Von Neumann not QBist

Blake C. Stacey has a new article on Von Neumann Was Not a Quantum Bayesian:

Wikipedia has claimed for over two years now that John von Neumann was the "first quantum Bayesian." In context, this reads as stating that von Neumann inaugurated QBism, the approach to quantum theory promoted by Fuchs, Mermin and Schack. This essay explores how such a claim is, historically speaking, unsupported.

This paper takes Wikipedia way too seriously.

Quantum Bayesianism, or QBism, is a modern defense of the Copenhagen interpretation, which was the mainstay of the XX century, but is often attack by popularist writers. Mermin advocates QBism partially by arguing that it is a modern new interpretation to compete with other modern interpretations, and partially by arguing that it is the same as what Bohr, Heisenberg, and Schroedinger promoted all along. In spite of his objections, articles on interpretations of quantum mechanics treat Copenhagen and QBism as essentially the same thing.

Von Neumann–Wigner interpretation is also a variant of Coperhagen defined by:

also described as "consciousness causes collapse [of the wave function]", is an interpretation of quantum mechanics in which consciousness is postulated to be necessary for the completion of the process of quantum measurement.

This is a useful term, because a lot of people hate Copenhagen because of the role of consciousness. In this Wikipedia terminology, the von Neumann interpretation depends on consciousness, and the Copenhagen interpretation is the same thing with the consciousness stripped out.

Stacey refuses to say von Neumann was a QBist because he was not a Bayesian. There are multiple probability interpretations, and von Neumann was more of a frequentist.

At this point, you may wonder what the relation to physics is. Quantum mechanics successfully predicts atomic phenomena. What difference does it make how it is interpreted? The Feynman "shut up and calculate" school of thought says that interpretations are unnecessary distractions. When interpretations posit proliferating parallel unobservable universes, it is hard to see why there is any point to talking about such nonsense. If two interpretations have the same physical outcomes, it is hard to see how science can say one is better than the other.

Feynman did not actually say "shut up and calculate", but he did advocate having multiple theories for getting the same results, and criticize philosophical arguments about interpretations.

The metaphysical problem is weirder in the above paper, as the von Neumann and QBism interpretations are essentially the same physically and mathematically, but differ only in the interpretation of what a mathematical probability means. And that difference hinges on consciousness, whatever that is. Supposedly Wigner once remarked that a dog was probably sufficiently conscious to cause the collapse of a wave function (and kill Schroedinger's cat), but a rat was not. He must have realized that he was on thin ice with that.

I think that these interpretations add some clarity to quantum mechanics, but it is a mistake to take them too seriously. Some people think that quantum mechanics is a flawed theory, and it needs a new interpretation to save it. Or we need to get everyone on board some version of many-worlds. I disagree. The interesting questions are the scientific ones, and these interpretational issues barely qualify. We cannot use them in experiments, such as asking a dog to watch Schroedinger's cat and checking to see if the wave function collapses. An interpretation is just a way of thinking about the theory.

Poe foresaw the Big Bang in 1848

The current NY Review of Books has an article on Edgar Allan Poe:

Poe’s mind was by no means commonplace. In the last year of his life he wrote a prose poem, Eureka, which would have established this fact beyond doubt—if it had not been so full of intuitive insight that neither his contemporaries nor subsequent generations, at least until the late twentieth century, could make any sense of it. Its very brilliance made it an object of ridicule, an instance of affectation and delusion, and so it is regarded to this day among readers and critics who are not at all abreast of contemporary physics. Eureka describes the origins of the universe in a single particle, from which “radiated” the atoms of which all matter is made. Minute dissimilarities of size and distribution among these atoms meant that the effects of gravity caused them to accumulate as matter, forming the physical universe.

This by itself would be a startling anticipation of modern cosmology, if Poe had not also drawn striking conclusions from it, for example that space and “duration” are one thing, that there might be stars that emit no light, that there is a repulsive force that in some degree counteracts the force of gravity, that there could be any number of universes with different laws simultaneous with ours, that our universe might collapse to its original state and another universe erupt from the particle it would have become, that our present universe may be one in a series.

All this is perfectly sound as observation, hypothesis, or speculation by the lights of science in the twenty-first century. And of course Poe had neither evidence nor authority for any of it. It was the product, he said, of a kind of aesthetic reasoning—therefore, he insisted, a poem. He was absolutely sincere about the truth of the account he had made of cosmic origins, and he was ridiculed for his sincerity. Eureka is important because it indicates the scale and the seriousness of Poe’s thinking, and its remarkable integrity. It demonstrates his use of his aesthetic sense as a particularly rigorous method of inquiry.

The book was written in 1848. Just glancing at it, it looks like nonsense to me, but I did not read enuf to judge.

SciAm's John Horgan is also excited by Poe's book, and says it reminds him of a drug trip.

It’s like a 19^th-century version of the many manuscripts I have received over the decades from brilliant but deranged autodidacts who have solved the secrets of the universe. Imagine what you might get if you toss Aristotle’s Metaphysics and Newton’s Principia in a blender along with scoops of gothic rhetoric and romantic philosophy. Eureka does indeed evoke some modern scientific ideas, but in the same blurry way that Christian or Eastern theologies do.

Tracing Einstein's sources

Einstein fanboi John D. Norton wrote in a 2003 paper:

Modern readers turning to Einstein’s famous 1905 paper on special relativity may not find what they expect. Its title, “On the electrodynamics of moving bodies,” gives no inkling that it will develop an account of space and time that will topple Newton’s system. Even its first paragraph just calls to mind an elementary experimental result due to Faraday concerning the interaction of a magnet and conductor. ...

It has also received considerable attention outside physics. It is the first port of call for philosophers and other thinkers, seeking to understand what Einstein did and why it changed everything. It is often also their last port. ...

It contains Einstein’s analysis of simultaneity, probably the most celebrated conceptual analysis of the century.

Many have tried to emulate Einstein and do in their fields just what Einstein did for simultaneity, space and time. For these reasons, many have sought to understand how Einstein worked his magic and came to special relativity. These efforts were long misled by an exaggeration of the importance of one experiment, the Michelson-Morley experiment, even though Einstein later had trouble recalling if he even knew of the experiment prior to his 1905 paper. ...

