On Sunday, October 13, 2019 at 3:47:31 PM UTC-5, Philip Thrift wrote: > > > > https://twitter.com/WKCosmo/status/1183381747511300102 > > Sabine Hossenfelder @skdh > · > If a tree drops in the forest, does it decohere and remain in a mixed > state of dropped and non-dropped until I come by and update the > wavefunction? > > (No, it doesn't. That's why decoherence does not solve the measurement > problem of quantum mechanics.) > > > Will Kinney @WKCosmo > Replying to @skdh > > Unless the mixed state density matrix simply encodes the probabilities of > various outcomes, in which case you're fine. > > > Sabine Hossenfelder @skdh > · > Replying to > @WKCosmo > > Have you suddenly become a fan of hidden variables models? In that case, I > am totally on your side. > > Will Kinney @WKCosmo > > I'm not sure why hidden variables are necessary in a probabilistic theory. > > > Sabine Hossenfelder > @skdh > > Oh, they are not necessary. The other alternative is that you give up on > reductionism. Is that what you want to advocate? > > > Will Kinney @WKCosmo > · > If the theory matches reality, sure. I really fail to understand > physicists' attachment to a clockwork universe fully determined by boundary > conditions. Nature apparently doesn't work that way. > > > Sabine Hossenfelder @skdh > > I see. That's fine with me as long as you acknowledge that in this case > the theory is necessarily incomplete because it lacks an explanation for > why you need a second postulate for macroscopic objects if their behavior > should be derivable, not an additional assumption. > > > > (continued)
Will Kinney @WKCosmo · Replying to @WKCosmo and @skdh Let me try something out on you and see if you agree, at least a little: Suppose that QM is in fact complete, and there is nothing additional underlying it. Shouldn't this tell us something extremely interesting about gravity, even if we haven't figured out what it is yet? Sabine Hossenfelder @skdh · Oh :( Sorry, I read this after I was just happy to think we agree that QM isn't complete. Well, there is no supposing here, because that view is just inconsistent, that's what I am saying. It's not an option. It cannot be how nature works, we already know that. Will Kinney @WKCosmo · Hmm. Why must quantum mechanics be incomplete to be probabilistic? Sabine Hossenfelder @skdh · If you want to interpret the update of the probability to 100% after observation as a statement about the observer's knowledge, you are implicitly assuming that you cannot calculate "observer's knowledge" from the constituents of the observer. Ian Wardell @Interesting_Ian · Replying to @WKCosmo and @skdh Physicists demand that reality conforms to their irrational metaphysical presuppositions i.e contiguous causes, reductionism, the mechanistic conception of reality. @philipthrift -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/5414190c-2c5e-4dcd-8015-3a2c046c70bc%40googlegroups.com.
