Wednesday, January 13, 2021

Physicist argues for Bayesian politics

Sean M. Carroll has a lengthy Mindscape podcast rant about the current American political situation.

His political views are just what you would expect. Typical leftist academic groupthink. I don't have much to say about that. But he claims to be driven by rational scientific thinking. He is essentially lecturing us on how a physicist should view President Trump.

The key is Bayesian analysis. The idea is to develop a healthy and enlightened set of prejudices, which he calls "priors", and then to accept or reject new evidence in the light of those priors.

As an example, he says you should think of allegations that the election was stolen in the same way that you treat the idea that the Moon is made of green cheese. That is, you should refuse to be distracted by evidence about cheese and ballots, and reject the whole thing out of hand as being too far contrary to the accepted worldview.

This is not rational thinking. The Trump allegations are summarized in the Navarro Report. You can read it, and then read a refutation. I cannot find any systematic refutation of the report. That tells me something. Some of the allegations are surely false.

It is possible to hold elections in a much more secure and reliable way. That was not done.

Carroll's soft-spoken demeanor and physics vocabulary give the illusion of reasonableness, but you have to remember that this is a guy who believes that we have no genuine free will, and that every time we appear to make a decision, we are actually witnessing a splitting of the universe into parallel worlds.

While he talks about probabilistic reasoning all the time, as should dominate any Bayesian analysis, his many-worlds view of physics involves extinguishing probability altogether.

If he made arguments this stupid, and then supported Trump, then physicists would start ostracizing him, and getting him banned from social media. But he supports the dominant Leftist agenda, so it's all good.

Tuesday, January 12, 2021

Why free will is beyond physics

Physics World:
Philip Ball argues that “free will” is not ruled out by physics – because it doesn’t stem from physics in the first place ...

If the claim that we never truly make choices is correct, then psychology, sociology and all studies of human behaviour are verging on pseudoscience. Efforts to understand our conduct would be null and void because the real reasons lie in the Big Bang. Neuropsychology would be nothing more than the enumeration of correlations: this action tends to happen at the same time as this pattern of brain activity, but there is no causal relation. Game theory is meaningless as no player is choosing their action because of particular rules, preferences or circumstances of the game. These “sciences” would be no better than studies of the paranormal: wild-goose chases after illusory phenomena. History becomes merely a matter of inventing irrelevant stories about why certain events happened.

I agree with this. If there is no free will, then even physics experiments are dubious because they usually assume from freedom to choose samples and draw statistical conclusions.

Denying free will is madness.

Evolutionist Jerry Coyne attacks Ball here and here, and claims that Physics has disproved free will.

If Physics had somehow disproved free will, then I ask, Where is the published paper with that demonstration? I want to see the assumptions, supporting data, and criticism from others.

There is no such paper, and no such demonstration.

Long-standing disputes about free will and physical law, with their philosophical jargon of compatibilism and libertarianism, have not really advanced our understanding of the problem of determinism since Pierre-Simon Laplace supposed in the early 19th century that he could predict the entire future from total microscopic knowledge of the present.
That's right. The issue is mostly philosophical.

Coyne responds:

Ball accepts the laws of physics as being the underlying basis of all phenomena, and so he is a naturalist (or a “physical determinist” if you will; I’ll simply use “determinism” to mean “naturalism”).
Philosophical arguments often play these games, where someone does some terminological substitutions, and pretends to have proved something.

Sure, I accept the laws of physics as underlying physical phenomena. That is a tautology. But from there Coyne leaps to naturalist, and then to determinist, and then to denier of free will.

Coyne's expertise is evolutionary biology:

Again I assert that, at bottom, the evolution of chimps was “dictated” by the laws of physics: the deterministic forces as well as the random ones, which could include mutations. (I’ve argued that the evolution of life could not have been predicted, even with perfect knowledge, after the Big Bang, given that some evolutionary phenomena, like mutations, may have a quantum component.)

