed distance.

[@fdsKedi]

20:22 When the lesson will finish in 5 minutes and teacher hurries:

[@samusbros66]

If you put a glass (3D object) under a lamp or something, you'll see that it's shadow makes a circle(a 2D form), imagine how complex a fourth dimensional thing is. Tesseract it's just the three dimensional shadow that we can see in our plane, it's real form it's unbelivable complex

[@nathanaelhahn]

Tease Pi is my new favorite pi creature

[@ffximasterroshi]

Wonderful video, glad that I revisited it. I'm currently doing hobby research on 4d spheres and have a great understanding of 4d hedra and a good understanding of 4d cuboids. The formulas will be great for analyzing. Btw, the ability to slice higher dimensional shapes into sets of sub-dimensional shapes is true for hedra (simplexes), square/cuboids, and circle/spheres. These slices can then be visualized in series to make an analog of the higher dimensional shape.

[@maistooo]

If my math teacher was like this man!

[@bananya6020]

maisto he actually wouldnt teach math like this lol

[@gruminatorII]

The video with all animation probably took far more time than your regular math teacher has to prepare a regular math class. ;) its not realistic to spend 20 hours to prepare 27 minutes of course. However awesome videos

[@jerrytomas3136]

Philippe durrer No, it’s not useful when it’s already been done 😂

[@pieceofbread5686]

My math teacher is like this, 3 out of 25 students only understand, what he is even talking about. Luckily, i'm one of those 3.

[@SimonPegasus]

@@pieceofbread5686 You must watch Rick and Morty then

[@brownfox651]

Got that 1st d The 2nd 3rd But can't even imagine the fourth

[@AntThinker]

@Evi1M4chine To hell with five dimensions. Who likes to try being a puffer fish?!

[@mirmalchik]

but the inner sphere is exactly the same size as the outer spheres! that really doesn't help at all? it's so much f***en rounder than 3D spheres...

[@smythee7835]

some people and i'm one of them can only learn on their own. so a very fast paced information delivery without any type of interactions including very long delays with useless questions like you provide is perfect. I always refused to stupidly learn math or to listen to professors forcing their half baked course to students. Because no one has shown to me how to visualize it. I have never passed 2+2 2-2. So i'm grateful to you for uploading these videos and finally change my understand of mathematics. I am convinced that if i've been confronted to a choice to learn in this way I could probably contribute to math by now if I could find a passion to it for example.

[@pigwiggy355]

10-dimensional cube: exists Sphere: *i t s f r e e r e a l e s t a t e*

[@RoxanneClimber]

4:47 that's free real estate

[@TheMessOfFate]

Wow... this just blew my mind. I don't know if anyone here is even interested in philosophy or spriituality, but the connection i'm seeing is just too profound. So here we go: In spirituality you have those things I like to call the dimensions of conciousness. (Most people would call those the seven chakras.) Your concoiousness is the inner sphere, your inner universe. The most important aspect of your psyche. (I like to see this as the spiritual realm, you could even call it the "spirit world".) The outer spheres are the outer world. So everything and everyone else. All the things that are influencing you from outside your own mind. (This is the "material world".) So as you are climbing up the dimensions of conciousness (or chakras if you want to keep it traditional) your inner world (the inner sphere) keeps growing bigger and bigger. This means your spiritual capacity is growing. Spiritual capacity is equal to willpower, which is equal to your ability to "manipulate" the outer world. In other words your ability to create things. (Creation is the act of transforming something from one state of beeing to another, which doesn't change what it is made of (the inside) but how it looks like (the outside). On the inside/the smallest level everything consists of the same things (particles and waves).) The craziest thing about all of this is that the teachings of how you should be able to percieve your reality when you reach a certain dimension (chakra) matches with the math. Remember that willpower equals your spiritual capacity? The diameter of the spheres equal willpower. On the lowest 3 dimensions the outer world has more power over you than you have over it. The inner sphere is smaller than the outer ones. On the 4th dimensions you gain enough willpower to not be an "slave" of the outer world. Your inner world equals the outer world in diameter. You can start to decide your path yourself. From the 5th dimension onwards your inner world starts to gain more strength than the outer world. You gain the ability to think outside of the box. You now have left the realm of conventional "materialistic" thinking. You will start to see the connections between EVERYTHING. When you reach the 7th dimension, youre inner world has grown so big that it "swallows up" all of the outer world. The "inner sphere" now contains all of the "outer spheres". Everything is now part of yourself. This is the point where mind over matter starts to really kick in and the abilities of such people start to seem like magic. (Walking over burning coals without burning your feet for example.) I hope i made my point somewhat understandable since it is pretty abstract and a bit offtopic. (But still not as abstract as that math. At least for me, lol.)

[@pronounjow]

Sure, but I don't think the inner hypersphere ever swallows the outer hyperspheres in the math.

[@fdsfsdfgfdsg1338]

and the burning coals?

