Astronomers spot the first "bounce" in our Universe
bigthink.com
A spherical structure nearly one billion light-years wide has been spotted in the nearby Universe, dating all the way back to the Big Bang.

A spherical structure nearly one billion light-years wide has been spotted in the nearby Universe, dating all the way back to the Big Bang

  • Kata1yst
    2•1 year ago

    But 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.

    • @btaf45OP
      1•1 year ago

      These days those assumptions are considered pretty fundamental

      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.

      https://en.wikipedia.org/wiki/Shape_of_the_universe

      [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.

      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.

      It also makes no sense to invoke the cosmological principal to “prove” there are no boundaries. The philosophical cosmological principal simply says that since we don’t see boundaries they must not exist anywhere. That makes no sense because we would expect any boundaries to only exist in a very small percent of the total volume of space.