Flatspace vs realmiverse

[PWrong]

I've noticed that since flatland and the planiverse are very different universes, this difference could apply just as well to 3D.

The planiverse is physically very similar to our universe, except with one less dimension. But flatland is physically very different.

Bionions and tetronians can move because we can push against the ground. We take hold of it (with gravity), swing our legs to move us along, and then let go. But how do flatlanders move? Either there's something there for them to push against, or the only way to accelerate is to lose mass.

I think there must be some kind of inherent friction in flatland, a bit like the aether, except you can hold on to it and pull youself along. This would hopefully make moving in flatland similar to walking in 3D.

Now what would our universe be like if space was filled of an aether like this? It's not the same as walking, because we're not confined to a plane. It's not the same as flying or being in space, because there's no way to stop. And it's not like swimming either, because that doesn't have the same "grabbing and pulling" motion. The only good analogy is to tetronions walking on the surface of a 4D planet.

What do you think?

[bo198214]

I've noticed that since flatland and the planiverse are very different universes

I am not sure to which "flatland"- and which "planiverse"-idea you refer ... :?

[PWrong]

They're the two types of planespace. The planiverse is Fred's world from Alkaline's website. It has gravity, so Fred can only move forward and backward, or jump up. Flatland is more like a flat surface with no "up" direction.
http://tetraspace.alkaline.org/wiki/index.php?title=Planespace

My point is that there is a physical distinction between the two universes, and the same distinction can apply in 3D.

[Hugh]

My point is that there is a physical distinction between the two universes, and the same distinction can apply in 3D.

That's interesting PWrong. To think about how gravity's direction would affect plainverse and flatland differently, and how things may be different in 3d too. I wonder if someone has already thought up names for the different 3d universe types based on this idea.

This reminds me a bit about something I've read, that some people think that the reason why gravity is so weak is that it is dispersed over 4 spatial dimensions, and that we may be confined to a 3d brane.

[Nick]

I already posted this on another thread, and I got an interesting response from iNVERTED:

These two possible worlds only make sense if they are effected by 3d gravity. It would make sense that the 2d spacetime would be warped by objects with large mass like our 3d spacetime is, so they would still have their own gravity, no matter what.

On edit: Another thing you have to consider is life in a dimension without gravity. What is there that the 2d guy would grab on to? It would be like you in space... unless there are other objects too, you would just sort of sit there. You can move your arms and legs as much as you want, but you can't project yourself. Also, in a world without gravity, people would be able to simply walk right into the sun. What's stopping them? Certainly not gravity.

[PWrong]

I don't think I ever saw that post. I'm sorry if it looks like I stole your idea . Where is it?

[Nick]

Here's the link: http://tetraspace.alkaline.org/forum/vi ... .php?t=515

[wendy]

The "flatland" of Abbot, and the "planiverse" of stewart both contain gravity, for what i recall. it is just that the flatland did not really think through the technical problems of 2d in the manner that the planiverse did.

However, imagining 2d without gravity is like looking at a plan of 3d with gravity: instead, think of 3d without gravity as a plan of 4d with gravity.

[papernuke]

well the people in flatland still have a gravitational pull on them from "down" they just dont have left and right but it dosent make them not havve gravity unless their universe was just made without gravity

and tetronians probably do walk because of the gravitational pull on them from wherever they are unless they dont have gravity in their dimension