Thread: Explain to me the 4th dimension.

Originally Posted by ThreeLetterSyndrom

If the universe is curved, the corners of a triangle wouldn't add up to 180 degrees.

Maybe, maybe not. I am familiar with the concept. That is certainly what would happen to a triangle in a 2 dimensional world that was curved in 3 dimensional space, but we cannot say for certain that that would also be the case for a triangle (or any object) in a 3 dimensional space that curves within a 4th spatial plane. It is not the qualities of a static object in space that suggest a fourth dimension, but rather the way all objects in our universe are moving relative to one another. Or are they moving at all? Is it possible that the space itself may just be expanding?

here's a video i saw a while ago of Carl Sagan explaining the 4th demension.

http://www.youtube.com/watch?v=UnURElCzGc0

its pretty much just the same flat land story and the teserect explanation.

.......But its carl sagan so that makes it cool

I thought this was the best explanation of 4d yet.

http://www.youtube.com/watch?v=uDaKz...eature=related

"A 4d world implies that there are an infinite number of 3d spaces adjacent to our 3d world" ( parallel universes? )


If i had 3 transparent boxes. And there was an entity in one of the boxes, he would only know of the box he's in. Because he can only experience 3 dimensions of movement. He's constricted into that one box. Yet, I'm a 4d creature so i know that there are more boxes. He might actually think i was crazy if i told him there was more boxes than just the one he's in.

Now if i was a 4d creature, my field of vision would be in 3d. Just as we are 3d, but we can only see in 2d.

So if i had a cube, i would see it in 3d....but i probably would be able to see all sides of it at once. That's as far as i got, before i was lost in that video lol.

So basically being taken into a 4dimensional place is being taken out of a 3d reality... which you can see a multitude of of other 3d realities.

So in my 4d vision, i would see all of the 3d spaces...i'm really lost now, and only think i got part of this right. Cause it's really hard to explain this...but i feel like i know how it is.

a 4D creature would be able to see a multiple of 3d objects within a box(reality?), us 3d creatures can see a multitude of 2d objects ( paper, hands, cup, etc. ) within our rectangle( field of view).


I'm sure all this is extremely complicated in mathematics.

It needn't be to be honest. Any point in four dimensions can be written as

x
y
z
w

and a line, for example, can be easily written in vector form as

r = [x, y, z, w] + t[a, b, c, d]

There's nothing particularly special at all about three dimensions in mathematics. It's an open question why the universe should happen to have three dimensions.

Here's the 4th dimension explained by the person that come closest to a hero to me

http://www.youtube.com/watch?v=Y9KT4...rom=PL&index=3

Carl Sagan reminds me of Agent Smith.

Originally Posted by grasshoppa

Carl Sagan reminds me of Agent Smith.

http://www.youtube.com/watch?v=lgfYPnA_iFI

crumbly but good