MWI is the strangest and least believable thing

In Sam Harris and Sean Carroll DEBATE Free Will & Laplace's Demon - YouTube, we get a discussion of many-worlds:

Sam Harris [at 4:00]: This is supposed to be science, right?

It sounds like the strangest and least believable thing [inaudible] So how is it that science, after centuries of being apparently rigorous, and parsimonious, and hard-headed, finally disgorges a picture of reality which seems to be the least believable thing that anyone has ever thought of?

Sean M. Carroll: You've come to the right place!

Carroll goes on to explain his beliefs in many-worlds quantum mechanics, block universe, Laplace's Demonm, determinism, and time reversibility.

The fact that we think we have free will, and we remember the past instead of the future, is all just a psychological illusion caused by the increase in entropy.

I wonder how Carroll ever got to be a physics professor. He is entitled to believe in whatever gods he chooses, but he represents these opinions as consequences of modern science. They are not.

Harris's question nails it. Scientists were rigorous, parsimonious, and hard-headed for centuries, but now the public image of science is dominated by professors like Carroll who present the least believable ideas.

A recent New Scientist article on how to think about the multiverse quotes him:

“One of the most common misconceptions is that the multiverse is a hypothesis,” says Sean Carroll at the California Institute of Technology in Pasadena. In fact, it is forced upon us.” It is a prediction of theories we have good reason to think are correct.”

If the multiverse really were a hypothesis, it would be testable. No, the multiverse is just some anti-positivist philosophical belief that has no empirical support, and does not follow from any accepted theory.

For someone who doesn't believe in libertarian free will, Carroll is intolerant of those who disagree with his leftist agenda. He is sympathetic to a restaurant for refusing to serve a Trump White House employee!

I would think that a science professor, who likes to talk about how great science is, would happily promote the open exchange of political ideas. But no, he apparently thinks that leftist Democrats should not necessarily be civil to Trump supporters.

Bell test experiments explained

Eight physicists have written an excellent new paper explaining quantum mechanics from the viewpoint of the Bell test experiments:

Understanding quantum physics through simple experiments: from wave-particle duality to Bell's theorem

Quantum physics, which describes the strange behavior of light and matter at the smallest scales, is one of the most successful descriptions of reality, yet it is notoriously inaccessible. Here we provide an approachable explanation of quantum physics using simple thought experiments that deal with one- and two-particle interference. We derive all relevant quantum predictions using minimal mathematics, without introducing the advanced calculations that are typically used to describe quantum physics. We focus on the two key surprises of quantum physics, namely wave-particle duality, which deals with the counter-intuitive behavior of single quantum particles, and entanglement, which applies to two or more quantum particles and brings out the inherent contradiction between quantum physics and seemingly obvious assumptions regarding the nature of reality. We employ Hardy's version of Bell's theorem to show that so-called local hidden variables are inadequate at explaining the behavior of entangled quantum particles. This means that one either has to give up on hidden variables, i.e. the idea that the outcomes of measurements on quantum particles are determined before an experiment is actually carried out, or one has to relinquish the principle of locality, which requires that no causal influences should be faster than the speed of light. Finally, we describe how these remarkable predictions of quantum physics have been confirmed in experiments. We have successfully used the present approach in a course that is open to all undergraduate students at the University of Calgary, without any prerequisites in mathematics or physics.

It concludes:

Bell's theorem indicates a deep contradiction between quantum physics and EPR's seemingly obvious assumptions about reality. Surprisingly, experiments demonstrate quantum physics to be correct and rule out the intuitively appealing possibility of local hidden variables. This implies that measurement outcomes are either not predetermined at all, or they are determined by nonlocal hidden variables, such as Bohm's pilot wave model.

My only quibble with this is that it is a sloppy about the alternatives to hidden variables.

Yes, experiments have ruled out local hidden variables. Nnonlocal hidden variables are possible but foolish; who wants a theory where inaccessible variable have magical effects at a distance? Such theories are useless and misleading.

This leaves us to conclude, according to the paper, "that measurement outcomes are either not predetermined at all". In other words, it says, we must reject "the idea that the outcomes of measurements on quantum particles are determined before an experiment is actually carried out".

There are actually two possibilities here. One is that photons, and other quantum objects, have a free will of their own where they can decide what properties they will have, within the range of possibilities. That is, the physics is not determinist.

The other possibility is that the outcomes are all predetermined in some physical sense, but not as mathematical variables like real numbers.

