philosophy

That's basically the question of a thought experiment. If it were possible for a being to exist that exhibits human behavior but isn't conscious, how would we be able to tell? What would need to be different? It's pointing to gaps in our current understanding.

They aren't gaps to a physicalist though. We would end up dissecting the P Zombies brain and concluding it's literally exactly the same as ours, and he was probably actually conscious.

We could even envision a technology that is able to capture, in data, the entirety of your brain state. We could then take a copy of your brain, and the p Zombies brain, and see if any differences exist. Once we determine that A = A (as the thought experiment claims at least) we would conclude the P Zombie is conscious.

This has actually happened before. People went diving for vital essences and came up with a better understanding of biology instead.

Instead of a computer with no processor we can just boil it down to what I actually think we are: biological agents with a proclivity for homeostasis. You remove the "agency" and you cannot achieve homeostasis. You can't achieve homeostasis you will not be a biological creature very long. The biological creatures that lack agency lose to my lawn mower every spring.

Consciousness simply is agency, which p Zombies lack in the thought experiment, but cannot lack in reality without being BTFO by the weather.