We have experimental evidence that certain light patterns have been observed. For any theory that has Jupiter in it, you could make the same theory without involving Jupiter. I don't see any fundamental difference between the evidence for Jupiter and the evidence for the multiverse.
Another universe, basically by definition, has no observable characteristics. We can seemingly only observe our universe, and have no way of knowing if something unobservable is impacting our universe.
Sure, but isn't it the same for multiverse theories? Obviously we don't observe the multiverse directly, but we observe data for which the best explanation also implies a multiverse, just as the best explanation for various observations implies the planet Jupiter.
> Another universe, basically by definition, has no observable characteristics. We can seemingly only observe our universe, and have no way of knowing if something unobservable is impacting our universe.
There's a lot we can't observe or interact with directly; we can't interact with the past, we can't observe the future, we have to real way of interacting with distant galaxies, we can't actually observe inflation at all... a good multiverse theory (of which I'm not sure there are any, but I think they're possible in principle) would be in much the same category as inflation AFAICS: we can't observe the thing itself but we can observe things that seem most likely to be consequences of it.
No, we don't have observational data supporting a theory of a multiverse. With Jupiter, if there were a planet there we would expect x to happen due to our understanding of planetary physics. We then observe, and x happens.
We can't repeat this with a multiverse, as all of our observational data ever provides no insight into how another universe works.
Two people keep saying this, it is easy to prove me wrong here.
>There's a lot we can't observe or interact with directly;
None of which are science. We have past observations, and we can make predictions of the future, but that's basically the extent of their place in science. We do observe distant galaxies, and that's where are understanding of them comes from.
As for inflation, like of space? As we do have experimental data for that, something about how long light takes to reach us. If you're talking economics, very little of it is science.
No we don't - I assume you're thinking of dark energy, which is a separate and (as far as we know) unrelated phenomenon. The evidence for inflation is basically "the cosmic microwave background looks like it was produced by the universe behaving in such-and-such a way"; it had no effects except for very shortly after the big bang, so we can't use it make predictions about the future and observe whether they happen or not. (We can, and have, made "predictions" about things that haven't yet been measured, e.g. inflation was used to predict what the CMB polarisation would be before we launched Planck to measure it - but what we're measuring is something that happened in the very early universe).
So I don't see a lot of difference between that and e.g. a theory that says (with evidence) that our universe is the result of a symmetry-breaking process that would naturally have produced an ensemble of similar universes.
I was talking about the expansion of the universe that is still ongoing.
Inflation has observational data already, the radiation you mention, and much of the work done with particle accelerators is to recreate the conditions of these kinds of events. This is enough to make it science, even if completely wrong.
I thought of perhaps a simpler way to put this. The realm of science is the observable universe. We can use that to develop theories of events in our universe we can't observe, as there are still remnants in the observable universe. We can't develop theories of things that never happened in the observable universe though.
Maybe someday someone will develop some method to observe effects that would show evidence of a multiverse. It hasn't happened, and personally it seems unlikely.
The prediction that objects continue to exist when we're not looking at them is not testable in the same sense (you could even say it's unfalsifiable and therefore not scientific); nevertheless most of us tend to believe in it.