However both can be 4.Neither true nor false. Doesn't that establish logical equivalence? — TheMadFool

In symbolic logic, we say that two well-formed sentences, call them A1 and A2, are logically equivalent iff A1--> A2 and A2-->A1.

'Well-formed sentence' is a precise property that means the symbol string meets certain well-defined syntactic requirements that are part of the symbolic logic language L. Different languages will have different requirements.

Since the definition of logical equivalence relies on the definition of well-formed sentence, which relies on the language L, we see that logical equivalence is only meaningful relative to a specified language. That is, when we say that A1 and A2 are logically equivalent, we actually mean they are logically equivalent in symbolic language L (which we can call the 'reference language').

Because the majority of symbolic logic is done in first-order predicate logic (FOPL), it is reasonable to assume that if L is not explicitly specified, a suitable form of FOPL is implied as the reference language.

We can extend the notion of logical equivalence to a natural language N as follows.

Two symbol strings S1 and S2 are logically equivalent in natural language N, relative to logical language L, iff all of the following are true:
1. there exist well-formed sentences A1 and A2 in symbolic language L such that most people that understand both N and L would agree that S1 means the same as A1 and S2 means the same as A2

2. In L, A1-->A2 and A2-->A1

As per the above, we can leave out reference to L if we assume it means a version of FOPL.

Under this definition, questions, commands, expletives and meaningless sentences cannot be logically equivalent to anything because they are not equivalent to any well-formed sentence in FOPL.

Similarly, the liar sentence does not have the same meaning as any well-formed sentence in FOPL and hence cannot be logically equivalent to anything - but, having been away, I don't know whether the discussion has moved beyond that sentence.

In logic we have no way of distinguishing ''what is yor name?'' from ''how old are you?'' These two are the same so far as logic is concerned. Likewise logic can't find a difference between ''this statement is false'' and ''this statement is neither true nor false''. Therefore they are logically equivalent. — TheMadFool

With my definition of logical equivalence, that is not the case. Neither sentence is logically equivalent to anything.

Yet, I'm disinclined to judge Thomas based upon how Jesus responded to him. — Heister Eggcart

The response: "You believe because you have seen me. Blessed are those who believe without seeing me"

You need to put that reaction in context. It was written by the author of that Gospel. We have no reason to believe that it was actually said by Jesus. I am almost certain it wasn't, because it's such a ridiculous piece of nonsense and most of the sayings attributed to Jesus are pretty good value.

Apart from anything else it's self-refuting. The person who believes Jesus resurrected just because some random person told him that will believe the next random person that comes along and tells him the first person was lying and that Jesus was a purely mortal prophet, and Muhammed is the only guy with a direct line to the almighty. Then they'll believe the next person who comes along to tell them that Quran business is all lies and Joseph Smith is The Man, and we need to follow the Book of Mormon.

Believing without good evidence is nearly always a harmful thing to do. Among the wrongs it causes are lynchings, mob violence, revenge killings, unnecessary marital breakup and friendship breakup. Just think about all the vicious gossip you've ever heard. Would it be good to believe that without evidence?

Given the reaction attributed to Jesus is so stupid, why would the writer(s) of John's Gospel put those words into Jesus's mouth? Because they were writing sixty years after Jesus's death, so their target audience had never even met Jesus. They wanted people to believe the amazing claims in their Gospel, despite having no first-hand evidence of its veracity, so they put in that chain-letterish ruse to make people feel that they would be especially holy if they believed everything this Gospel said.

I thought I heard somebody once say that St Thomas is the patron saint of scientists. But when I Google it, all I find is that apparently St Albert the Great has that honorable title. So maybe I made up that idea myself. I certainly think Thomas should be the patron saint of scientists. He was the only one that one could respect in that story. The rest carry on like a bunch of hysterical schoolkids.

Anyway, listen to Hanover or Charles Murray — Emptyheady

No, don't.

Listen to somebody who (a) cares about you and (b) knows what they're talking about.

