10 ms·

How to walk through walls using the 4th dimension [video]

218 points by numo16 12y ago

smtddr 12y ago
I've been watching this vid on repeat trying to fully comprehend what's happening. This is another vid trying to explain the same thing - https://www.youtube.com/watch?v=UnURElCzGc0 https://www.youtube.com/watch?v=UnURElCzGc0 I really want to believe this is possible and this is how we'll be able to travel far into space. Like how we have to spend time walking around a very long wall when a bird can just fly over it in a fraction of the time, we wouldn't have to think about traveling light-years because there would something else we can do that's faster than a straight line.
- sp332 12y ago
  That's not very likely, because you don't have to walk around some kind of obstacle to get to a star. Even as a bird, you still have to travel the full distance to your destination. You could make a shortcut in space, which is called a wormhole. You can either make one using extra dimensions, or in 3 dimensions with negative energy to stabilize it, but neither of those seem to exist. Edit: link https://en.wikipedia.org/wiki/Wormhole#Traversable_wormholes https://en.wikipedia.org/wiki/Wormhole#Traversable_wormholes
  - JoeAltmaier 12y ago
    Unless 3d space is 'wrinkled'; in 4D you could travel straight there. Imagine a crumpled sheet - the 2D traveler would have to trace a route through all the convolutions to reach the other end of the sheet. The 3D traveler may only have inches to go. 'A Wrinkle in Time' was a story about this.
    - sp332 12y ago
      You'd just have to hope that the place you want to go to is wrinkled up so that it's next to you, and not still far away.
      - mordocai 12y ago
        From my vague recollections they were somehow causing the wrinkles to be close together. It has been years since i've read the series though.
      - JoeAltmaier 12y ago
        Actually going anyplace at all that way would be hugely exciting.
- foolrush 12y ago
  You might find NASA's page on warp drives interesting. http://www.nasa.gov/centers/glenn/technology/warp/warpstat_prt.htm http://www.nasa.gov/centers/glenn/technology/warp/warpstat_p...
laxatives 12y ago
I remember being really excited about this game a few months ago. Part of me is a little concerned whether there is enough to gain some sort of intuition on where you are and what is exactly transforming with each input. I'm a little concerned it will just become a game where you try things and hope for the best and have a very incomplete mapping of whats really going on. But anyways, its neat to see such a well produced game attempt to take on these challenges.
ericHosick 12y ago
As a game, this is really cool. But when he got to the 4th dimension it didn't make much sense as an explanation (rubble from 3rd dimension showing up in the 4th). However, if the 4th dimension was time, then you would walk back (or forward) in time to when the wall wasn't there (isn't there anymore cause it is now rubble), move "past the wall", and then walk forward/backward to the original time.
- sp332 12y ago
  Some rubble fell to the side, along the 4th axis. This is a 4th spatial dimension, not time.
  - foolrush 12y ago
    But the fourth dimension is timespace, is it not? At least that was what I gathered from Special and General Relativity and the relativity of simultaneity. X^t, Y^t, Z^t?
    - sp332 12y ago
      This game isn't real life! In the game there are four spatial dimensions, just because the game designer decided to have four.
      - foolrush 12y ago
        Which is an awful lot like a 4th dimension. Arguably we are all 4th dimensional travellers, albeit somewhat constrained along one of the axes. Granted, you had me at “This game isn't real life!”
        sp332 12y ago
        Oh, and the game also has a time dimension (which works normally I think, just one-way at one speed), so I guess that's 5 :)
    - pizza 12y ago
metadept 12y ago
I was really hoping for a continuous (rather than discrete) fourth dimension. The concept is cool and looks to be well executed, but it's not very different from other alternate reality implementations such as the Dark World in Legend of Zelda.
- kazagistar 12y ago
  Adanaxis is an open source space shooter game that lets you move in all 4 axis, or rotate continuously along any combination of axis. All models are 4 dimensional. Needless to say, it is confusing to the point of unplayability past a certain point, but utterly fascinating. You can grab a copy from your Ubuntu, Fedora, or Arch repos, and it is certainly worth trying to wrap your head around for an hour or two, if you are into that sort of thing.
  - devin_lane 12y ago
    Had a blast with this thanks to your recommendation!
- DougWebb 12y ago
  That would be really cool. The mathematics involved don't seem too difficult; you have to add another axis to your vectors, points, and transform matrices, and you can place and orient your models in 4D space, set up lights and a camera in 4D space, and project the camera's view into 3D space first then onto the 2D display. I think the hard part is creating the models and writing the rendering engine. Creating 4D models, rather than just putting 3D models into 4D space, would be hard to wrap your head around. And the tools, both for world creation and for rendering, are almost certainly limited to 3D so you'd have to write your own tools for everything. No more GPU acceleration, unless your 4D to 3D transformation creates models and textures on-the-fly to pass to the GPU.
  - viewer5 12y ago
    What would the 4th dimension coordinate of your models even represent, though? I'm having trouble wrapping my head around it.
anoother 12y ago
