Church–turing Thesis Puns

Particularly the "physical version" of the thesis by David Deutsch. (Church Turing Deutsch Thesis, CTD)

I've been told by an "expert in computational theory" that,

>Brains are physical objects that obey the laws of physics and all known laws of physics are computable. And we know from Church Turing [Deutsch] that every attempt to build a machine that exceeds a Turing machine in power has failed entirely. So we finally just theorized there was no such machine and so far that universal law has held no matter how much we try otherwise
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>It's not a dogmatic or statement or intended as doctrine, it's just a straightforward statement of what the current theory (with no competitors) implies right now.
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>The way I know it's the case is simple: If it weren't true, it would be trivial to show me how to build a machine that can exceed a Turing machine.
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>I'd know the other experts were right because they wouldn't be making philosophical arguments, they'd simply describe what the machine does.
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>In fact, this is trivial. I could describe machines to you right now that can exceed a Turing machine.
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>I know of several. But they exist only theoretically because they all happen to violate the laws of physics. This is why Deutsch said Computational Theory is actually a branch of physics, not mathematics.

And when asked about the possibility of minds requiring non-physical processes as some philosophers of mind have suggested. This was the response,

>How would we ever know that minds are using non-physical processes? You'd never be able to describe them mathematically unless they were using physical processes So they'll never be a paper on how mind's actually work in that case. They simply become inscrutable to science.
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>But there be no way to know that that's the case.
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>So we just dumbly keep thinking that they are physical objects that follow physical processes. And in fact that would be the right guess. Even though it's wrong.
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>What you've really done is you've created a world that is inscrutable and incomprehensible. There's no real point in being a philosopher anymore either. In science has only really worked by chance up to this point[not sure if mispelling here]. That's why there's no reason why I need to take that view seriously.

To protect this person's identity I won't reveal who they are but he said he is a Master in Computational Theory at a top University

Based off this lecture http://www.alanturing.net/turing_archive/pages/reference%20articles/The%20Turing-Church%20Thesis.html and this stack exchange answer https://cstheory.stackexchange.com/a/875, to prove the Church-Turing thesis we have to prove that the functions that a Turing machine and lambda calculus can calculate are exactly the "effectively calculable functions". Is this correct, or is there something more to proving this thesis?

If this is all there is to proving the thesis, then I have the question of why we would want to prove this at all. Can't we just forget about "effectively calculable functions" and only think about Turing machines and/or lambda calculus, because they are just better and more useful versions of the idea of "effectively calculable functions"?

I think there is some insight I am missing here. Why do we want to know whether Turing machines and lambda calculus are equivalent to "effectively calculable functions"?

I do know that if an iterative approach is possible to a problem, so is a recursive approach and vice versa. Does this also guarantee that there are two approaches, one from each side, giving us the same big o time complexity? If an iterative approach has linear time for a problem, is it guaranteed to have a recursive approach with linear to the same problem?

People keep saying both ways can give the same time complexity, but is that possible for both to give the best case scenario?

I apologize if there is already a post about this I was unable to find it.

I'm having trouble finding the original paper. I have an understanding of what the thesis says and its implications in Computer Science. However I am unable to locate it after several web searches. The net is covered with other papers, articles, and lectures that have Church-Turing in the title.

Can anyone point me in the right direction or suggest a more relevant sub that might be able to?

I didn't know this was a thing. Was asked about the Church-Turing thesis, then I was asked to describe the Halting Problem and provide a real-world example.

Not sure how common questions on computability theory are in interviews this is, but it's certainly not something I expected.

I apologise in advance if this is not the subreddit for such questions. I asked this question 24 days ago here. Despite the many answers there, I just wanted to confirm if what I understood was correct. Does the impossibility of solving the halting problem depend on the validity of the Church-Turing thesis?
I initially asked this over at /r/askcomputerscience, but there weren't any replies.

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I have been a programmer for several years now, and have also taught Programming 1 at my alumni for a year before going back to the industry.

One of my current work colleagues mentioned that the difference between good programmers and mediocre programmers are whether they understood the Church-Turing Thesis or not.

Sadly, It's the first time I heard about this. I know about automata, recursion and turing machines (from the wikipedia page*, but I can't quite put them all together.

*-http://en.wikipedia.org/wiki/Church%E2%80%93Turing_thesis