Suppose you fire a photon at a screen, thru a double slit. Maybe its path is determined once it passes the double slit. Maybe it is determined even before the slit. Maybe the photon is still deciding what it wants to be right up to the point that it hits the screen. Our experiments cannot really distinguish between this possibilities.

What we can say is that you cannot model the photon by introducing some non-measured variables like which slit the photon is passing thru. It doesn't work. The experiments show that.

My view is that we do measurements with real numbers because that is the only way we know how to make observations. But there is no reason to believe that a photon can be fully described by real numbers. Photons are strange objects. So are real numbers. But they are not the same.

If you have a single electron, then it appears that you can describe it by a wave function okay. The above paper does a good job of explaining this. But with two particles, they can be entangled. Then wave functions can still predict experiments, according to quantum mechanics, but they don't truly match what appears to be the photon internal structure. After all, photons appear to behave locally, but the wave functions seem somewhat nonlocal in the case of an entangled measurement.

Quantum mechanics is s positivist theory. It predicts experiments, and if that is all you require, then it is a complete theory. But if you think that you are representing the true internals of a photon with wave functions, forget it. It cannot be done. The wave functions are just tools for predicting experiments. The photons could be sentient beings with their own free will and God-given souls, for all we know, as long as they are constrained to obey quantum mechanics.

There are a lot of papers on Bell's theorem that make strong conclusions because of faulty assumptions about reality. The above paper does an excellent job of explaining the experiments that must be accepted. The experiments are not really that strange, as they do not show nonlocality or pilot waves or anything that bizarre. Quantum mechanics is not really so strange, if you let go of your preconceptions about how photons can be modeled.

Note: Quantum field theory teaches that photons are not really fundamental, and discussions about photons like the above are convenient simplifications of fields.

Was relativity positivist or anti-positivist?

A famous string theorist wrote:

Albert Einstein famously believed that, given some general principles, there is essentially a unique way to construct a consistent, functioning universe.

That is much of the rationale behind string theory. Ignore experiment, follow abstract principles, and devise laws of nature.

Put another way, he believed in a top-down approach, instead of a bottom-up approach. See recent postings by Allanach, Lumo, and Bee. They would all like to believe in the top-down approach, but they differ in the extent that they are willing to reconsider their beliefs in the face of contrary LHC evidence.

Sabine Hossenfelder (aka Dr. Bee) has a new book, Lost in Math, that critcizes various purely mathematical approaches to theoretical physics that have failed to get any empirical results. I have not read it.

Some people think that Einstein did this top-down approach with relativity. That is, he just adopted some philosophically attractive postulates, and derived special relativity.

That is not exactly what happened. Maxwell developed his electromagnetic theory from experiments by Faraday and others, and noticed a paradox about the motion of the Earth. The Michelson-Morley experiment tested Maxwell's ideas, and found a symmetry of nature that was not obviously apparent in his equations. Lorentz found a way to reconcile the theory and experiment. Poincare showed that the Lorentz transformations generated a symmetry group for 4-dimensional spacetime, and that Maxwell’s equations could be understood geometrically on spacetime. Einstein adopted two of Lorentz's theorems as postulates, and showed how they could be used to derive the Lorentz transformations. Minkowski elaborated on the non-Euclidean geometry of Poincare’s spacetime, and formulated the version of special relativity that became popular at the time.

There are philosophers who say that getting relativity from experiment is just positivist propaganda. They say Einstein ignored the Michelson-Morley and other experiments, and applied non-empirical thinking. Polyanhi even said that special relativity was proposed "on the basis of pure speculation, rationally intuited by Einstein before he had ever heard about it."

So Einstein’s 1905 special relativity paper is widely praised, but some praise it for being positivist, and some for it being anti-positivist!

It was not really either, because it was just an exposition of the ideas of others. The theory was created by Lorentz, Poincare, and Minkowski, and they all explicitly relied on empirical findings in their papers, and did their work independently from Einstein.

I don’t think physics has ever had substantial advances from anti-positivist thinking.

But if there were to be an anti-positivist invention of relativity in some alternate universe, what would it look like? That is what I wish to propose in several subsequent posts.