The game looks fascinating. I'm still trying to get my had around the analogies, but get the feeling that playing the game for real will bring a level of intuition to the experience. In the meanwhile, can anyone help me out? In the 2D->3D example, you have one shared axis (Z -- vertical), and an alternating pair for the second axis (X and Y -- horizontal). In effect, from the 2D character's point of view, 'jumping' into the third dimension is just swapping your horizontal axis. Your previous horizontal axis is a vertical section through your current one, and vice versa. As such, when swapping axes, you would expect one 1D line (ie. a 1-pixel-wide vertical band) to be the same before and after the swap. When going 3D-> 4D, you have 2 shared axes. Your third axis alternates, as before. When switching between your 'third' axes, then, you would expect one entire 2D plane of your perceived world-view to remain the same[1]. This doesn't seem to be the case. What am I missing? [1] EDIT: This plane is likely to be a section through some concrete objects, so you won't necessarily have 'seen' it before, though it will have been there.
- DougWebb 12y ago
  In the first case, the 1D vertical line is the same, but it's "seen" from a different angle. It looks the same because it's 1D and it doesn't happen to change because of the rotation. For the second case, maybe it's the ground plane that's the same; it certainly has some of the initial texture in it, but it's been rotated and it's now seen from a different angle. But now we can tell the different because it varies along the dimensions it rotated around. Or maybe I just can't visualize the rotation through the fourth dimension... I'm not sure.
- roywiggins 12y ago
  This is exactly right: when rotating in 4D, you can rotate "around" a plane, leaving it in place. You can also rotate around a line (permuting the other three axes). So, in the video. The Z axis doesn't change (up and down) so that's one axis. The other one that doesn't change is at a 45 degree angle from lower left to upper right. Watch the tree: it is just as wide along this axis as it was before. Everything else sort of smoooshes around but that plane stays the same. I suggest interested people check out adanaxis, a 4D space shooter. It's not particularly playable, but it is true four-dimensional space with four-dimensional spaceships zipping around.
biot 12y ago
This is a very interesting way of explaining the 4th dimension by relating it to the difference between the 2nd and 3rd dimensions. However, I think what would really solidify my understanding is to see the 4D level editor. I'm not sure how truly 4D this world is, but it appears to let you switch between a fixed set of different 4 dimensional positions, each of which has a different 3D representation. Just as a plane in a 3D environment is a 2D slice, a plane in a 4D environment is a 3D slice. You could effectively fake this by imagining a triangular prism (like a cylinder, but triangular instead of round). Each face of the prism contains a fully defined 3D world. Switching to the alternate face of the prism is effectively doing the swap to the other 4th dimension, where you can walk along the alternate 3D environment to avoid the obstacle, then switch back to the original 3D environment.
- sp332 12y ago
  That's not quite what a 4th dimension is like. In your example, the faces are completely separate from one another. But really they would be connected, in a continuous line. You'd be able to push something a little bit along the dimension, or run a long distance. You could rotate an object in 4D so that parts of it ware poking a little bit into each dimension at the same time.
  - biot 12y ago
    > That's not quite what a 4th dimension is like. Of course not. You'll notice that I questioned how truly 4D the game was and said the game appears to have fixed sets of 4D positions (ie: not a continuous range). I also said that my example was fake 4D. If the developer were to show the level editor, I suspect that we'd see it's not really 4D at all, but my fake approximation of 4D via a fixed number of 3D environments that the player can transition between.
jader201 12y ago
This is exactly what Guacamelee does: https://www.youtube.com/watch?v=FQDwqrqAvwk https://www.youtube.com/watch?v=FQDwqrqAvwk
- readerrrr 12y ago
  Yep, except it is in 3d. I was hoping for some continuous movement, but it looks like it only switches between two worlds. Maybe they will implement some more levels to make it look seamless. But there is simply too much work to design the world in 4d as a single piece of land holds a lot more information.
panarky 12y ago
Flatland: A Romance of Many Dimensions is an 1884 satirical novella by the English schoolmaster Edwin Abbott Abbott. Writing pseudonymously as "A Square", the book used the fictional two-dimensional world of Flatland to comment on the hierarchy of Victorian culture; but the novella's more enduring contribution is its examination of dimensions. "A Square" feels sorry for poor, limited "A Line", but can't wrap his two-dimensional head around what "A Sphere" can do. https://en.wikipedia.org/wiki/Flatland https://en.wikipedia.org/wiki/Flatland
- gdubs 12y ago
  Wonderfully illustrated by Carl Sagan in the original Cosmos: http://www.youtube.com/watch?v=UnURElCzGc0 http://www.youtube.com/watch?v=UnURElCzGc0
  - shangxiao 12y ago
    So that's what a tesseract is!
- clwk 12y ago
