Understanding 4D -- The Tesseract 

When trying to find the longer side of the blanket

you show me a 4D object in 3D world on my 2D screen and I try to understand this with my 1D brain

"the obvious answer is to take a 3x4 matrix and multiply by that" ah yes, just what i was thinking

I've been trying to "picture" tesseracts in my head and other four dimensional shapes and I feel seriously unwell.

I played myself thinking I was smart enough to watch this video

Me : okay brain, so what you got? My last active brain cells : Cube is a box

I think i remember seeing something that may help visualize the 4th dimension. Let us imagine a drawing of a stick figure holding a box, and a stick figure behind them. We in the 3rd dimension who look into this image can see everything. The contents of the box, and the stick figure behind them. The stick figures can only see in the 1st dimension, so the stick figure can only see lines and any lines stop their field of view. Hence why they cannot see through the box as they only exist in the X and Y axis. If a person in the 3rd dimension were to try to interact with the second dimension, like trying to stick their hand through a page, the stick figure would only see first your finger tips, then the rest of your hand coming through, and they wouldnt understand the sequence of what this ever changing thing, one line at a time. When it is really a hand. Let us then picture the same scenario, where we are holding a box and someone is behind us. We cant see whats in the box, and we cant see the person behind us. A being in the 4th dimension can see whats in the box, the person behind us, and everything else going on around us. It trying to interact with us in the 3rd dimension would be something similar to us sticking our hand in a stick figure's line of sight. It would come seemingly out of nowhere from some other spatial reality or rift and we wouldn't understand what is really happening.

After watching the video (watching, not understanding), I can say that I absolutely love the guitar playing in the background.

I understood the part when he said see you next time

*Before watching Me : I am confused *After watching Me : I am con and fused

Played this to see how smart I am, and discovered that im just a simple person .

I wouldn’t even begin to comprehend this when I’m awake, let alone watching this at 2am...

*You lost me at "hello "*

Trying to explain the 4th dimension is like explaining colors to a person blind since birth. There's no way to actually visualize is correctly.

I find it so fascinating that there are concepts, such as the concept of 4 or more dimensions or the concept of being dead, that completely short-circuit the human brain and we as a species are physically incapable of comprehending them.

I remember learning about this as a kid and I made it a point to try drawing a tesseract on all of my homework so that long into the future people would be perplexed as to why a kid was drawing 4d shapes 😂

"So, there you have it..." No I don't...

⚠ Brain.exe has stopped working.

As someone who lives in the 4th dimension I thought you did a mighty fine job.

This was the best one thus far. Thank you for your time and perspective.

2:46 ah yes, the obvious answer. I was just about to say that

Physics: How much of that did you understand? Me: No.

I was so confident about my comprehension of four dimensional time space, and you just threw in so many new curveballs with the different types of physics, and the different types of ways that our physics could be perceived differently on other places

One of the best explanations of 4D that I have heard. Thank You!!

This makes me feel like I live in Flat Land and an apple is messing with me

just when i thought i wasnt smart enough for this video i was comforted by the comments

Years ago I had a spontaneous out of body experience and felt quite confused after. I swear I could see everything with a 360º vision. Inside and outside of objects at the same time. Couldn't really feel like I was separate from the objects I saw anymore. Whatever I focused on my attention on, I would become it. It was weird AF but it felt natural at the same time.

a minute and thirty seconds explained a tesseract with the best explanation I've heard

I'm watching this video in front of my parents, pretending I'm so smart.

I legit have no clue what you're saying, so when you said "the obvious answer" at 2:47 I wasn't happy

This was very helpful in explaining why 2D representations of tesseracts look as they do! I've always considered the w axis to be time, or duration, and tesseracts are coherent sequences of expanding/contracting 3D cubes (a simple model, to be sure). Now I see people combine the x,y and z,w planes to fit the 2D monitor. Very informative; thank you ~

This is awesome! I'm currently trying to program a tesseract into desmos and this really helped me visualize the math side of it. Great stuff!

Came here thinking I'd understand this. Now my brain's spinning like that tesseract

I'll just pretend to understand this......