Why did special relativity emerge when it did? The answer is already given in Einstein’s 1905 paper. It is the fruit of 19th century electrodynamics. It is as much the theory that perfects 19th century electrodynamics as it is the first theory of modern physics. 4 Until this electrodynamics emerged, special relativity could not arise; once it had emerged, special relativity could not be stopped. Its basic equations and notions were already emerging in the writings of H. A. Lorentz and Henri Poincaré on electrodynamics. ...

All efforts to recount Einstein’s path face one profound obstacle, the near complete lack of primary source materials. ...

To demonstrate this result, Einstein imagined two places A and B, each equipped with identically constructed clocks, and a simple protocol to synchronize them using light signals

That protocol is known as Poincaré–Einstein synchronization, as Poincare published it in 1898, 1900, and 1904.

We actually have all Einstein's source materials. Besides the Poincare synchronization, Einstein is known to have gotten the electrodymanics, space-time transformations, postulates, and everything else from Lorentz and Poincare.

Einstein himself agreed that Michelson-Morley was crucial to the development of relativity, as he explains in a 1909 paper:

The Michelson and Morley interference experiment showed that, in a special case, second-order terms also cannot be detected, although they were expected from the standpoint of the ether-at-rest theory. To include this experiment in the theory, Lorentz and FitzGerald introduced the postulate that all objects, including the parts of Michelson and Morley's experimental set-up, changed their form in a certain way, if they moved relative to the ether. ...

Michelson's experiment suggests the axiom that all phenomena obey the same laws relative to the Earth's reference frame or, more generally, relative to any reference frame in unaccelerated motion. For brevity, let us call this postulate the relativity principle.

Einstein was unsure about Michelson-Morley in 1905 because he did not realize the experiment's importance at the time. Lorentz and Poincare emphasized that the experiment was crucial to their reasoning, but Einstein was just giving an expository account of their conclusions, not their reasoning. So as Einstein explained in 1909 how Michelson-Morley was crucial to the development of relativity, it was crucial to Lorentz and Poincare, but not to Einstein's 1905 paper.

I just discovered the Marauders of the Lost Sciences blog, that regularly posts excerpts of old math and physics papers that are particularly interesting, such as anticipating later results. A recent one is Poincaré discussing relativity a year before Einstein. Poincare traveled to the 1904 St. Louis Missouri World's Fair, and gave a lecture about relativity and other topics. He speaks of a "wholly new mechanics which would be characterized above all by this fact, that there could be no velocity greater than that of light, any more than a temperature below that of absolute zero."

Post-WWII philosophers have lost it

Scientia Salon has another article on scientific realism. This one is on the attempts, by philosophers and physicists, to make quantum mechanics are more "realistic" theory by adding interpretations with hidden variables, Bohmian pilot waves, and parallel universes. At least this article tacitly admits that all such attempts have been colossal failures, altho philosophers cling to a notion of realism that requires such nonsense.

As usual, the moderator says that I am wrong. He defends philosophers believing in scientific realism, even tho it leads them to say nonsense about quantum mechanics.

Lubos Motl attacks a Tom Siegfried essay in ScienceNews, and makes points that apply to the Scientia Salon philosophers as well:

Only armchair physicists, third-class physicists, and "philosophers" may consider these foundational debates about quantum mechanics to be a part of the actual research in 2015. Physicists know that all these questions have been settled since the middle or late 1920s.

I agree with that, altho I would say that they were settled in the 1930s. Here was my response to Scientia Salon:

Summary: Bohr was right in the Bohr-Einstein debates. 80 years of attempts at philosophical realism have just layered conjectures on top of the theory. Those conjectures have either been proven false, become unworkable dead-ends, or imagined outlandish untestable fantasies.

The philosophical realists mock Ernst Mach for skepticism about atoms, but Motl defends his philosophy:

Positivism states that all of our trustworthy knowledge about Nature comes exclusively from sensory experience – from observations, if we use a little bit more physical jargon. In the context of physical theories, it means that a physical theory a priori declares "all objects in the world around us" and words describing them as meaningless. Every physical theory has the right to do so. Every physical theory may work with its own fundamental and auxiliary concepts to describe our experience. The experience is the only "provably real" thing. But the point is that every question about Nature that can't be reduced to our experiences is considered physically meaningless or unphysical.

(The Vienna Circle elaborated upon these important positivist observations and probably was the culmination of philosophers' understanding of the essence of modern science. When other philosophers such as Thomas Kuhn or Karl Popper began to be popular, the degeneration and putrification of philosophy of science was already underway. To return to Mach and his positivist predecessors, they generally erred by forecasting that "something would remain unobservable forever". For example, the founder of positivism Auguste Comte would predict that the chemical composition of stars would remain a mystery forever – just years before spectroscopy answered all those questions. But this error must be seen as a side effect of their important and right understanding that certain questions and claims are physically meaningless.)

That is right, and this form of positivism is entirely rejected by philosophers today.

With a grain of salt, we could argue that about 100 years ago, the philosophers were actually useful for the progress in physics. That's also why most of the greatest theoretical physicists of that time considered themselves part-time philosophers. After the Second World War, the philosophers had largely lost it. The greatest physicists of the post-war generation, the likes of Feynman and Schwinger, to mention two, were no longer admiring philosophy in the usual sense. They diverged. The propagation of the anti-quantum delusions by the contemporary philosophers may be viewed as a revenge against physics – revenge for the fact that science had to completely escape away from philosophy and the best physicists no longer have any intellectual respect towards the contemporary philosophers.

That is correct, as I have also argued that Philosophy became useless in 1950. Nearly every post-WWII philosopher is rabidly anti-science. They refuse to accept XX century physics, and they deny that scientists discover truth. They have diverged from science like astrology.

Ivan Deutsch says no true qubit yet

Quanta magazine has an interview:

For more than 20 years, Ivan H. Deutsch has struggled to design the guts of a working quantum computer. He has not been alone. The quest to harness the computational might of quantum weirdness continues to occupy hundreds of researchers around the world. Why hasn’t there been more to show for their work? As physicists have known since quantum computing’s beginnings, the same characteristics that make quantum computing exponentially powerful also make it devilishly difficult to control. The quantum computing “nightmare” has always been that a quantum computer’s advantages in speed would be wiped out by the machine’s complexity.

