Andrew M

Generally, yes. One exception is where a detector is placed at only one slit. The detector will not interact with the photons going through the other ...

To apply your example, consider the double-slit experiment. When there is no measurement at either slit, the originally emitted particles build up an ...

Lots of interesting comments there. I'll focus on the Born rule for the moment. Yes, fair point. MWI aside, the puzzle is whether the observed probabi...

See the brief discussion earlier in the thread (with a link to Sean Carroll's solution).

Per "reality doesn’t supervene on my experience", it seems to me that that is how me ordinarily use language. It works well, while other uses are prob...

I'm not saying anything like that. It seems to me obvious that without ordinary, everyday human experience we wouldn't be talking about trees falling ...

As in illustration of an unmoved mover, consider how a cat is attracted to a saucer of milk. The milk does not move but it does move the cat. An excel...

I agree. Trees have a separate existence and evolution to us. Nonetheless the idea of trees falling only has meaning in the context of human experienc...

Yes. Though, of course, we've found through observation that Newtonian theory is incorrect. Also, the "action-at-a-distance" aspect was suspect to New...

Yes, that's the intention. However it's not surprising that the TV images correlate. Whereas quantum entanglement is surprising. Yes, that's correct. ...

Yes, decoherence doesn't depend on whether anyone looks or not. Nonetheless the observer - or, even better, agent or person - closes the loop in the s...

I think it's useful since we are observers. At any rate, since our understanding of quantum mechanics is incomplete, there's going to be differences o...

Just to comment on the quantum mechanics: The card shuffling idea is incorrect. I don't know where they get that from. It's necessary to keep track of...

Note that Wigner's friend is a thought experiment that is not practical (to say the least) with humans, but may one day be done using human-level AI's...

It's the Wigner's friend thought experiment where the system in question (in this case Walmart rather than a laboratory) is isolated from the rest of ...

OK. But as physicist Sidney Coleman says (via Peter Woit): Which is to say, we view quantum mechanics through the lens of our classical concepts and i...

A piezoelectric "tuning fork".

No, I suggested that idea was a deux ex machina. Everything follows quantum principles, whether acorns, water waves or particles.

Yes, an acorn has the potential to become a tree, as Aristotle would have correctly noted. That simply means that an acorn has the capability or possi...

Yes I think I see what you're getting at. Yes, the pattern will be the same in both cases. I think it's deeper than just an analogy. The wave dynamics...

Cantor's proof assumes an enumeration of the set of real numbers (any enumeration, not just an ordered one), and then proves that there can't be one. ...

In the Introduction, Ryle says: While Ryle's anti-Cartesian goal is obvious, his theory cuts across both dualist and behaviorist theories. For example...

Nice example. There can be three ducks in a row, in a pond, in danger. All recognizable, yet categorically different, ways for things to be.

Ryle says "the University has been seen". But yes, if the university didn't have buildings, then one would say something different, as you have done.

Ryle's purpose there was to illustrate what is meant by the phrase "category mistake". Not to argue that people make that mistake with respect to univ...

Ryle's critique reframes the mind/body debate. As you may know, Ryle was part of the ordinary language philosophy movement which included other lumina...

Cantor's diagonal argument assumes that the set of real numbers are countable and then shows that that assumption leads to a contradiction. You may fi...

Cantor's proof (by contradiction) shows that the set of real numbers is uncountable and thus can't be enumerated. Since the set of real numbers can't ...

So far, so good. Pinter's asserted view of "the way the present universe is outside the view of any observer" is a performative contradiction. That's ...

Here's one such demonstration, concluding with: It isn't a computable number (though it is a real number) - see the section entitled "A counter proof?...

Per MWI, branching is the process of a system becoming entangled with the environment (of which the observer or measuring apparatus is a part) such th...

Yes he does. I'm further saying that the view from nowhere should be rejected in its entirety, not supplemented by a further error (the Cartesian subj...

I don't think it's either obvious or insignificant. Nagel critiques "the view from nowhere" but he doesn't reject it. He instead proposes an additiona...

The computable numbers are countable since they be put in a one-to-one correspondence with the natural numbers. However the real numbers are not count...

Touché! As John Bell inquired, "Was the wave function waiting to jump for thousands of millions of years until a single-celled living creature appeare...

Carroll defines what he means by "observation" and "observer" in comments here: In the main post he says: So in this case, the observer is the hot pla...

Yes, one can use diagonalization to produce a number that isn't in the set. Another example is the probability that a randomly constructed computer pr...

Yes, computable numbers. How would we know that such ratios aren't representable? That question seems relevant to the physical Church-Turing thesis (C...

We may still be able to have a precise geometrical representation. For example: So a balanced beam splitter will have a 1/sqrt(2) amplitude for each p...

Any irrational number can be approximated to an arbitrary degree of accuracy by a rational number. From the associated paper: Yes, it is quite differe...

From the MWI side, the claim is that QBism is solipsist and empty of content: The post is of particular interest because Araújo and Pienaar (both phys...

Yes, they were actually shutting up. :-)

Yes, Copenhagen can be understood as the operational interpretation - shut-up-and-calculate. But without the shutting up, as Scott Aaronson likes to s...

I put the question to ChatGPT:

We don't know that science is unable to ascertain it. Note that Deutsch follows Popper. MWI is a conjecture, and the quantum AI experiment that he des...

It's a different philosophical temperament. Deutsch's argument (from the earlier quote) is that, "that attitude involves saying that there are certain...

There's an 'observer effect' in Einsteinian relativity which nobody objects to. That's not the problem. As Deutsch puts it, what we want to understand...

It's similar, and in that experiment Wigner observes interference as predicted by quantum theory (which the paper describes as observer-dependence, si...

Here's the relevant part of the conversation between physicists David Deutsch and Markus Arndt: Essentially, Deutsch's proposed experiment would imple...

You might be interested in Sean Carroll's post on Why Probability in Quantum Mechanics is Given by the Wave Function Squared.