Am I just being a pussyfoot or should I stick to my very rewarding minimum wage job at a nursery (which I find ideal) and live happily with my mother? It's not a bad life, sleep wake work eat sleep, repeat. — Question

'Pussyfoot' is a meaningless concept based on the mistaken notion that people are under some obligation to achieve big things with impacts that reverberate around the world. I blame this notion on the Parable of the Talents, which I find one of the meanest, most vindictive parables in the new testament (it's as if it were written by a Trump speechwriter or a Rand acolyte, although I doubt Trump has ever read it).

Also, there is nothing wrong with living with your mother. Leaving one's parents at an early age is a modern development. Until recently, people didn't leave until they became partnered and started their own family. In fact, earlier still, people lived in tribes based on extended families, so they didn't really leave even then. In non-AngloSaxon cultures (Chinese and Greek come immediately to mind) young people still tend to live with family until they start their own. So forget the faddish 'must leave as soon as I finish uni or I'm bad' nonsense.

Having dispensed with all that puerile 'must be manly and independent' nonsense, you can now turn to the only question that matters: what will make you, and others happy? The usual reason to reach for something more difficult and risky despite the fact that it is more uncomfortable in the short term is the realisation that staying with the current comfort will make you unhappy in the long term - that you will become bored with your job or that you will start to chafe under the financial constraints of low pay. Whether that is the case depends on your psychological makeup, which only you and those that know you well can judge. So reflect, talk to others that know and care about you. Maybe even see a counsellor who, although they will know you less well, can bring professional expertise and experience to the task.

Society needs people with high ambition and people with low ambition and all the ones in between. Remove any segment and it will collapse. The trick is to work out where you can most happily fit. As soon as anybody 'advising' you starts to make personal criticisms, stop listening.

When Davies says there is an asymmetry, he is thinking of the laws as being prescriptive, rather than descriptive. Prescriptive laws tell processes what they must do, as opposed to descriptive laws, which simply describe what they do.

Hence If we think of laws as being Prescriptive, as Davies does, then the laws affect the processes but not vice versa. On the other hand if we think of the laws as being Descriptive, the processes affect the laws, but not vice versa (the patterns in the processes determine what the laws are).

And lo, the symmetry is recovered.

Consider that I give a ring to my wife-to-be. What does that mean?

If you smash it, what have you smashed and what have you not smashed? — Agustino

A ring? Good choice!

It is not possible to mock a ring. At least, I have never seen a ring mocked, and cannot imagine how one would do that.

Nor do I think it could be smashed. I think the only way for the would-be smasher to destroy it would be for them to make their way to the cracks of Doom at Orodruin, and cast it in there.

- synthetic conditional : a conditional whose consequent is not contained in its antecedent
- analytic conditional : a conditional whose consequent is contained in its antecedent — Real Gone Cat

The question is what does 'contained in' mean? The question cannot be resolved because in Kant's time - and it was he who was so terribly insistent on the synthetic/analytic distinction - logic was not sufficiently well understood to allow a clear definition of what that means. So we cannot know how he might have attempted to define 'contained in' using the more precise modern tools.

A natural approach would be to say that 'contained in' means that the antecedent is a conjunction of propositions, one of which is syntactically identical to the consequent. In that case we may or may not be able to say that:

(1) IsBachelor(x,t) -> IsUnmarried(x,t)

is analytic, where IsBachelor(x,t) means 'x is a bachelor at time t'.

Here are two logically equivalent, but syntactically different, possible definitions of the atomic formula IsBachelor(x,t):

(2) IsUnmarried(x,t) & IsAdult(x,t) & IsMale(x,t) & IsAlive(x) & IsHuman (x,t) & (for all t') (t'<t -> IsUnmarried(x,t'))

(3) IsAdult(x,t) & IsMale(x,t) & IsAlive(x,t) & IsHuman (x,t) & (for all t') (t'<=t -> IsUnmarried(x,t'))

With interpretation (2), the proposition (1) is analytic, but with interpretation (3) it is not, because the consequent of (1) does not appear in (3).