I do not know whether he is related to David Deutsch, another quantum computing pioneer. Ivan's big hope:

Before I die, I would love to see just one universal logical qubit that can be indefinitely error corrected. It would instantly be classified by the government, of course. But I dream on, regardless.

Remember that, next time you read that someone has achieve 10 qubits, or 20 qubits, or whatever. No one has truly made a single qubit.

QUANTA MAGAZINE: Why would a universal quantum machine be so uniquely powerful?

IVAN DEUTSCH: In a classical computer, information is stored in retrievable bits binary coded as 0 or 1. But in a quantum computer, elementary particles inhabit a probabilistic limbo called superposition where a “qubit” can be coded as 0 and 1.

Here is the magic: Each qubit can be entangled with the other qubits in the machine. The intertwining of quantum “states” exponentially increases the number of 0s and 1s that can be simultaneously processed by an array of qubits. Machines that can harness the power of quantum logic can deal with exponentially greater levels of complexity than the most powerful classical computer. Problems that would take a state-of-the-art classical computer the age of our universe to solve, can, in theory, be solved by a universal quantum computer in hours.

Yes, he is dreaming. Just because we can create states where we do not know whether a measurement will give a 0 or 1, that does not mean that the alternate possibilities of 0 and 1 can be used for exponential computational advantage.

I wonder how many years or decades the Deutsches and others will be able to get away with this. Their argument is essentially:

When you shine a laser thru a double slit, you get a diffraction pattern, just like what you get with water waves or any other waves. But with light it is different, because light is made of particles called photons, not waves, and the pattern is the result of photons being in two places at once. Quantum mechanics explains how something can be two things at once, such as putting Schroedinger's cat in a box and if you do not know whether it is alive or dead then you just say that it is in a superposition of live and dead states. The problem of quantum mechanics is the engineering problem of making devices that act like Schroedinger cat boxes, and so that the interaction between the live cat and the dead cat in the probabilistic limbo can be harnessed to do a computation.

This is a good story, if it works, but it is a fantasy. Yes, I would love to see one universal logical qubit also. There would be a Nobel Prize for that. But when is anyone besides me and a handful of others going to get skeptical? In 10 years? In 20 years? I do not see that the quantum computing failures* have caused any skepticism so far. I have listed my reasons for skepticism.

Marek Zukowski has a new paper on some quantum paradoxes, but it admits that the argument that quantum mechanics disproves "local causality" only holds if you define that term to mean a hidden variable theory that is directly contrary to quantum mechanics. Also, the paradoxes disappear if you just assume that "unperformed experiments have no results". Quantum computing is all about trying to get computational results from unperformed experiments.

* A comment below disputes the term "quantum computing failures".

Anti-Scientia Salon

A major theme of this blog is to expose anti-science ideas, especially when they come from universities and research institutions in the name of science. I do not bother with dubious religious claims or the Flat Earth Society, or even academic postmodernists. I leave them for the professional skeptics. I focus on respectable nonsense that is seriously contrary to the modern scientific pursuit of truth. For example, my last post on geocentrism focused on what scientists say, not Bible scholars.

A source of anti-science philosophy is Scientia Salon, a philosophy-driven site that claims to tell scientists what science is all about. It recently restricted its essays to academics who are more in line with the moderator's desire to promote academic philosophy. I have been allowed to post comments there, but usually with a moderator note that I am wrong or a threat to block my message or ban me from the site.

I previously posted disagreements on causality, realism, and reductionism.

Now the site has essays by Marko Vojinovic against science reductionism, in Part I and
Part II.

I left several critical comments, including this:

Here is yet another philosophical essay that claims that physicists do not know what they are doing. The core of your argument is 2 claims.

I. If you define the Second Law in a way that makes it false, then it is not reducible to things that are true.
II. If you define a theory of everything to include ZFC, then it includes well-known paradoxes of ZFC.

You blame belief in scientific reductionism on a “lack of education in mathematical logic”. The consequences of Goedel’s theorems have been well-understood for 80 years. Goedel would not agree with you, and neither would those who actually have an education in math logic, as far as I can see.

This is like complaining that the equations of general relativity cannot explain cosmology because they contain pi, and pi is irrational. Yes, the irrationality of pi may seem paradoxical to people who first learn it, but it has almost nothing to do with scientific reductionism. It will only cause a problem if you give some completely artificial requirement that pi must be reduced to rational numbers.

This is the first essay with SciSal’s new policy of restricting to academics. I expected to see philosophers explaining what they have published. Instead we have someone with training in relativity who makes an anti-science argument that has nothing to do with his training. ...

I say anti-science because Marko’s arguments, in his own words, “stand in sharp contrast to the popular opinion among scientifically-oriented people”. I do not question his expertise in relativity, but his essay is about philosophy, emergence, and math logic, not relativity.

I do not know why you keep threatening to ban me. I am expressing mainstream science views. If an essay makes claims that are contrary to standard science textbook knowledge, then someone should call the author out on those points. What else are the comments for?

Questioning reductionism like this is a little like talking creationism. If Marko wanted to argue that dark matter might be new form of matter that only emerges at a galactic level and cannot be reduced to some microscopic theory, then I would let it pass as a legitimate intellectual possibility. But it would be a little like saying that dark matter is supernatural stuff that God put there in order for the galaxies to form. My objection is that he claims to have disproved reductionism with his examples and his Goedel argument. ...

Daniel, anyone who talks about science progressing by paradigm shifts is anti-science also. The paradigm shift is defined to be a change in views that has no rational or measurable advantages. It is an idea that is popular among philosophers, but not scientists. You only hear a scientist talking about paradigm shifts when he is promoting an idea that has no evidentiary support.

And this:

I use the term “anti-science” just to mean going against the scientific establishment, for reasons other than scientific evidence.

I agree that occasionally someone like Chomsky is right, and that his insights were valuable even if they are wrong. He would be a fine example of someone who can be brilliantly wrong.

I just heard a radio talk show caller say that he does not believe in global warming because the theory depends on computer climate models, and they are just garbage in garbage out. I regard this as an anti-science argument, because scientists nearly all believe that there is at least some validity to the data and models, and the caller has not identified any specific flaws.

