Wednesday, July 31, 2019

Newton would accept modern physics

A reader sends me this Nautilus interview from last year:
Kuhn’s popular because of his phrase, “the paradigm shift.” The idea, roughly, is that Einstein came along and displaced Newton. He superseded the old view about the universe and now Newtonians couldn’t talk with Einstein’s people because they had two fundamentally different versions of reality.

And this is nonsense because of course scientists talk to each other all the time. We are endlessly changing the nature of science without losing our ability to communicate with each other about it. It’s inconceivable to me that Newton and Einstein, if they had the opportunity to get together and carry on a conversation, would have stared at each other in kind of mute incomprehension. ...

So Kuhn’s idea, correct me if I’m wrong, is that to some degree we’re always trapped inside of our own biases, our own theories. We can’t see beyond the paradigm. And this stays on until a new paradigm comes along and then our view becomes outdated.
If Isaac Newton could somehow be brought from the past and educated in XX century physics, he would certainly reject Kuhnian ideas that the newer physics was revolutionary or incommensurable.

I think that Newton would conclude:

1. Newtonian physics is still considered valid on scales far beyond any he proposed or contemplated.

2. Relativity solves the problem of how gravity is transmitted at finite speed. (Poincare solved this in 1905 based on Lorentz's ideas; Einstein had nothing to do with it.)

3. The only planetary orbit requiring a post-Newtonian correction requires centuries of observations to get a very slight effect.

The modern philosophical ideas about scientific revolutions are complete nonsense. Physics has advanced a lot since Newton, but not so much that Newton would think that he had been proved wrong, or that he would find the new physics unrecognizable.

Monday, July 29, 2019

Dr. Bee endorses superdeterminism

Sabine Hossenfelder is usually fairly sensible, but now she has gone off the deep end:
A phenomenologist myself, I am agnostic about different interpretations of what is indeed the same math, such as QBism vs Copenhagen or the Many Worlds. ...

I find superdeterminism interesting ...

The stakes are high, for if quantum mechanics is not a fundamental theory, but can be derived from an underlying deterministic theory, this opens the door to new applications. That’s why I remain perplexed that what I think is the obvious route to progress is one most physicists have never even heard of. Maybe it’s just a reality they don’t want to wake up to. ...

Really, think about this for a moment. A superdeterministic theory reproduces quantum mechanics. It therefore makes the same predictions as quantum mechanics. (Or, well, if it doesn't, it's wrong, so forget about it.) Difference is that it makes *more* predictions besides that. (Because it's not probabilistic.)
I don't know how anyone can say that Copenhagen, Many Worlds, and superdeterminism all make the same predictions.

Not only is that false, but Many Worlds and superdeterminism are so absurd that there is nothing scientific about either one. They don't make any predictions. They are amusing philosophical thought experiments, but they have no "same math" as anything with any practical utility. They are like saying that we all live in a simulation, or as a figment of someone's imagination. Not really a scientifically meaningful idea.

I really wonder what Dr. Bee's conception of probability is, that she says these things. There is no way to make sense out of probability, consistent with her statements above. Maybe physics books never teach what probability is. I don't know how anyone can get it this wrong.

Wednesday, July 24, 2019

We have past our peak

Everyone celebrated the 50th anniversary of the Moon landing, leaving many to wonder if we will ever do anything so great again. It is like the Egyptian pyramids -- a symbol of a once-great civilization.

Bruce Charlton claims:
I suspect that human capability reached its peak or plateau around 1965-75 – at the time of the Apollo moon landings – and has been declining ever since.
The Woodley effect claims that intelligence has been declining for a century.

Another guy claims science is dead:
Briefly, the argument of this book is that real science is dead, and the main reason is that professional researchers are not even trying to seek the truth and speak the truth; and the reason for this is that professional ‘scientists’ no longer believe in the truth - no longer believe that there is an eternal unchanging reality beyond human wishes and organization which they have a duty to seek and proclaim to the best of their (naturally limited) abilities. Hence the vast structures of personnel and resources that constitute modern ‘science’ are not real science but instead merely a professional research bureaucracy, thus fake or pseudo-science; regulated by peer review (that is, committee opinion) rather than the search-for and service-to reality. Among the consequences are that modern publications in the research literature must be assumed to be worthless or misleading and should always be ignored. In practice, this means that nearly all ‘science’ needs to be demolished (or allowed to collapse) and real science carefully rebuilt outside the professional research structure, from the ground up, by real scientists who regard truth-seeking as an imperative and truthfulness as an iron law.

