Quantum mystics

One of many over the years, starting with Bohr. Among the others are David Bohm, Fritjof Capra, and Brian Josephson.

They’re distinguished from the mechanistic materialist majority merely by being wrong in the opposite direction.

Almost all physicists make horrible philosophers, some worse than others. It’s an occupational hazard.

When Tommy’s mum doesn’t make him clean up his own room because he’s so smart, Tommy needs an unusually level head to avoid becoming a conceited ass.

Cheers

Phil Hobbs

He did

Sounds like stuff from the "stuff everyone knows" department.

Maybe one of those cases where the presenter has spent so much time at a certain level they overestimate the background of the audience.

Good so far!

Light isn't packaged in discrete photons of measurable energy?

Of course you can't say much about a thing that has never been detected. It's just a rumor.

Do people still say "duh" ?

Most measurements, and the measuring instruments, are defined in advance of the event. Calibrated even.

That's hardly usual, or a reason to call him wrong. He won the Nobel Prize just to get free plane tickets.

Link please? It is impossible to comment without seeing his talk.

It was true when I was an undergraduate and it is still just as true today that if you claim to fully understand quantum mechanics then you don't fully understand quantum mechanics.

It is a bit more nuanced than that. You can certainly show from metal work functions that the energy they carry is quantised and also that for very low photon densities such that only one photon can be in the instrument at a time the diffraction pattern still occurs. That is pretty conclusive evidence that QM is a real phenomena.

Likewise you can get diffraction patterns from silver ions or buckyballs. I'm not sure what the current record mass is today.

We can haggle about mechanism and it is likely that a better theory will eventually come along that is much less "action at a distance" than the QM one we have now. In the same way that GR displaced Newtonian gravity.

Everything that we observe has to be detected somehow. It is possible for systematic errors to creep in. The speed of light with error bars as a function of time is a salutary lesson on that.

The intensity interferometer Hanbury-Brown & Twiss was a canonical example of a QM prediction that almost no physicists believed at the time until they actually made it work at Jodrell Bank. Today they can do long(ish) baseline coherent optical interferometry up to the near IR.

Life gets tricky in relativistic QM but you can still get around it by making the signals travel around loops and/or moving atomic clocks very slowly to each measurement point. 5km long optical fibres are relatively cheap...

"Simultaneous" is only well defined at a particular point in space-time.

I'm not quite sure what he has said that annoyed JB - usually any popular science programme for a general audience dumbs down quantum mechanics to a point where it is completely unrecognisable to professional physicists.

Plug his name into Youtube and his Nobel speech pops up.

I suspect that aspects of this universe, big and small, can never be understood by our brains. We can experiment, confirm, and accept.

The split-beam interferometer was designed specifically to mess with our heads.

The general public tends to be exceptionally mathematics-averse. Even many people with advanced degrees in fields outside the hard sciences tend to be pretty math-averse.

There's a modest subset of the population that's math-averse but is not averse to trying to learn something qualitative about quantum physics or the Riemann Hypothesis or some other mathematical aspect of the hard sciences and enjoy the satisfaction of feeling like they know _something_ more than they went in, even if the details aren't within their grasp.

In contrast to the rather large subset of the population, even people with college degrees, who are OK with not knowing the first thing about such topics, and tend to prefer it that way.

People are different. I like it that way.

Most people don't need much math. Hardly anyone uses algebra, much less number theory or calculus. They manage to buy enough paint for the living room, or enough chickens to feed a family gathering.

Simulation has taken a lot of math out of engineering. I do only primitive algebra and no calculus. We have used some number theory to design DDSs and frequency synthesizers and such.

Absolutely correct. I was ok with mathematics in school until we started on calculus. I could not, and still cannot, understand concepts such as "vanishingly small". I learnt to use the formulae for differentiation and integration and passed my exams, but my eyes clouded over then as far as abstract mathematical concepts are concerned, and they've never cleared! It's quite possible that I have to be able to imagine most things to understand them, and, to me, mathematics is just not within my imagination.

