What is space-time made out of ?

[FZ+]

There aren’t any 4 spatial dimensions. There are only three. There are the x, y, and z Cartesian coordinates, and that is it.

Exactly. And as long as you consider straightness by these 3 dimensions, you can easily make adjustments to move in a "straight line" with curved non-euclidean space.

 

[David]

Originally posted by FZ+
Exactly. And as long as you consider straightness by these 3 dimensions, you can easily make adjustments to move in a "straight line" with curved non-euclidean space.

My point is, with these three dimension and the x, y, and z coordinate system, that represents Euclidean space. If we insert spherical masses and their curved gravitational fields into this coordinate system, we still have the same coordinate system, and inserted into it are curved masses and curved gravity fields. It’s like inserting a spherical basketball into a cubical box. The ball remains spherical and the box remains cubical. The box doesn’t change shape to conform to the outline of the ball.

 

[yogi]

David - it isn't that space distorts into a sphere around a spherical mass - what occurs is a change in the measured radius of a sphere relative to the surface area of the sphere measured at that radius - in other words, the surface area of a spherespace encompassing a mass is no longer exactly 4(pi)R^2 For the Sun, the change (excess radius) if I remember correctly is about 1/2 a kilometer

 

[clicky]

Spacetime is simply how we describe and try to understand nature.
Spacetime is made of what the Euclidean space is made of - just a mathematical description. The space and time are created in the process of perception from multiscale sources of unifying interaction according to the emerging theory of interaction developed by the space
physicist Eugene Savov.

 

[Phobos]

Originally posted by David
There aren’t any 4 spatial dimensions. There are only three. There are the x, y, and z Cartesian coordinates, and that is it.

I think he's extending the analogy to help understanding. He's not saying there are 4 spatial dimentions in Relativity.