Thanks for bringing up strong Church-Turing. It was interesting to read about it here (https://plato.stanford.edu/entries/church-turing/#StroWeakFo...) I think I had a broader interpretation of Church-Turing than I should. I was thinking that if we somehow discovered a working oracle machine on Mars, it would invalidate Church-Turing. But that article says:
> the thesis concerns what a human being can achieve when working by rote, with paper and pencil (ignoring contingencies such as boredom, death, or insufficiency of paper)
Defining what you can't prove isn't a dodge. It's the foundation of all rigorous thinking. You can only prove anything within the bounds of a formalism, and anything is impossible only within that formalism. Thus in Einstein Lorentz space, going faster than light is impossible. Out here, it's true only if E-L is right about that. (And we know it's not right about everything, but still maybe -- probably -- about that.)
There are some machines that don't exist which are categorically more capable than a Turing machine, such as Clock Doubling Machines, (which get to do an infinite amount of Turing computation in finite time) but those don't exist at all so while philosophers can insist upon debating them it won't do you any practical good.
But it's normal to accept Church-Turing (though not Strong Church-Turing) because once you follow what Gödel, Church and Turing had uncovered the alternatives seem intuitively crazy - Church-Turing has to be right. It's like accepting Modus Ponens and Modus Tollens. I can't present a useful logical argument for why you should accept those because my logical argument will end up relying on them, if you won't accept them then we've nothing further to talk about.