So flat earthers have given up on earth being flat and now want to confuse people with the universe being flat. Flat universe lends well into the creationism theory verse the big bang theory and the expanding universe theory. No doubt the flat universe people will come up with some reason why some galaxies have a bulge in the middle, why some galaxies appear to stand at oblique angles compared to others.
Explosions happen in space, when they do happen in space the shock waves travel in all directions not just along one flat plane.
These are not flat earthers though. These are scientists who made observations and came up with a suggestion. Also, a flat universe can incorporate the big bang theory too. The two are not mutually exclusive. By a flat universe, the scientists don't mean that the universe is 1D. It can be 3D and be flat at the same time. It's just that the scale is so huge that from our perspective, it seems round or some other shape.
Lots and lots of theories, there always will be. I myself lean more to the Bubble universe theory, that I can wrap my head around a little bit, but a flat 3D universe is a bit hard for me to see. The torus field as a possible shape I can see also, but I just have a hard time figuring a flat 3 dimensional universe. To me the terms flat and 3D are exclusive of each other, but then again I am neither a scientist nor a mathematician.
Personally, I lean towards a bubble universe too. Makes it easier to comprehend a possible multiversal structure, where each bubble is its own universe.
I agree. Lots of theories. To the point that it can get frustrating for anyone who wants to make sense of it all. I really really hope we have some concrete answers within our lifetime.