The prohibition of worshipping another god is a way of insisting on loyalty to the tribe. Different tribes had different gods and, according to the book, the Hebrews were bent on conquering other tribes in the region. Worshipping a god of one of those tribes would be seen as a pathway towards sympathising with them, and hence doubting the fairness of killing them to take their land. So it makes sense for the authorities to ban it.

The second one is a clever strategy to make their own totem seem superior to, and less vulnerable than, those of other tribes and hence to further enhance patriotism. It is easy to mock a god with an image by defacing its statue, dressing it up in silly clothes, jeering at it, or even just smashing it. If the god has no statue, one cannot do that.

'Nothing matters very much. And very few things matter at all.'

I don't remember who said that, but somebody did, and it has always stuck with me.

Yes, when it's a million ravens it becomes almost obvious. I wonder what underlies this. I'm trying to formulate it in terms of statistical hypothesis testing.

The usual approach is to have a 'null hypothesis' that some parameter is zero (eg the impact of a certain drug on the chances of curing a disease), and then assess the probability of having observed the data we did if that hypothesis were true. If the probability of that observation is small enough, we reject the null hypothesis and conclude, with a stated level of confidence, that the parameter is nonzero.

Here, say we let the parameter be the proportion p of ravens that are not black. the trouble is that the null hypothesis that we wish to challenge via evidence is that p>0. I don't recall if there is a way to do that, as the hypothesis testing I've been involved with always involves a null hypothesis that the parameter of interest is zero.

What we could do is pick a value of p, say 1%, and make our null hypothesis be that p>1%. Then, given enough observations of black ravens, and none of non-black ones, we can reject that null hypothesis at a high level of confidence. That is, we can be very confident that the proportion of ravens that are non-black is less than 1%.

But I can't see any way of gaining any level of confidence that the proportion is zero. Perhaps somebody that has done wider and more varied hypothesis testing can comment.

Michael, you're right that this is the problem of induction. It never occurred to me before to wonder whether any statistical basis could be found for using the principle of induction, by considering it in terms of hypothesis testing. If not, that seems to lend even greater weight to Hume's insight.

The thinking is that if a black raven is supporting evidence that all ravens are black (not proof, note), then by the same token a green apple is supporting evidence that all non black things are non-ravens. — unenlightened

Yes, I can readily accept that statement. What I'm having trouble with is finding a reason to believe the antecedent - that observation of a black raven is evidence for the proposition that all ravens are black. It is conclusive evidence for the proposition that SOME ravens are black, but I can't see why it should be any evidence at all for the ALL proposition.

I'm having trouble seeing why a green apple is evidence that
(forall x) (not black x) --> (not raven x)

Prima facie, it seems to be no evidence at all, since the claim is universal, and a single datum doesn't help us with the universal.

But I wonder if Bayes' Law can help us. Using P(A) to indicate the probability of A, and | do denote the conditional, we aim to prove that P(Black | Raven) =1, ie Probability that something is Black, given that it is a raven, is 1.
This is the same as P(~Black | ~Raven) = 1.

Now Bayes Law tells us that

P(~Black | ~Raven) = P(~Raven | ~Black) P(~Black) / P(~Raven)

Say we start with guess probabilities that there half the things in the world are ravens, and half of the things in the world are Black, and the two properties are independent (eg so that half of Ravens are Black), then observing a green apple will .................... aaargh, this seems to be leading to a dead end, and I'm late for work so I'm giving up for now.

I have a feeling that Bayes Law can somehow be used to interpret the observation of the green apple as evidence for the hypothesis, but right now I'm not getting there.

Can anyone see a way to make that argument, either using Bayes Law or something else.

If we can't make the interpretation then there's no paradox.

I imagine that to answer this one need only look at how a retiree, who has a reasonably comfortable pension, spends their time.

