Civilization was inspired by Astronomy

Thought experiment:

Imagine that over the last 11 thousand years (that is, the period of stable climate following upon the last ice age which allowed the human civilisation to develop)the atmospheric conditions on Earth were different: the skies were always covered, even in the absence of clouds, by a very light haze, not preventing the developmentof agriculture, but obscuring the stars and turning the sun and the moon into amorphous light spots. Would mathematics have had a chance to develop beyond basic arithmetic and geometry sufficient for measuring fields and keeping records of harvest? I doubt that. Civilisations which developed serious mathematics also had serious astronomy (it was an equivalent of our theoretical physics). But I claim even more: the movement of stars in the sky was the paradigm of precision andreproducibility, the two characteristic features of mathematics. Where else could humans learn the concept of absolute precision?

I agree with that. Without astronomy, we would not have much civilization today.

Trusting CDC to be science-based

From a Time magazine article, a year ago:

As the new coronavirus COVID-19 spreads in the U.S., people who are well want to stay that way. But since no vaccines are currently available, the strongest weapons Americans have are basic preventive measures like hand-washing and sanitizing surfaces, according to the Centers for Disease Control and Prevention (CDC).

The simplicity of those recommendations is likely unsettling to people anxious to do more to protect themselves, so it’s no surprise that face masks are in short supply—despite the CDC specifically not recommending them for healthy people trying to protect against COVID-19. “It seems kind of intuitively obvious that if you put something — whether it’s a scarf or a mask — in front of your nose and mouth, that will filter out some of these viruses that are floating around out there,” says Dr. William Schaffner, professor of medicine in the division of infectious diseases at Vanderbilt University. The only problem: that’s not effective against respiratory illnesses like the flu and COVID-19. If it were, “the CDC would have recommended it years ago,” he says. “It doesn’t, because it makes science-based recommendations.”

The science, according to the CDC, says that surgical masks won’t stop the wearer from inhaling small airborne particles, which can cause infection.

Remember this, next time you are told to trust the experts at the CDC.

Maybe the CDC was right that the masks were useless. The evidence for masks is dubious. I am not sure myself. But the official CDC recommendations don't seem to be any better than common-sense judgments from the average person.

Hard Science Journals have gone Leftist

Respected publications that used to stick to hard science are increasingly politicized.

The American Institute of Physics (AIP) published:

Gun violence rises in TV dramas over two decades, paralleling US gun homicide trends

. Historian Clayton Cramer points out that US gun homicides did not increase over the same period.

Scientific American currently has articles on Human Genetics Needs an Antiracism Plan and Trans Girls Belong on Girls’ Sports Teams. These articles advocate extreme leftist political positions that even most leftists would have rejected several years ago.

I would not mind this so much if the journals would occasionally publish right-wing views. But they do not. It is all Leftism, all the time.

Cashing in on the Quantum Hype

A quantum computing company is going public:

IonQ has entered into a definitive merger agreement with dMY Technology Group III (NYSE: DMYI.U)
IonQ To Become The First Publicly Traded Pure-Play Quantum Computing Company

Scott Aaronson is getting concerned about the unbound money and enthusiasm compromising the legitimate science:

What’s new is that millions of dollars are now potentially available to quantum computing researchers, along with equity, stock options, and whatever else causes “ka-ching” sound effects and bulging eyes with dollar signs. And in many cases, to have a shot at such riches, all an expert needs to do is profess optimism that quantum computing will have revolutionary, world-changing applications and have them soon. ...

As some of you might’ve seen already, IonQ, the trapped-ion QC startup that originated from the University of Maryland, is poised to have the first-ever quantum computing IPO — a so-called “SPAC IPO,” which while I’m a financial ignoramus, apparently involves merging with a shell company and thereby bypassing the SEC’s normal IPO rules. Supposedly they’re seeking $650 million in new funding and a $2 billion market cap. If you want to see what IonQ is saying about QC to prospective investors, click here. Lacking any choice in the matter, I’ll probably say more about these developments in a future post.