  For a visceral and entertaining exploration of what a literal fourth spatial dimension might be like from our perspective, try Rudy Rucker's hilarious 'Spaceland'. 'In a tribute to Edwin Abbott's Flatland, a classic mathematical fantasy about a 2-dimensional being (A. Square) who receives a surprise visit from a higher-dimensional sphere, Rudy Rucker's Spaceland describes the life of Joe Cube, an average, modern-day Silicon Valley hotshot who one day discovers the fourth dimension from an unexpected visitation. Spaceland contains scenes that are violent and sexual in nature as well as suggestive illustrations.' https://en.wikipedia.org/wiki/Spaceland_(novel) https://en.wikipedia.org/wiki/Spaceland_(novel)
alpeb 12y ago
If this topic interests you, you should definitely check "Imagining the Tenth Dimension" https://www.youtube.com/watch?v=zqeqW3g8N2Q https://www.youtube.com/watch?v=zqeqW3g8N2Q
- tfgg 12y ago
  That video is incoherent nonsense, especially from the '5th dimension' and onwards, and in no way resembles the modern understanding of dimensions in physics or mathematics. I wouldn't bother watching it except for entertainment.
  - gabriel34 12y ago
    Care to expand? I'm not sure if it is possible to imagine these dimensions with the "modern understanding of dimensions in physics or mathematics", but it would be nice to at least know why this way is incorrect
    - tfgg 12y ago
      One could waste one's entire life trying to correct rubbish attempts at physics on the internet, especially when it's full of non-sequiturs like the video. But as a start, the description of quantum mechanics is nonsense and I'm guessing the narrator got their understanding of it by reading popsci books (I'm trying to avoid a personal attack on the author, but it's hard when they've said a lot of wrong things so very confidently). The dimensionality of a typical QM Hilbert space is infinite, not five. People get wound up wondering what the N^th dimension is, when all dimensionality is, somewhat simplified, is how many numbers you need to describe the position of something. The top comment on this stack exchange thread has more: http://physics.stackexchange.com/questions/55824/is-imagining-10-dimension-video-by-rob-bryanton-has-any-invalid-wrong-informatio http://physics.stackexchange.com/questions/55824/is-imaginin...
  - alpeb 12y ago
    Thanks for setting the record straight. The video looked interesting and coherent for layman like myself (gotta admit though I only watched at first the older version that didn't mention quantum mechanics), but I never cared to check what real physicist made of it. Gotta love physics stack exchange!
archagon 12y ago
I've been getting progressively more excited about Miegakure over the past year, but I haven't heard anyone who's played the game talk about how easy it is to "grok". Does moving between dimensions become intuitive over time? Or do you always have to consciously think about what you're doing?
- cuu508 12y ago
  I think it would become intuitive if there was some way to plug 4th dimension in our senses. Have you read stories about people who implant magnets? After a while they develop a sense of direction. Brain adapts to new signals and starts to interpret them. Different example, I remember reading about experiment where people had to wear glasses that flip the picture upside down. After not too long time they adapted and saw things normally. And everything would be upside down when taking the glasses off. Yet another example is asking blind people what they see. They don't see black or grey, the sense of vision simply isn't there. Like our sense of 4th dimension isn't there. So, one thing to try would be to give us sense of rotation and acceleration in 4th dimension and see how it goes. Next, maybe, a new "color channel" for our vision, and let the brain figure out how to represent it "internally".
  - doorhammer 12y ago
    One really interesting example of this is that of humans who perform echo location. Parts of the brain normally reserved for sight are activated, to some degree, by regions of the brain responsible for vision. Basically, they're not just 'hearing' in the traditional sense, though that happens as well; they're also 'seeing' the sound that bounces back. Kind of crazy
- marctenbosch 12y ago
  Jim Rossignol from Rock Paper Shotgun played a recent build: http://www.rockpapershotgun.com/2014/03/18/miegakure-preview/ http://www.rockpapershotgun.com/2014/03/18/miegakure-preview... He said: "Flipping through dimensions is remarkably intuitive- [...] I shifted dimensions, messing about with this strange toy until I quickly understood most of the problems that I faced."
moblahbl4hblah 12y ago
Its really awesome, but its a portal game where you play between two maps. It's not "4D" in any real geometric sense. 4D objects projected into 3D space would be warped in "the same way" that a map is warped projecting the globe onto a plane. 4D objects would be warped projecting into 3D which would then be warped as it was projected into 2D. It would be worse than the way that Iceland looks bigger than North America on some maps. This is really inventive game play, so I'm not slagging it off. I'm just saying that the "4D" explanation is more of a metaphor than a real geometric projection.
blahbl4hblahtoo 12y ago
It's not 4D. Its a 3D portal based game where you can switch between maps. 4D objects projected first into 3D and then into 2D would look weirder than how Iceland is bigger than everything else on a map.
mattwad 12y ago
Looks like a neat game, but I'm skeptical how it would work in reality. For example, it looks like the 4th dimension (time) gets frozen (for the observer) when you want to traverse it. That means, the second you 'travel in time,' the Earth, at its current velocity, would already be 30km away.
- 0x0 12y ago
  ... or did the rest of the universe move 30km the other way? :)
- tsmash 12y ago
