Honnan tudják a csillagászok, hogy a belátható világegyetem sugara 13 700 000 000 fényév?

"The best estimate of the age of the universe as of 2015 is 13.799±0.021 billion years but due to the expansion of space humans are observing objects that were originally much closer but are now considerably farther away (as defined in terms of cosmological proper distance, which is equal to the comoving distance at the present time) than a static 13.8 billion light-years distance. It is estimated that the diameter of the observable universe is about 28.5 gigaparsecs (93 billion light-years, 8.8×1026 metres or 5.5×1023 miles), putting the edge of the observable universe at about 46.5 billion light-years away."

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A lényeg: "the edge of the observable universe at about 46.5 billion light-years away"

A megfigyelhető univerzum széle kb. 46,5 milliárd fényévre van tőlünk.