Comment on Astronomers spot the first “bounce” in our Universe

Kata1yst@kbin.social 1 year agoBut the existence of a "geometric center" breaks several of the base assumptions of astrophysics. If there were a geometric center as you say, then there would have to be "edges" of the universe, or the inflation would need a center.

Both of which we think are not the case, due to lots of battle tested theories that tell us space is generally of flat curvature and homogenous, meaning one random chunk of space (the actual stuff of space, not like looking at stars and other structures of the universe) should be indistinguishable from another.

These days those assumptions are considered pretty fundamental to any understanding of space itself and the universe at large that we have.

## btaf45@lemmy.world 1 year ago

Nope. The reason why the FLRW model does not include modelling boundaries is because it is very hard to model boundaries, not because they are unlikely.

en.wikipedia.org/wiki/Shape_of_the_universe

The reason a “flat” universe does not have boundaries is because none of the 3 curvature possibilities in the FLRW model have boundaries.

[For example, in the Friedmann–Lemaître–Robertson–Walker (FLRW) model, the universe is considered to be without boundaries…]

[Many finite mathematical spaces, e.g., a disc, have an edge or boundary. Spaces that have an edge are difficult to treat, both conceptually and mathematically. Namely, it is very difficult to state what would happen at the edge of such a universe.

For this reason, spaces that have an edge are typically excluded from consideration.]Conclusion: The primary reason why an apparent “flat” universe could still have boundaries is because the FLRW model is either incomplete or possibly even not the right model.