  You're one of the fools who thinks that the fourth dimension is time. Get over yourself. This is talking about a fourth spatial dimension, not a temporal one.
kazinator 12y ago
People use 4D to go through walls all the time, when those walls take the form of sliding doors. They stand in one place in space, in front of the door, while naturally moving forward in the fourth dimension (time) to arrive to a slice of space-time in which the door isn't there. In this range of space-time they traverse space by a small distance (a meter or two), and also slip forward in time by a several seconds (which is not long enough to leave this special range of space-time). By so doing, they reach a point in space on the other side of where the door was. Then they slip forward in time again, to a time when the door is there again, at which time they smugly find themselves on the other side of the door.
yutah 12y ago
Can you travel faster then the speed of light if you use the fourth dimension? (my Internet ping is too high)
- aruss 12y ago
  No, mathematically speaking the 4th dimension is no different than the 3 that we are used to dealing with, and is held to the same physical constraints.
  - ars 12y ago
    It would certainly looks like you traveled faster than light. But you didn't actually, you just took a "shortcut" as it were.
    - gtremper 12y ago
      There are no shortcuts. The straight line connecting 2 points in 3d space is shorter than any path connecting the points that goes through a higher dimension. The same applies to 2d compared to 3d. If you have 2 points on a sheet of paper, the shortest path is on the paper. Any path that went "off" the paper into the 3rd dimension would be longer, so no "shortcuts".
      - ars 12y ago
        Imagine a strip of paper bent into a U. You can travel from one end of the strip to the other through 3D space with a much shorter distance than along the entire paper.
        lmm 12y ago
        Sure, but that's not what we're talking about here. We're talking about Euclidean 4D space projected orthogonally onto Euclidean 3D slices, not some nonstandard projection onto some weird 3D surface embedded in 4D space.
aoldoni 12y ago
I saw something similar on the demos of what was supposed to be the Sonic X-treme game. This was supposed to be the debut of the Sonic franchise in the 32-bit world. https://www.youtube.com/watch?v=wzvS_beXtXk https://www.youtube.com/watch?v=wzvS_beXtXk http://en.wikipedia.org/wiki/Sonic_X-treme http://en.wikipedia.org/wiki/Sonic_X-treme
dschiptsov 12y ago
Why not consider the idea that any "dimensions" are nothing but "[useful] concepts of the mind", like "universal time" and even "limited space", the way some ancient mystics (?) of various cultures believed? The simplest example is about time - we (humans) have notion of time "entirely" due to the certain properties of our environment in which we have evolved - that there is day/night, Moon phases, seasons, periodical changes (due to rotation of the planet and its motion around the Sun, of course, but this is a very recent discovery). Now imagine that you are somehow "suspended" in the outer space without any motion relatively to the Sun. What would be your notion of time? The time of a certain process (a mass in motion) has nothing to do with time of another, completely different process (like radioactive decay) and the notion of some "common, universal time" is just a "creation of the mind" which is very handy and useful but "does not exist in reality". Ancient Buddhist notions of "emptiness" or "void", and pre-Buddhist (Upanishadic) notions of "everything is mind" (which is wrong, but very close and accurate) are insights to the same "truths". Your "dimensions" are "primitive concepts" of the same kind. Any coordinate system imposed on so-called "reality" is nothing but a "concept of the mind".)
- polarix 12y ago
  Thanks for the reminder.
- bottled_poe 12y ago
  > we (humans) have notion of time "entirely" due to the certain properties of our environment That sounds very philosophical and all, but it seems to me that we have an internal perception of time based on the rate that electrical impulses propagate throughout our brains. Perhaps it would be distorted based on the lack of external stimulus, but I believe we would feel the passage of time all the same.
nanoleoo 12y ago
That made me think a lot at this really nice open source game : http://stabyourself.net/orthorobot/ http://stabyourself.net/orthorobot/
teapartyBS 12y ago
It's awesome game play, but it's not really 4 dimensional. It's basically a portal based game where you can switch between two different 3D maps. At best the 4D thing is a metaphor. Projecting 4D objects into 3D space warps them in the same way that map projections warp the surface of a globe. Going from 4D into 3D would be weird, but then also projecting into 2D for the screen would compound the effects. Like I said, it's really inventive gameplay. It's not, however, truly "4D". I hear you...I mean it even if the 4th D is another space-like dimension. Just picture stepping through a orange hole in Portal to a completely different map and then stepping back into a different spot on the source map. That's this game. If you transformed a 3D object along an arbitrary "new" space-like dimension...let's say you add your "W" axis and took away the X...you would by definition tear it apart in your XYZ projection. (That's the one that you are looking at it in, remember?) I've read some of the other comments. gliese1337 sounds more like what you would go through to build an actual 4D game engine. In one sense you could say that Prince of Persia was 4D because you could move through time. That's the secret...Having a non-space 4th D is visually easier to pull off.