[@pronounjow]

@@fdsfsdfgfdsg1338 From how I understand the OP, I would say your willpower would end up bigger than the ability of the burning coals to control you as you walk over them. They remain a separate but accessible entity, though, just as the outer hyperspheres stay separate from, though still tangential to, the inner hypersphere.

[@fdsfsdfgfdsg1338]

@@pronounjow that’s crazy i see so what about death?

[@WhisperVT]

3Blue1Brown: The only content creator that's get's a like on the video BEFORE I watch it.

[@kyzer42]

So in infinite dimensions, the corner spheres have zero area, and the inner sphere has infinite? Wow. AMAZING video by the way, now I get why this works!

[@jeffreychandler8418]

Naviron Ghost technically the outer spheres are ALWAYS 1 but the inner sphere approaches infinity (but never reaches it ;) )

[@Pronobozo]

You know what 10D's go good with? plum sauce

[@JoelDowdell]

uuuuuhh. Had this explained before, didn't actually realize how crazy that was. Now my head hurts.

[@livintolearn7053]

That ending quote... Man, what a mic drop!

[@GREGGRCO]

I caught a glimpse of how the universe is even bigger. Particles appearing and disappearing. Electron energy states. Tunneling effect. Thank you very much!! Great graphics and explanations !

[@RPDBY]

man, what do you do for living? I wonder who has the time, desire, interest and knowledge to make such a high quality video

[@huhneat1076]

(x^2 goes down) y^2: *_it's free real estate_*

[@toferg.8264]

I think i need to rewatch at least one of your videos per day until i cannot forget them. I love how intuitive you make all this!

[@Daniel-Rosa.]

This made it *so simple.* This area of knowledge is not _my major_ in any sense, but I felt enveloped. I take special notice of your narration and how you leave some breathing room (needed!) often enough.

[@crazycripple3797]

The trick to visualizing other dimensions is impossible because other dimensions are not visual. They're like frequencies on a radio

[@Evan490BC]

Well, yes and no. You can't visualise them as true objects in 2- or 3-dimensional space, but you can _project_ them down to 2 or 3 dimensions and try to _infer_ (deduct) their shape.

[@barnaby12345]

Excellent video. This makes the counter-intuitive nature of high dimensions make sense. Here are a few facts that were just touched on in this presentation: An infinite dimensional sphere has no volume, regardless of radius (volume has no meaning in an infinite dimensional space) Every (multi dimensional) unit sphere contains all the unit spheres of lesser dimensions In higher dimension spheres, the vast majority of the volume lies near the equator, as does most of the surface area In higher dimension spheres, the vast majority of the volume lies near the boundary The most efficient sphere packing in dimension 8 is E(sub 8), and in dimension 24, it is the Leech lattice Each sphere in the dazzlingly symmetrical packing in the Leech lattice touches 196,560 other spheres In 8 dimensions, the densest packing fills about 25% of space, and in 24 dimensions, the best packing fills only 0.1% of space High dimensional hypercubes are spiky - as Dim for the unit hypercube goes up, the longest diagonal is sqrt(Dim)

[@benjaminbrady2385]

Really well made and outright beautiful video as always!!! ❤️

[@sergeboisse]

Wait ! If, in 4 dimensions, we can have 16 spheres touching themselves (whose centers are the corners of an hypercube of side 2, and whose bounding box is an hypercube of side 4), and if the inner sphere also has radius one, that means we can pack 17 identical spheres inside the larger hypercube ? And is the central sphere special in some way ? I'm puzzled. Very nice video with cute animations and explanations, indeed !

[@ThatJosiahGuy]

yes, at 4 dimensions we'll have 17 identical hyperspheres. but again, it's impossible to visualize, hence the slider example. he's showing that, in higher than 4 dimensions, the center n-sphere that touches each surrounding n-sphere exactly once, will be larger in size than those surrounding n-spheres. it's counter-intuitive because we only know how to visualize 2 and 3 dimensions -- but that's the very point of this video.

[@parkershaw8529]

The center sphere will never touch the corner of the bounding box and the its volume will be smaller and smaller than the box.

[@TrueMathSquare]

I just found this channel a week or two ago. I almost watch all of the videos on it.

[@loljustice31]

Why almost D: YOU'RE NOT A REAL FAN! D:< *rage* *rage*

[@nagahumanbeingzooofparticl8836]

but did u understand it?

[@VjJowo]

ohhh nice! Which software do you use for this awesome animations?

[@ishwar8119]

He, like a boss, created his own: github.com/3b1b/manim

[@elizabethmaas3907]

Another superb video by 3Blue1Brown clearly explaining the nearly unexplainable. Thank you! PS. I knew of the inner sphere's outcome from the beginning, but hadn't considered it in this manner previously.

[@cheydinal5401]

Or you could show the 4th dimension using not 4 sliders but 2 2D flats