[Houshalter]

Why? "Turtles" is a bad hypothesis because it's so arbitrary. It is no more likely than "ducks all the way down", etc. The fact that it's not testable is the least of it's problems.

Whereas a multiverse is a much higher prior probability. In fact believing we are the only universe is just as untestable a hypothesis, and even more silly.

[julius]

Please stop with the probabilities.

We can demonstrate, our universe exists. Claims about the number of universes (>= 1) are untestable (for now) and should therefore be considered speculation.

[Houshalter]

I'm not saying that there isn't any evidence our universe exists. That would be silly. I'm saying there is no evidence that our universe is alone and it would be incredibly surprising if it was. I don't know why "number of universes = 1" should be a default hypothesis.

[mratzloff]

There is no evidence for unicorns, but I don't know why everyone assumes they don't exist. Isn't it equally likely that they are just really good at hiding?

[Houshalter]

You are making my argument for me. The hypothesis "unicorns don't exist" has zero proof. You can never ever prove that unicorns don't exist. Therefore, the statement "unicorns don't exist" is just wild speculation and outside the realm of science. Therefore, until someone shows proof we will assume that unicorns do exist.

The idea that our universe is the only universe is just as crazy to me as saying unicorns exist. The laws of physics are incredibly arbitrary, and the probability of a random set of laws of physics supporting intelligent life is ridiculously small.

More formally, via Solomonoff induction, the hypothesis of multiple universes should be more likely by several orders of magnitude, since it can necessarily be expressed with fewer bits of complexity. E.g. "all computable programs" vs "one specific program", or "all possible laws of physics", vs "one very specific set of laws of physics."

[kazinator]

If the multiverse hypothesis is true, then beasts which resemble unicorns most likely do exist among the infinitude of universes. I mean, it would be astonishing if that could be ruled out: that there is an infinity of universes of all imaginable kinds, but none of them have anything that fits the description of unicorns.

Also, many universes probably have a being which serves, essentially, as a god: that is, these worlds are partitioned into an intelligent part, and a remainder which the intelligent part created and controls.

(Not this one, though, as far as anyone credible has been able to tell.)

[TheOtherHobbes]

I see you missed this:

http://phys.org/news/2014-10-interacting-worlds-theory-scien...

[jqm]

Per your statement, (number of universes >= 1) is testable and true ("demonstrated").

Maybe you mean (number of universes > 1)?