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Comment by GuB-42 | Hacker News Reader

If the universe is infinite like we think it is, then there is life somewhere, in fact, there is an infinite number of copies the earth exactly like or own, with a copy of you and me on it. We are just "blinded" by the limits of the observable universe.

So, we are almost 100% sure that there is extraterrestrial life somewhere in the universe, but if there is no possible causal relationship between us, what's the point? It is also the same reason why "the universe" is often shorthand for "the observable universe". There is probably something beyond it, but we have no way to know what it is, so it might as well not exist.

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> If the universe is infinite like we think it is, then there is life somewhere, in fact, there is an infinite number of copies the earth exactly like or own, with a copy of you and me on it.

This requires more assumptions than just infinite scale.

Right, like in math, not all infinite sequences contain every finite subsequence. For example, a non-repeating sequence of 2's and 7's contains no sequence "4". The further condition is that the number be normal[1].

Also, TIL we don't know whether π is normal thus the popular claim that "every string of numbers eventually occurs in π" is not known to be true

[1] https://en.wikipedia.org/wiki/Normal_number

I am not aware of any models of the universe that posit an infinite mass.

Edit: Also, "observable universe" is a frequently misunderstood concept. Just because something is now outside the observable universe (the distance between them and us is big enough so that the rate of expansion of the universe between us and them is higher than the speed of light) doesn't mean that we aren't, today, receiving light from a long time ago when the object was closer. If you go far enough back in time you can "see" the entire universe . As time passes, more and more mass moves outside of the observable universe since the size of the sphere is constant relative to the rate of expansion.

That would imply there’s an edge to be closer to, which doesn’t align with my understanding of it.

this is such a commonly-repeated fallacy. just because something is infinite, doesn't mean everything is possible. the sequence 1,3,5,7,9,... is infinite, and yet it contains no even numbers. there are many such cases.

In this case, the existence of earth is an even number, so I don't see how this is a fallacy.

Take the sequence of prime numbers, with Earth = 2. ;)

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