218 points by numo16 12y ago

I've been watching this vid on repeat trying to fully comprehend what's happening. This is another vid trying to explain the same thing - https://www.youtube.com/watch?v=UnURElCzGc0 https://www.youtube.com/watch?v=UnURElCzGc0 I really want to believe this is possible and this is how we'll be able to travel far into space. Like how we have to spend time walking around a very long wall when a bird can just fly over it in a fraction of the time, we wouldn't have to think about traveling light-years because there would something else we can do that's faster than a straight line.

sp332 12y ago
That's not very likely, because you don't have to walk around some kind of obstacle to get to a star. Even as a bird, you still have to travel the full distance to your destination. You could make a shortcut in space, which is called a wormhole. You can either make one using extra dimensions, or in 3 dimensions with negative energy to stabilize it, but neither of those seem to exist. Edit: link https://en.wikipedia.org/wiki/Wormhole#Traversable_wormholes https://en.wikipedia.org/wiki/Wormhole#Traversable_wormholes
- JoeAltmaier 12y ago
  Unless 3d space is 'wrinkled'; in 4D you could travel straight there. Imagine a crumpled sheet - the 2D traveler would have to trace a route through all the convolutions to reach the other end of the sheet. The 3D traveler may only have inches to go. 'A Wrinkle in Time' was a story about this.
  - sp332 12y ago
    You'd just have to hope that the place you want to go to is wrinkled up so that it's next to you, and not still far away.
    - mordocai 12y ago
      From my vague recollections they were somehow causing the wrinkles to be close together. It has been years since i've read the series though.
    - JoeAltmaier 12y ago
      Actually going anyplace at all that way would be hugely exciting.
foolrush 12y ago
You might find NASA's page on warp drives interesting. http://www.nasa.gov/centers/glenn/technology/warp/warpstat_prt.htm http://www.nasa.gov/centers/glenn/technology/warp/warpstat_p...

laxatives 12y ago

I remember being really excited about this game a few months ago. Part of me is a little concerned whether there is enough to gain some sort of intuition on where you are and what is exactly transforming with each input. I'm a little concerned it will just become a game where you try things and hope for the best and have a very incomplete mapping of whats really going on. But anyways, its neat to see such a well produced game attempt to take on these challenges.

ericHosick 12y ago

As a game, this is really cool. But when he got to the 4th dimension it didn't make much sense as an explanation (rubble from 3rd dimension showing up in the 4th). However, if the 4th dimension was time, then you would walk back (or forward) in time to when the wall wasn't there (isn't there anymore cause it is now rubble), move "past the wall", and then walk forward/backward to the original time.

sp332 12y ago
Some rubble fell to the side, along the 4th axis. This is a 4th spatial dimension, not time.
- foolrush 12y ago
  But the fourth dimension is timespace, is it not? At least that was what I gathered from Special and General Relativity and the relativity of simultaneity. X^t, Y^t, Z^t?
  - sp332 12y ago
    This game isn't real life! In the game there are four spatial dimensions, just because the game designer decided to have four.
    - foolrush 12y ago
      Which is an awful lot like a 4th dimension. Arguably we are all 4th dimensional travellers, albeit somewhat constrained along one of the axes. Granted, you had me at “This game isn't real life!”
      - sp332 12y ago
        Oh, and the game also has a time dimension (which works normally I think, just one-way at one speed), so I guess that's 5 :)
  - pizza 12y ago

metadept 12y ago

I was really hoping for a continuous (rather than discrete) fourth dimension. The concept is cool and looks to be well executed, but it's not very different from other alternate reality implementations such as the Dark World in Legend of Zelda.

kazagistar 12y ago
Adanaxis is an open source space shooter game that lets you move in all 4 axis, or rotate continuously along any combination of axis. All models are 4 dimensional. Needless to say, it is confusing to the point of unplayability past a certain point, but utterly fascinating. You can grab a copy from your Ubuntu, Fedora, or Arch repos, and it is certainly worth trying to wrap your head around for an hour or two, if you are into that sort of thing.
- devin_lane 12y ago
  Had a blast with this thanks to your recommendation!
DougWebb 12y ago
That would be really cool. The mathematics involved don't seem too difficult; you have to add another axis to your vectors, points, and transform matrices, and you can place and orient your models in 4D space, set up lights and a camera in 4D space, and project the camera's view into 3D space first then onto the 2D display. I think the hard part is creating the models and writing the rendering engine. Creating 4D models, rather than just putting 3D models into 4D space, would be hard to wrap your head around. And the tools, both for world creation and for rendering, are almost certainly limited to 3D so you'd have to write your own tools for everything. No more GPU acceleration, unless your 4D to 3D transformation creates models and textures on-the-fly to pass to the GPU.
- viewer5 12y ago
  What would the 4th dimension coordinate of your models even represent, though? I'm having trouble wrapping my head around it.

