Response To an Editorial About Understanding Quantum Theory and Defining the Laws of Physics (theguardian.com) 46
John Charap, Emeritus professor of theoretical physics, Queen Mary University of London and Norman Dombey Emeritus, professor of theoretical physics, University of Sussex, writing at The Guardian: Your editorial on quantum physics starts with a quote from Richard Feynman -- "nobody understands quantum mechanics" -- and then says "that is no longer true." One of us (Norman Dombey) was taught quantum theory by Feynman at Caltech; the other (John Charap) was taught by Paul Dirac at Cambridge. Quantum theory was devised by several physicists including Dirac, Erwin Schrodinger and Werner Heisenberg in the 1920s and 1930s, and Dirac made their work relativistic.
It is absurd to say that quantum mechanics is now understood whereas it was not 50 years ago. There have of course been advances in our understanding of quantum phenomena, but the conceptual framework of quantum physics remains as it was. The examples you give of nuclear plants, medical scans and lasers involve straightforward applications of quantum mechanics that were understood 50 years ago. The major advance in the understanding of quantum physics in this period is a theorem of John Bell from Cern, which states that quantum physics cannot be local -- that is to say that it permits phenomena to be correlated at arbitrarily large distances from each other.
This has now been demonstrated experimentally and leads to what is known as quantum entanglement, which is important in the development of quantum computers. But even these ideas were discussed by Albert Einstein and coworkers in 1935. The editorial goes on to say that "subatomic particles do not travel a path that can be plotted." If that were so, how can protons travel at the Large Hadron Collider at Cern and hit their target so that experiments can be performed? We agree with Phillip Ball, who wrote in Physics World that "quantum mechanics is still, a century after it was conceived, making us scratch our heads." There are many speculative proposals in contention but none have consensus support.
It is absurd to say that quantum mechanics is now understood whereas it was not 50 years ago. There have of course been advances in our understanding of quantum phenomena, but the conceptual framework of quantum physics remains as it was. The examples you give of nuclear plants, medical scans and lasers involve straightforward applications of quantum mechanics that were understood 50 years ago. The major advance in the understanding of quantum physics in this period is a theorem of John Bell from Cern, which states that quantum physics cannot be local -- that is to say that it permits phenomena to be correlated at arbitrarily large distances from each other.
This has now been demonstrated experimentally and leads to what is known as quantum entanglement, which is important in the development of quantum computers. But even these ideas were discussed by Albert Einstein and coworkers in 1935. The editorial goes on to say that "subatomic particles do not travel a path that can be plotted." If that were so, how can protons travel at the Large Hadron Collider at Cern and hit their target so that experiments can be performed? We agree with Phillip Ball, who wrote in Physics World that "quantum mechanics is still, a century after it was conceived, making us scratch our heads." There are many speculative proposals in contention but none have consensus support.
Okay then (Score:4, Insightful)
I find it rather weird that a newspaper / news website contained an editorial regarding quantum mechanics in the first place.
Re:Okay then (Score:5, Funny)
The probability of a newspaper publishing an editorial on quantum mechanics is non zero. He did not publish a scientific paper proving this. It was from his private communications archives. In 1933 after delivering his acceptance speech for his Nobel Prize, he was heard muttering, yeah, any time now the newspapers are going start writing editorials about quantum mechanics, but don't hold your breath.
Re:Okay then (Score:5, Funny)
Don't come after me if you laboriously go through the entire pdf without finding any reference to the incident I mentioned. Chalk it up to you living in a different quantum universe than me.
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If I had mod points, this post definitely made me chuckle.
Re: Okay then (Score:1)
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I can't find the article even though I know its velocity precisely.
Re: (Score:1, Troll)
The Grauniad thinks it can tell you what you should be believing today, about anything.
And the blathering woke idiots who read it love to be told.
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People at The Guardian seem to have a desperate, existential need to declare every unknown known to man "understood."
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There's a popular attitude towards quantum mechanics that verges on magical thinking. We think we understand it, but we don't. But we, as a culture engaged in bizarre conspiracy theories, new ageism, mysticism, quackery, and so forth, like to use quantum theory to explain our pet ideas. The eminent fraudster, Deepak Chopra, is a notable example here of misusing quantum mechanics.
Quantum theory is like physics. You cannot say you understand it IF YOU CANNOT DO THE MATH! We don't even undstand gravity y
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There's a popular attitude towards quantum mechanics that verges on magical thinking. We think we understand it, but we don't. But we, as a culture engaged in bizarre conspiracy theories, new ageism, mysticism, quackery, and so forth, like to use quantum theory to explain our pet ideas.
I wish I'd taken a picture of this quote of some nobody that was posted on an ex-landlord's wall. It talked about how if they weren't careful, focusing on negative thoughts could send them into a different quantum state. I didn't know whether to laugh or cry.
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You cannot say you understand it IF YOU CANNOT DO THE MATH!
Indeed the math is quantum theory, and anytime
you try to describe it using words like "particle", "wave",
"uncertainty" or "teleportation", you are bound to confuse
people who are unfamiliar with physicist jargon.
Which is practically everyone.
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I think the point is that even the people who can do the math don't understand it. I took graduate courses in advanced QM, solved all the problems, but still don't understand how a piece of quartz "knows" not to let a photon through when it's polarised the "wrong" way.
If you put two polarizers, i.e., pieces of quartz, at 90 degrees to each other, send some light through them, nothing comes out. Why? The first one only lets light through with, say, vertical polarization, and none of that gets through the nex
Simple (Score:1)
It's half-ass cats all the way down.