But if Ball thinks biologists can figure out what “caused” the evolution of chimps, he’s on shaky ground. He has no idea, nor do we, what evolutionary forces gave rise to them, nor the specific mutations that had to arise for evolution to work. We don’t even know what “caused” the evolution of bipedal hominins, though we can make some guesses. We’re stuck here with plausibility arguments,

He is less confident about the physics, so he relies on "physicists like Sean Carroll and Brian Greene". They deny free will, and that is good enough for him.

Coyne makes it clear that he relies on Physics to deny free will:

Anthony Cashmore defines free will “as a belief that there is a component to biological behavior that is something more than the unavoidable consequences of the genetic and environmental history of the individual and the possible stochastic laws of nature”.  A simpler but roughly equivalent definition is this one: “If you could replay the tape of life, and go back to a moment of decision at which everything — every molecule — was in exactly the same position, you have free will if you could have decided differently — and that decision was up to you.”

If you pressed most people, you’d find that they agree with these definitions, though the second one is clearer to the layperson. These forms of “libertarian” free will are accepted by many, including of course, those religionists who believe that we are able to freely decide whether or not to accept Jesus or Mohamed as the correct prophet, and if you make the wrong choice, you’ll fry. Only a loony Christian would argue that God would still make you fry if a quantum movement in your neurons made you reject Jesus. No, your “decisions” have to be under your control.

At any rate, physics — naturalism — rules out this type of free will.

So where is the Physics in this argument? Yes, I do believe that I can freely choose Jesus or Mohammad, and that my flesh obeys the laws of nature. Those things seem self-evident. If Physics proves otherwise, I want to see the proof.

Update: Coyne posted a rant the next day on how scientists never rely on faith, as a religious believer would. I would like to agree, but there is no scientific evidence whatsoever for his free will opinions. He claims that they follow from the laws of physics, but he is really just acting on faith.

Thursday, January 7, 2021

The Dunning–Kruger effect

The Dunning–Kruger effect is a favorite of pseudo-intellectual leftists. Wikipedia defines it as:
a cognitive bias in which people with low ability at a task overestimate their ability. It is related to the cognitive bias of illusory superiority and comes from people's inability to recognize their lack of ability. Without the self-awareness of metacognition, people cannot objectively evaluate their level of competence. ...

Colloquially, people experiencing this bias are said to be "on Mount Stupid".

It is used to mock people all the time, without addressing the substance of what they say, such as:
Mr. X says Y, but he doesn't realize that he lacks the competence to say that. It is an example of the Dunning-Kuger effect. Ha, ha. He probably doesn't even know what the Dunning-Kruger effect is. Ha, ha, ha. People with his opinions never do. Ha, ha.
It turns out that it is the jerks who cite Dunning-Kruger who are the dummies, as the effect is bogus. This article explains that it is just a data artifact.

Suppose you measure something in two different ways, each with some error. Simple statistical considerations tell us that the extremes of one measurement are not likely to be so extreme in the other measurement. That was the main thing that Dunning and Kruger found.

In particular, they found that when someone does very well on a test, he often does better than he expected. And when he does poorly, it is often worse than he expected. Using some innumerate mumbo-jumbo, they expressed this as a profound result, as defined above.

Apparently mathematicians and statisticians have been aware for years that the effect is bogus, and yet it continues to be cited by academics, psychologists, social commentators, and even the NY Times anyway.

I know what you are thinking: Aren't the people who cite the Dunning-Kruger effect good examples of the effect? Ha, ha.

There are still examples of cognitive biases, and here is a long list. But citing Dunning-Kruger in lieu of a substantive argument is just a sign of ignorance.

Monday, December 28, 2020

Big players double down on quantum computing

Cnet reports:
For years, quantum computing has been the preserve of academics. New advances, however, are pushing this potentially revolutionary technology toward practical applications.