Meanwhile, PsiQuantum, the Palo-Alto-based optical QC startup, has said that it’s soon going to leave “stealth mode.” And Amazon, Microsoft, Google, IBM, Honeywell, and other big players continue making large investments in QC—treating it, at least rhetorically, not at all like blue-sky basic research, but like a central part of their future business plans.

I think that this is obviously a bubble, as none of these efforts have any reasonable chance of making money in the foreseeable future. But when it might burst, I cannot say.

Tesla Motors and GameStop also seem like bubbles. But they at least sell products successfully.

In June 2019, quantum computing progress was said to be doubly exponential. That is, the exponent is another exponent. If that were true, then these companies would be cashing in already.

Aaronson hints that he might be selling out himself. I would say that he is a fool if he does not cash in somehow. These bubbles/opportunities do not come often.

Update: The Aaronson blog generated these comments:

[Tamas V] I teach intro-level courses on QC, and once a participant mentioned that quantum computers could be used by fortune tellers. You can create a nice story, e.g. “nobody in the universe knows what the result of measuring a |+⟩ state in the computational basis will be… so it must be God’s way of giving you advice when I run this and that quantum program, because God is beyond our universe…”. And this can be done even with today’s devices, but not with pseudo- or classical randomness! Now it’s your part to convince the believers that God has nothing to do with the results

This example made me think that there might be some early unexpected commercial applications of QC, it’s only a matter of imagination…

[Scott] The problem with the fortune-telling “application” is not what you think it is. It’s that there a quantum random-number generator (let’s say, a Geiger counter next to a chunk of uranium) is all you need, and that’s been available for more than a century. A quantum computer simply isn’t needed for this.

[Tamas V] OMG, don’t approach it from the scientific side, it’s all about marketing.

1. You cannot *sell* such an idea with Geiger counters. Quantum computers are absolutely necessary, and they also allow the fortune teller to program more complicated/obscure “predictions”.
2. One cannot easily access and program a bunch of radioactive atoms via the cloud.

That could be a metaphor for the whole field. You cannot find anything useful, or sell anything honestly. The whole trick is to present something useless as magical.

Defining Mathematics

New Yorker magazine essay tries to define mathematics:

Mathematicians know what mathematics is but have difficulty saying it. I have heard: Mathematics is the craft of creating new knowledge from old, using deductive logic and abstraction. The theory of formal patterns. Mathematics is the study of quantity. A discipline that includes the natural numbers and plane and solid geometry. The science that draws necessary conclusions. Symbolic logic. The study of structures. The account we give of the timeless architecture of the cosmos. The poetry of logical ideas. Statements related by very strict rules of deduction. A means of seeking a deductive pathway from a set of axioms to a set of propositions or their denials. A science involving things you can’t see, whose presence is confined to the imagination. A proto-text whose existence is only postulated. A precise conceptual apparatus. The study of ideas that can be handled as if they were real things. The manipulation of the meaningless symbols of a first-order language according to explicit, syntactical rules. A field in which the properties and interactions of idealized objects are examined. The science of skillful operations with concepts and rules invented for the purpose. Conjectures, questions, intelligent guesses, and heuristic arguments about what is probably true. The longest continuous human thought. Laboriously constructed intuition. The thing that scientific ideas, as they grow toward perfection, become. An ideal reality. A story that has been written for thousands of years, is always being added to, and might never be finished. The largest coherent artifact that’s been built by civilization. Only a formal game. What mathematicians do, the way musicians do music.

Those are good, but this gets to the heart of the matter:

Mathematicians live within a world that is essentially certain. The rest of us, even other scientists, live within one where what represents certainty is so-far-as-we-can-tell-this-result-occurs-almost-all-of-the-time. Because of mathematics’ insistence on proof, it can tell us, within the range of what it knows, what happens time after time.

I will have to ponder this:

In Book 7 of the Republic, Plato has Socrates say that mathematicians are people who dream that they are awake.

Denyse O'Leary writes:

The Oregon Department of Education (ODE) recently encouraged teachers to register for training that encourages “ethnomathematics,” an education trend that argues, “among other things, that White supremacy manifests itself in the focus on finding the right answer”:

“The concept of mathematics being purely objective is unequivocally false, and teaching it is even much less so,” the document for the “Equitable Math” toolkit reads. “Upholding the idea that there are always right and wrong answers perpetuate objectivity as well as fear of open conflict.” …

An associated “Dismantling Racism” workbook, linked within the toolkit, similarly identifies “objectivity” — described as “the belief that there is such a thing as being objective or ‘neutral'” — as a characteristic of White supremacy.

