physics comes closer to being that comprehensive underlying microscopic description of the world than any other science does. So you can certainly study neuroscience or democracy knowing nothing about physics at all. They are independent autonomous subject matters that you might be interested in but they had better be compatible with the underlying principles of physics. David Miloch says, is it possible is the possibility of machine consciousness, not any particular machine, but in general, something that is for you subject to credence? If so, what evidence could lead you to updating your credence? It depends on what you mean by machine consciousness.