The 4th dimension... Can we get there?

[link_elfwarrior]

I want to see your thoughts on multi-dimensions...especially the 4th dimension since thats the nearest dimension to our current 3rd dimension in which we live in. Many say that astral projecting will take you into the 4th dimension (astral plane)... Discuss this! Enlighten us! Here's the video I watched that got me interested in it...this is actually a pretty kickass vid. http://www.youtube.com/watch?v=XjsgoXvnStY&list=FLtoPqCfNeKGbLU-PBgZihzA&index=1&feature=plpp_video

[VorpalNeko]

Surgeon General's Warning: Viewing this video may cause permanent damage to your intelligence. Watch at own risk.

[Layra-chan]

I'm glad that you're interested in higher dimensions, but we should warn you that actual thoughts about higher dimensions, by mathematicians and physicists, doesn't look like anything that video says. Nothing past the third minute or so of that video has any resemblance to reality.

There is no way to view the third dimension as being defined as something to curl the second dimension into. There are two-dimensional objects that are "curled" in such a way that they can't even be realized in three-dimensional space. For instance, the Klein bottle, which, if you try to make one in three-dimensional space, will always intersect itself.

More importantly, there is absolutely no way to view the fourth dimension as something that three-dimensional objects curl into. While there is only really one curling parameter for two-dimensional objects, there are six independent ones for three-dimensional objects, and hence we would need at least six more dimensions to handle the curling of a three-dimensional object, not just one. For four-dimensional objects, the number jumps to 20.

I suppose the bit about curling time also ought to be addressed: time doesn't work that way. Yes, it is possible to curve time relative into the other dimensions, but not in a way that will let you go backwards; in fact, curving the time direction only makes you go more forwards in time (if you want a less stupid sounding explanation, you'll have to see a bit of math).

Everything else in the video is nonsensical trash. Probability? Really? No, the many-worlds hypothesis of quantum mechanics doesn't look like that. No reasonable alternate universe model looks like that; if it was possible to travel to an alternate universe, then things would already be doing it and they wouldn't be "alternate"; they would be part of this universe.

Also, no, nobody refers to that as infinity. At least, nobody did before that stupid video.

But still, it's good that you're interested.

[link_elfwarrior]

Layra-chan

I'm glad that you're interested in higher dimensions, but we should warn you that actual thoughts about higher dimensions, by mathematicians and physicists, doesn't look like anything that video says. Nothing past the third minute or so of that video has any resemblance to reality.

There is no way to view the third dimension as being defined as something to curl the second dimension into. There are two-dimensional objects that are "curled" in such a way that they can't even be realized in three-dimensional space. For instance, the Klein bottle, which, if you try to make one in three-dimensional space, will always intersect itself.

More importantly, there is absolutely no way to view the fourth dimension as something that three-dimensional objects curl into. While there is only really one curling parameter for two-dimensional objects, there are six independent ones for three-dimensional objects, and hence we would need at least six more dimensions to handle the curling of a three-dimensional object, not just one. For four-dimensional objects, the number jumps to 20.

I suppose the bit about curling time also ought to be addressed: time doesn't work that way. Yes, it is possible to curve time relative into the other dimensions, but not in a way that will let you go backwards; in fact, curving the time direction only makes you go more forwards in time (if you want a less stupid sounding explanation, you'll have to see a bit of math).

Everything else in the video is nonsensical trash. Probability? Really? No, the many-worlds hypothesis of quantum mechanics doesn't look like that. No reasonable alternate universe model looks like that; if it was possible to travel to an alternate universe, then things would already be doing it and they wouldn't be "alternate"; they would be part of this universe.

Also, no, nobody refers to that as infinity. At least, nobody did before that stupid video.

But still, it's good that you're interested.

What are your thoughts on astral projection?

[Layra-chan]

What do you mean?

If you're asking whether I think astral projection could be used to go beyond the three dimensions we know of, then my answer is no. There is no reason that astral projection would be able to traverse the physical universe in ways that ordinary matter and radiation cannot.

If you're asking whether I think astral projection is possible at all, the answer is still no. The human brain is not equipped to send or receive signals other than through the nervous system; that we can even detect the magnetic field created by brainwaves outside the head is kind of amazing. But certainly the brain isn't able to read any such signals; it would be counterproductive to do so, considering how noisy that medium is.
Given the energy requirements needed to simply maintain the normal activity of the brain and the inverse-square nature of electromagnetism, anyone capable of projecting a significant field outside his own head would starve to death in the process.
I suppose with technological augmentation it might be possible for minds to leave physical bodies without using the intermediary of muscles and physical senses, but in those cases the channels are limited by the inputs and outputs of the technological system, so it's not a terribly different from what we have.

And before you ask, no, I do not believe in a human existence that isn't rooted in our physical bodies. I have no reason to believe in, and have never encountered any evidence for, a distinct mind or soul or anything of the like, and it is immeasurably simpler for there to only be the physical.

[Suicidesoldier#1]

VorpalNeko

Surgeon General's Warning: Viewing this video may cause permanent damage to your intelligence. Watch at own risk.

[Suicidesoldier#1]

I think the better question is; do you think it's possible to break the fourth wall.