Instead of focusing on one right answer, the toolkit encourages teachers to “come up with at least two answers that might solve this problem.”

Sam Dorman, “Oregon promotes teacher program that seeks to undo ‘racism in mathematics’” at Fox News (February 11, 2021)

Opponents of the new trend offer varying accounts of its origin — perhaps it results from in changes in overall philosophy of life or perhaps from the practical need to placate teachers’ unions, which may have various objectives apart from enabling numeracy in students. No matter, not only are x and y under attack but so is 2 + 2 = 4.

It is embarrassing how many respected scientists allow this nonsense to persist without saying anything. I am happy to see that physicist Lawrence Krauss wrote a Quillette essay denouncing some of the leftist propaganda:

Social justice activists have been arguing for some time that scientific societies and institutions need to address systemic sexism and racism in STEM disciplines. However, their rationale is often anything but scientific. For example, whenever percentages in faculty positions, test scores, or grant recipients in various disciplines do not match percentages of national average populations, racism or sexism is generally said to be the cause. This is in spite of the fact that no explicit examples of racism or sexism generally accompany the statistics. Correlation, after all, is not causation. Without some underlying mechanism or independent evidence to explain a correlation of observed outcomes with population statistics, inferring racism or sexism in academia as the cause is inappropriate.

One might have hoped for more rigor from the leadership of scientific societies and research institutions. Alas, this has not been the case.

My guess is that other scientists are afraid to say this out of fear that they will be canceled. Krauss only dares because he has already been canceled. His enemies tried to get him fired, based on gossip. I don't know if they succeeded or not.

Anti-free-will pitch from Sam Harris

I posted on the errors of solipsum, including criticism of the free will deniers.

The leading spokesman against free will and religion today is probably Sam Harris. He has been refining his free will argument for about ten years, as he wrote a 2012 book on the subject. He has now posted a podcast with his best argument against free will. If you prefer to read, it is summarized here.

He has a few omissions.

Religion. Harris was a Jewish atheist who converted to Buddhism, and is very negative about Christianity and Islam. This colors everything he says, even though he does not directly mention the Christian notion of free will.

Drugs. Harris spent his college years taking hallucinogenic drugs, and these seem to have permanently altered his brain. He talks about it in other podcasts. The drugs appears to have robbed him of some mental abilities.

Hypnosis. About 5% of the public is highly suggestible to hypnosis, and Harris has described himself as being one of those. That means that he is the type of person that stage hypnotists use to perform silly stunts to show off a lack of will. Harris is also a big believer in using his podcasts to hypnotize his listeners to follow his thinking. He does this in both his "Making Sense" podcast, where he advocates political and other opinions, and his "Waking Up" podcasts, where he more directly asks the listener to meditate on what he says.

Politics. His political views can best be described as Trumpism while denouncing Trump personally and pretending to be a leftist. Harris is anti-Islam, anti-immigration, pro-gun, pro-police, and most all, vigorously against the excesses of the Left. But he seems to lack the free will to say he supports Trump, and has had many podcast guests who severely denounce Trump personally. He appears to mainly associate with Leftists, and not understand right-wingers at all.

Science. Harris denies that is just making a philosophical argument, but he omits any arguments for or against free will from physics, biology, or neuroscience.

Harris's main argument is that when he appears to make a choice, such as naming a favorite movie, he does not feel as he is freely making the choice. It is all determined by voices in his head, or some such mechanism. He feels no sense of self, and always feels like a slave to external forces.

Of course he ends with a pitch for money, and a promise for more enlightenment if you send money. He denies that he is contradicting himself by asking us to choose to donate, because he says that we will have no choice but to do what is right. Furthermore, he says that it is liberating to a slave to reason and logical persuasion, because then you will be a rational being all the time.

If you are still reading this, and had not heard of Sam Harris, you must think that he is some sort of con man.