**Confused Oonga Boonga**

Such a cool animation to show this concept! Very interesting, thanks!

This video should be age restricted

I showed this to one of my coworkers and all he said was, "nigga what?", thus proving my theory that humans are not ready for this type of knowledge

I had no idea what a 4D thing looked like til i watched your video...great stuff

thank you! i don't think i'll ever get close to understanding it, but you did a great job and now i understand a bit more...

I swear i never tried to understand so hardly about something in my life before

2 mins in and he says "ok lets now get a little crazy." Buddy it was already crazy for my brain after 10 seconds.

Up till now the best explanation I could find of 4d

It is fun knowing people were able to visualize this.

Imagine fourth dimensional beings finding this and being like: “okay yeah kindergarten stuff”

*Loki wants to know your location* *Connection with Loki has been lost* *Thanos wants to know your location*

omg beautifully explained, loved it !

still I dont understand it

I’m entering NTU’s faculty of mathematical sciences soon, and I understood everything you said till 0:05

If 5D cube was visible it’d be seen as a cube with Mental conditions

ouhhhh adding the concept of time really helped me! because it’s all at once. so that’s how you would see all those extras

This is probably the first video I've seen with examples of the math used to make these models. Interesting

imagine 4th dimensional beings trying to understand the 5th dimension. we couldn't even comprehend a, v w x y z, axis. interesting none the less

3:43 "So there you have it." Me: searches for cat videos

This was, in fact, incredibly cool.

Thank you so much, I was having some trouble sleeping but I feel sleepy now.

I was simply listening to the band "tesseract" and somehow wound up here. Now my fascination with the geometric shape of the tesseract leaves me incapable of returning to whatever state of boredom I was in. Staring at the animation of the tesseract is about as close as I have ever came to experiencing being in a trance. This is certainly what Copernicus felt when he realized we're traveling around the sun, not the other way around. The concept of "perspective" takes on more and more importance the more I learn.

2:42 “If we have a 4 dimensional point, how do we represent it in 3D?” “Well, the OBVIOUS answer is: (shows super duper advance math equation)” 🥴

Awesome explanation. Thank you

Intriguing video which I understood thoroughly. I liked when the box went squonchy

Cool, now explain like I'm 2

But to a 4th dimensional being, if one hypothetically existed, would see the rotation of the tesaract as a simple rotation, much like we would see if a cube was rotating.

thanks for sharing the video. so knowledgeable

TIMECUBE has answered and explained all of these questions decades ago!

Me: *watches video* Me at end of video: So it's a cube within a cube connected with lines

I understand the concept of 4d but I cant visualize it in my mind.

It helped me a little bit: a square face is a line, a cube face is a square, a tesseract face is a cube. Each side of the tesseract is a three-dimensional cube! And there are a total of 8 of them in the tesseract, including: the inner cube (which is like hanging inside the big cube), the big cube itself, each cube if you rotate the tesseract left or right (there are 4 of them) and the two cubes at the top and bottom. And if the cube is rotated in such a way that you feel like your brain is melting, if you look closely, you can see as if the inner cube is being stretched over the outer cube every time.

Ma'shAllah, it's a great concept of 4d.

But.. but.. I just heard Alan Walker Alone in 8D

I gotta admit, I really enjoyed making this video. I have always heard about the 4th dimension, but it wasn't until I actually implemented the double rotations that I really came to understand how cool 4d stuff can be! In particular, the projections from 4d -> 3d were hard to find on the internet, so I hope that helped someone! As always, let me know what you think. Thanks for watching / I'll see you next time!

I came here from wiki wondering why there's 8 cubes in there and realized the 8th one is the outer most cube containing the entire thing when I saw the animation. Thanks!

The world if teachers are explain like this man *inserts futuristic city image

0D - its a point = point 1D - is't an vector of points = vector. 2D - it's an vector of vectors = plane. 3D - it's an vector of planes = space. 4D - it's an vector of spaces = vector of spaces. 5D - and so one... Tesseract it's 4D cube? Really?

