About the universe generally

[moonlord]

irockyou, you might try not scare off ignorants.

Anyway, I think a Mobius strip is two dimensional, since you can put a circle in it, but not a sphere (stupid example, I know). I don't quite fully understand the Klein bottle, but I think it's also 2D.

As I see it, there cannot exist a nD world embedded in a (n+1)D one. This is because the nD world would not be able to interact or be observed with/by a (n+1)D entity.

moonlord: Split from "tetraspace beings". What title would you give this thread anyway?

[bo198214]

I don't quite fully understand the Klein bottle, but I think it's also 2D.

Yes, its even a closed 2D-Manifold.

As I see it, there cannot exist a nD world embedded in a (n+1)D one. This is because the nD world would not be able to interact or be observed with/by a (n+1)D entity.

Yes, that is an interesting question. So I take an arbitrary cut/plane through my 3d world. This can I regard as a 2d world. But the problem that first catches my eye is: When I throw someting through the plane, in this 2D world it looks as if an object appears, grows, shrinks and disappears. In this kind this 2d world seems different from our 3d world, where object do not simply appear and disappear (disregarding quantum mechanics ... :? ) So at least we can say a cut through an nd-world behaves different as the nd world with respect to the persistence of objects.

[moonlord]

That's not quite what I was reffering to, but it's similar. I was saying about the following problem: the entities in there do not have volume, thus they should not have mass. There are also others, but I can't think of any other right now.

The solution I see is considering 2D entities as 3D, having infinitely small width. Perhaps under the Planck length (?).

[bo198214]

I was talking about exactly the same. The plane through 3d has no thickness. The objects of the 2d world have no mass, they are in some way virtual. But if we still allow that all as being a world, then it additionally behaves different in respect to the 3d world.

If we for example take an object that accellerates via F=ma in 3d then in the cut the object also accellerates. But a 2d inhabitant could not compute the mass via the (2d-)volume for example, i.e. the cut with the object, because there are various objects with different masses in 3d, that have the same cut with this plane.
All in all it makes no sense to speak of a 2d world in a cut of 3d world.

[moonlord]

Perhaps 2D density should be implemeted.

[thigle]

so this boils dow to Zenon's paradoxes anyway. is the space continuous or discontinuous (discrete) ? are the points of some extremely small size, maybe well under Planck, or are they actually "infinitely small" only epsilon far form nothing ? (which still is something anyway ?)

so one sees clearly ho does this all relates to the question of 0 & infinity.

feynmann was of the opinion that points are not nothing. some physicist believe that space is discrete, i.e. points are more than infinitely densely packed zeros(or nothings)

btw, geometrically, Klein bottle is 2d-manifold, but topologically (intrincically to its own topos), from inside, Klein's bottle is 4d. that's why it doesn't fit into 3d without singularity (in the form of self intersection).
one can get a klein bottle by joining 2 mobiusbands along their edge. or take a figure 8 tube and join its 8-like edges with a half-twist.

also. apparent density is a zooming function: what appears dense from 1 metre or 10 cm to our eyes, appears full of holes with a simple microscope.

[bo198214]

but topologically (intrincically to its own topos), from inside, Klein's bottle is 4d

Concrete, means this what? By which definition of dimension?

[moonlord]

thigle:

It depends on which type of points are you reffering to. Mathematically, a point has no size at all. I don't think we can speak of physical points. They must have a shape. Perhaps spheres with diameter under Planck would do. If we set a unit for density, it is not a zooming function any more. A piece of metal has 7.8 g cm^-3 no matter if we look at it from a kilometer or a nanometer.

Kahlar:

We don't use 'out there' because your and almost anybody's notion of 'out there' is not suitable. Think of dimensional analogy: a 2D being would consider 'out there' something in his plane. Which is not correct.

[thigle]

moonlord, your 'density' is different from 'apparent density'. 'apparent density' means 'density-perceived' or 'density-as-perceived', 'density-as-it-appears'.
the 'density' of the perceived surely stays the same, but that's why the apparentDensity can change with zooming.

what i meant with apparentDensity is (and we don't need to go underPlanck this time) that any matterial is actually full of holes on certain scale. one can think a sugarcube to be solid, but with good-enough microscope, one would see the molecular lattice full of empty space running through it - a porous structure.
so a piece of metal would look much more porous(=apparently less dense) than it feels when one hits one's finger with a hammer.

as for the essence of points question, that's a whole another topic. i think what we take for info/energy/matter is just twisting of teeming microstructure of emptyspace itself, as someone once said "undulations of the fabric of space". it's geometry is believed by some to be spin-like, taking advantage of possibility of spherical-rotation (or spin) that is possible in 3-space. then there lies those quantum-gravity theories that claim to potentially unify the 4 forces into a symmetry, like quantum-foam and spin-networks approaches of Smolin, Baez, etc. also Penrose is taking the fundamental point to be some twistor-like structure, (from sequence scalar, vector, tensor, spinor, twistor), not a sphere(point) as such.

until we create underPlanck technology (which is unnecessary and wastefull, for we have natural underPlanck technology integrated in our Being, only we usually don't know where is the interface-panel, nor do we know how to use it when we occasionally come across it), we cannot decide in aristotelian logic frame whether the space is continuous or discontinuous. so until we come to our full senses, we have to accept that it can be BOTH (continuous AND discontinuous) AND ( NEITHER of these 2 ).
meanwhile, we can agree upon different consensus for different contexts/domains though, while keeping in mind that it's nothing more or less than that.