I believe him. I think he genuinely lacks the free will that most people have. I don't know if he lost it from drugs, or Buddhism, or Leftism, hypnosis, or what. Maybe he never had it. Listening to him is like listening to an advanced AI automaton.

The closest he comes to a scientific argument is where he repeatedly refers to randomness. He has an extremely determinist world view, but obviously someone told him that quantum mechanics is an exception. So he qualifies himself by saying things are determined except for quantum randomness. But he strenuously argues that free will is supposed to come from the self, and a pre-programmed computer cannot be the self, and the random actions of some quantum particles cannot be the self either.

Being a determinist is tough, because we have no scientific theories that are 100% determinist. There are zillions of scientific papers where the outcomes are 95% explained by the data, but never 100%. A determinist might argue that the papers might get 100%, but for experimental error. If determinism were really false, and assuming reductionism, then it ought to be possible to find experiments with purely unpredictable outcomes. Quantum mechanics provides exactly that.

So Harris's argument is like saying human consciousness does not exist because it depends on an autonomous mind, and the brain is made of atoms, and atoms are not conscious. Not much of an argument.

The physics argument is not his main argument. I mention it here because it is the only part that relates to science.

Harris has mostly made his reputation attacking Islam and Christianity, and espousing atheistic rationality. He talks about morals a lot, and pretends that he is taking the scientific rational approach.

I think that attitudes towards free will explain a lot. To most of us, free will is the most directly observable fact about the natural world. And yet our leading Physics popularizers have abandoned it. Scott Aaronson was one of the last holdouts. But now that he has adopted many-worlds theory, he has implicitly dropped free will. After all, a choice causes the world to branch, and each parallel world is equally real, with each copy thinking it made a choice. So no one ever really makes a choice.

Rejecting probability is worthless

As more professors fall for nonsense like many-worlds, I explain the biggest problem. This applies to many-worlds, superdeterminism, multiverse, simulation, and similar theories.

The problem is the same as for solipsism, and were identified two millennia ago.

Nearly all of science works like this. Collect some data, form a hypothesis, collect more data, and construct a theory that makes predictions. The prediction is that, for a set of given conditions, a particular measurement will be observed, with some confidence. The prediction might be: The displacement will be 95% likely to be between 1.4 and 1.5 meters.

There is nearly always a probability involved, even in a supposedly deterministic field like celestial mechanics. It is hard to think of examples that do not fit this pattern. Reader Andrei suggests quantum mechanics predicting that the H2O molecule is stable. Maybe also Darwin's "survival of the fittest". But 99+% of all scientific work involves probabilities.

Many-worlds theory rejects all probabilities. They have no notion of some worlds being more likely than others. Your branch of the wave function is all that is real to you, and all possibilities happen in parallel worlds. The seemingly unlikely possibilities are just as real. Some researchers have arguments for why we might subjectively perceive probabilities, but these arguments are not widely accepted, and do not function as real probabilities anyway.

Superdeterminism also rejects probabilites, for different reasons. It denies that you can even set up a controlled experiment. You might toss a coin 100 times and get 50 heads, and that is no indication of a fair coin. The coin could be weighted to come up heads 90% of the time, but a conspiracy of forces going back to the Big Bang might have forced a misleading statistical outcome. In short, probabilities are meaningless.

Gerard ’t Hooft was one of the top geniuses being the Standard Model, and he has been sucked into superdeterminism. To show how twisted his thinking has become, his latest paper says:

A complete answer to the question ‘what happens in an EPR-Bell experiment?’, is not given here, but we do summarise what, according to this author, the principal weaknesses are in Bell’s argument, which is not the mathematical calculations but the general assumptions, in particular those connected with causality and ‘free will’. ...

All this implies for instance that Alice and Bob have no free will. Not in a deterministic world. For unfathomable reasons, many experienced scientists have difficulties with that.[15]

Really, he cannot fathom why scientists believe in free will? I don't think he is joking, as he has written papers against free will, such as this one. And sure enough, he shows no clue to understanding why anyone would believe in it.

He is so eager to abolish free will that he also abolishes probabilities.

Sean M. Carroll and Scott Aaronson back many-worlds theory, and hence also reject probabilities.