At the Q2B conference this month, quantum computer makers Google, IBM, Honeywell, IonQ and Xanadu detailed specific steps they expect by 2024 that will push their machines further down the road of commercial practicality. Those achievements include increasing quantum computers' scale, performance and reliability. Private sector spending on quantum computing products and services will likely more than triple to $830 million in 2024, up from $250 million in 2019, according to a forecast from Hyperion Research.

"We're in the early industrial era of quantum computing," said Seth Lloyd, an MIT professor who helped found the field in the 1990s. He says the "huge advances" are comparable to the early use of steam engines to power factories, ships and trains.

There is still no one who can make a scalable qubit, or a quantum computer that speeds up some classical algorithm.
One of the most bullish voices is Eric Schmidt, who in his former job as Google's chief executive and executive chairman approved that company's long-term quantum computing program. That work produced last year's "quantum supremacy" experiment that showed quantum computers could surpass classical computers for at least one narrow (though not practical) computing chore.

"We know this stuff is going to happen six to eight years from now," Schmidt said. "It's going to be incredible when it happens."

Where are those self-driving cars?

That technology has also been a lot slower than promises and expectations. But there are prototypes that prove that self-driving can be done, even if they are not quite reliable enough for commercial use.

We still have no such proof for quantum computing.

Thursday, December 24, 2020

The Marxist critique of Bohr’s alleged idealism

A recent paper on Niels Bohr, objectivity, and the irreversibility of measurements says:
There are three reasons (listed by Catherine Chevalley [15]) why Bohr seems obscure today. The first is that Bohr’s views have come to be equated with one variant or another of the Copenhagen interpretation. The latter only emerged in the mid-1950’s, in response to David Bohm’s hidden-variables theory and the Marxist critique of Bohr’s alleged idealism, which had inspired Bohm.
It is curious. For decades, Bohr was considered the authority on the orthodox interpretation of quantum mechanics. So much so that it was called Copenhagen. He is the one physicists who pointedly refuted Einstein, and everyone at the time was convinced that Bohr was right and Einstein was wrong.

At some point it became fashionable to badmouth Bohr. They didn't say that he was wrong, but vehemently argued that he didn't make any sense. He became "obscure".

How could he be so right that the textbooks copied him for decades, and yet others say that he was unintelligible?

Here we have an explanation: David Bohm’s hidden-variables theory and the Marxist critique of Bohr’s alleged idealism.

Wow, I thought that physicists were much too hard-headed to be swayed by the mystical ramblings of Bohm, and certainly not influence by a "Marxist critique"! But there you have it.

I have been suspicious that there is some subversive political or mystical ideology behind pilot wave theory and related matters. This confirms it. 

The above paper also has some interesting things to say about irreversibility. Maybe I will revisit that later.

Merry Christmas.

Monday, December 21, 2020

Physics does not predict rigid trajectories

Free will is mostly a philosophical issue, but some of the arguments are subject to scientific analysis. Jerry Coyne writes:
The fact that articles keep coming out assuring us that we do have free will, yet each assurance is based on a different premise, tells us that the philosophical debate will never end. Yet I consider it already ended by science: we do not have libertarian free will because our thoughts and our actions are decided by the laws of physics and not by some numinous “will” that interacts with matter in ways that physicist Sean Carroll has said is impossible. Ergo the appearance of compatibilists, who admit that yes, determinism rules, and at any one moment we can behave only one way—a way determined by physical law—but nevertheless we have other kinds of free will compatible with determinism.

That, of course, won’t satisfy the majority of people who do believe in libertarian you-can-do-otherwise free will, among these the many religionists whose faith absolutely depends on our being able to choose our path of life and our savior, and your salvation depends on making the right choice (Calvinists and their analogues are an exception). Compatibilists, when they tell us that nobody really believes in libertarian free will, are simply wrong: surveys show otherwise, and there are all those believers.

No, this is just wrong. The laws of physics are not so deterministic as to rule out libertarian free will.

I recently criticized Sean M. Carroll on free will.

Coyne is responding to this essay:

We need not think about the fundamental laws of physics as rails directing reality along a rigid trajectory. Rather, we can think of them as constraints on what kinds of physical transformations are possible and impossible. ...

