Drifter said:
It's only objectively measurable because we agree on a simple definition of water. It wasn't until the mid 1990's that we had scientific evidence that water, in the form of H2O, exists on the sun. Given the possibility that modern physicists may be right that sub-atomic particles can appear out of nowhere because they are formed by waves in quantum fields rather than being bits of indestructible matter, we can't say with certainty that water is not present in any region in the universe. The elements that make up water could potentially form anywhere.
But we can say for certain that water
is objectively present in some places ... such as the Pacific Ocean. No reasonable person would contest that water is present there; you can swim in it if you like.
By contrast, as you have noted earlier, the presence of sentience in anything other than oneself can only be assumed.
Drifter said:
Yes, I agree. We can't objectively measure sentience because we can't adequately define "sentience" objectively.
To be even more specific (maybe even pedantic): the definition of sentience cannot be expressed in terms of measurable physics. This is not due to lack of research or appropriate philosophizing nor technology, but is instead the result of the very nature of the concept.
Drifter said:
Whether or not a rock can be sentient will always, I believe, be beyond the scope of science.
You may find
Integrated Information Theory very interesting
Drifter said:
Scientists who believe that human intelligence, emotions, and self-awareness are merely emergent qualities of a physical brain will undoubtedly reject the idea that rocks can possess these qualities because there is no known evidence that rocks have brains.
Haha, nope, rocks don't have brains. But they can tell stories. Which is to say, an individual rock can
store and process information in a very limited capacity. Very limited, but non-zero. A large group can tell us a great deal about the history of our planet before any humans were around...
A virus also has no brain, and yet a viral disease can "outsmart" our immune systems and our brightest pharmaceutical scientists.
For that matter, the immune system is a decision-making (AKA information processing) system that is not composed of neurons. And it
really needs to make correct judgment calls when presented with new situations...
Drifter said:
While I'm not sure exactly what role the brain plays, I believe sentience is confined to the living. But that is just a belief. I remain open to the possibility that the entire universe is being perpetually created by a life force whose essence permeates every corner of it.
But then wouldn't that just be a different belief, if you came to think that?
How do you suppose we might go beyond relying on arbitrarily chosen belief regarding the
whereabouts of sentience? Is it possible? ... and if not, then (taking the bull by the horns) this suggests we have constructed an
imponderable, a question that can never be answered by virtue of its underlying assumptions. It's kinda the opposite of a paradox, as discussed earlier. Not a dead end for inquiry...