Wasn't project Orion a really bad idea version of this? But I think the fuel scoop was the only missing technology?

I enjoy the debate, and fully admit I may be wrong. An infinite number of monkeys will create Shakespeare, but cannot produce a list of all typewritten lists that do not contain themselves as it is simply a paradox, not an improbability.

This is why I compare to pi. You can find an infinite number of 1s, infinite number of 14159s an infinite number of a million digits of pi, but it does not repeat. So if you say an exact earth is 15 digits long then yes you will find an infinite number of those digits (and every other combination of 15 digits). But you will not find anywhere that pi starts at 14159 runs any distance and then repeats 14159 and on exactly. How does this relate to the copy of earth? Earth has influenced and been influenced by everything within 14 billion light years, so 14 digits of pi let's say, you can certainly find an infinite number of those, but at the edge of that 14 billion years those influenced objects have been influencing things for 14 billion years as well. (I'll grant that we're probably getting into less than plank lengths so I'll admit I'm wrong here, but hear me out anyway) the continuous expansion of the sphere of influence encompasses the entire infinite universe in this way. So in order to create an exact copy, with the same history, same future, same influence you need a copy of the whole universe, the entire length of pi... And pi does not repeat, though it is infinite.

Anything less than an entire universe copy will eventually diverge from our earth (perhaps after the heat death of the universe and be really really really hard to notice but would be different none the less)

If you are talking about a multiverse, infinite big bangs, then clearly yes this happening once is proof it is possible, and would happen infinite more times.

If the size of your copy is infinite you need a new infinite universe to put it in.

The other point I'd like to raise is that not everything is random, so something like the same earth but I'm left handed may not be a possibility. The genetics of my parents may not be capable of creating left handed children, and the mutations that would create left handedness probably require several other changes to the world, plus the experiences I would have being left handed my entire life would shape me into a different person with different thoughts.

So the exact way the earth was assembled is a cause and effect relationship, without one you don't get the other. If you don't care what history the atoms of earth had before assembly then you can find infinite earths, but I argue that is not an exact copy.

Thank you for your thoughtful and respectful responses.

Yes, our disagreement is that "an exact replica of earth" is possible without the exact universe we have.

I do not dispute that in an infinite universe anything that can happen has happened.

I just don't think that an exact replica is one of the things that can happen.

Let me put it this way, when does exact earth stop being exact? Light from 14 billion years ago is reaching the earth just now to inform our astronomers about the early universe, if that history is not a part of your 'copy' of earth, then your earth's astronomer is different than the ones here, your earth is different. So our observable universe is necessary to copy earth. But to copy our observable universe, everything that universe can observe is necessary, and so on.

You say Andromeda is irrelevant, but our history is filled with usages of Andromeda to inform ourselves what our galaxy may look like, the pull from our galaxy on Andromeda informs us of the mass of our galaxy, Andromeda contains several important stars we use as standard candles... So yes, I think life happened, humans probably happened, a moon, a 8/9 planet solar system happened, but not an exact replica.

You are saying earth (the variables that brought about earth, etc.) are a piece of the infinite universe, and so can be found in multiple places. I'm arguing that what set the earth in motion was not in fact a separate piece, but is the entire thing. If the moon had slightly more or less mass, the tides would have been different, if Jupiter was not exactly where it is, the meteors that created the moon would have impacted differently, if our neighboring stars had a different make up, the heavy elements necessary for life would not have been prevalent in this part of the galaxy, if our neighboring galaxy was drifting away instead of gravitationally locked with ours the spin of our galaxy would be altered and we may have been in the wrong part of space to gather the elements necessary... Earth is not one of an infinite number of unrelated 5s in an endless string of random digits, earth is a 5 in the 6728th position and any alteration anywhere along the string of digits alters every adjacent digit and propagates through the entire string. So in order to find a second earth, you would need an exact copy of the entire universe, you would need pi to repeat.

What about the digits of pi? They do not repeat yet they are infinite.

How many digits before pi starts repeating?

Galaxy collision rarely causes stellar collision.

I love could be headlines... It could be making penises bigger... It could be making parents choose the name Dwayne more often, it could be santa in drag blowing pixie dust into your butt hole, we don't know.