The same way I don't need to understand aerodynamics to know that I have no reason to believe that turtles might be capable of flight.
You don't need to know the underlying mechanics, but you do need to know what flight is.
You're saying we don't even know what consciousness is.
To argue that this means we can only have an ethical problem with running dubious experiments on brains at that stage of development
No one is arguing that. I am saying that if you claim to have a problem, you have to be more specific about what your problem is and what might convince you that it is not a problem.
"Prove to me something I don't know what" is not a useful attitude.
You're saying we don't even know what consciousness is.
Not in the least. I know what consciousness is because I am a consciousness. The need for a theory of consciousness is necessary to tie the concept to the material world, so that you can make statements like "a rock cannot be conscious, in principle".
I am saying that if you claim to have a problem, you have to be more specific about what your problem is and what might convince you that it is not a problem
What might convince me is a satisfactory theory of consciousness. Do I have to pro...
This seems significant:
http://www.theguardian.com/science/2015/aug/18/first-almost-fully-formed-human-brain-grown-in-lab-researchers-claim