Scott Aaronson writes:

The original papers by Gerard ‘t Hooft on “superdeterminism” were shockingly blase about the absurd implications I mentioned — implications that would mean you could explain basically anything (telepathy, superluminal signaling, etc.) via similar devices, and that physics would be over — and (to their credit) were also clear enough that there was no possible other way to interpret them. None of the other papers I saw about “superdeterminism” showed any inkling of appreciating the enormity of the problem. And none of them contained what I saw as the slightest hint of a promising idea to balance the absurdity.

By the usual standards I apply to anything else, this would be more than enough reason for me to ignore the topic thereafter.

That is all true, but the same is true about many-worlds. Because anything can happen in the parallel worlds and there is no way to say how unlikely those things are, the theory can explain basically anything. And the proponents show no inkling of appreciating that they are rejecting 99% of all modern science, and offering nothing in return.

And I mean literally nothing. There is no paper on many-worlds or superdeterminism that has ever contributed anything to modern science. No paper has made a successful prediction, or even explained how a prediction could be made. No paper has explained anything that we don't already know.

It is as if some smart person announced: Maybe 99% of all science is wrong, and it only seems right because God is performing miracles to trick us.

I cannot disprove such a statement, just as I cannot disprove solipsism. But what is the point? There is no evidence for such thinking. The view has no benefits. It cannot predict or explain anything. And it discards most of the best of human knowledge.

I am flabbergasted at the sloppy thinking of our intellectual leaders.

Update: Andrei writes:

Superdeterminism is a generic concept like “field theory”. Is it possible for a field theory to predict telepathy? Yes. Does it mean that all field theories are non-scientific? Not really. General relativity or electrodynamics are field theories and are universally accepted as science. ... the superdeterministic theory that reproduces QM would not predict telepathy either.

His argument is that someone might construct a superdeterministic theory that reproduces known physics, and so that would be scientific.

No. He could say the same about solipsism, simulation, or anything else that denies reality. Under those theories, no one can do any experiments to test the theory, so there cannot be anything scientific about them.

Scott writes:

Yes, I really believe that belief or disbelief in MWI should have no bearing whatsoever on what risks you’re willing to take in your life. Or to put it differently: whatever about MWI causes you to think it would bear on that, that’s precisely the part you need to discard in order to continue along the Zen path.

He is also denying reality. Under MWI, he has no ability to take risks. If, say, he goes skydiving, he will crash in some branches and land safely in others. MWI has no way of saying which branches are more likely. The concept makes no sense in MWI, as the copy of him that survives will think that he is the real Scott, and nothing bad happened. He also has no free will in MWI, as every apparent choice puts him in a branch, but the opposite choice puts him in another branch and that Scott will think that he made that opposite choice.

All these forms of solipsism are unscientific, and nothing in life makes any sense if you believe in them. Andrei and Scott both pretend that you can adopt these beliefs, and go on with life just as before. You cannot.

Update: Scott responds:

My argument is simply that the superdeterministic theory that does all these wonderful things — e.g., naturally reproduce QM while not superluminal signaling or telepathy — is a nonexistent construct. I personally see no reason why anything like it should exist; at any rate it doesn’t exist at present. But it’s more than that: I don’t accept the framing that this is a “promising research program that just needs more time to succeed.” I’ve seen nothing — nothing — of the slightest scientific interest ever come out of it. I don’t see why anything would, given that

(1) its original motivation was a terrible one (basically, people who didn’t understand the Bell inequality, and then after it was finally explained to them, searched for some arbitrarily exotic way in which they might still be right), and

(2) the “mechanism” they decided on is effectively indistinguishable from magic — it’s just that you arbitrarily declare that this magic is only for violating the Bell inequality, and not for any of the more interesting things that magic would seem able to do once you introduce it into the universe.

I agree with all that, but the same could be said for many-worlds and the other solipsist theories. In particular (1) MWI was motivated by people with a philosophical objection to Copenhagen QM, and searched for an exotic way to avoid measurements; and (2) the mechanism is a form of magic that defies all scientific analysis.

Scott does not agree with that, of course, as he has joined the MWI cult. He just brushes aside the magic by calling it Zen.