Famous ‘free will sceptics’ like Jerry Coyne and Sam Harris are rightly worried about ditching the concept of physical determinism. In their view, the only alternative is a mysticism allowing for all kinds of silly miracles and supernatural beings. ... we still live in a universe governed by timeless, fixed laws — it’s just that these laws do not dictate by themselves how exactly the future will unfold.

..., we don’t need to accept the notion that the universe evolves according to some predetermined plan, set in stone from the beginning of time. Our best theories of physics don’t require it, and our best ethical, psychological, and political theories must reject it.

The essay refers to this 2014 paper for theoretical support. That paper is sympathetic to many-worlds theory, which is another can of worms.

Regardless, it is true that the laws of physics impose contraints on motions, and not rigid trajectories.

In a freshman physics textbook, you might see an exercise that calculates the trajectory of a cannonball, and that may seem to have infinite precision. But that is just the simplified freshman version. If you apply the laws of physics properly, you find that the forces, masses, and other parameters can only be known to be in some range of values, and the predicted trajectory is really a contraint on a range of possible trajectories.

Calvinists and academic atheists aren't the only exceptions to believing in free will. So do Moslems, and a lot of Protestant theologians.

Friday, December 18, 2020

Latest Quantum Supremacy claim starts to crumble

Scott Aaronson backtracks on quantum supremacy. After telling us for years that Gil Kalai was wrong to be skeptical about quantum supremacy, he now admits that one of Kalai's criticisms turned out to be correct.

There are now two high-prestige publications claiming quantum supremacy. Aaronson was the referee on both, and thus he got to decide that these papers were worthy of the claim.

Here is the game. Some quantum researchers do a complicated experiment, and then declare that it would be hard to simulate. But no one is particularly interested in simulating it, and we don't know how hard the problem is.

An example of a hard quantum problem is protein folding. Proteins naturally fold in milliseconds, but researchers have spent decades trying to find algorithms to predict foldings. If the protein were a quantum computer, then Aaronson would say that it has acheived quantum supremacy.

Except that Google DeepMind may have just cracked the problem. This work is very exciting, and may be worthy of next years Nobel Prize in Chemistry. They did not use quantum computers.

So it does not show quantum supremacy at all.

Maybe all these quantum supremacy experiments could be simulated by classical computers, if a team of experts spent 30 years finding a good algorithm.

Ultimately someone may find a quantum experiment that is hard to simulate. But in my mind, it won't really be quantum computation unless it computes something like Shor's algorithm that cannot be in reasonable time on a classical computer.

Update: Also amusing is Aaronson's new blog tagline:

If you take nothing else from this blog: quantum computers won't
solve hard problems instantly by just trying all solutions in parallel.

"The Far Right is destroying the world, and the Far Left is blaming me!"
The first part has been there for a while, and it refers to the facts that nearly everyone describes quantum computers as trying solutions in parallel, but they have never been shown to do that.

The new part refers to him agreeing with 95% of the Leftist agenda, but that makes him seem like a right-winger in today's academia.

Monday, December 14, 2020

Free Will v. Insanity

If somebody said that he hears voices in his head, or that he has a twin that no one can see, or believes in an invisible world, then you would infer that he is schizophrenic, or suffers some similar mental illness.

If somebody believes in Heaven, Hell, angels, and devils, and prays to an invisible god, you would infer that he is religious, but not crazy.

But what do you make of somebody with an advanced scientific degree who believes:

* You have identical twins in distant universes.

* Our world is just a simulation, running on a computer in a more advanced civilization.

* The universe constantly splits into parallel universes, where every possibility is played out for real.

* All events have been pre-determined, from the first second of the Big Bang.

* We have no free will, and all actions are controlled as with a robot or puppet.

All these things seem like symptoms of mental illness to me.

