You could at least acknowledge the divergence between some classic views of recent decades, and ideas like decoherence and MW, and even the way you talk about it, that are not orthodox in terms of those previous views.

That there are disagreements among genuine quantum physicists about the interpretation of QM is old news. This might well last another thousand years. But when you spam this blog with endlessly regurgitated comments about the “stupidity” and “hypocrisy” and “repellent emperor’s new clothes” of anyone who believes that decoherence can look like a collapse, you’re just showing your ignorance; every quantum physicist, whatever interpretation they favour, understands and accepts that this is the case. I’m actually entirely agnostic about the MWI, but I’ve studied enough QM to know what decoherence is. (There was a time when I did not understand what it was. At that time, I did not rush around telling everyone who did that they were fools and hypocrites.) Instead of dismissing my example as irrelevant, you might want to contemplate this: whenever those “hits” you are so enamoured with take place, the particle in question is interacting with a great many other particles in the screen or detector, none of which are accessible to detailed quantum experiments by the observer. Having seen what happens in the simplest case — when a particle is correlated with one other particle, to which we temporarily deny ourselves access — and noting that that gives the appearance of a collapse, you shouldn’t be surprised that having no access to billions of particles correlated with the one of interest has the same kind of effect. But to actually reason about this in detail, you need to go and learn about density matrices and observations on sub-systems, not just wave your hands and waffle about the philosophical issues that you imagine somehow trump everything else.

You flatter yourself with the notion that you are engaged in some kind of Socratic dialogue here. The reason almost nobody responds to your thought experiments in GR is because they’re so steeped in misconceptions and misapplied concepts that it’s obviously going to be a massive, thankless job trying to disentangle your delusions about the subject. Yes, it’s obvious that you’ve glanced at some academic papers, textbooks and Wikipedia articles on GR, but the result of you nibbling around the edges is that you’ve acquired some buzz-words and a formula or two, but none of the fundamentals of the subject: you just keeping trying to jam Newtonian, or at best special-relativistic, pegs into GR-shaped holes. If you actually had an interest in gravitomagnetism, why is it that you hadn’t even read the warning at the start of the Wikipedia article you cited on the subject that stated that this model only applied to slow-moving particles? That kind of oversight and misapplication isn’t the exception with your comments on this blog, it’s the pattern shared by almost all of them.

I know it’s a daunting prospect to study GR systematically outside an academic setting. Nobody’s blaming you for not knowing the subject. What’s exhausting and offensive about reading your comments is that you either don’t grasp that there are basic things you simply don’t know, or you expect people here to fill in all the gaps for you by responding to an endless stream of really dumb questions — many of which are posed as “Hey, looks like you experts don’t really understand anything, because I can come up with this scenario that shows that your theory means black equals white!” Like a customer complaining that the screwdriver you bought is really bad for opening cans of soup, there’s only so much of that kind of thing that anyone’s patience is going to bear. As a newby to this blog, I’ve done my stint of pointing out to you what screwdrivers are good for, and how much a can-opener will set you back. I’ll leave it to other newbies, and the occasional saint or masochist, to keep trying to hammer that message home.

I get the clear impression that what I’ve said about collapse for example really was the orthodox way to talk about it until a recent sort of revisionism (based on not *wanting* to accept the apparent intractability of the collapse problem>) You could at least acknowledge the divergence between some classic views of recent decades, and ideas like decoherence and MW, and even the way you talk about it, that are not orthodox in terms of those previous views. Remember finally that I am making Socratic digs more than final arguments. Sometimes, as per the planar field question, you make a clear specific response, and other times, as per collapse issues, I don’t think you do. As for issues like multiple universes and the anthropic principle, you should realize that everyone, amateur gadfly or real physicist, are blind men poking at an elephant.

I should have singled out Feynman as the exception, of course. I re-read QED recently, and it’s just stunning the way he manages to make it all accessible, but he keeps a conscientious list of all the simplifications, keeps reminding the audience when he’s cutting corners, and comes back to dot most of the i’s later.

it also cripples the ability to connect statements via reasoning

Absolutely. All the user-friendly maths-free metaphors are provided with the best of intentions, but unless some substantial aspect of the reality is isomorphic to some non-trivial degrees of freedom of the metaphor, you don’t have a tool for deducing anything — but you might believe you do. The science blogosphere is clogged with the consequent frustration and delusions.

Nice job on comment #58.

Even a lot of pop science written by good physicists is full of misleading statements that will confuse lay people who try to pursue the subject further. It’s a pity — but get over it, and recognise that if you want to learn real science, you’re going to have to throw away half of what you’ve convinced yourself you know.

Have you seen Feynman’s comments on this problem in The Character of Physical Law? He argues the point quite well, I think, emphasizing the problems which happen because popularizations leave out the mathematics. This makes the statements of individual ideas vague, of course, but it also cripples the ability to connect statements via reasoning. (The lectures on which that book was based used to be on Google Video, until a lawyer noticed — more’s the pity, really.)

As I have told many of you before, you don’t always get the semantics issues. (I still think you don’t appreciate how we should *talk* about the fall of bodies relative to “floors” in falling reference standards, and the implications thereof.) Studying lots of science won’t ensure that you do.

And studying absolutely no science ensures that you mistake your notions of “correct semantics” for some kind of insight into actual phenomena. Once you’ve learned the mathematics that unambiguously describes the predictions of GR and QM, then you can start sensibly debating how those predictions should best be discussed in plain English. At present, you just take a drizzle of pop-science factoids, combine it with what you imagine is philosophical and linguistic rigour, and generate a half-baked “critique” of ideas you don’t actually understand at all.

I was hoping you at least had the high-school level trigonometry and calculus to analyse the geodesics on a sphere and come to grips first-hand with the consequences of non-Cartesian coordinates that are causing you so much angst in GR, but apparently hell will freeze over before you actually test your intuitions against even the simplest real examples.

The very existence of “a pattern” [of little "hits"] instead of eternal continuous waves is just what I and basically everyone else mean by “collapse”

“Everyone else”? That there are more people who have learnt to emit cocktail-party-level bluff about QM from crappy popularisations than people who’ve actually studied the theory is beside the point.

I’ve only been reading this blog a short time, but in that time virtually all your hundreds of remarks about scientific matters have derived from the fact that you’ve read some half-baked version of a theory, found it wanting (a good thing), but then decided that you’re wedded immutably to the misconceptions you’ve already acquired, and that all the discrepancies are really down to lack of what you so charmingly call “linguistic hygiene” by professional scientists.

Yes, pop science books are full of crap. Even a lot of pop science written by good physicists is full of misleading statements that will confuse lay people who try to pursue the subject further. It’s a pity — but get over it, and recognise that if you want to learn real science, you’re going to have to throw away half of what you’ve convinced yourself you know.

Just look at this sentence of yours:

In other words, you get exactly the pattern you’d expect from photons only passing through a single slit at a time.

The very existence of “a pattern” [of little "hits"] instead of eternal continuous waves is just what I and basically everyone else mean by “collapse” of the wave of each photon – ending up in a certain place, regardless of higher-level interpretations. BTW what do you think of the Afshar experiment? It raises issues similar to what you bring up.

As I have told many of you before, you don’t always get the semantics issues. (I still think you don’t appreciate how we should *talk* about the fall of bodies relative to “floors” in falling reference standards, and the implications thereof.) Studying lots of science won’t ensure that you do.