My impression is that some enjoy their retirement, doing further education, gardening, volunteering, craft and other hobbies, visiting friends and relatives, and travel. But some find the psychological transition to retirement an ordeal, and feel like they are going mad with the time hanging so heavy on their hands.

Perhaps a post-work world would be like a world full of retirees, only they'd be younger on average.

Russell interprets (4) in expanded natural language as something like the following:

- There exists a person that is currently king of France
- If anybody is currently king of France then they are the same person as the one mentioned in the previous point
- that person is bald

This can be symbolised in First-Order Predicate Logic as

∃x (IsKingOfFrance(x) ∧ ∀y(IsKingOfFrance(y) → y=x) ∧ IsBald(x))

There is no need for second-order logic or set theory in this case.

I don't know what 'The F is G' means either. Can you give a concrete example, using natural language predicates that people would understand - like 'is a mammal' and 'is an animal', rather than letters like F and G?

The equivalent to (3) in second-order logic is just (3). Since it can be expressed in first-order logic, no translation is required.

(1) says that there is exactly one object (x) that satisfies unary predicate F.
(2) says that there exists some unary predicate (X) for which there is exactly one object (x) that satisfies it, and that object also happens to satisfy unary predicate F.

The sentences are not equivalent. In particular, the second statement does not say that only one object satisfies F. It could be the case that there is a different unary predicate G that is satisfied by exactly one object a, and that Fa is true but so is Fb for some b not equal to a.

What is the statement you are trying to encode? 'There is the F' doesn't mean anything to me, and hence cannot be rendered meaningfully in either natural language or formal logic.

Who is Charles Murray and why should anybody outside his friends and family be interested in anything he has to say?

There seems to be very little acceptance of Marquez's 'Epistemic' argument for conservatism, and I certainly am completely unpersuaded by it.

What I don't understand is why he thinks a new argument for conservatism is needed. There are plenty of good arguments around for conservatism, going back to Edmund Burke and beyond. That's provided we interpret conservatism as simply meaning 'giving the benefit of the doubt to existing laws, practices and institutions, so that an onus of proof lies on those that wish to have change'.

Etymologically, that's what 'conservative' means. It's only in the bizarre world of US politics that it has come to mean things like wanting to enforce Christian morality on people, denying anthropogenic global warming, opposing immigration and wanting to wind back labour laws and environmental protections.

It's perfectly possible to be a 'conservative' in the etymological or Burkean sense and yet be a pinko, atheist, commie, greenie liberal on the majority of issues of public debate.

Conservatism of that type is simply a practical way of managing public policy. It doesn't need fancy words like Epistemic to justify it.

Hello Darkaristotle. I think the problem is that the issue you are concerned about was incorrectly described in your original post. In that post you said

An interviewer asks a scientist, who personally engages in spiritual practices in the comfort of his own home, what the definition of spirituality is? — Darkaristotle

That conjures up images of the scientist meditating, praying, doing pujah, or maybe even having seances. It doesn't suggest anything about 'spiritual healing'.

But then in your latest post you say this

The question was asked if techniques of a spiritual nature (Spirituality) should be prescribed by Doctors that claim to use evidence based medicine? — Darkaristotle

which conjures up images of the sort of 'healing' that televangelists do.

The latter is viewed very negatively by the majority of the scientific community. The former is nobody's business but the scientist involved.

The only people I have ever seen ask what the definition of a word is are children that have encountered a word they do not know, and want to learn about it. Unless the person asking the scientist the question was a child, I expect what they wanted the scientist to do was tell them what the word 'spiritual' meant to him, the scientist - in which case the scientist gave an entirely appropriate answer.

Well in fact, under that criterion, not only does a God exist (you didn't specify which one) but almost every god ever conceived exists, because they (or the idea of them) have all had an effect on people.

If philosophers can't agree on whether a person instantiated in a human body today is the 'same' person as the one that was instantiated in that body yesterday, it's hard to see any prospect for making sense of whether different people's notions of a deity are the 'same' deity.