Another tipoff is having crazy ideas about randomness. Insane people sometimes think that nothing is random, and every coincidence is a manifestation of some bizarre conspiracy of causes. Or they think that randomness is one of the fundamental forces in the universe, disrupting everything. Either way, the insane man is troubled by imaginary demons that are sabotaging his life.

So how am I supposed to think about respected physics professors who believe in this crazy stuff? I do not have a good answer for this.

I have reviewed some debates on free will, from respected professors. I think that they are all insane. I wonder how they can even function in their daily lives with such peculiar beliefs.

As an example, see Sean M. Carroll's most recent podcast. He is pretty good at explaining physics, but he also believes in a lot of wacky stuff. He believes in the many-worlds multiverse. He claims to believe in free will, but he also believes in a deterministic multiverse. At 2:10:40, he gets a question about free will and determinism. He concedes that our branch of the multiverse may not be deterministic, but he adamantly argues:

There is a question about whether or not the laws of physics are deterministic or indeterministic, but that has zero to do with the question of free will. The strong sense of free will, the libertarian sense of free will, has to do with whether or not you personally can violate the laws of physics, just by thinking about it. And I don't think that's true, but whether or not it's true, has nothing to do with whether the laws are deterministic or indeterministic.
This is just nutty on multiple levels.

What does he mean by "laws of physics"? He includes many-worlds multiverse, even tho it makes no predictions and has no relation to reality. It is just a fantasy game, where he pretends that all possibilities are happening in some parallel universe. He does not include strong or libertarian free will, as he thinks that means willing a law violation.

If a law of physics is violated, then it is not really a law of physics. Defining free will as a violation does not solve anything.

Part of his problem is that he is always talking about what is "fundamental" or not. Some laws of physics are, and some are not. Some are emergent. Many of these opinions are based on what he thinks will be in some hypothetical Final Theory, from which all else will be derived.

My personal opinion is that consciousness and free will are real, and consistent with the laws of physics. We may or may not get better theoretical understandings of them in the future, but personal experience today convinces me of the nature of consciousness and free will. It is not contrary to any known law of physics.

But Carroll says free will has zero to do with determinism. He doesn't believe that he has any ability to make any choices, as they are all determined. There could be parallel universe branching to confuse matters, but that does not affect his view that all his choices are just illusions.

Elsewhere in the podcast, he explains his belief in eternalism. The present time is just another illusion, and all times are equally valid. Our minds just remember the past instead of the future, because entropy is increasing in the brain.

I think that Carroll would be considered insane, except that he is also able to explain coherently a lot of textbook physics.

On the subject of what is fundament, the "Ask a Physicist" blog tries to explain Carroll's many-worlds nonsense, without much success, and notes:

Very, very frustratingly, without declaring a measurement scheme in advance, you can’t even talk about quantum systems being in any particular set of states. For example, a circularly polarized photon can be described as some combination of vertical and horizontal states, so there’s your two worlds, or it can described as a combination of the two diagonal states, so there’s your… also two worlds. This photon is free to be in multiple states in multiple ways or even be in a definite state, depending on how you’d like to interact with it. For the world to properly “split” a distinction must be made about how the photon is to be measured, but that isn’t something intrinsic to either the photon or the universe.
It is this sort of argument that makes me doubt whether it is useful to even talk about something being fundamental. Which type of polarization is the fundamental one? It is impossible to say, as each type appears non-fundamental when viewed in the context of the other. You are apt to think one is fundamental if it happened to be explained first in whatever textbook you used.

Much of Physics is this way. Things seem fundamental when explained one way, but there is often an equivalent theory where something else is fundamental. For example, some people think particles are fundamental and fields are derived, while others think fields are fundamental and particles are derived.

Wednesday, December 9, 2020

Einstein plagiarized Kaluza-Klein

A reader named Peter writes:
It is possible that Einstein had some character flaw because totally unnecessarily already after his Nobel prize and when he was more famous than any other physicist before him in 1927 he plagiarized 1926 paper of Oscar Klein that lead to the Kaluza-Klein theory. But he was caught and the editor of the journal forced Einstein to write a statement that everything he showed was done year earlier by Klein.
I did not know that story when I wrote my book, but I am not surprised. Yes, Einstein had a character flaw where he avoided crediting anyone. As Peter says, the Einstein collected works acknowledge that Einstein knew of the Kaluza-Klein work, and deliberately omitted any citation.