[moonlord]

I see now. Well, it seems the closer we look, the more empty it seems to be (atom -> nucleus -> nucleon -> quark -> ??).

[thigle]

yep. until there's actually just open vibrant (aware) space left.
it's a good model for embodying a simple infinity - infinite smallness (which is just infinite vastness, if you look at it "the other way around")

perhaps ...->quark->string->ether undulation... ?

[darthbadass]

There have been reports of 3D "shadow people". After all, a 4D person's shadow would be 3 dimensional.

[moonlord]

I share Wendy's opinion on tetronians' 3D shadows. They won't have human appearance.

[4D guy]

I have a thought that a tetra being might be god. and if he had a "vivarium" called the universe, he would be able to travel unseen around the universe and of course the earth.

[Nick]

If we for example take an object that accellerates via F=ma

Last time I checked, I think F = ma²

Yes but we could obviously tell that they were 4d because they could have a whole other axis to move on. Maybe they could fly or walk through walls. Something that obviously no human being or any other creature that we know of could do. Therefore we would assume that they are 4d.

I have a thought that a tetra being might be god. and if he had a "vivarium" called the universe, he would be able to travel unseen around the universe and of course the earth.

There's your 4d being, Kahlar: God. It makes sense that God could be a being from a higher dimension, though there's no way to prove it.

[houserichichi]

Last time I checked, I think F = ma²

F=ma

[jinydu]

Last time I checked, I think F = ma²

F=ma

Or more generally, F = dp/dt.

It is easy to check that F = ma^2> can't possibly be right; the units don't match up.

[Nick]

It is easy to check that F = ma2> can't possibly be right; the units don't match up.

Heh.. In school, the Women's Rights club put on a play for everyone showing the importance that women had in history. One of the mini skits was that a women disproved Isaac Newton's theory of F=ma. She dropped two pennies of equal mass into a block of soft clay. I'm not sure exactly how it went, but they said that if Newton was right, they would only fall three inches into the clay, but if she was right, then they would fall 9 inches. Well, they fell 9 inches, and after the skit they gave us a lecture that this helped Albert Einstein find E=mc².

I decided to emulate this experiment in Art class (after you posted) and apparently, they were wrong . I tried to tell them that they were completely wrong, but they wouldn't listen. Feminists...

:rofl:

[jinydu]

I don't see how you could feasibly make such a prediction using only Newton's Second Law; how could you possibly predict the force of the clay on the pennies? And in any case, Einstein did not postulate E = mc² (which is not true in general anyway), he derived it from the fundamental postulates of Special Relativity. I think that the play is just a work of fiction.

edit by Irockyou: Fixed your "sup" tags

[moonlord]

Especially when there is no link between F=ma and E=mc².

[bo198214]

What, the universe? Oh I thought it was 11dim.
But the by a human experienced dimensions are 3.
And this is not a cut through the 11 dims.
The other (wrapped) dimensions are so small that we do not notice them in our daily life even if we traverse them some millions times a day (or who knows the number *gg*)

[houserichichi]

There's not even a shred of experimental evidence to suggest an 11 dimensional universe. I suspect the argument will hold up for a long time, however, based on that particular detail that string theory supporters seem to overlook. On the other hand if something crops up that supports it I'll happily change my tune.

[Nick]

I'm with House. I doubt M-Theory will hold up.

[PWrong]

There's not even a shred of experimental evidence to suggest an 11 dimensional universe.

But it's such a nice theory

[Bannin]

I don't think that I've done nearly enough research on any of this, so don't be brutal, please, but I DO have a theory:

If the strings in M-theory do "contain" dimensions, couldn't they be the "slices" we recieve from other dimensions? I mean our slice in planespace is just a line, so wouldn't the 3d version of a line be a string? The reason for strings being in all matter would be that it would be impossible to be in 4d space without being in 3d space. This goes back to having 3d SPACES "contained" in 4d space. To me this makes sence because we are always interacting with different 2d spaces, we just don't realise how many different planes we are traversing or touching at any given time. So: all things in 4d space would be "touching" or interacting with different parts of different 3d spaces, creating the strings.

Well that's my try anyway. I don't know all the specifics of all the theories, but this makes sence to me.

[Bannin]

I don't see what you mean.

What I mean is that strings are the 3d visual parts of the 4d entities passing through our realm. Just a theory.

[PWrong]

What I mean is that strings are the 3d visual parts of the 4d entities passing through our realm.

Ah, I see. Well, string theory requires that the 6 extra dimensions are pretty much filled up. There's no room for anything extra. Your theory would need another large dimension, that we can't interact with. That's not impossible, but it might be impossible to prove.

[Bannin]

Sounds like a lot of theories then!

[PWrong]

String theory's the only plausible theory I know of that can't yet be proven. But your theory doesn't actually explain or generalise anything, as far as we know.

[houserichichi]

String theory's the only plausible theory I know of that can't yet be proven.

*cough* religion *cough* flying spaghetti monster *cough*