I'm interested in almost anything scientific, even if I can't understand it. Perhaps it's better that way - I don't have to see the wood for the trees!

Calculus is to arithmetic what astrology is to astronomy.

:-)

More years ago than I care to remember I was coming back from the USA in business-class and sitting next to me was a woman dripping with jewellery. She was using a laptop and I could see she was writing horoscopes, from the Leo, Virgo, Scorpio, etc headings on the screen. Under them she was typing the details of each one for the day. Not only was she not referring to anything as to what astrologers might consider relevant for that day and that sign of the Zodiac, but she was cutting and pasting between them at random!

I assumed she was someone well known for writing horoscopes and they were syndicated. It sure seemed to pay well from the jewellery she had!

The talk is this one:

What irritates me is that QM is presented as if it's a great mystery and that no example of an experimental setup is shown, even schematically. That denies the listeners the opportunity to think about it for themselves. His argument using dice is entirely empty of any useful meaning.

Some years ago, I had a closer look at a publication of his: "Quantum imaging with undetected photons", doi:10.1038/nature13586, in which the observed phenomenon was described as some quantum mechanical miracle. While the experiment was certainly not easy to conduct, what was actually going on is trivial to understand, and in classical terms too.

The QM clique doesn't *want* to make things understandable.

Jeroen Belleman

Interesting electronics is nonlinear. I recall some college professor mumbling about solving nonlinear differential equations but it wasn't encouraging.

Having some gut-level feeling for integration and differentiation and diff equations and initial conditions and control theory is good, but Spice can do the actual work.

I taught a course once on dynamic systems. The final assignment was to write a Basic program to simulate refilling a toilet tank after a flush. Surprisingly, everybody got it right.

But photon entanglement can't be explained, or even thought about, in classic-physics terms.

Nor can single-photon interferance.

Just accept and enjoy it.

On 6/10/24 01:56, john larkin wrote: [...]

Was it? I think it behaves exacly like you'd expect from a wave phenomenon observed with quantized detectors.

Jeroen Belleman

It helps if you get exposed to finite differences. In my Ph.D. work I had to do a certain amount of numerical integration, using small but finite steps.

To prove that the steps were small enough, I cut the step size by a factor of three and got an integral that was the same out to five significant digits (and the difference was probably rounding error in the digital arithmetic).

There's no wood without trees.

It saves time. It probably isn't a wise choice.

Rubbish. You can't have astrology without astronomy, but the conclusion astrologers draw from astronomical events are total nonsense.

You can't have calculus without arithmetic, but calculus is just a device that lets you get accurate arithmetic results with less computation. Newton used it exactly that way. Leibniz

Rubbish.

Also rubbish. Most electronics is non-linear, but the interesting stuff does tend to be linear in the regions of interest.

Not encouraging enough to get your attention.

Perhaps.

You kept the course down to a level that you could understand.

I'm not all that math-averse, but a formula is a shorthand notation of some relation, and often it will take some time to parse. If it contains unfamiliar symbols, there is little hope of making sense of it. If someone throws a formula at me that is more than a little involved, I tend to skip over it in the hope that the accompanying text will give me enough context.

Formulas are often enlightening. For a long time, I was puzzled by "forces that drop off faster than 1/r^2". How could that be? It turns out the reason is that whatever transmits the influence

It's not always productive to try to visualize problems. That many mathematical objects may not be within your imagination I don't think is any reflection on you, it's likely the same with many mathematicians.

The mathematical formalism of quantum mechanics is IMO a lot easier to understand and feel like you've learned something from than with classical electromagnetics or any of those wretched spinning top problems from classical physics...much less "introductory" books on general relativity which tend to start out like "It's therefore clear that this bijection of a compact homeomorphism is a subset of a Minkowski fiber bundle..."

With respect to the differential or "vanishingly small" dx in calculus it can also be productive to, instead of trying to visualize what a differential "actually is", look at it from the linear algebra/functional programming perspective. Everything's a function. f(x) is a function. x is a function. dx is a function, and the "dx" function behaves like a linear map as described in the second half of: