How can a 3d universe be flat?

On a cosmic scale, the curvature created in space by the countless stars, black holes, dust clouds, galaxies, and so on constitutes just a bunch of little bumps on a space that is, overall, boringly flat. is easily explained, too: spacetime is curved, and so is space; but on a large scale, space is overall flat.

Why is the universe flat?

The usual explanation of the universe’s formation includes a period just after the big bang called inflation, when the universe rapidly expanded. Our current models of inflation naturally lead to a flat universe, so if the universe is actually closed, they would have to change.

Can the universe be flat and finite?

We do not know whether the Universe is finite or not. The surface of the torus is also spatially flat, but it is finite. So you have two possibilities for a flat Universe: one infinite, like a plane, and one finite, like a torus, which is also flat.

Why is space 3d?

Space has three dimensions because the length of a box is independent of its width or breadth. In the technical language of linear algebra, space is three-dimensional because every point in space can be described by a linear combination of three independent vectors.

Is the universe flat or curved?

It’s easy to make examples in 2D space (ie. a flat piece of paper vs. a curved piece of paper, or the surface of a balloon). It’s not so easy to illustrate flat 3D space – since we are 3D! So it’s totally understandable that the concept is confusing This is refering to the theory that the whole universe is flat.

Is space flat or flat?

Moreover, when they talk about the flatness of space cosmologists are referring to the large-scale appearance of the universe. When you “zoom in” and look at something of less-than-cosmic scale, such as the solar system, space—not just spacetime—is definitely not flat.

Will the universe extend forever like a piece of paper?

But if the actual density of the universe is equal to the critical density, as scientists think it is, then it will extend forever like a flat piece of paper. (Image credit: NASA/WMAP Science team.)

How many dimensions does the universe have?

The universe is four-dimensional—three for space, one for time. The universe has nine, or ten or eleven dimensions. is just a matter of clarifying language. For all we know, space is 3-D, and spacetime is 4-D; but if string theory is true, then space turns out to be 9-D, and spacetime 10-D.