Properly crediting Kaluza-Klein theory is tricky. It appears that mathematician H. Weyl clearly understood that you could get general relativity and Maxwell's equations from and appropriate curvature on a 5-dimensional manifold. One dimension is time, and one is electromagnetic phase. Surely others understood this also. However I cannot find where anyone wrote it down clearly until many decades later, where it uses a connection on a circle bundle over a spacetime.

Another example that was new to me was his refusal to credit Gerber for the Mercury precession formula. Einstein claimed to not know that Gerber published the formula before, but even said that he would not have cited Gerber even if he had known.

I mostly judge Einstein for his Physics, not his personal ethics. But it is sometimes hard to figure out what he rediscovered, and what he stole.

Peter also says:

When Einstein derived (did not show details) the superposition of velocities he stated that the operation constitute a mathematic group. Interestingly pretty much the same phrase was in Poincare 1905 paper. Somehow I have difficulty believing that Einstein would use such a cool and fairly modern at that time mathematical concept which obviously was natural for Poincare.
Yes, I agree with that. At best, Einstein was saying that the one-dimensional set of transformations in one direction form a group, as there is no sign that he grasped the significance of all Lorentz transformations forming a group. He likely got the term "group" from Poincare's paper.

Also:

It is interesting that in many textbooks Michelson precedes STR that is present as explanation of Michelson but it never is stated that Einstein did not use or was aware of Michelson. What motivated Einstein work, which experiments?
Historians have debated this, and I have my own theory. I say that Einstein was not directly influenced by any experiment.

Michelson-Morley and other experiments clearly influenced Lorentz's 1895 paper, and Poincare's work. The purpose of Einstein's 1905 paper is just to give an alternate derivation of Lorentz's formulas, and not to give an empirical argument. There was no reason to rely on any experiment directly.

Einstein's comments on this seem confusing, but I think he was simply saying that Michelson-Morley was important to the history of special relativity, but not to his own 1905 paper. Those things are true. They are not confusing if you understand that special relativity had a history before Einstein.

Monday, December 7, 2020

Difference between Mathematicians and Physicists

For the last 50 years, physics has gotten so mathematical that many people view mathematics and physics as two variants of the same field. The star of this view is Ed Witten, who is widely for both his mathematics and physics.

This is mistaken. Mathematics and Physics are not so similar. Yes, they both use numbers and fancy symbols, but here are three big differences.

Proof v experiment. Mathematics is all about what can be proved from the axioms, like ZFC. The mathematician seeks 100% certain knowledge, and settles for nothing less. The physicists gains validation by doing experiments. Truth is just a tentative shorthand for explaining some observations.

Infinity. All the interesting mathematics uses infinities. The concept is essential to everything. There are no infinities in the natural world. While they occasionally crop up in some physics theories, they are not essential to anything, and there is no reason for a physicist to believe in them.

Spin. Mathematicians are like fermions, and physicists like bosons. Each mathematician is like a unique piece to a giant jigsaw puzzle of knowledge. Physicists do not see things that way at all, as they replicate the work of others and are susceptible to groupthink.

These are huge differences. They are so large that I don't think that it makes sense to say that the fields overlap.

Sure, math gets applied to physics, and there are some mathematical physicists who are really mathematicians in their outlook. But mostly, mathematicians and physicists are different animals.

Dr. Bee writes on whether infinity is real:

Infinity and zero are everywhere in physics. Even in seemingly innocent things like space, or space-time. The moment you write down the mathematics for space, you assume there are no gaps in it. You assume it’s a perfectly smooth continuum, made of infinitely many infinitely small points.