Kuhn’s paradigm shift theory is similarly anti-science. It is a direct attack on what most scientists believe about science. You say that his thesis is meant to be a descriptive view, but that is a common misconception about Kuhn. He did write descriptions of science, such as a whole book on the early history of quantum theory, but he was never able to relate those descriptions to his paradigm thesis. Quantum theory had many rational and measurable advantages that everyone else recognized.

We are getting a little off-topic here, but this site seems to have a theme where scientists somehow got science all wrong on issues like reductionism, realism, free will, causality, positivism, unity, infinity, axiomatic math, paradigms, emergence, and empiricism. Maybe it should be renamed Anti-Scientia Salon. Okay, I sometimes think that the conventional wisdom is wrong also.

Vojinovic responded to some comments, but did not address any of my criticisms.

His argument is to say that popular scientist ideas about what science can do are all wrong, because he has some misunderstandings of some elementary paradoxes that are properly explained on the Wikipedia pages for Second law of thermodynamics and Goedels incompleteness theorem.

Of course there are plenty of crackpots saying stupid things about entropy and Goedel. Those two subjects are very well understood, and yet they seem to invite people to misunderstand them and say crazy things.

Moderator SciSal (aka Massimo Pigliucci) responds:

Your own example of climate change denialism is a good one: that definitely is anti-science, for the reasons you mentioned. But Marko has been engaging in a philosophical discussion based on the available science, and he has taken positions that are compatible with the established science. Nothing to do with “anti-science.” Second, Kuhn was a physicist and historian of science. He described what he saw as a historical pattern. Since scientists don’t do history of science, it is pretty much irrelevant whether what Kuhn said did or did not go along with the opinions of most scientists: even if it didn’t, it wouldn’t be anti-science.

I am going to post another essay, just on his attitude about how philosophers know what science is about better than scientists.

But no, all of that is wrong. Marko has not engaged in a philosophical discussion, because he refuses to address my points. He has taken positions on entropy and Goedel that are contrary to textbook knowledge. Kuhn never found a historical pattern to back up his paradigm shift theory. Kuhn certain was anti-science when he argued that science works by jumping on fads, without rational or measurable evidence.

What all this philosophical arguments have in common is that they are attacks on the idea that math and scientific methods can give us truth about the world.

All this academic philosophy of science is like listening to a Marxist professor. He will babble on and on about how 19th century trends prove the merits of a Marxist revolution. If you try to tell him that history does not back up his theories and his objectives are not desirable anyway, he will say that he is the professional historian and his Marxist colleagues agree with him.

Modern philosophy of science is like Marxism. It ignores history of the last century, it misunderstands history before that, it distorts everything for ideological purposes, and it is dominated by crackpots.

Update: I may post separately on how Goedel's theorem is widely misunderstood, even by academic philosophers who should know better. The theorem is well-explained on Wikipedia and elsewhere, so there is no excuse for it.

Mercury enters retrograde motion

A NY Times essay says:

On Jan. 21, at 10:54 a.m. Eastern Time, Mercury will begin its first pass by Earth of the new year. For about three weeks, it will appear to move backward across our sky and will, according to astrologers, disrupt technology, communication and human concord. ...

The astrological belief that Mercury retrograde leads to confusion and breakdown is inherited from the time before we understood that Earth is not the center of the cosmos. From our perspective, Mercury appears to move quickly and erratically, so the ancients called it a messenger and a trickster. It took three millenniums to figure out that this was an illusion. Before that, Ptolemy constructed elaborate models in which the other planets spun around us like insane tops, and the models stayed with us long after the observations stopped matching the math. Copernicus’s heliocentric theory explained retrograde motion much more elegantly, but he kept it unpublished nearly until his death. Mercury told its story, anyway: To understand the illusion of its movement means to realize that we are not at the center of things, that there is a reality beyond the one we see.

[image caption] Stuck in the Middle | A geocentric model of our universe, from James Ferguson’s 1756 “Astronomy Explained,” highlights its absurdity; the Ptolemaic system required that the planets in our solar system orbit Earth in strange, looping arcs.

You will not find anything like that 1756 diagram in Ptolemy's Almagest, because his model never said anything about those strange looping arcs. He did not attempt to model the distance from the Earth.

The Mercury retrograde motion is an illusion, but the same reasoning says that so is the rising and setting Sun, and the apparent motion of the stars in the night sky.

Ptolemy's model was in use for well over a millennium, probably longer than any other scientific model of any kind. Yes, some data needed to be updated. I think that some of it was already out of date when Ptolemy was alive, as he did not have the latest astronomical data. But his model was pretty good.

It is amazing how people get confused on this issue. I criticized Jerry Coyne, and now he has asked Sean M. Carroll to explain whether the Earth goes around the Sun or vice-versa:

The short answer would be that it is possible to choose whatever coordinate system you like, including ones centered on the Earth, and then say “in that coordinate system the Sun goes around the Earth.” Hell, it’s possible to choose coordinate systems in which neither the Earth nor the Sun move at all! But some coordinate systems are better than others, and for understanding Solar System dynamics, an Earth-centered one is particularly dumb. If some Orthodox Jews want to argue that they have the right to be dumb, who am I to stop them?

The Earth-centered coordinates may be dumb for understanding Solar System dynamics, but preferable for other purposes. So Carroll is wrong to say that they are dumb.

Somewhat more careful (dare I say “rabbinical”?) discussion by me here:
Note, however, that while you can say “I am using a coordinate system where the Earth is at the center,” you can not say “Coordinate systems where the Sun [or the Solar System’s barycenter] is at the center are wrong.” So “geocentrism” is flatly incorrect.
Also, not to belabor the obvious: early geocentrists were not relying on coordinate invariance, and attempts by modern ones to save the old ideas are kind of pitiful.

I guess he is trying to say that Ptolemy got the right answer for the wrong reason, and so he should not get any credit.

Ptolemy did not show how to convert from one coordinate system to another, or show the equivalence of coordinate systems. I do not know who first did those things. But regardless, there is nothing wrong with choosing a coordinate system and sticking to it. Maybe it is not as good for understanding dynamics, but it might be better for mapping the night sky.

