> but consciousness is far more that just software

Citation needed.

> The only proof of consciousness we have is that a brain is required

I think I get what you mean, but that's going a bit too far. For example, in 1950 we could have said "consciousness requires a planet within 100 miles", then the space race would have proved us wrong: being close to a planet isn't required, it's just a coincidence, likely due to life and evolution being more likely to spontaneously occur on planets than off planets.

I would say a similar thing about brains: the fact that up until now we've only seen consciousness in brains is a coincidence, likely due to complex behavioural circuitry being more likely to spontaneously occur in meat (brains) than rocks (chips).

Regarding computability, current scientific understanding goes something like the following:

- The universe, and everything inside it, seems to behave according to some sort of mathematical laws

- The known laws of physics are definitely incomplete (e.g. we have no quantum theory of gravity, we don't have enough experimental evidence to choose between theories of dark matter and dark energy, etc.)

- The known laws of physics seem to be a very good approximation in almost all 'non-extreme' circumstances (this is why we must build giant underground atom smashers if we're to find any discrepancies, and we still don't find any)

- The known laws of physics are computable, i.e. we can use a turing machine to implement the known laws of physics.

- Consciousness arises inside small, warm sacks of meat.

- Small, warm sacks of meat are a 'non-extreme' circumstance.

- Therefore, it seems highly likely that turing machines are sufficient to implement consciousness

This is a non-constructive argument, it doesn't give us an example of a conscious turing machine; yet it's not much different than, say, arguing that collections of atoms can form living creatures, without giving an exact definition of "life" or a receipe for constructing a living creature out of a collection of atoms.

This argument does make some assumptions, e.g. where I've said "seems to be" rather than "is"; these are areas where more research could help, but it seems unlikely that they'll yield refutations to the above argument. The burden of proof is on those arguing that consciousness is unlike anything we've ever studied.

Such a refutation would have to:

- Find new fundamental physics

- Show that this new physics is incomputable, unlike all previous theories

- Calculate a prediction from this new theory (quite tricky, since it's incomputable!), which contradicts predictions of existing theories

- Test the prediction experimentally

This would refute the "turing machines can implement known physics" part, but the argument might still be plausible regarding "non-extreme circumstances" (e.g. if your prediction involves black holes or other exotic situations).

To refute the argument convincingly, you'd need to demonstrate that your previously unknown effect can have macroscopic consequences at ambient temperatures, pressures, in a weak gravitational field, etc. and hence may occur in the brain.

Bonus points if you can demonstrate that your previously unknown, macroscopically-relevant, unlike-anything-else-in-science phenomenon has been routinely occuring inside pregnant women for millions of years (at least) without anyone noticing :)