It is established by different observations a 13.4 Gyr and 93 Glyr diameter Universe. However, how can be sure about the size of the Universe if there are portions of it we can not see? Is due to recollapse due to gravity?
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- this may have been a typo but the diameter is 93 billion ly. You're missing a small factor of a billion. 2) That's the diameter of the observable universe. We know full well the entire universe is larger, but the unobservable stuff has no impact on us
– Jim Aug 17 '18 at 19:02 -
Typos. Right. Giga factor lost, sorry – riemannium Aug 17 '18 at 19:24
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1@Jim the two statements "We know full well the entire universe is larger", and "the unobservable stuff has no impact on us" put together don't really make much sense to me.. – QCD_IS_GOOD Aug 17 '18 at 20:14
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@JoshuaLin We know there's stuff that used to be in our observable universe but has, by now, passed outside of it. Thus we know the entire universe is larger than the observable one. Furthermore, anything beyond the observable limits is out of causal contact with us presently (and for the foreseeable future), which means it has no impact on us (I'm not saying it had no impact, just that it does not have any now) – Jim Aug 20 '18 at 11:43