Mathematically, that’s a convenient assumption because it’s easy to work with. And it seems to be working just fine. That’s why most physicists do not worry all that much about it. They just use infinity as a useful mathematical tool.

But maybe using infinity and zero in physics brings in mistakes because these assumptions are not only not scientifically justified, they are not scientifically justifiable. And this may play a role in our understanding of the cosmos or quantum mechanics. This is why some physicists, like George Ellis, Tim Palmer, and Nicolas Gisin have argued that we should be formulating physics without using infinities or infinitely precise numbers.

Infinity and zero are everywhere in mathematics, so if you are applying math to physics, they will be there. But they are only mathematically real, and do not exist in the natural world.

Friday, December 4, 2020

Quantum Supremacy claimed again

SciAm reports:
For the first time, a quantum computer made from photons—particles of light—has outperformed even the fastest classical supercomputers.

Physicists led by Chao-Yang Lu and Jian-Wei Pan of the University of Science and Technology of China (USTC) in Shanghai performed a technique called Gaussian boson sampling with their quantum computer, named Jiŭzhāng. The result, reported in the journal Science, was 76 detected photons—far above and beyond the previous record of five detected photons and the capabilities of classical supercomputers. ...

This is only the second demonstration of quantum primacy [supremacy], which is a term that describes the point at which a quantum computer exponentially outspeeds any classical one, effectively doing what would otherwise essentially be computationally impossible.

The article uses "primacy" instead of "supremacy", because of George Floyd. Or maybe Donald Trump or George Washington, I am not sure.

Scott Aaronson brags about it, as they needed to get his approval to call it quantum supremacy. He didn't invent the term, but he owns it now.

Okay, I am going to have to study this. What was really computed?

The setup for boson sampling is analogous to the toy called a bean machine, which is just a peg-studded board covered with a sheet of clear glass. Balls are dropped into the rows of pegs from the top. On their way down, they bounce off of the pegs and each other until they land in slots at the bottom. Simulating the distribution of balls in slots is relatively easy on a classical computer.

Instead of balls, boson sampling uses photons, and it replaces pegs with mirrors and prisms. Photons from the lasers bounce off of mirrors and through prisms until they land in a “slot” to be detected. ...

Even so, she acknowledges that the USTC setup is dauntingly complicated. Jiŭzhāng begins with a laser that is split so it strikes 25 crystals made of potassium titanyl phosphate. After each crystal is hit, it reliably spits out two photons in opposite directions. The photons are then sent through 100 inputs, where they race through a track made of 300 prisms and 75 mirrors. Finally, the photons land in 100 slots where they are detected. Averaging over 200 seconds of runs, the USTC group detected about 43 photons per run. But in one run, they observed 76 photons — more than enough to justify their quantum primacy claim.

It is difficult to estimate just how much time would be needed for a supercomputer to solve a distribution with 76 detected photons—in large part because it is not exactly feasible to spend 2.5 billion years running a supercomputer to directly check it. Instead, the researchers extrapolate from the time it takes to classically calculate for smaller numbers of detected photons. At best, solving for 50 photons, the researchers claim, would take a supercomputer two days, which is far slower than the 200-second run time of Jiŭzhāng.

It appears to me that they didn't compute anything. They just concocted a complicated setup that would be hard to simulate. It is hard for me to see how anything like this could be applied to a useful computation.

But I should study this more before jumping to conclusions. I am still trying to figure out what is so impressive about observing 76 photons in one run.

Wednesday, December 2, 2020

Einstein's God

Nautilus essay:
In 1929, Einstein received a telegram inquiring about his belief in God from a New York rabbi named Herbert Goldstein, who had heard a Boston cardinal say that the physicist’s theory of relativity implies “the ghastly apparition of atheism.” Einstein settled Goldstein down. “I believe in Spinoza’s God, who reveals himself in the lawful harmony of the world,” he told him, “not in a God who concerns himself with the fate and the doings of mankind.”

