However, this has only proved to be useful to make predictions in the observable universe, so extending it to the entire universe would not be empirically justifiable.
Useful so far! The problem of induction applies to all of our predictions based on past observations. Everything could be totally different in the future. Why think the laws of physics or observations will be similar tomorrow, but very different outside our observable universe? It seems like essentially the same problem to me.
As a result, I get the impression the hypothesis of an infinite universe is not falsibiable, such that it cannot meaningly be true or false.
Why then assume it’s finite rather than infinite or possibly either?
What if you’re in a short-lived simulation that started 1 second ago and will end in 1 second, and all of your memories are constructed? It’s also unfalsifiable that you aren’t. So, the common sense view is not meaningfully true or false, either.
Why think the laws of physics or observations will be similar tomorrow, but very different outside our observable universe? It seems like essentially the same problem to me.
I agree it is essentially the same problem. I would think about it as follows:
If I observed the ground around me is pretty flat and apparently unbounded (e.g. if I were in the middle of a large desert), it would make sense to assume the Earth is larger than a flat circle with a few kilometers centred in me. Ignoring other sources of evidence, I would have as much evidence for the Earth extending for only tens of kilometers as for it being infinite. Yet, I should not claim in this case that there is empirical evidence for the Earth being infinite.
Similarly, based on the Laws of Physics having worked a certain way for a long time (or large space), it makes sense to assume they will work roughly the same way closeby in time (or space). However, I should not claim there is empirical evidence they will hold infinitely further away in time (or space).
Why then assume it’s finite rather than infinite or possibly either?
Sorry for the lack of claririty. I did not mean to argue for a finite universe. I like to assume it is finite for simplicity, in the same way that it is practical to have physical laws with zeros even though all measurements have finite precision. However, I do not think there will ever be evidence for/​against the entire universe being finite/​infinite.
Useful so far! The problem of induction applies to all of our predictions based on past observations. Everything could be totally different in the future. Why think the laws of physics or observations will be similar tomorrow, but very different outside our observable universe? It seems like essentially the same problem to me.
Why then assume it’s finite rather than infinite or possibly either?
What if you’re in a short-lived simulation that started 1 second ago and will end in 1 second, and all of your memories are constructed? It’s also unfalsifiable that you aren’t. So, the common sense view is not meaningfully true or false, either.
Thanks for jumping in, Michael!
I agree it is essentially the same problem. I would think about it as follows:
If I observed the ground around me is pretty flat and apparently unbounded (e.g. if I were in the middle of a large desert), it would make sense to assume the Earth is larger than a flat circle with a few kilometers centred in me. Ignoring other sources of evidence, I would have as much evidence for the Earth extending for only tens of kilometers as for it being infinite. Yet, I should not claim in this case that there is empirical evidence for the Earth being infinite.
Similarly, based on the Laws of Physics having worked a certain way for a long time (or large space), it makes sense to assume they will work roughly the same way closeby in time (or space). However, I should not claim there is empirical evidence they will hold infinitely further away in time (or space).
Sorry for the lack of claririty. I did not mean to argue for a finite universe. I like to assume it is finite for simplicity, in the same way that it is practical to have physical laws with zeros even though all measurements have finite precision. However, I do not think there will ever be evidence for/​against the entire universe being finite/​infinite.