Per David Chalmers - A verbal dispute.

Slavery.

This post used to be much longer, until I saw that unenlightened and csal have already eloquently covered this obvious test case. So all that remains to say is (again)

Yeah. Slavery.

I don't regard Intelligent Design as a credible argument, but I find Amio's argument unconvincing. She sets herself too hard a burden of proof by conceding that (1) the world was created and (2) that intention played a role in there somewhere. Consider her last sentence (emphasis added by me):

'The precision of the Universe doesn’t guarantee that it was not created by an accident.'

An 'accident' is something that happens contrary to the intention of the agents involved. So by suggesting that the world was 'created by accident' she is conceding that there was some sentient entity in some way 'prior' to the existence of the world, and that that entity did not intend to create the world, or at least did not intend it to turn out the way that it did. Such a position is borderline incoherent. I certainly wouldn't want to have to defend it.

Yes, I wondered about Fire, and the wheel (there's also Sliced Bread, as in 'the best thing since...'). Really by pencil and paper I mean writing, by whatever form, and I suppose the printing press is a later evolution of that. I suppose clay tablets with cuneiform inscriptions from a stylus may be the first ones do you think?

I'm happy to give ground to anybody that thinks Fire is more important (or maybe even spoken language - although I wonder whether some might class that as an evolved ability rather than an invention). I just love writing and drawing on paper with pencils, is all. :D

If I'm understanding you correctly, you're surmising that the way that an algorithm is implemented matters to the outcome, as well as the abstract nature of the algorithm itself.

If so, I agree wholeheartedly.

Also, I'm delighted that you used pencil and paper, which I think is still the greatest technological innovation that our species has accomplished.

Let's take the example of cheap flights, mentioned in the song. .... In Marx's time my forebears were poor uneducated rural labourers..... It's unlikely they ever set foot outside Britain and Ireland. But here I am now in sunny Spain, having been to several countries in several continents — jamalrob

This is a point in which I'm particularly interested. I wonder a great deal about whether people are generally happier now than they were say 150 years ago. Travel can be fun, but is happiness dependent on it? More importantly, to me, the perceived intensity (novelty value?) of the travel one does is a function of how different the culture one visits is from that in which one habitually lives. Might it be the case that someone hiking to the next county in 1867 rural England would experience more intense novelty - more genuine travel - than someone flying from London to Benidorm in 2017? Put another way, do we in 2017 really think we would be any happier if we could to Mars or Proxima Centauri?

What is the limit beyond which we should not have gone? — jamalrob

Indeed, that's the billion dollar question, and one that greatly interests the more thoughtful economists. Few would contest that developments that greatly improved public health like the discovery of immunisation have also improved net happiness. And few would contest that the 'invention' of the iPhone 8 makes no difference at all to net happiness. But there's an enormous no-mans-land between the two, somewhere within which lies a boundary. Unanimous agreement, or even a strong consensus, on where that boundary lies is impossible. But only the Trumps of the world would deny that there should be some boundary. Even the USA (for now, at least) places some limits on what limited liability corporations are allowed to do.

I have a hunch - based on nothing but anecdotal evidence and vague impressions - that most of the innovations that improved quality of life were not products of capitalism. Many of them arose in universities or other government-funded research institutions, or were discovered by individuals operating solo - rather than by people working for corporations.

In addition, capitalism wasn't really possible in the way we understand it today until the creation of an ability to form limited liability companies, which did not happen in the UK until 1855. Even companies with non-limited liability wasn't possible until around 1600, and they could only be created by royal charter until the passing of the 1844 Joint Stock Companies Act.

Most of the technological innovations that make a genuine improvement to net happiness arose before that. Many innovations since then improved happiness, but I think they were mostly political and social - things like emancipation, universal adult suffrage, labour laws and tolerance for minorities. Such innovations arise usually under opposition from capitalism rather than with its support.