What that amounted to for Einstein, according to a 2006 paper, was a “cosmic religious feeling” that required no “anthropomorphic conception of God.” He explained this view in the New York Times Magazine: “The religious geniuses of all ages have been distinguished by this kind of religious feeling, which knows no dogma and no God conceived in man’s image; so that there can be no church whose central teachings are based on it. Hence it is precisely among the heretics of every age that we find men who were filled with this highest kind of religious feeling and were in many cases regarded by their contemporaries as atheists, sometimes also as saints. Looked at in this light, men like Democritus, Francis of Assisi, and Spinoza are closely akin to one another.”

So, as Einstein would have it, there is no necessary conflict between science and religion — or between science and “religious feelings.”

Monday, November 30, 2020

Most accurate in the history of science

New paper:
Quantum Electrodynamics (QED) is considered the most accurate theory in the history of science. However, this precision is limited to a single experimental value: the anomalous magnetic moment of the electron (g-factor). The calculation of the electron g-factor was carried out in 1950 by Karplus and Kroll. Seven years later, Petermann detected and corrected a serious error in the calculation of a Feynman diagram; however, neither the original calculation nor the subsequent correction was ever published.Therefore, the entire prestige of QED depends on the calculation of a single Feynman diagram (IIc) that has never been published and cannot be independently verified.
If this is really the most accurate and impressive prediction in the history of science, you are probably thinking that the theorists and experimentalists worked independently. Nope.

The theorists, who did it wrong, knew about the experimental value they were supposed to match. And they matched it, but the experimental value was wrong. The theoretical value happened to be also wrong in the same way. Then the experiment got redone to give a more accurate value, and an embarrassing disagreement with theory. So the theoretical value was redone, with this knowledge, and the new theoretical value matched the new experiment. The details were never published.

I have heard of experiments being cooked to match the theory. The history of this seems to be the opposite.

Friday, November 27, 2020

Bohm and his groundbreaking ideas

I just got an email (ie, spam) saying:
If you are considering a gift to a family member or a friend this THANKSGIVING, why not consider the gift of David Bohm and his groundbreaking ideas. Bohm’s ideas are an enduring gift to mankind, enabling a paradigm shift for the transformation of self and society.

PURCHASE GIFT
The recent and current political events taking place in the United States and the Covid-19 pandemic has given us all time to reflect on the vulnerability of our Political, Economic, Spiritual and Social structures. David Bohm’s enduring answers to mankind’s big questions opens a door to coherence, wholeness and interconnectedness. We just need to pay more attention!

So once again we want to THANK YOU all so much for your support and encourage you to share INFINITE POTENTIAL with family, friends and those who you feel would appreciate the gift of Bohm.

Wow, is that a reference to Pres. Trump challenging the vote count in several states? That and some flu-like virus are supposed to make me purchase a movie about David Bohm and give it to a friend for Thanksgiving?!

Let us be clear about his groundbreaking ideas. He believed in (1) Communism; (2) determinism; and (3) spooky action-at-distance. Each of these is fundamentally wrong, and we should be happy that we live in a world where they are wrong. The world would be a depressing place if any of these were correct.

But do they "opens [sic] a door to coherence, wholeness and interconnectedness"? I don't know what there nuts are even thinking, and I watched the movie. I post this in case anyone else wants to try to figure it out.

For more reading, try his biography, or philosophical essays. I previously posted a link to the movie, but it has been taken down.

Wednesday, November 25, 2020

The dark state is erased

Mikhail Gromov, one of the greatest living geometers, once wrote:
This common and unfortunate fact of the lack of an adequate presentation of basic ideas and motivations of almost any mathematical theory is, probably, due to the binary nature of mathematical perception: either you have no inkling of an idea or, once you have understood it, this very idea appears so embarrassingly obvious that you feel reluctant to say it aloud; moreover, once your mind switches from the state of darkness to the light, all memory of the dark state is erased and it becomes impossible to conceive the existence of another mind for which the idea appears nonobvious.
This is actually a common view among mathematicians, but only mathematicians. It is one of the things that makes Mathematics difficult for outsiders.