anoother 12y ago

The game looks fascinating. I'm still trying to get my had around the analogies, but get the feeling that playing the game for real will bring a level of intuition to the experience. In the meanwhile, can anyone help me out? In the 2D->3D example, you have one shared axis (Z -- vertical), and an alternating pair for the second axis (X and Y -- horizontal). In effect, from the 2D character's point of view, 'jumping' into the third dimension is just swapping your horizontal axis. Your previous horizontal axis is a vertical section through your current one, and vice versa. As such, when swapping axes, you would expect one 1D line (ie. a 1-pixel-wide vertical band) to be the same before and after the swap. When going 3D-> 4D, you have 2 shared axes. Your third axis alternates, as before. When switching between your 'third' axes, then, you would expect one entire 2D plane of your perceived world-view to remain the same[1]. This doesn't seem to be the case. What am I missing? [1] EDIT: This plane is likely to be a section through some concrete objects, so you won't necessarily have 'seen' it before, though it will have been there.

DougWebb 12y ago
In the first case, the 1D vertical line is the same, but it's "seen" from a different angle. It looks the same because it's 1D and it doesn't happen to change because of the rotation. For the second case, maybe it's the ground plane that's the same; it certainly has some of the initial texture in it, but it's been rotated and it's now seen from a different angle. But now we can tell the different because it varies along the dimensions it rotated around. Or maybe I just can't visualize the rotation through the fourth dimension... I'm not sure.
roywiggins 12y ago
This is exactly right: when rotating in 4D, you can rotate "around" a plane, leaving it in place. You can also rotate around a line (permuting the other three axes). So, in the video. The Z axis doesn't change (up and down) so that's one axis. The other one that doesn't change is at a 45 degree angle from lower left to upper right. Watch the tree: it is just as wide along this axis as it was before. Everything else sort of smoooshes around but that plane stays the same. I suggest interested people check out adanaxis, a 4D space shooter. It's not particularly playable, but it is true four-dimensional space with four-dimensional spaceships zipping around.

biot 12y ago

This is a very interesting way of explaining the 4th dimension by relating it to the difference between the 2nd and 3rd dimensions. However, I think what would really solidify my understanding is to see the 4D level editor. I'm not sure how truly 4D this world is, but it appears to let you switch between a fixed set of different 4 dimensional positions, each of which has a different 3D representation. Just as a plane in a 3D environment is a 2D slice, a plane in a 4D environment is a 3D slice. You could effectively fake this by imagining a triangular prism (like a cylinder, but triangular instead of round). Each face of the prism contains a fully defined 3D world. Switching to the alternate face of the prism is effectively doing the swap to the other 4th dimension, where you can walk along the alternate 3D environment to avoid the obstacle, then switch back to the original 3D environment.

sp332 12y ago
That's not quite what a 4th dimension is like. In your example, the faces are completely separate from one another. But really they would be connected, in a continuous line. You'd be able to push something a little bit along the dimension, or run a long distance. You could rotate an object in 4D so that parts of it ware poking a little bit into each dimension at the same time.
- biot 12y ago
  > That's not quite what a 4th dimension is like. Of course not. You'll notice that I questioned how truly 4D the game was and said the game appears to have fixed sets of 4D positions (ie: not a continuous range). I also said that my example was fake 4D. If the developer were to show the level editor, I suspect that we'd see it's not really 4D at all, but my fake approximation of 4D via a fixed number of 3D environments that the player can transition between.

jader201 12y ago

This is exactly what Guacamelee does: https://www.youtube.com/watch?v=FQDwqrqAvwk https://www.youtube.com/watch?v=FQDwqrqAvwk

readerrrr 12y ago
Yep, except it is in 3d. I was hoping for some continuous movement, but it looks like it only switches between two worlds. Maybe they will implement some more levels to make it look seamless. But there is simply too much work to design the world in 4d as a single piece of land holds a lot more information.

panarky 12y ago

Flatland: A Romance of Many Dimensions is an 1884 satirical novella by the English schoolmaster Edwin Abbott Abbott. Writing pseudonymously as "A Square", the book used the fictional two-dimensional world of Flatland to comment on the hierarchy of Victorian culture; but the novella's more enduring contribution is its examination of dimensions. "A Square" feels sorry for poor, limited "A Line", but can't wrap his two-dimensional head around what "A Sphere" can do. https://en.wikipedia.org/wiki/Flatland https://en.wikipedia.org/wiki/Flatland