World's fastest random number generator

Nature/SciAm reports:

Researchers have built the fastest random-number generator ever made, using a simple laser. It exploits fluctuations in the intensity of light to generate randomness—a coveted resource in applications such as data encryption and scientific simulations—and could lead to devices that are small enough to fit on a single computer chip.

True randomness is surprisingly difficult to come by. Algorithms in conventional computers can produce sequences of numbers that seem random at first, but over time these tend to display patterns. This makes them at least partially predictable, and therefore vulnerable to being decoded.

To make encryption safer, researchers have turned to quantum mechanics, where the laws of physics guarantee that the results of certain measurements — such as when a radioactive atom decays — are genuinely random. ...

They recorded the light output of 254 independent pixels, which together produced random bits at a rate of around 250 terabits per second, or 250 terahertz. That’s several orders of magnitude faster than previous such devices, which recorded only one pixel at a time. ...

These could have useful applications, such as encryption technology on mobile phones.

No, there are no useful applications to having terabits of random numbers. You can do all the encryption that you would ever want to do, with a mere 256 random bits.

I wonder if they were trying to do something constructive, got garbage, and then decided to repackage their research as a random number generator.

They say "true randomness" and "genuinely random", but these phrases are meaningless.

First, there are physicists who believe in determinism. They are probably wrong, but surely they object to anything being truly random. If anything could ever be shown to be truly random, then determinism would be settled once and for all. That apparently has not happened, as the determinists are still trying to hold their ground.

Second, there are 50-cent chips that generate random numbers from thermal noise or something similar. See this article. There is not really any good reason to think that a quantum generator is better than a non-quantum one.

Quantum supremacy claims are disproved

Scott Aaronson now admits that a new paper has swung an axe at Google's claims of quantum supremacy. He had endorsed those claims as proving that a quantum computed did a computation that was not feasible on a classical.

Now a pair of Chinese researchers have show that the computation can be done fairly easily on a classical computer.

Aaronson has bet his career on quantum computing, and he is not giving up. He says that the quantum computer might be tweaked to make it supreme again. We shall see.

Update: Aaronson also now admits that the Microsoft quantum computing research has failed. I previously reported the Microsoft retraction in February.

Copenhagen is not about fire-breathing

Scott Aaronson responds:

Why isn’t the fact you’re saying “A quantum state is a wave-function that evolves according to the Schrodinger equation; the rest is commentary” makes you simply a many-worlder (albeit in denial….)?
Don’t you agree that this is the claim to fame of the Everettians? All other interpretations suggest that something is missing in the theory (whether the wave-functions are an incomplete description of the physical reality, or the Schrodinger equation is an incomplete description of the way they’re evolving).

If I’m just an Everettian in denial, then by the same standard, almost every informed person nowadays is likewise just an Everettian in denial! Besides Penrose and GRW, I don’t know anyone today who thinks of “collapse” as an actual physical thing. Certainly not the Copenhagenists or QBists! The way they’d put it is that for them, quantum states are personal, “collapse” is just Bayesian updating, and there’s no such thing as the “quantum state of the universe.” The way I’d put it is that, if you force them (kicking and screaming) to write down a quantum state that includes human beings, they’ll simply deny that the fire of experience gets breathed into more than one of its branches.

No, this is a straw man attack on Copenhagen/QBism.

The Copenhagenists do not believe that the wave function is a actual physical thing. It is a mathematical tool for predicting measurements.

To the extent that it is the best tool we have, it certainly does collapse. The collapse is real. Saying that the collapse is real is another way of saying that a measurement on an entangled state yields a single value.

They also believe that quantum mechanics can be used for everything, including stars, human beings, and the universe at large. There is no such notion of breathing fire of experience into a wave function. Aaronson just made that up.

The many-worlds/Everett folks would rather say that the measurement causes a branch of the wave function to become irrelevant. Okay, that is another way of expressing the collapse. The difference is that the many-worlders go a step further and say that the irrelevant branches continue on in a parallel universe. That is the kooky part that is the heart of the theory.

Aaronson joins the many-worlds cult

Scott Aaronson is one of the more sane popularizers of quantum mechanics. Or he used to be. Now he comes out of the closet as a many-worlder:

I have tenure, and anyone who doesn’t like it can close their broswer tab. ...

