Querying my expectations I find that my expectations of reality aren't at all related to verbal statements like "The Atomic Theory of Matter" even if my verbal centers want to endorse it strongly.
I currently believe that the atomic theory of matter is a descriptive, predictive theory relating to the sorts of objects physicists have categorized and the sorts of tools that exist.
Asking "How confident are you that there are discrete units" feels like asking "how confident are you that jumping on one goomba's head in mario gives you 100 points" (or whatever, it has been a while.)
The answer is, if you upload the code for the game and hack it then the question of points stops being relevant.
So the translation of what my expectations is is that I believe that "elementary particles" are indivisible insofar as the theory of elementary particles treats them as particles. But if everything is probability distributions further down, then I don't even know what it means to say that something is indivisible. Does it mean that the distribution emerges from an indecomposable, finite-dimensional representation? In that case these distributions will have an atomic theory, but I don't think that will actually be true, and it may be better at a smaller scale to switch analogies to something where the previous idea of atomic theory no longer makes any sense at all.
I guess that puts me at about -10 decibans; I don't see an a priori reason that probability distributions should be atomic, and I can imagine them being fundamental. And if they aren't, that adds to the probability of our formalisms being overturned over and over again.
How much confidence do you place in the scientific theory that ordinary matter is made of discrete units, or 'atoms', as opposed to being infinitely divisible?
More than 50%? 90%? 99%? 99.9%? 99.99%? 99.999%? More? If so, how much more? (If describing your answer in percentages is cumbersome, then feel free to use the logarithmic scale of decibans, where 10 decibans corresponds to 90% confidence, 20 to 99%, 30 to 99.9%, etc.)
This question freely acknowledges that there are aspects of physics which the atomic theory does not directly cover, such as conditions of extremely high energy. This question is primarily concerned with that portion of physics in which the atomic theory makes testable predictions.
This question also freely acknowledges that its current phrasing and presentation may not be the best possible to elicit answers from the LessWrong community, and will be happy to accept suggestions for improvement.
Edit: By 'atomic theory', this question refers to the century-plus-old theory. A reasonably accurate rewording is: "Do you believe 'H2O' is a meaningful description of water?".