That depends on the definition of consciousness I guess. Of course you could define it in a physical way but that would be something different than what many people mean by consciousness - i.e. that it's my feelings, perceptions, thoughts, etc.
I think that's not quite the whole picture. We also make judgments about the consciousness of others, and those judgments are based at least partially on physical criteria. Think about judgments of consciousness regarding those suspected to be "brain dead" or in vegetative states.