I’ve dodged the question of which interpretation (if any) I really believe myself. Today, at last, I’ll emerge from the shadows and tell you precisely where I stand.

I hold that all interpretations of QM are just crutches that are better or worse at helping you along to the Zen realization that QM is what it is and doesn’t need an interpretation.  ...

If you had to, you could call even me a “Many-Worlder,” but only in the following limited sense: that in fifteen years of teaching quantum information, my experience has consistently been that for most students, Everett’s crutch is the best currently on the market. At any rate, it’s the one that’s most like a straightforward picture of the equations, and least like a wobbly tower of words that might collapse if you utter the wrong ones.  Unlike Bohr, Everett will never make you feel stupid for asking the questions an inquisitive child would; he’ll simply tell you answers that are as clear, logical, and internally consistent as they are metaphysically extravagant. That’s a start.

This is pathetic. Many-worlds does not answer any questions. It cannot explain why some outcomes are more probable than others, or how the worlds split, or anything else you might ask.

Why are there probabilities in QM? Because QM is a (the?) generalization of probability theory to involve complex numbers, whose squared absolute values are probabilities. It includes probability as a special case.

No, QM is not probability with complex numbers. Probabilities only range from 0 to 1, as real numbers. Furthermore, many-worlds loses the probabilities altogether.

If you start with a quantum state for the early universe and then time-evolve it forward, then yes, you’ll get not only “our” branch but also a proliferation of other branches, in the overwhelming majority of which Donald Trump was never president and civilization didn’t grind to a halt because of a bat near Wuhan.  But how could we possibly know whether anything “breathes fire” into the other branches and makes them real, when we have no idea what breathes fire into this branch and makes it real?

This is just nonsense. No one has ever been able to demonstrate a statement about the majority of branches in many-worlds theory. Nor is there any concept of breathing fire into a branch and making it real.

Aaronson used to talk about writing a new book. His view of QM has not become a hopeless muddle.

You might think that I am being harsh on Aaronson, for merely choosing an interpretation. I don't think so. First, he doesn't describe his view that way. Second, the probabilities make no sense. Let me quote Wikipedia:

To address the quantitative [probability] problem, Everett proposed a derivation of the Born rule based on the properties that a measure on the branches of the wavefunction should have.[4]:70–72 His derivation has been criticized as relying on unmotivated assumptions.[35] Since then several other derivations of the Born rule in the many-worlds framework have been proposed. There is no consensus on whether this has been successful.[36][37][38]

The three references for saying "no consensus" actually argue that probabilities are meaningless in many-worlds. The last says "no plausible set of axioms exists for an MWI that describes known physics."

Even if you think that it might be possible to reconcile many-worlds with probability theory, it is clear that no one has done. There is no published paper that uses many-worlds to derive a probability for anything.

You can find advocates who speak in probabilistic terms. For example, that Wikipedia article says:

DeWitt has stated that "[Everett, Wheeler and Graham] do not in the end exclude any element of the superposition. All the worlds are there, even those in which everything goes wrong and all the statistical laws break down."[87]

Max Tegmark has affirmed that absurd or highly unlikely events are inevitable but rare under the MWI. To quote Tegmark, "Things inconsistent with the laws of physics will never happen — everything else will... it's important to keep track of the statistics, since even if everything conceivable happens somewhere, really freak events happen only exponentially rarely."[88]

But there is no published paper with computations to back up any of those claims. Nobody can say that freak events happen only rarely, because no one can say that any branch is any more probable than any other branch.

The whole field is a big con, and Aaronson just joined it.

He writes:

The many-worlders love to use the example of Copernicus and Galileo, who introduced a bizarre and extravagant hypothesis — that the earth, far from being stationary, circles the sun at unimaginable speed — but then argued that, starting from that hypothesis, you could derive that our experience on earth would be just like it actually is, and this time with no need to postulate epicycles.

There are sophisticated arguments against many-worlds, but I think that a good first step along the Zen path, for someone who already knows QM, would be to understand the strength of the case in many-worlds’ favor.