Quantum mechanics has no action-at-a-distance

Stephen Boughn writes:

There Is No Action at a Distance in Quantum Mechanics, Spooky or Otherwise

I feel compelled to respond to the frequent references to spooky action at a distance that often accompany reports of experiments investigating entangled quantum mechanical states. Most, but not all, of these articles have appeared in the popular press. As an experimentalist I have great admiration for such experiments and the concomitant advances in quantum information and quantum computing, but accompanying claims of action at a distance are quite simply nonsense. Some physicists and philosophers of science have bought into the story by promoting the nonlocal nature of quantum mechanics. In 1964, John Bell proved that classical hidden variable theories cannot reproduce the predictions of quantum mechanics unless they employ some type of action at a distance. I have no problem with this conclusion. Unfortunately, Bell later expanded his analysis and mistakenly deduced that quantum mechanics and by implication nature herself are nonlocal.

He has some additional argument in Making Sense of Bell's Theorem and Quantum Nonlocality.

He is correct. His explanations are routine textbook stuff, with nothing particularly original. None of it would need to be said, except that most of the popular explanations of quantum mechanics insist on saying that the theory is nonlocal. Some physicists even say this. Some even say that Bell proved it.

Boughn's explanations are clear enough, but it would have been nice if he quoted the respectable authorities who say that quantum mechanics is nonlocal. it would prove that he is not attacking a straw man, and justify writing a paper to explain some textbook material.

For Solstice, celebrate Earth's uniqueness

Astronomers are always claiming that they found a distant planet that might support life, or that there must be millions of Earth-like planets in our galaxy.

But there may be no others. Earth has many unusual properties that are essential for life, and that may never be found elsewhere.

The NY Times reports:

As you mark the longest day of the year, consider the debate among astronomers over whether Earth’s tilt toward the sun helps make life on our world and others possible. ...

The solstice occurs because Earth does not spin upright but leans 23.5 degrees on a tilted axis. Such a slouch, or obliquity, has long caused astronomers to wonder whether Earth’s tilt — which you could argue is in a sweet spot between more extreme obliquities — helped create the conditions necessary for life. ...

Is life only possible on an exoplanet with a tilt similar to ours? ...

Mars’s slouch, for example, is currently akin to Earth’s at 25.19 degrees, but it shifts back and forth between 10 degrees and 60 degrees over millions of years. That means that the seasons and climate of the red planet — which is currently experiencing an extreme dust storm — vary wildly. That could create conditions that make life impossible.

Take Earth as an example. Although our planet’s obliquity is relatively constant, it does change by a mere few degrees. Such slight variations have sent vast sheets of glaciers from the poles to the tropics and entombed Earth within a frozen skin of solid ice. Luckily, Earth has managed to escape these so-called snowball states. But scientists are not sure whether the same will be true for planets like Mars with larger variations in their tilts. ...

As such, a stable tilt just might be a necessary ingredient for life. It’s an interesting finding given that the Earth’s tilt never changes drastically thanks to the Moon. And yet astronomers don’t know how common such moons are within the galaxy, said John Armstrong, an astronomer at Weber State University in Utah. If they turn out to be uncommon across the galaxy, it could mean that such stability — and therefore life — is hard to come by.

That's right, the Earth has a tilt that is stabilized by the Moon, giving regular seasons over billions of years. Having a single large moon is probably very unusual.

Earth also has large amounts of surface water, geologic activity (volcanoes and plate tectonics), a large variety of minerals, etc. It also has a huge outer planet, Jupiter, to further stabilize the orbit. There are probably many other such factors that I don't even know about.

We don't have the ability to detect whether distant planets have these features. But common sense would indicate that they would be very unlikely. I think it is likely that Earth has the only intelligent life of this galaxy.

Standard Model of Physics at 50

Yvette Cendes writes in SciAm:

The Standard Model (of Physics) at 50

It has successfully predicted many particles, including the Higgs Boson, and has led to 55 Nobels so far, but there’s plenty it still can’t account for

Just over a half-century ago, the physicist Steven Weinberg published a seminal paper titled “A Model of Leptons in the journal Physical Review Letters.” It was just three pages long, but its contents were revolutionary: in the paper, Weinberg outlined the core of the theory now known as the Standard Model, which governs elementary particles.

If this was really such a great paper, then why didn't anyone notice at the time?

As you can see here, it was only cited once in 1968 (by Salam), once in 1969, and once in 1970.

The paper proposed a model for electroweak interactions. It was the same as quantum electrodynamics, except that the gauge group was U(2) instead of U(1), a Higgs field was added to make the weak force short range, and no one knew how to cancel the infinities.