gdubs 12y ago
Wonderfully illustrated by Carl Sagan in the original Cosmos: http://www.youtube.com/watch?v=UnURElCzGc0 http://www.youtube.com/watch?v=UnURElCzGc0
- shangxiao 12y ago
  So that's what a tesseract is!
clwk 12y ago
For a visceral and entertaining exploration of what a literal fourth spatial dimension might be like from our perspective, try Rudy Rucker's hilarious 'Spaceland'. 'In a tribute to Edwin Abbott's Flatland, a classic mathematical fantasy about a 2-dimensional being (A. Square) who receives a surprise visit from a higher-dimensional sphere, Rudy Rucker's Spaceland describes the life of Joe Cube, an average, modern-day Silicon Valley hotshot who one day discovers the fourth dimension from an unexpected visitation. Spaceland contains scenes that are violent and sexual in nature as well as suggestive illustrations.' https://en.wikipedia.org/wiki/Spaceland_(novel) https://en.wikipedia.org/wiki/Spaceland_(novel)

alpeb 12y ago

If this topic interests you, you should definitely check "Imagining the Tenth Dimension" https://www.youtube.com/watch?v=zqeqW3g8N2Q https://www.youtube.com/watch?v=zqeqW3g8N2Q

tfgg 12y ago
That video is incoherent nonsense, especially from the '5th dimension' and onwards, and in no way resembles the modern understanding of dimensions in physics or mathematics. I wouldn't bother watching it except for entertainment.
- gabriel34 12y ago
  Care to expand? I'm not sure if it is possible to imagine these dimensions with the "modern understanding of dimensions in physics or mathematics", but it would be nice to at least know why this way is incorrect
  - tfgg 12y ago
    One could waste one's entire life trying to correct rubbish attempts at physics on the internet, especially when it's full of non-sequiturs like the video. But as a start, the description of quantum mechanics is nonsense and I'm guessing the narrator got their understanding of it by reading popsci books (I'm trying to avoid a personal attack on the author, but it's hard when they've said a lot of wrong things so very confidently). The dimensionality of a typical QM Hilbert space is infinite, not five. People get wound up wondering what the N^th dimension is, when all dimensionality is, somewhat simplified, is how many numbers you need to describe the position of something. The top comment on this stack exchange thread has more: http://physics.stackexchange.com/questions/55824/is-imagining-10-dimension-video-by-rob-bryanton-has-any-invalid-wrong-informatio http://physics.stackexchange.com/questions/55824/is-imaginin...
- alpeb 12y ago
  Thanks for setting the record straight. The video looked interesting and coherent for layman like myself (gotta admit though I only watched at first the older version that didn't mention quantum mechanics), but I never cared to check what real physicist made of it. Gotta love physics stack exchange!

archagon 12y ago

I've been getting progressively more excited about Miegakure over the past year, but I haven't heard anyone who's played the game talk about how easy it is to "grok". Does moving between dimensions become intuitive over time? Or do you always have to consciously think about what you're doing?

cuu508 12y ago
I think it would become intuitive if there was some way to plug 4th dimension in our senses. Have you read stories about people who implant magnets? After a while they develop a sense of direction. Brain adapts to new signals and starts to interpret them. Different example, I remember reading about experiment where people had to wear glasses that flip the picture upside down. After not too long time they adapted and saw things normally. And everything would be upside down when taking the glasses off. Yet another example is asking blind people what they see. They don't see black or grey, the sense of vision simply isn't there. Like our sense of 4th dimension isn't there. So, one thing to try would be to give us sense of rotation and acceleration in 4th dimension and see how it goes. Next, maybe, a new "color channel" for our vision, and let the brain figure out how to represent it "internally".
- doorhammer 12y ago
  One really interesting example of this is that of humans who perform echo location. Parts of the brain normally reserved for sight are activated, to some degree, by regions of the brain responsible for vision. Basically, they're not just 'hearing' in the traditional sense, though that happens as well; they're also 'seeing' the sound that bounces back. Kind of crazy
marctenbosch 12y ago
Jim Rossignol from Rock Paper Shotgun played a recent build: http://www.rockpapershotgun.com/2014/03/18/miegakure-preview/ http://www.rockpapershotgun.com/2014/03/18/miegakure-preview... He said: "Flipping through dimensions is remarkably intuitive- [...] I shifted dimensions, messing about with this strange toy until I quickly understood most of the problems that I faced."

moblahbl4hblah 12y ago

Its really awesome, but its a portal game where you play between two maps. It's not "4D" in any real geometric sense. 4D objects projected into 3D space would be warped in "the same way" that a map is warped projecting the globe onto a plane. 4D objects would be warped projecting into 3D which would then be warped as it was projected into 2D. It would be worse than the way that Iceland looks bigger than North America on some maps. This is really inventive game play, so I'm not slagging it off. I'm just saying that the "4D" explanation is more of a metaphor than a real geometric projection.

blahbl4hblahtoo 12y ago

It's not 4D. Its a 3D portal based game where you can switch between maps. 4D objects projected first into 3D and then into 2D would look weirder than how Iceland is bigger than everything else on a map.

mattwad 12y ago

Looks like a neat game, but I'm skeptical how it would work in reality. For example, it looks like the 4th dimension (time) gets frozen (for the observer) when you want to traverse it. That means, the second you 'travel in time,' the Earth, at its current velocity, would already be 30km away.