The history is a little strange, because Copernicus used epicycles, and Galileo did not have a mathematical model of the solar system.

But the argument makes no sense anyway, because many-worlds cannot derive our experience on Earth.

The elephant in the room here is quantum computing. That is Aaronson's chief academic field of interest. His essay on many-worlds says nothing about quantum computing. For some in the field, such as David Deutsch, many-worlds is the main reason for believing in quantum computing. Or maybe quantum computing is the main reason for believing in many-worlds, I am not sure. At any rate, they are related. But Aaronson says nothing. What goes?

And what is all this Zen stuff? Is he conceding that this is all a set of religious views? Is this knowledge that is only available to enlightened geniuses like himself, and not accessible from logic, empiricism, and reasoned argument? Apparently yes.

Update: Commenter Andrei gives arguments for superdeterminism, both below and on Aaronson's blog, and Aaronson responds:

The original papers by Gerard ‘t Hooft on “superdeterminism” were shockingly blase about the absurd implications I mentioned — implications that would mean you could explain basically anything (telepathy, superluminal signaling, etc.) via similar devices, and that physics would be over — and (to their credit) were also clear enough that there was no possible other way to interpret them. None of the other papers I saw about “superdeterminism” showed any inkling of appreciating the enormity of the problem. And none of them contained what I saw as the slightest hint of a promising idea to balance the absurdity.

By the usual standards I apply to anything else, this would be more than enough reason for me to ignore the topic thereafter.

I agree with that. Superdeterminism is essentially the same as rejecting all of modern physics, and adopting solipsism. No one has explained how it is any better. It does not help with any theoretical or experimental problem in physics.

Dr. Bee on the Quantum Cat

Dr. Bee's latest video is on Schroedinger's Cat, and she concludes:

What this means is that one of the following three assumptions must be wrong:

1. No Superdeterminism.
2. Measurements have definite outcomes.
3. No spooky action at a distance.

The absence of superdeterminism is sometimes called “Free choice” or “Free will”, but really it has nothing to do with free will. Needless to say, I think what’s wrong is rejecting superdeterminism.

No, all three assumptions are completely consistent with textbook treatments of quantum mechanics.

Superdeterminism says that all of your choices have been completely determined since the Big Bang. Yes, it is directly contrary to free will. There are philosophical compatibilists who are that you can think of yourself as having free will, even tho you don't. But that is not free will. It is just the illusion of free will.

One such philosopher is Daniel Dennett who argues that all your choices are determined, but that it would be irresponsible to tell people that they have no free will. He makes a good argument that disbelief in free will is destructive.

Everyone says measurements have definite outcomes, except the many-worlds advocates. As I have argued else, many-worlds is unscientific nonsense. So is superdeterminism. I criticized her superdeterminism, and also here, here, and here.

That leaves spooky action. There is no experiment showing spooky action, and it is foolish to believe in it. They only show spooky action if make another assumption, namely hidden variables, and that assumption was properly rejected decades ago.

Hossenfelder says "physicists would rather throw up objective reality". That is true, if objective reality means that every electron has a precise position and momentum, whether measured or not. That is impossible, by the uncertainty principle. But the measurements are definite, and objectively real.

Update: Commenter Andrei, probably the same one who comments below, asks:

Are the measured spins predetermined or not? If not how do you think the results are anticorrelated?

I guess he is suggesting that the spins are predetermined by a superdeterminism. Aaronson answers:

The Bell inequality shows that the measured spins cannot be “predetermined,” under minimal assumptions of no superluminal signalling and no insane cosmic conspiracies. ...

More broadly, the idea that there are only two possibilities,

(1) local hidden variables or
(2) superluminal signalling,

with nothing intermediate between the two, is a perfect example of the “classical baggage” that the Zen anti-interpretation of quantum mechanics counsels us to discard.

Here, "predetermined" is the opposite of "random". A lot of people take the Bell test experiments as proof of randomness. A lot of others believe in determinism. A very small number believe in superdeterminism.

I do not think that the experiments can tell us whether the spins are predetermined.

I do agree with Aaronson that local hidden variables and superlumninal signaling are the only possibilities. In fact, I would say that both of those have been ruled out.