The idea of using U(2) for weak/electroweak was due to Schwinger and Glashow in 1961, and the idea of using a Higgs was due to Higgs and others in 1964. A scheme for canceling infinities in a gauge theory was published by 'tHooft in 1970.

So Weinberg's paper was no big deal at the time. It did not solve any physical problem. It wasn't much of a theory, because he had no way of computing anything. By 2015, it had 9289 citations, no. 2 on the list.

I am not trying to put down Weinberg, but he and Salam lucked into that Nobel prize. The works of Higgs and 'tHooft were more essential to creating the Standard Model.

The SciAm author ends with a complaint about a physics party:

And one Nobel laureate, who shall go unnamed, proceeded to frame our introduction by stating I was clearly invited because I was pretty, and that I looked old enough to finish my PhD already. (The Nobel Prize in Physics is still such an old boys club that only two women have ever won the prize out of 207 recipients. The last was in 1962 — a greater gap than in any other field, and not for a lack of good scientists.)

I guess she is saying that female physicists were unfairly deprived of Nobel prizes, but maybe they were too pretty, or taking care of babies instead of finishing a PhD.

Video rant against Jewish Physics

I just found an amusing video from a couple of years ago titled Weev talks about relativity. Weev is a well-known internet troll, and doesn't actually say much about relativity, but has two others talking about relativity.

While they talk, the video shows flashes of Donald Trump, and news footage related to Trump. I guess this was posted during Trump's campaign for the Presidency, and Weev was a Trump supporter.

One rants about "Jewish Physics", while the other is a skeptic. The main guy talks about how physics has gotten away from experiment, and says a lot of it is "academic circle jerk ... like the epicircles of astronomy". He means "epicycles".

He argues that Einstein's special relativity was just untestable philosophical ideas, not physics. He just took the math and theory from Lorentz's papers of 10 years earlier, and added some untestable philosophical re-imagining about there being no place of rest. Weev adds that Einstein did not cite his sources.

The skeptic doubts that there could be a Jewish conspiracy about such matters, and the main guy says that it is not really a conspiracy, and not just Jews. It is more a matter that Jews like philosophical unscientific ideas.

The explanations are a little garbled, but most of it is essentially correct. It is true that Einstein's famous 1905 special relativity theory was mathematically and observationally equivalent to what Lorentz has already published, and what Einstein failed to cite. Historians of science agree to this.

It is also true that saying that there is no rest frame, or no aether, is just untestable philosophy. It does not add anything useful to Lorentz's theory.

You might say that it is testable, because you could prove Einstein wrong by finding a rest frame or aether. In fact, you can define a rest frame in terms of the cosmic background microwave radiation, and an aether in terms of the quantum electrodynamic vacuum, but nobody says this proves Einstein wrong.

You might say that Einstein's 1905 paper was a big advance if it were conceptually superior, or if led to other advances in the field. But that is not true. Einstein's approach was not seen as being much different from Lorentz's at the time. The conceptually superior approach was considered to be the spacetime geometry relativity of Poincare and Minkowski, and subsequent work built on Minkowski's, not Einstein's.

Einstein has sort of a cult following, and most of the followers appear to be non-Jews. So how is this Jewish Physics?

The term "Jewish Physics" is inaccurate and unnecessarily inflammatory, but there can't be any doubt that Einstein is a Jewish saint. He was aggressively promoted and idolized by Jews. I hesitate to call it a religious thing, as Einstein was not very religious and it is the secular Jews who idolize him, not the orthodox Jews.

It is also hard to separate Einstein's science from his ideological beliefs. His deepest beliefs include Zionism, determinism, Jewish pantheism, anti-positivism, and Communism. When he attacks quantum mechanics, he relied on his anti-positivism and determinism. When he promoted his version of relativity over that of Lorentz, he relied on his beliefs, and not any math or empirical science.

You would think that his membership in Communist front organizations would detract from his popularity, but it does not seem to have had any such effect. It is also well-known that Einstein did not really contribute anything to special relativity, as Whittaker explained it in his 1953 book.

Einstein did have substantial scientific accomplishments, but not nearly enough to be TIME Man of the Century. Idolizing him is largely ideological.

On another topic, some freshman physics courses give a problem on what would happen if everyone in China jumped up and down at the same time. Pure fiction, right? Apparently everyone in Mexico jumped at the same time, and it caused an earthquake!