Monday, July 22, 2019

Free will is like magnetism and lightning

Leftist-atheist-evolutionist professor Jerry Coyne writes in Quillette:
... his a
rgument is discursive, confusing, contradictory, and sometimes misleading. ...

And you needn’t believe in pure physical determinism to reject free will. Much of the physical world, and what we deal with in everyday life, does follow the deterministic laws of classical mechanics, but there’s also true indeterminism in quantum mechanics. Yet even if there were quantum effects affecting our actions — and we have no evidence this is the case — that still doesn’t give us the kind of agency we want for free will. We can’t use our will to move electrons. Physical determinism is better described as “naturalism”: the view that the cosmos is completely governed by natural laws, including probabilistic ones like quantum mechanics.
So how does he lift a finger if he cannot use his will to move electrons?

There could be naturalism as well as free will. Perhaps consciousness and free are governed by natural laws, just like everything.

Saying that "the cosmos is completely governed by natural laws, including probabilistic ones" is just nonsense. If your laws are probabilistic, then they are not completely governing what happens. A probability is, by definition, and incomplete and indefinite statement about events.
As the physicist Sean Carroll has pointed out, ditching the laws of physics in the face of mystery is both unparsimonious and unproductive ...

Contracausal free will is the modern equivalent of black plague, magnetism and lightning — enigmatic phenomena that were once thought to defy natural explanation but don’t.
Remember that Carroll believes in the totally unscientific many-world interpretation. It would be better to listen to an astrologer on what is science.

I agree with his comparison of free will to magnetism. They seem mysterious only when they are not better understood.

"Contracausal free will" is just a term Coyne likes to make it sound self-contradictory. I say that he has libertarian free will to lift his finger. I would not call it contracausal, because his will causes his finger to rise, via blood, nerves, chemistry, and other natural processes.
For many reasons, belief in free will resembles belief in gods, including an emotional commitment in the face of no evidence, and the claim that subverting belief in either gods or free will endangers society by promoting nihilism and immorality. But a commitment to truth compels us to examine the evidence for our beliefs, and to avoid accepting illusions simply because they’re beneficial.
These atheists act as if they are making a compelling argument when they say "no evidence".

There is plenty of evidence for free will, just as primitive people had plenty of evidence for lightning.

There is also plenty of evidence for benefits to belief in free will. Just look at the difference between Christianity and Islam.

Friday, July 19, 2019

Yang 2020 wants quantum crypto

Presidential candidate Andrew Yang has this policy position:
However, quantum computers, using qubits, will theoretically be able to perform the calculations necessary to break our current encryptions standards in under a day. When that happens, all of our encrypted data will be vulnerable. That means our businesses, communications channels, and banking and national security systems may be accessible. ...

Second, we must heavily invest in quantum computing technology so that we develop our own systems ahead of our geopolitical rivals.
We must invest in the technology that will destroy our communications security infrastructure!

But don't worry, robots will take all our jobs and we can just collect $1k per month free and play video games all day.

It is nice to see a presidential candidate try to anticipate future trends, but I don't see this getting him any votes.