This US NSFA 2012 study measured public understanding of science by asking 10 questions.

Physical science
The center of the Earth is very hot. (True)

The continents have been moving their location for millions of years and will continue to move. (True)

Does the Earth go around the Sun, or does the Sun go around the Earth? (Earth around Sun)

All radioactivity is manmade. (False)

Electrons are smaller than atoms. (True)

Lasers work by focusing sound waves. (False)

The universe began with a huge explosion. (True)

Biological science
It is the father’s gene that decides whether the baby is a boy or a girl. (True)

Antibiotics kill viruses as well as bacteria. (False)

Human beings, as we know them today, developed from earlier species of animals. (True)

Whoever made this list does not understand that motion is relative. General relativity teaches that "Earth go around the Sun" and "Sun go around the Earth" are both correct.

I would also re-phrase "The universe began with a huge explosion." We know that the universe is expanding, and that our best model has a big bang at a finite time in the past. But it is possible to believe that the universe existed in some other form before the big bang, so that it might not have started with an explosion. A quiz like this should be based on facts we know for sure.

Chinese proved Pythagorean Theorem

I thought that the ancient Greeks invented the mathematical proof. Euclid's Elements gives an axiomatization of geomety, and proves the Pythagorean Theorem. But now I read this:

The Pythagoras theorem 'should either be an Egyptian theorem if you look at the standard of just having an idea about it, an Indian theorem if you're looking for a complete statement of it, or a Chinese theorem if you're looking for the proof of it,' Fields Medal winner and Princeton University Professor Dr Manjul Bhargava tells P Rajendran/Rediff.com ...

"The Shuba Sutras do contain proofs in some special cases and contain numerical proofs in general, but the first actual rigorous proof of the Pythagorean theorem that's on record originates in China -- after the Shuba Sutra."

"So in China in school textbooks they often call it the Gougu theorem. And that was first given in a Chinese manuscript some years later (the Zhou Bi Suan Jing, the material for which dates back to sometime between the 1046 BC and 256 BC)."

"So maybe the statement of the theorem went from India to China, but the actual proof -- the complete, rigorous proof -- was given in China, at least as far as written records go. That's why the Chinese ... (named) the Pythagorean theorem after the person who first proved it (and) who was in China."

He sounds as if he knows what he is talking about, but the Chinese proof given on Wikipedia is only for the 3-4-5 triangle. I would not call that a complete rigorous proof. I also do not see any evidence that the Chinese even had an understanding of what a proof is. Yes, it appears that the diagram can be easily adapted to other right triangles, but a lot of things are easy in retrospect.

Proving a theorem requires postulates and logical deductions.

The zero is obvious in retrospect, and so are a lot of other math concepts. So is heliocentrism, and conservation of energy. There is often someone claiming in Wikipedia that some particular ancient civilization had these concepts. There is almost never clear-cut evidence of the concept. Euclid very clearly had the concept of a geometrical proof. It is doubtful that any previous civilization did.

Supposed advance in quantum computing

MIt computer scientist Scott Aaronson has finished defending himself against weirdo feminist attacks on his personal life, and is back to promoting quantum computing:

Within the last couple months, there was a major milestone in the quest to build a scalable quantum computer, and also a major milestone in the quest to figure out what you would do with a quantum computer if you had one. As I’ve admitted many times, neither of those two quests is really the reason why I got into quantum computing — I’m one of the people who would still want to study this field, even if there were no serious prospect either of building a quantum computer or of doing anything useful with it for a thousand years — but for some reason that I don’t fully understand, both of those goals do seem to excite other people.

I am pretty sure he is being sarcastic here. Yes, of course interest in quantum computing is based on the hope that such computers can be built and do useful things. He sounds like G.H. Hardy showing contempt for math doing anything useful.

Scott sure gets excited if someone like D-Wave claims that a quantum computer has been built, or someone like me claims that it is impossible.

I am wondering what these guys think about the possibility that we live in a computer simulation. Since I don't believe that scalable super-Turing quantum computing is possible, the simulator would be a classical computer. So if these quantum computing experiments are successful, then they would put an incredible computational strain on the simulator. What if they overload the simulator? We would all effectively die. This is a bigger threat to the world than the possibility of the LHC making a black hole that swallows the Earth.

Update: A comment says:

If the simulating computer of our world is resource scarce, what if we try to construct a quantum computer to apply Shor's algorithm? Do it for discrete logs or elliptic curve logs because they are uniformly hard. To pick a "hard" integer to factorize as a test, we pretty much have to come up with two large prime numbers first, and our simulator can just read off the prime numbers during generation, and then feed them into the output of the simulated quantum computer. But if we pick a random instance of a discrete log or an elliptic curve log, either Shor's algorithm would myseriously break down, or our simulator is at least partially a quantum computer on its own.

The answer is that it would deplete the resources of the simulator, and give us a cosmic blue screen of death. You have been warned.

Not accepting God playing dice

A reader comments:

Einstein was not the only one of the founders to have misgivings about intrinsic probability. This from Max Born’s Nobel lecture of December 1954:

“ ... when I say that the physicists had accepted the concepts and modes of thought developed by us at the time I am not quite correct. There are some very noteworthy exceptions, particularly among the very workers who have contributed most to building up the quantum theory. Planck, himself, belonged to the sceptics until he died. Einstein, De Broglie and Schrodinger have unceasingly stressed the unsatisfactory features of quantum mechanics and called for a return to the concepts of classical Newtonian physics while proposing ways in which this could be done without contradicting experimental facts. Such weighty views cannot be ignored.”

It is interesting that those he mentions were more the wave mechanics people, rather than the Copenhagen and Gottingen matrix crew. Waves evolve and interfere in a peculiarly local and causal manner, whereas the matrix approach was developed from a stance that ignored all possibility of underlying but unobservable deterministic processes. Yet matter and radiation are in some sense ultimately wave-like in behaviour.

For my money, it is far too early to be denying the possibility of a deterministic explanation of the Born rule. N. P. Landsman had it right I think in commenting in connection with that rule that the “notion of strictly ‘irreducible’ randomness ... which is only defined through negation ... quite possibly makes no philosophical sense at all”. ( arXiv:0804.4849v1 (quant-ph 30 Apr 2008 ). But in this of course he is philosophising!