Penrose et. al. (Score:2)
There's been some steady progress, neither done nor just begun. Penrose, in particular, did both spinors and objective reduction based on gravitation. More on that is being done in tapping vacuum energy for work in biological systems.
Understood? (Score:4, Interesting)
CERN (Score:3)
Isn't it CERN [wikipedia.org] (all-caps acronym)?
Editorial couldn't even avoid mangling the letter from these scientists.
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Language evolves. LASER is a proper acronym, but almost no one writes it with full capitalization. NASA is correct, but its written usage is evolving.
Superdeterminism (Score:3)
In Superdeterminism Bell's theorem does not apply.
https://arxiv.org/pdf/1912.064... [arxiv.org]
https://www.youtube.com/watch?... [youtube.com]
Re:Superdeterminism (Score:4, Interesting)
Superdeterminism is a cop-out. It's basically equivocating the entire universe to following a script. Sure, perhaps, but there's zero predictive or intuitive power in that.
People don't listen to Feynman (Score:5, Insightful)
They may have attended his classes, but it isn't like he endorsed them as some sorts of Apprentices on whom his name wore off until they understood everything.
I've listened to his lectures, I've read his memoirs; he didn't talk about, "the general public doesn't understand quantum mechanics." He was saying, professional physicists don't understand quantum mechanics and also that the human brain cannot generate an intuitive understanding of quantum mechanics. You have to do the math for each thing you want to know about, and focus on developing an intuition for math and math mistakes. And then you can calculate the results, which you have to trust. But experience will not generate intuition.
These physicists are just as stupid as the ones that were brilliant enough to work alongside Feynman. But unlike Feynman, they won't admit the limitations of the human brain, they want to be more exceptional than everyone else, even the guy whose name they want to rub off on them.
"subatomic particles do not travel a path that can be plotted." If that were so, how can protons travel at the Large Hadron Collider at Cern and hit their target so that experiments can be performed?
After starting out well, the moron goes off the rails here. Lacks basic critical thinking skills. They arrange things so the probability of hitting the target is very high. That doesn't mean you can plot the path; quantum theory requires calculating the probabilities of all the possible paths; those paths are all possible. Possible is possible. This guy refuses to believe that, simply because the experiment was designed so that the probable paths would land in the right spot. That exact paths cannot be plotted is why the results are entirely statistical.
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Surely 'plotted' can also mean laying out a graph of probabilities? A statistical diagram can be plotted, and that would surely help 'arrange things so the probability of hitting the target is very high'. So the path can be plotted, just not as a single fixed path.
Also, I did not get he impression he was arguing with Feynman at all. He was arguing with the article and the suggestion that they just didn't understand it back then but we do now. If anything he was supporting Feynman (although there's nothing e
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No, a Feynman Diagram is not a plot.
And I'm sure wasn't intending to argue with Feynman, he probably just didn't know what Feynman actually said about people not understanding. He probably read the quote as excerpted and reprinted at the start of a chapter in some book. People with letters next to their names rarely notice that Feynman was talking about them. Feynman was saying that Feynman cannot understand quantum mechanics intuitively, and neither can anybody else. He was explaining that he was doing goo
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He was saying, professional physicists don't understand quantum mechanics and also that the human brain cannot generate an intuitive understanding of quantum mechanics.
Yes, pretty much. And that is as true today as it was back then.
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After starting out well, the moron goes off the rails here. Lacks basic critical thinking skills. They arrange things so the probability of hitting the target is very high. That doesn't mean you can plot the path; quantum theory requires calculating the probabilities of all the possible paths; those paths are all possible. Possible is possible. This guy refuses to believe that, simply because the experiment was designed so that the probable paths would land in the right spot. That exact paths cannot be plotted is why the results are entirely statistical.
I think you're going way too far calling him a moron. What have you ever done for physics??
Anyway, it seems they are looking at it from different perspectives. The Guardian is probably talking about things like double-slit experiments, where the path information is spread out, while the physicist is taking what was said as an absolute statement, so also other cases.
And yes, there are many paths that can be plotted (usually a straight line), because all the other possible paths cancel each other out in the p
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I respect your low user ID, but please pardon me if I don't entertain your random conjectures as being quite as relevant as a renown physicist who has spent much of his career working with notable geniuses.
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Thanks, I'll stick with Feynman and ignore this whoever guy. I'm sure his coworkers are great, too.
dumb dumb dumb.. (Score:1)
Get off my ... damn. (Score:2)
There's a joke about a grumpy old physicist and a quantum lawn here, somewhere, but I can't find it...
bleah. (Score:4, Interesting)
I hate how the popular media takes scientific discovery and somehow always conclude that "everything is relative" and "there are no facts".
Or perhaps that's exactly how the popular media views the world. Scary.
We scientists know better.
I understand quantum mechanics (Score:2)
and simultaneously do not understand it. Whether you find that I understand it depends on how you test me.
Something fundamental is missing (Score:2)
That is pretty obvious. The current "Quantum Computing" hype bullshit is not helping. (No, with what we currently have and understand, we will _never_ get quantum computers that have any use for computing. That means that either something fundamental is missing or that we will _not_ get QCs of meaningful power.)
Old Prof. Simpson. (Score:2)
Locality & causality (Score:2)
".... which states that quantum physics cannot be local "
Acually it cannot be both local and causal in the strict sense. It could be local and retrocausal, or causal and nonlocal.
Charap forgot... (Score:2)
Charap forgot the first fundamental theorem of polemics: don't argue with fools.
Lemma: Journalists are invariably ignoramuses.
Do a Search on "Quantum Physics Humor" (Score:2)
It'll make you feel much much better, I promise.