What constitutes a measurement?
Another article that bears re-reading, at least for me.
I discussed this idea in a different context previously with a friend. If I recall, we asked if the act of setting up equipment to make a measurement was part of the act of measuring, and down a rabbit hole my brain went…
Anyway, I was reminded of the recent article where hidden Markov states were discussed when in the article above the author says “When we’re not making an observation, we don’t, and can’t, know the actual values of the hidden variables.” when talking about pilot-wave theories.
The discussion of the many-worlds explanation just happens to coincide with my re-reading of Phillip Pullman’s “The Subtle Knife”. Pullman relies on the many worlds idea to explore various themes in the book. The novels are said to be for young adults, but I would argue that those after the first explore some very interesting ideas that are worth reading at any age.
(BTW, I am very much looking forward to the new British series https://en.wikipedia.org/wiki/His_Dark_Materials_(TV_series))
Anyway, when it comes to the many-worlds explanation it’s interesting that the author states “But in the real world, the wave function branches incredibly fast, on timescales of 10^−21 seconds or less.” How does that fit with what Barbour has said? That question is not addressed (probably because this is just an article).
By the end of the article I feel no better than at the beginning. Partly that’s because I have too little time to read all I should read, but of course I can’t say that will actually help :-)