I agree that irreducible randomness makes no philosophical sense at all.

Philosophy became useless in 1950

Here are some philosophers promoting the field:

Rebecca Newberger Goldstein -- philosopher, author, and Genius-grant recipient -- returns to the Rationally Speaking podcast to discuss her latest book, "Plato at the Googleplex: Why Philosophy Won't Go Away." Rebecca, Julia and Massimo argue over the value of philosophy in modern science, and whether it makes sense to designate "experts" in ethical reasoning.

They gripe about physicists saying that philosophers have been useless since about 1950.

They argue that philosophizing has been important to physics in the past, but all of their examples are before 1950.

These philosophers don't actually rebut the physicists. Sure philosophy can be important, and Plato was influential, but modern philosophers went nuts about 1950, and they have been useless since.

Goldstein is married to Steve Pinker, and also says:

The philosopher and mathematician AN Whitehead described the history of philosophy as a “series of footnotes to Plato”. Do you agree with him?

If that were the case, what a silly field philosophy would be! A 2,400-year-old man had all the answers? I would like to think that what he meant was that this methodology, this view of maximising coherence, was begun by Plato and that he also formulated questions from a wide range of different areas of inquiry — mathematics, epistemology, metaphysics and political theory — and saw their commonality. In that sense, you can say that all philosophy follows in Plato’s footsteps.

Was Plato a “Platonist” in the modern sense of being committed to a claim about the existence of abstract entities, numbers for example?

The one area of philosophy in which Platonism is constantly referred to is philosophy of mathematics. There was apparently a survey done by the American Mathematical Association and something like 98 per cent of mathematicians described themselves as “Platonists”. There is [in mathematics] very much a sense that you’re discovering rather than inventing. So this is a kind of commitment to the existence of the abstract, but necessarily in insolation [sic, isolation or insulation] from the physical — the structure of physical reality is given by the abstract, but the abstract can’t be reduced to sensory particulars. So it doesn’t have to involve a commitment to a kind of Platonic “heaven” that Russell, for example, makes fun of; it can be the claim that reality can’t be intelligible without referring to abstractions which cannot themselves be reduced to anything other than themselves.

Was Plato a Platonist? Well, there’s the Platonism of the forms which I think he gave up. In the Parmenides, he really criticises the theory of forms. It’s interesting that Socrates is a young man there and he can’t answer Parmenides’ questions. In the Timaeus, which is one of my favourite dialogues, it’s not the forms, it’s mathematics that is the key to intelligibility.

Every theoretical physicist I’ve ever known has believed that not only is reality given to us in the language of mathematics, but that when we have two empirically adequate theories, you go with the one that has the most beautiful mathematics — that’s in the Timaeus too. That’s a Platonism that’s still working. When my scientist friends say that the structure of reality is given in the most beautiful mathematics, I say to them, “That’s a metaphysical argument you’re using right there.” Steven Weinberg said of string theory, “Maybe it’s not true, but we’re going to find some application for it, because never in the history of science has it been the case that such beautiful mathematics didn’t somehow reveal reality.” Whoah! That’s Plato!

Those physicists are misguided. There is lots of beautiful math, such as p-adic numbers, that give a mathematical reality but not a physical reality.

There are hundreds of papers on P-adic quantum mechanics, so apparently some people believe in physical p-adics. I haven't read any of those papers, but I am going to go out on a limb here, and say that I am skeptical.

Established 500 years ago by observations

Leftist-atheist-evolutionist professor Jerry Coyne writes:

Dear Yiddish Girl,
Regardless of what “we Jews believe” — and I consider myself a secular Jew — you’re simply wrong about the Sun going around the Earth. The truth about that, which is the reverse, was established 500 years ago by observations, and only those blinded by adherence to ancient books of fiction could think otherwise. —Professor Ceiling Katz

As a matter of historical accuracy, this is not correct. Observations never established that the Earth went around the Sun, and early XX century relativity proved that such establishment was impossible.

Heliocentrism was proposed in ancient Greece over 2000 years ago, and by Copernicus in 1543. It became generally accepted in the 17th century based on theory, not observation. Proof that the Earth was not an inertial frame and that it moved relative to the distant stars did not come until much later.

Here is a new paper on 18th century Catholic scholarship:

The general prohibition of books advocating heliocentric theory put many progressive Jesuits in a difficult position. One of the most prominent Jesuit scientists of the 18th century, Rogerius Boscovich, was in particularly affected by conflicts between a beautifully simple theory of gravity by Newton, his Jesuit peripatetic education, Church doctrine and the lack of crucial experimental evidence for the motion of the Earth. I present the development of Boscovich's ideas prior to the lifting of the ban, and his retrospective considerations in later writings. These show that Boscovich's acceptance of the motion of the Earth was primarily driven by the existence of a working physical theory that also explained the motion of the Earth, and the lack of a consistent theory that supported any variation of a geocentric system.

So Newton had a heliocentric theory that was a lot more persuasive than any geocentric theory, but the observational evidence was more recnt.

Coyne also mocks the idea of a Biblical Adam and Eve, but again does not give science to back up his view. The academics have redefined hominid to include apes, to emphasize that humans and apes are all the same. But if we define human in a way that distinguishes us from apes, then there must have been a first human. It seems possible that there were two crucial genes that made us human, and a first Adam had one and mated with a first Eve with the other. Or perhaps there was a first Adam and Eve that made sudden progress in some non-genetic way, such as discovering tools or language or moral responsibility.

Admittedly a more gradualist view seems much more likely, with each generation barely distinguishable from the one before. And no one is going to dig up bones for Adam and Eve, so evidence for them will be very difficult.

The Bible itself is somewhat ambiguous about whether there were other people around with Adam and Eve, and most Bible students do not take a strictly literal interpretation.

I really don't mind Coyne and others launching scientific attacks on religious beliefs. I just think that they should get the science and the facts right. If science has ruled out certain religious views of Adam and Eve, I would like to see the explanation, with cites to the scientific literature.

Update: Coyne backtracks here, and asks readers whether the Earth goes around the Sun.

Inspired by Einstein to do meaningless theory

A SciAm writer interviews:

Horgan: Why did you become a physicist?

