That is a pretty big hole Hannibal. biggrin

If the universe is closed, then we will never know because it is expanding more rapidly than we can see. For example, we are just now seeing the light from the stars that were moving away from us several billion or so years ago. If they are continuing to move away they are probably still moving faster.

Also, if the universe is closed, what would be the boundry? What is the difference from the vaccum of the universe and nothing outside. Also, how could one determine if they had left the universe? Take one more step and look back?


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