No, we don't.
Because, while an individual may experience it, the conjecture that other things do or do not have it is without exception an unverifiable assumption, not an observed phenomenon which calls for an explanation.
> it's actually easier to conceive of a world like ours without subjective experience than one with it.
This is demonstrably false, because no experiencer can observe subjective experience other than their own, and, despite that, describing the world in terms of subjective experience occurring in a vast array of other beings beside the speaker is near-universal, to the point that we pathologize not viewing the universe that way.
Yes, but ultimately, either they do or they don't, and the default assumption is that they don't, unless you favor panpsychism.
You and I have the experience of talking about being conscious because we have the experience of being conscious in the first place. But for a p-zombie to behave exactly the same as us, it would have to have some other mechanism for talking about being conscious that is not dependent on being conscious. So that would mean that our talking about consciousness can be explained by some mechanism other than our being conscious in the first place! Our experience of consciousness, and our talking about experiencing consciousness, could just happen to be one massive coincidence rather than being causally linked! Doesn't seem likely, ergo no p-zombies.
https://www.lesswrong.com/posts/kYAuNJX2ecH2uFqZ9/the-genera...
The entropy gradient is the first one. Of course lots of natural processes have a bit of energy generated so it's not the only part.
Memory is the next one. Being able to take some of that entropy and put it in a more orderly fashion while rejecting the disorganized part. Crystals can use energy to create ordered systems, but they don't have any means of error correcting.
Execution/replay/updating of said memories based on input from the world around it.
Now before humans came along 'life' was the only thing that could readily manage these traits, and that was after a few billion years of trial and error. Humans now have been going down the path of giving other non-living objects these traits. Advanced computer systems are getting closer to the point of recording information and acting on it in a manner that certainly seems like a subjective experience.
Pointing to statistical mechanics and saying the derivative of an exponent is an exponent is an odd way to explain qualia.
Welcome to eliminative materialism!