Just curious if any of the folks who are against showering, deodorant, brushing their teeth, etc. have at least one romantic partner. — Terrapin Station

Yes. In fact I often rely on my romantic partner to know when to shower, if I haven't had one for several days. She has a more sensitive olfactory sense than me, so she can tell me if I need one.

Did you know that the main thing one is washing off when one showers, and which smells if left a long time, is dead skin cells? The build-up of those over a day or two is not enough to create a discernible odour.

Also, do you folks clean yourself including your hands after you go to the bathroom, or is that an evil plot against you in your view, too?

Now, now. Don't pretend that you don't understand the difference between the reasons for washing the hands after defecating, which are based on hygiene and are scientifically uncontroversial, and the reasons for daily showering, which are purely based on advertising and unexamined compliance with social norms.

The other issue I was trying to bring to your attention is the nature of the time-energy uncertainty relation. Some may say that this uncertainty relation is just a form of expression of the Heisenberg uncertainty, but it is impossible that these are the same uncertainty because time and energy are not canonically conjugate variables. — Metaphysician Undercover

Quite right, they are not the same uncertainty and, as far as I know, Heisenberg had nothing to do with the time-energy relation. The explanation of the relation in Shankar is just a hand wave, not a mathematical derivation. When I looked it up in my hard copy I found some scathing comments I had written about it at the time I read it, which is probably why I dismissed it from my mind and didn't remember it.

I have not studied the time-energy relation and so do not know whether it can be deduced from the bare postulates. My pencilled comments on the text indicate a suspicion that other, non-core, assumptions are being used. But because the Shankar presentation is so lacking in detail, one cannot be sure of that.

So the question is what is the relationship between these two distinct uncertainties, the time-energy uncertainty, and the Heisenberg uncertainty. .......... There's a Soviet paper, by Mandelshtam and Tamm, (Journal of Physics, vol. 9 no. 4, 1945), entitled "The uncertainty relation between energy and time in non relativistic quantum mechanics" which is quite descriptive. — Metaphysician Undercover

According to wikipedia, those are the people that invented that relation, and published it in that paper. One would have to read the paper to find out what assumptions it uses, and I have not read it.

I suspect the time-energy uncertainty relation is not very important anyway since (1) it only appears in a short appendix to the Shankar chapter on uncertainty relations and (2) while the wiki article on Heisenberg highlights his uncertainty principle (for complementary observables) as the discovery for which he is best known, the energy-time relation is not directly mentioned in the articles on its discoverers, Mandelshtam and Tamm.

No, that's not what he was arguing for. Binney stated several times that the probabilistic nature of the value obtained was due to our epistemic uncertainty about the exact quantum state of the measuring device, and not anything fundamental about the state of the particle prior to being measured. A little reading up on HMI reveals that this particular interpretation understands probability to be entirely epistemic (our ignorance or inability to measure everything accurately) and not ontological or fundamental. — Marchesk

That's fine. I am sympathetic to everything you report him as saying there, and it's a widely held interpretation. All I was concerned about was whether he was rejecting either the postulates of QM, or results derived from them alone, such as the Heisenberg Uncertainty Relation. It is now clear that he was not. Questions of whether certain things are epistemological or ontological are matters of pure interpretation, since the postulates make no distinction between the two.

In your later post you said Binney said people shouldn't take the QM postulates literally or realistically. I can agree with that too, because it also is about the interpretation, not the calculation. He's not saying we shouldn't believe the predictions they make, which are purely about observations. I do not subscribe to the ontological perspective sometimes known as 'Realism' - but which I think of by the (IMHO) more accurate title 'Materialism'. I lean towards Bohr rather than Einstein.