0x0 12y ago
... or did the rest of the universe move 30km the other way? :)
tsmash 12y ago
You're one of the fools who thinks that the fourth dimension is time. Get over yourself. This is talking about a fourth spatial dimension, not a temporal one.

kazinator 12y ago

People use 4D to go through walls all the time, when those walls take the form of sliding doors. They stand in one place in space, in front of the door, while naturally moving forward in the fourth dimension (time) to arrive to a slice of space-time in which the door isn't there. In this range of space-time they traverse space by a small distance (a meter or two), and also slip forward in time by a several seconds (which is not long enough to leave this special range of space-time). By so doing, they reach a point in space on the other side of where the door was. Then they slip forward in time again, to a time when the door is there again, at which time they smugly find themselves on the other side of the door.

yutah 12y ago

Can you travel faster then the speed of light if you use the fourth dimension? (my Internet ping is too high)

aruss 12y ago
No, mathematically speaking the 4th dimension is no different than the 3 that we are used to dealing with, and is held to the same physical constraints.
- ars 12y ago
  It would certainly looks like you traveled faster than light. But you didn't actually, you just took a "shortcut" as it were.
  - gtremper 12y ago
    There are no shortcuts. The straight line connecting 2 points in 3d space is shorter than any path connecting the points that goes through a higher dimension. The same applies to 2d compared to 3d. If you have 2 points on a sheet of paper, the shortest path is on the paper. Any path that went "off" the paper into the 3rd dimension would be longer, so no "shortcuts".
    - ars 12y ago
      Imagine a strip of paper bent into a U. You can travel from one end of the strip to the other through 3D space with a much shorter distance than along the entire paper.
      - lmm 12y ago
        Sure, but that's not what we're talking about here. We're talking about Euclidean 4D space projected orthogonally onto Euclidean 3D slices, not some nonstandard projection onto some weird 3D surface embedded in 4D space.

aoldoni 12y ago

I saw something similar on the demos of what was supposed to be the Sonic X-treme game. This was supposed to be the debut of the Sonic franchise in the 32-bit world. https://www.youtube.com/watch?v=wzvS_beXtXk https://www.youtube.com/watch?v=wzvS_beXtXk http://en.wikipedia.org/wiki/Sonic_X-treme http://en.wikipedia.org/wiki/Sonic_X-treme

dschiptsov 12y ago

Why not consider the idea that any "dimensions" are nothing but "[useful] concepts of the mind", like "universal time" and even "limited space", the way some ancient mystics (?) of various cultures believed? The simplest example is about time - we (humans) have notion of time "entirely" due to the certain properties of our environment in which we have evolved - that there is day/night, Moon phases, seasons, periodical changes (due to rotation of the planet and its motion around the Sun, of course, but this is a very recent discovery). Now imagine that you are somehow "suspended" in the outer space without any motion relatively to the Sun. What would be your notion of time? The time of a certain process (a mass in motion) has nothing to do with time of another, completely different process (like radioactive decay) and the notion of some "common, universal time" is just a "creation of the mind" which is very handy and useful but "does not exist in reality". Ancient Buddhist notions of "emptiness" or "void", and pre-Buddhist (Upanishadic) notions of "everything is mind" (which is wrong, but very close and accurate) are insights to the same "truths". Your "dimensions" are "primitive concepts" of the same kind. Any coordinate system imposed on so-called "reality" is nothing but a "concept of the mind".)

polarix 12y ago
Thanks for the reminder.
bottled_poe 12y ago
> we (humans) have notion of time "entirely" due to the certain properties of our environment That sounds very philosophical and all, but it seems to me that we have an internal perception of time based on the rate that electrical impulses propagate throughout our brains. Perhaps it would be distorted based on the lack of external stimulus, but I believe we would feel the passage of time all the same.

nanoleoo 12y ago

That made me think a lot at this really nice open source game : http://stabyourself.net/orthorobot/ http://stabyourself.net/orthorobot/

teapartyBS 12y ago

It's awesome game play, but it's not really 4 dimensional. It's basically a portal based game where you can switch between two different 3D maps. At best the 4D thing is a metaphor. Projecting 4D objects into 3D space warps them in the same way that map projections warp the surface of a globe. Going from 4D into 3D would be weird, but then also projecting into 2D for the screen would compound the effects. Like I said, it's really inventive gameplay. It's not, however, truly "4D". I hear you...I mean it even if the 4th D is another space-like dimension. Just picture stepping through a orange hole in Portal to a completely different map and then stepping back into a different spot on the source map. That's this game. If you transformed a 3D object along an arbitrary "new" space-like dimension...let's say you add your "W" axis and took away the X...you would by definition tear it apart in your XYZ projection. (That's the one that you are looking at it in, remember?) I've read some of the other comments. gliese1337 sounds more like what you would go through to build an actual 4D game engine. In one sense you could say that Prince of Persia was 4D because you could move through time. That's the secret...Having a non-space 4th D is visually easier to pull off.