That is what we mean when we say “quarks exist”: We mean that the predictions obtained with the hypothesis agrees with observations.
That’s not literally what we mean. I can easily imagine a universe where quarks don’t exist where Omega intervenes to make observations agree with quark-based predictions in response to predictions being made (but not, say, in parts of the universe causally inaccessible to humans). Maybe this is a strawman interpretation, but if so, it’s not obvious to me what the charitable interpretation is.
edit: by “quark-based predictions” I mean predictions based on the hypothesis that quarks exist outside of the mind of Omega, including in causally inaccessible parts of the universe
It’s certainly not what I mean by “exist”. Sabine is offering a new definition, and the problem with new definitions is that they don’t solve old problems.
Certainly we can imagine this Russel’s teapot universe, where pink unicorns frolic between the stars smiling conspiratorially while hiding from human senses and tools. These kinds of universes exist in human imagination, and are useful in some contexts, but not in physical research. Certainly a lot of physicists, contrary to what Sabine is saying, mean more than “the predictions obtained with the hypothesis agrees with observations” when they say that something exists. Hence all the interpretations of quantum mechanics, for example. My charitable interpretation of what you quoted is something like following Occam’s razor, which would imply that there is no need to add Omega to the mix, or assume that the universe is wildly different beyond the cosmological horizon, unless there is a relevant hypothesis with enough predictive power.
That’s not literally what we mean. I can easily imagine a universe where quarks don’t exist where Omega intervenes to make observations agree with quark-based predictions in response to predictions being made (but not, say, in parts of the universe causally inaccessible to humans). Maybe this is a strawman interpretation, but if so, it’s not obvious to me what the charitable interpretation is.
edit: by “quark-based predictions” I mean predictions based on the hypothesis that quarks exist outside of the mind of Omega, including in causally inaccessible parts of the universe
It’s certainly not what I mean by “exist”. Sabine is offering a new definition, and the problem with new definitions is that they don’t solve old problems.
Certainly we can imagine this Russel’s teapot universe, where pink unicorns frolic between the stars smiling conspiratorially while hiding from human senses and tools. These kinds of universes exist in human imagination, and are useful in some contexts, but not in physical research. Certainly a lot of physicists, contrary to what Sabine is saying, mean more than “the predictions obtained with the hypothesis agrees with observations” when they say that something exists. Hence all the interpretations of quantum mechanics, for example. My charitable interpretation of what you quoted is something like following Occam’s razor, which would imply that there is no need to add Omega to the mix, or assume that the universe is wildly different beyond the cosmological horizon, unless there is a relevant hypothesis with enough predictive power.
What these thought experiments are useful for is emphasising the lack identity between prediction and correspondence.