At the beginning of the talk I linked to, Alan Bar introduced the measurement problem for the audience, then Simon Saunders argued for MWI, followed by James Binney discussing HMI, I guess, although he didn't give his interpretation a name. The Youtube title is: "The 1st Ockham Debate - The Problem of Quantum Measurement - 13th May 2013". — Marchesk

Thank you, that clarifies it nicely. Given that it's about the 'measurement problem', the references to uncertainty will have nothing to do with the Heisenberg Uncertainty Relation and instead will refer to the lack of knowledge prior to measurement about which of the eigenvalues of the ket of the observed system will be the result of the measurement.

Discussion of that issue involves interpretation, not just core QM, as is indicated by the letter 'I' at the end of the two abbreviations 'MWI' and 'HMI'. So it would appear that the people involved are debating interpretations and not challenging the postulates of QM, or deductions therefrom like the Heisenberg Uncertainty Relation, which would have been a worry.

But what does the operator operate on? — tom

Good question. The rough answer is that it 'operates on' kets. A more mathematically pure answer is that the name 'Hermitian operator' is simply a formal label for an element of a subset of H x H (the Cartesian product of the Hilbert space with itself) that obeys certain properties (functionality, linearity, Hermiticity), so we don't have to think of it as operating on anything.

Except when a measurement is made according to 3. — tom

Quite right. I forgot to add that bit.

None of this [postulate 3] is a necessary axiom to do quantum mechanics though. Why not drop it? — tom

You're right that there's no need for it in the context of a discussion about the 'measurement problem' (which I'm guessing this thread is somewhat related to, but I'm still very unsure of that), as Decoherence gives us all we need (I think). But in applied QM it is very useful as it removes the need to think about the measuring apparatus.

I like your questions. This one touches upon an important issue. When we say there is a unique ket for each physical state, we are saying that the relation between physical states and kets is a 'function', as that word is technically understood in mathematics. That means that any physical state can only have one associated ket. It does not, however mean that two different physical states cannot have the same ket, and that's where your point about complete descriptions comes in. For any two different states to necessarily have different kets would imply that the ket is a complete description of the physical state. The postulates of QM do not claim that the ket is a complete description. Claims of completeness or otherwise of the kets are either interpretations of QM, or part of theories that seek to extend QM. They are not part of core QM.

If the ket is a complete description then the function that maps physical states to kets is one-to-one ('injective' is the technical term). If it is not complete then the function is many-to-one, like for instance the functions f(x)=x^2 and g(x)=sin x.

I didn't completely grasp all of your question, but I answered it as best I could. Let me know if I left anything out.

The measuring device is the source of uncertainty in these experiments. — Marchesk

The sentence is way too vague to be considered a claim. 'Uncertainty' could mean any of several very different things, each of which involves a completely different discussion. The statement reminds me of some of the debating topics we used to have, when there was a (mercifully temporary) fashion to set deliberately vague topics in order to make the debates less predictable. A favourite was 'The end is nigh'.

Just to pick up one of the possible meanings, if 'uncertainty' refers to the probabilistic nature of the value obtained from the measurement, as assessed prior to the measurement, and based only on information about the observed system and not the measurement apparatus, then that agrees with the Decoherence theory, which is widely accepted. If that's what was meant then the prof is not saying anything controversial, or new, at all.

That's entirely dismissive and not a good counter argument. — Marchesk

I'd go further: it's not a counter-argument at all, because no argument has been presented to counter.

I like the wording in section 9.4, "Applications of the Uncertainty Principle". You will find this: "Now the hand waving begins. — Metaphysician Undercover

Brilliant pick-up MU! I love it. I'd never noticed it before, as I only skimmed the rest of the chapter once I'd worked through the derivation of the uncertainty relation (item 9.2.14 in the Second Edition). It perfectly exemplifies what I'm saying. Section 9.2, in which the uncertainty relation is derived, is two pages of pure maths. As the chapter goes on, he starts to discuss interpretations and consequences of the relation that rely on more assumptions and approximations than are justified by the bare postulates. That's where that quote you found comes in.