Smolin: I decided to become a physicist one spring evening when I was 17, as a result of reading Einstein’s autobiographical notes. He wrote that quantum mechanics needed a completion, which must include its unification with general relativity. At that moment I was a high school dropout planning to study architecture; but suddenly I was seized with the idea that I could follow Einstein, become a theoretical physicist and work on those two problems. That has defined my life.

How many physicists wasted their lives with such a delusion?

Most of what Einstein said on this topic was nonsense. He did not accept quantum mechanics, and there is no practical conflict between quantum mechanics and relativity. He induced a couple of generations of theorists to pursue untestable ideas according to a warped idea of what science is all about. This is largely why I wrote my book, How Einstein Ruined Physics. Smolin once gave this definition of science:

Science is not about what's true, or what might be true. Science is about what people with originally diverse viewpoints can be forced to believe by the weight of public evidence.

So if they convince the experts that we live in an 11-dimensional multiverse, then that is science whether it is true or not, according to Lee Smolin.

People think that Smolin has a reasonable view of science because he wrote a book critical of string theory. But if you read his book to the end, his beef is that he is much more radically anti-science than the string theorists. He and the multiverse proponents almost make the string theorists sound reasonable.

New 2015 FQXi essay contest

FQXi has announced a new essay contest"

The theme for this Essay Contest is: "Trick or Truth: the Mysterious Connection Between Physics and Mathematics".

In many ways, physics has developed hand-in-hand with mathematics. It seems almost impossible to imagine physics without a mathematical framework; at the same time, questions in physics have inspired so many discoveries in mathematics. But does physics simply wear mathematics like a costume, or is math a fundamental part of physical reality?

Why does mathematics seem so “unreasonably” effective in fundamental physics, especially compared to math’s impact in other scientific disciplines? Or does it? How deeply does mathematics inform physics, and physics mathematics? What are the tensions between them — the subtleties, ambiguities, hidden assumptions, or even contradictions and paradoxes at the intersection of formal mathematics and the physics of the real world?

This essay contest will probe the mysterious relationship between physics and mathematics.

I have submitted essays in the past. One of them was actually leading in the ratings at one point, but none of them won any prizes.

These are mainly physicists who are always going nuts with wild speculations about multiverses, quantum teleportation, and stuff like that. So they do not like my positivist and skeptical attitudes.

They do not give prizes to the more speculative essay either. You cannot say something that the judges think is false. Some of the winning essays are interesting, but most do not say much.

One question seems to be influenced by one of my essays:

What would it mean for something in the physical world to be NOT describable or model-able in terms of mathematics?

My 2012 essay said:

Much of modern theoretical physics assumes that the true nature of reality is mathematics. This is a great mistake. The assumption underlies most of the paradoxes of quantum mechanics, and has no empirical justification. Accepting that the assumption is wrong will allow physics and mathematics to progress as distinct disciplines. ...

The 2011 FQXi essay contest asked, “Is Reality Digital or Analog?” The answers accepted the premise that reality had to be one or the other, and no one admitted the possibility that it might be neither because both are mathematical.

I could be wrong, of course, but I seem to be the only one who seems to have considered the possibility that fundamental physics is not describable by math.

Doing without causal talk

Philosopher Massimo Pigliucci posted arguments against causal reductionism, whatever that is, and commented:

To begin with, because it is well established in philosophy of science that “special sciences” (i.e., everything but fundamental physics, including non-fundamental physics) do effectively deploy causal talk and cannot, apparently, do without it [9]. The puzzle of causal vs non-causal talk in science has always been at the fundamental level. ...< It simply means that explanation in the special sciences always invokes — or seeks to invoke — causality. This is not the case, or rarely so, in fundamental physics.

I replied:

SciSal, you have said before that fundamental physics has no use for causal talk, and yet it is shown to you that Einstein and the physics textbooks use causal language. Causality is indeed central to fundamental physics, and I defy you to show me some part of physics that does not use causality.

You say that it is "well established in philosophy of science" that fundamental physics can do without causality. Maybe so, but I doubt that you can find one physics textbook anywhere that agrees.

It is also false to say "the field equations of GTR do not explicitly include any causal talk". Those equations are hyperbolic partial differential equations, and solutions are causally determined by the Cauchy data. The GTR equations are as explicitly causal as any equations in all of science.

Maybe you are using some peculiar concept of causality. I do not see why P1 (no causation) would imply C (causal reductionism). I would say that all fundamental physics is based on causality, and that is the best basis for causal reductionism.

No one has to accept all solutions to GTR equations, such as time-like curves and backwards causation. It has always been understood that these equations constrain reality, but that lots of solutions are likely to be unphysical for other reasons.

I also disagree with your claim that "we know" that GTR is not a fundamental theory. It is as fundamental as anything in physics. Even the string theorists, who argue that string theory is the truly fundamental theory, take GTR as one of their premises.

SciSal, you say that there is no causality in fundamental physics, but then you say that none of the known theories are fundamental. So your statement is vacuous.

As Coel explained, quantum mechanics is causal. So is string theory. Both formally and in interpretation. The details are in any textbook.

I looked at your references, and only Raatikainen addresses it most directly:

... that there is genuine causation only at the fundamental micro-physical level. It would be important to note, though, that this is emphatically not how numerous distinguished philosophers of physics and experts in the theory of causation view the issue. ...

Now, in what follows, I do not want to commit myself to the view that there is no causation in fundamental physics – I do not even want to pretend that I am competent to judge the issue. However, it is important to keep in mind that many able philosophers have concluded this. But be that as it may, it just is not the case – contrary to what numerous physicalistic metaphysicians take for granted – that causation is uncontroversially present in fundamental physics. Therefore, such philosophers should perhaps think twice before declaring, from the armchair, that there is causation only at the fundamental physical level.

He is saying that people who understand physics say that causation is uncontroversially present in fundamental physics. Philosophers say the opposite. He does not understand physics, so he is not judging.