So it isn't a storage for the Space Stone

I like the superpower of space manipulation, so it’s something I think about occasionally, and I think I got something to _maybe_ explain part of 4D, though I’m not sure if it’s just 3D space still. So imagine; before you is a normal, wooden desk-with nothing but a flat surface sat on four legs. On that desk is a similarly normal piece of blank paper. That is 3D space. Now shift your view to the side, to where you can see where the desk and paper meet. The space between that desk and piece of paper is 4D space. From the view of 3D it’s practically nothing, true, but in 4D the distance between the two may as well be immeasurable. Think of it like the 4D plane is the ocean, the piece of paper is "floating" on the surface of the 4D plane right above the deepest part, the part just where the water meets ground again being that desk. Of course, this metaphorical ocean can’t be seen, so if you grabbed a pencil and "pushed" it down into that water, it would disappear, but if you had the ability (spatial manipulation) to see it and interact with it, you could "grab and pull" it back out. Like a magician twisting their hand and making an object seem to disappear, or pulling a object out from behind a person’s ear. Of course, this space is anywhere and everywhere, you could even "put" or "grab" a pencil from thin air, or from "inside" a cube. And I know this may sound a bit similar to the "house bigger on the inside" thing but I like to explain that through "density", increasing the amount of space in a space. For example; having a football field’s amount of space in a 5 foot area, so traveling through it would take the amount of time it’d take to cross a football field. I could honestly go on a rant of how I imagine to/explain to myself how space manipulation works using only more simple things, like using a pipe/tube to explain the looping hallway/area trick, but this is already long xD

You made this so easy!! Thanks

Just give me a 4D object and I'll understand it.

I went to a "4D" movie once but it was just a guy in the theater would punch you in the face during the movie

This isn't the content I wanted, nor was it what I expected based off the title.

Appreciated this 🙏💕

This would be great to see in VR. Perhaps the rotation would make more sense when observed in 3d instead of 2d flat screen.

My DAILY BROWSING OF WIKIPEDIA 😂😂😂

Whatever the video is, I enjoyed reading the comments it made me feel that we are all the same

Do DMT and you will see 12 dimensions

AND I CAME TO UNDERSTAND INTERSTELLER !

What happens when you try to draw the 4D dice on a 3D paper, like these drawings made half on the street and half on the wall. If you look at it from the right point it’s a perfekt drawing, but when you move it’s distortioned. I would love to play and try with this kind of thoughts.

Very COOL! The 4D matrix: even better

So I think I can explain the link that I had to make in order for this to make sense to you guys, and the part he kinda glossed over. Each group of edges corresponds to a dimension. A cube consists of length, width, and height edges. Length alone gives you a line, adding width makes a square, which is a series of lines, and then height makes a cube, which is a series of squares. The final dimension we have for the hypercube has the diagonal edge which links the innermost cube to the outermost, with a series of cubes in between these, like the lines in a square or the squares in a cube. Did that make sense? It would probably help to have a visual to point to, but sadly I do not have the software this guy used.

THANKS 😊 for all the comments it really made me happy knowing that i wasn't the only one who doesn't get this

I was trying to visualise this in my head this morning this is a good attempt at a 3d representation of a hypercube

This just left me with more questions while I didn't get an answer to the one I wanted.

One thing to note is that the projection of a 4-D hypercube animation onto a 3-D plane causes the lengths of some sides to appear longer. In reality each and every one of the sides of the hypercube is the same length in 4-D space.

Me: RU-vid: Hey kid you want a headache?

This is the sound of your mind blowing!

awesome. Thank you for this

Me:*watches* Also me:*makes meme to cover the fact that I didn't understand a word*

For more 4D visual presentations, consult your local DMT vendor.

Good video,i enjoyed.

Thank you veeery much!

Further clarification: The cube on the inside is the cube furthest away from us in the 4th dimension, the cube on the outside is the one closest to us. The other six deformed cubes are inbetween. When you rotate in the 4th dimension the cubes change order, this is because you are changing your distance from one to another. The same thing happens with an 3 dimensional cube where we have 6 squares. The smallest square is the face away from us and the largest is the one closest. The deformed squares are somewhere inbetween. If we rotate around a cube the size of the squares changes.