As for the postulates, here's a rough attempt to give them in prose:

1. To any possible state of a system (collection of particles) there corresponds a unique set of information about it, called a 'quantum state', which is uniquely represented by a mathematical object called a 'ket' which is part of a collection of such objects, called a 'Hilbert Space'. [Later on, this is generalised so that kets are replaced by operators, in order to allow for non-pure states, but we won't worry about that here]

2. To every aspect of the system that can be measured as a number - called an 'observable' - there corresponds a unique mathematical object called a 'Hermitian operator'

3. If a system is in state s, to which corresponds ket S, and a measurement is made of observable m, which corresponds to Hermitian operator M then, immediately after the measurement is made, the particle will be in a state s' whose associated ket has the mathematical property of 'being an eigenket of the Hermitian operator M', and the value observed from the measurement will be a number that is 'the eigenvalue of that eigenket'. Further, as assessed prior to the measurement, the probability of the state after the measurement having ket S' is proportional to the square of the 'inner product' (another maths term) of S with S'.

4. The ket associated with a system evolves over time according to a known differential equation, called Schrodinger's Equation.

Yes, I have no idea what he is saying, let alone what he meant to say. I am suspicious of all prose presentations of QM. QM is mathematics and needs to be presented as such. As soon as a significant amount of prose enters the picture it becomes an interpretation. I know what the uncertainty principle is as a mathematical inequality, derived straightforwardly from the postulates. If someone wants to characterise it as more than that then they are doing interpretation, regardless of whether they realise that.

I'm not going to criticise Prof Binney though because I haven't watched his video, just as I don't read designs for perpetual motion machines or proofs that one can trisect an angle. I don't need to because I know it either doesn't say what people think it does, or it is wrong.

sounded to me like he was denying that the Uncertainty Principle was fundamental instead of a useful approximation based on epistemic limitations. — Marchesk

I expect he just expressed himself poorly - not an unusual occurrence for scientists trying to communicate to a non-scientific audience. The Uncertainty Relation is derived directly from the four postulates of quantum mechanics, with no additional assumptions*. It doesn't get more fundamental than that.

By the way, of the list you gave of weird things about QM - 'indeterminism, ... pilot waves, ... non-locality, ... other worlds, ... weird collapse' only one - non-locality - is potentially implied by bare QM - ie by the postulates. The others are implied only by interpretations such as Copenhagen, Bohm or Many Worlds.

As for non-locality, whether that is implied by bare QM depends on how we define locality. If we restrict it to observables - ie interpret it to say that one observation can only affect another observation in its future light cone, then bare QM does not contradict locality - even with Bell, Aspect etc. It's only if we define locality to mean that unobservables - in particular, quantum states - also cannot be affected outside of the future light cone, that bare QM, in conjunction with Bell and Aspect, implies non-locality.

* See for example Chapter 9 of Shankar's 'Principles of Quantum Mechanics'.

The problem is that we can't measure the exact state of something made up of many particles, because that would involve an enormous number of measurements. — Marchesk

Even if we could make enough measurements simultaneously to know the exact state of a system, it would not dispel uncertainty.

It is a common misconception that the 'state' of a system is a specification of the exact value of every observable of the system - location, momentum, spin, energy, etc. But the Heisenberg Uncertainty Principle - which is core QM, not interpretation - tells us that for any pair of dual observables - of which position and momentum are the most commonly cited - a state that has a narrow range of possibilities for one of the observables must have a very wide range of possibilities for the other. This has nothing to do with the practical ability to make measurements and is instead based on what 'state' means in QM. It is a purely theoretical, mathematical result. To reject that result we would have to radically alter, or even jettison, QM, not just choose another interpretation.

However, I wonder whether what your physicist was actually referring to was the notion of Decoherence, which is a fairly intuitive (some might say 'pseudo-classical, but one has to be careful using vague terms like that) way of explaining what happens in a measurement of a quantum system. The reason I think he might be referring to that is the reference to the interaction between the state of the observed system and the state of the measuring apparatus, which is what Decoherence addresses.

I certainly hope not. I adore Angela Merkel.