[VorpalNeko]

Layra-chan

More importantly, there is absolutely no way to view the fourth dimension as something that three-dimensional objects curl into. While there is only really one curling parameter for two-dimensional objects, there are six independent ones for three-dimensional objects, and hence we would need at least six more dimensions to handle the curling of a three-dimensional object, not just one. For four-dimensional objects, the number jumps to 20.

But m-hypersurface in R^n also increases the number of curvature parameters as m increases. The above reasoning suggests isometrically embedding an m-manifold would require n = O(m^4) dimensions, but although embedding issues are a bit more involved, only n = O(m³) are sufficient. However, that doesn't really change the point: you're completely right in that this is crud. Heck, technically there's even a problem in seeing the third dimension as something two-dimensional spaces 'curl into', as RP² cannot be embedded in R³, nor can any other non-orientable compact 2-manifold.

(For everyone else, RP² is sort of like a Möbius strip illustrated in the video, except with the half-twist-and-glue operation done to both of the opposite pairs of edges of the strip, instead of just one pair. Its three-dimensional version, RP³, is one of the four possible geometries the space of our universe could be, assuming the universe is roughly the same everywhere and in every direction.)

Layra-chan

Everything else in the video is nonsensical trash. ...
Also, no, nobody refers to that as infinity. At least, nobody did before that stupid video.

Although Layra-chan gives it a good try, mere words are incapable of adequately expressing the sheer magnitude of the disconnect between this video and anything resembling reality and physics. Sorry for being a curmudgeon, but it's true. Props for being very imaginative, but that's the only semi-positive thing that can be reasonably said about it.

[Layra-chan]

The isometric immersion into O(n³) only works because the dimensions don't correspond to curling parameters at all; anyway, regardless of how many extra dimensions it takes to actually fit an m-manifold, the point is that it isn't 1.
I was trying to avoid topological issues, since those are a lot harder to explain than simple counting arguments.

And I was also trying to tone down how little respect I have for that video out of regard for the OP, but since you don't seem to mind I suppose I shouldn't either. I'm not even sure I can say that the video is imaginative with any sincerity, since the only thing original to it is that misuse of the term "infinity". And that's part of the problem, since the familiarity of a lot of the ideas is why people find them plausible. It's garbage that falls apart at the least bit of rational thought, but it's familiar garbage.
At best, I might be able to say that the grammar isn't too bad, but faint praise and all that stuff.

I'm trying to think of a metaphor for how terrible the video is, but I can't think of any that don't involve either pathological lying or Darwin-Award level incompetence. The closest I can come is the Book from Anathem by Neal Stephenson.

[VorpalNeko]

Right: they don't so correspond. That's what I was saying, and why I was puzzled why you were counting the independent Riemann tensor components 1,6,20,...,m²(m²-1)/12,... as if they had such correspondence. But yes: I don't think there's good way to explain how many it actually takes without a lot of geometry, and the main point is still that it isn't just +1.

Layra-chan

At best, I might be able to say that the grammar isn't too bad, but faint praise and all that stuff.

You are right. Mea culpa. 3nodding

[Day7]

Astral etc etc is just a way that your brain's unconscious state (subconscious state?) makes you view random as hell thoughts..

[viper232]

Psikoaktive

Astral etc etc is just a way that your brain's unconscious state (subconscious state?) makes you view random as hell thoughts..

... What? Can't we just say 'these concepts are nice for science fiction and fantasy shows, but don't exist'? Why must people try to treat fanciful absurd notions as real concepts? Harry Potter is fiction no matter how many times you wave a stick around.

Layra-chan

I'm trying to think of a metaphor for how terrible the video is, but I can't think of any that don't involve either pathological lying or Darwin-Award level incompetence. The closest I can come is the Book from Anathem by Neal Stephenson.

Come now, you're not thinking hard enough.

Somehow, I envy evolutionary biologists. Creationists are called crazy fundamentalists, but for some obscure reason, people can say things just as wrong about physics and have it be much more culturally accepted. People seem really ******** willing to play armchair physicist with QM.

[Layra-chan]

viper232

Layra-chan

I'm trying to think of a metaphor for how terrible the video is, but I can't think of any that don't involve either pathological lying or Darwin-Award level incompetence. The closest I can come is the Book from Anathem by Neal Stephenson.

Come now, you're not thinking hard enough.

Nothing in the video you linked is explicitly wrong. The video doesn't even make enough assertions to start being really wrong. It's hokey and informal, but not wrong, not in the painful, debilitating, "let me go find my cyanide pills and a nuke" way that Imagining the Tenth Dimension is.

[Suicidesoldier#1]

Just follow me!

UP UP AND AWAY! scream

[Day7]

viper232

Psikoaktive

Astral etc etc is just a way that your brain's unconscious state (subconscious state?) makes you view random as hell thoughts..

... What? Can't we just say 'these concepts are nice for science fiction and fantasy shows, but don't exist'? Why must people try to treat fanciful absurd notions as real concepts? Harry Potter is fiction no matter how many times you wave a stick around.

I wasn't saying it was real I was saying that the only thing that happens is pretty much that you're dreaming. As in, it's not real.