Ok. Now, in a closed universe, what would be an interpretation for its closed form, besides angles not adding to 180°?mfb said:Yes. It also means angles in triangles add up to 180 degrees.
kent davidge said:Ok. Now, in a closed universe, what would be an interpretation for its closed form, besides angles not adding to 180°?
Thanks.Jorrie said:Your straight rods will converge and cross over at some large distance in any direction.
Take note that in our presently accelerating expansion universe, even it it has a small positive spatial curvature, your rods will break long before they reach that crossover point, because they cannot extend past our Hubble radius.
When we say that the universe is spatially flat, we mean that the overall geometry of the universe is flat, rather than curved. This means that if you were to travel in a straight line for a very long distance, you would eventually come back to your starting point.
Scientists have used various methods, such as measuring the cosmic microwave background radiation and studying the large-scale structure of the universe, to determine that the universe is flat on a large scale. This is also supported by observations of the shapes and sizes of galaxies and galaxy clusters.
Some other possible shapes for the universe include spherical (closed) and hyperbolic (open). In a spherical universe, if you were to travel in a straight line, you would eventually come back to your starting point from the opposite direction. In a hyperbolic universe, the opposite is true - if you were to travel in a straight line, you would eventually diverge from your starting point.
The shape of the universe can have a significant impact on its ultimate fate. For example, a flat universe would continue expanding forever, while a closed universe would eventually stop expanding and collapse in on itself. The amount of matter and energy in the universe also plays a role in determining its fate.
It is possible that the shape of the universe could change over time, as the expansion and contraction of the universe can affect its geometry. However, these changes would likely occur on a very large scale and over extremely long periods of time. Currently, the evidence suggests that the universe has maintained a flat shape since the Big Bang.