He also says:

To begin with, it is a historical fact that the notion of cause has disappeared from physics as the subject has developed (see Kuhn 1971; cf. Loewer 2001). More importantly, many philosophers who apparently know their physics have argued that the whole idea of causation is not even applicable to fundamental physics, or is incompatible with it. Very briefly, and roughly, one of the problems is that in some cases, one has to specify the entire state of the whole universe at one time in order to determine the state of even a small region at some later time. And in such a case, it is difficult indeed to consider anything as a cause (Latham 1987, Redhead 1990, Field 2003, cf. Loewer 2001, Hitchcock 2007, Elga 2007; this idea goes back, of course, to Russell 1912-13).

Yes, Russel said this, as I pointed out before. But this is crazy stuff. Almost every word of that paragraph is false. In particular, it is not true that "one has to specify the entire state of the whole universe at one time". It is akin to astrology to believe that things are affected by the distant universe. The physics textbooks say that this is impossible. I assure you that Nobel prizes would be given to anyone who could show that the entire state of the universe was needed to determine the state of a small region.

This is another example of how modern philosophy has diverged from science. Every single reference is over a century out of date in its understanding of science. It was foolish when Russell said it in 1913, and it is more foolish today.

I did not know Kuhn (Mr. Paradigm Shift) wrote an essay attacking causality. I could not find it online.

This is weird. I don't want to pick on Pigliucci, because he appears to be just reciting conventional wisdom among philosophers of science. But physics is all about causality, such as predicting the future from the present. I don't know how anyone could get any other impression. What do they think physics is about, if not causality?

Update: Pigliucci now says:

Let me try a different take: there are degrees of fundamentality, where, for instance quantum mechanics is more fundamental than relativity, and string theory (if true) would be more fundamental than QM. The point is that the further “down” one goes the less there seems to be need for talk of causality. ...

At the very least I don’t understand how a formalism (i.e., a set of equations) can be causal. It’s math, not physics. It becomes physics only once it is given a particular interpretation. Beyond that, QM for instance describes the probabilities of certain events without invoking talk of causes. When we predict the spontaneous decay of an atom or particle, for instance, we just say that it happens with probability X, we don’t say “and it is caused by Y.” ...

I don’t count nomological entailment as causation.

I have criticized him before on this point, and I am trying to figure out how he could be so wrong. He seems to be saying that if physics ever finds a truly fundamental theory, where everything is reduces to equations, then there will be just nomological entailment and not causality. Nomological means "relating to or expressing basic physical laws or rules of reasoning".

To me, this is like saying: "Energy does not arise in physics. In a fundamental theory, energy is described by formulas, and a formula is not the same as energy." It is just playing some stupid word game and pretending that it is profound.

Update: I posted:

I think that the argument is that if the laws of physics are explaining why "punching John in the face caused his nose to break", then we do not need causality anymore. That is, it is not really causality once it is understood. This reminds me of the philosophers who say that artificial intelligence (like playing chess) is not really intelligence once it becomes a cheap app on your smart phone.

QM for instance describes the probabilities of certain events without invoking talk of causes. When we predict the spontaneous decay of an atom or particle, for instance, we just say that it happens with probability X, we don’t say “and it is caused by Y.”

That was true a century ago. Physicists could measure the half-life of a radioactive element, and thereby say that the atom decays with probability X, but beyond that, spontaneous events were mysterious. Then quantum mechanics was discovered as a way to find causal explanations. Physical states are described by a wave function, time evolution is governed by a differential equation, and probabilities of (apparently spontaneous) events are given by a Hilbert space operators.

Quantum mechanics is routinely applied to explain and predict chemical reactions, silicon chips, lasers, and much of modern technology. The explanations are completely causal, or you would not be able to read this message. While it might seem that your computer is spontaneously sending a signal, every component is designed with a causal understanding of how a state at one time is causing a state at a nanosecond later.

I would go further, and say that incorporating causality into fundamental physics was the most important intellectual achievement in modern times. Before 1850, we did not have causal explanations for any of the four fundamental forces. Now we have fully causal theories for all four, and those theories have led to the most striking technological progress in the history of the planet.

Panu, I appreciate your clarification, but it does appear that all the physicists believe that causation is present in fundamental physics, and all the philosophers believe the opposite. This is a funny controversy, because it does not appear that any philosophers actually talk to any physicists. If they did, then no one would say "it is a historical fact that the notion of cause has disappeared from physics as the subject has developed".

As usual, Pigliucci says I am wrong.

Update: Here is a good page on why scientists disrespect philosophers.

Update: After I claim that the philosopher understanding of quantum mechanics was a century out of date, someone claiming to be a physicist tries to rebut me by citing an authority from 1916! Supposedly that 1916 theory showed that quantum mechanics was probabilistic and hence not causal. So he is only 99 years out of date. Here was my post:

Mathias Frisch does indeed say, "According to a view widely held among philosophers of science, the notion of cause has no legitimate role to play in mature theories of physics." He is not too interested in the opinions of physicists except to note that a popular modern textbook says that the principle of causality is "the most sacred tenet in all of physics". Elsewhere I found a philosophy book that said that physicists adhere to "causal fundamentalism, which claims that the job of all of physics is to uncover the prevalent causal relations in nature." So yes, there is a severe split between philosophers and physicists on this issue.

Dominik, in EM theory the fields at some spacetime point are caused by the fields and waves in the backwards light cone from that point, as per Maxwell's equations. And yes, that has commonly been called causation for 150 years.

You seem to be saying that causality in GR is not fundamental because gravity waves are emergent. However there is not any (relevant) distinction between fields and waves in GR. Not in EM either. The Sun causes the Earth to stay with a gravity field. You can think of it as the Sun sending gravity waves to the Earth, altho the ripples in the waves are not detectable. If you admit that the waves are causal, then you have to admit that the fundamental field is causal.

Marko, all of the sciences talk about probabilities, so that talk does not make anything "really spontaneous". And whether or not it is really spontaneous does not have anything to do with causality. Something can be caused whether spontaneous or not. Maybe there are philosophers of science who think that causality is restricted to deterministic systems, but not physicists.

You say that redshifts are caused, but that QM does not provide causal explanations. If you are really a physicist, then you surely know that those redshifts are displacements of spectral lines that are entirely explained by QM. So what are you trying to say, that there is no causal explanation for the lines, but there is one for the shifts in the lines? You will not find anything like that in a physics textbook.

Marko confirmed that I was stating his causality theory correctly.