Wednesday, July 17, 2019

Early work on curved cosmological space

A new paper, Historical and Philosophical Aspects of the Einstein World, explains work on cosmological non-Euclidean geometry:
Pioneering work on non-Euclidean geometries in the late 19th century led some theoreticians to consider the possibility of a universe of non-Euclidean geometry. For example, Nikolai Lobachevsky considered the case of a universe of hyperbolic (negative) spatial curvature and noted that the lack of astronomical observations of stellar parallax set a minimum value of 4.5 light-years for the radius of curvature of such a universe (Lobachevsky 2010). On the other hand, Carl Friedrich Zöllner noted that a cosmos of spherical curvature might offer a solution to Olbers' paradox5 and even suggested that the laws of nature might be derived from the dynamical properties of curved space (Zöllner 1872). In the United States, astronomers such as Simon Newcomb and Charles Sanders Peirce took an interest in the concept of a universe of non-Euclidean geometry (Newcomb 1906; Peirce 1891 pp 174-175), while in Ireland, the astronomer Robert Stawall Ball initiated a program of observations of stellar parallax with the aim of determining the curvature of space (Ball 1881 pp 92-93; Kragh 2012a). An intriguing theoretical study of universes of non-Euclidean geometry was provided in this period by the German astronomer and theoretician Karl Schwarzschild, who calculated that astronomical observations set a lower bound of 60 and 1500 light-years for the radius of a cosmos of spherical and elliptical geometry respectively (Schwarzschild 1900). This model was developed further by the German astronomer Paul Harzer, who considered the distribution of stars and the absorption of starlight in a universe of closed geometry (Harzer 1908 pp 266-267).
It cites a 2012 Helge Kragh paper, Geometry and Astronomy: Pre-Einstein Speculations of Non-Euclidean Space, for more details.

The finiteness of the speed of light was first detected by astronomers, and that turned out to be more-or-less equivalent to spacetime being non-Euclidean. Poincare and Minkowski showed this in their relativity papers.

Efforts to find a large-scale cosmological curvature of space have failed. Gravity can be interpreted as spacetime curvature, but the universe seems flat on a large scale.

General relativity is commonly interpreted as gravity being spacetime curvature, but Einstein did not view it that way. He did not really buy into non-Euclidean geometry explanations as we do today.

Charles S. Peirce wrote in 1891:
The discovery that space has a curvature would be more than a striking one; it would be epoch-making. It would do more than anything to break up the belief in the immutable character of mechanical law, and would thus lead to a conception of the universe in which mechanical law should not be the head and centre of the whole. It would contribute to the improving respect paid to American science, were this made out here. . In my mind, this is part of a general theory of the universe, of which I have traced many consequences, - some true and others undiscovered, - and of which many more can be deduced; and with one striking success, I trust there would be little difficulty in getting other deductions tested. It is certain that the theory if true is of great moment.
This seems to be a clear anticipation of the possibility of curved space for cosmology.

Kragh writes:
While the possibility of space being non-Euclidean does not seem to have aroused interest among French astronomers, their colleagues in mathematics did occasionally consider the question, if in an abstract way only. As mentioned, many scientists were of the opinion that the geometry of space could be determined empirically, at least in principle. However, not all agreed, and especially not in France. On the basis of his conventionalist conception of science, Henri Poincaré argued that observations were of no value when it came to a determination of the structure of space. He first published his idea of physical geometry being a matter of convention in a paper of 1891 entitled “Les géométries non-euclidiennes,” and later elaborated it on several occasions.
I do think that this is a misunderstanding of Poincare's conventionalism.

Euclidean geometry is axiomatized mathematics. No observation can have any bearing on the mathematical truth of a theorem of Euclidean geometry. If Euclidean geometry turns out not to match the real world, then there are multiple ways to explain it. One could use Euclidean geometry as the foundation, or some other geometry.

That is surely what Poincare was saying. After all, Poincare was a pioneer in non-Euclidean geometry, and was the first to discover the non-Euclidean structure of spacetime. I have seen philosophers claim that Poincare was somehow opposed to geometrical interpretations of space, but I don't see how that could be true. He was simply distinguishing between mathematical and physical truths. Mathematicians consider the distinction to be very important, but physicists sometimes deny that there is a distinction.

Monday, July 15, 2019

No respect for MWI physicists

Lubos Motl has another explanation of what is wrong with the Many Worlds Interpretation:
The implicit assumption is that MWI can do "at least as well as Copenhagen, everyone can". Except that this statement is completely and totally wrong. ...

The MWI fairy-tales are among the top reasons why I lost my respect for many physicists who have done some nontrivial technical things. But they're just lousy thinkers if they can't figure out the lethal problems with the MWI above – in fact, they seem unable to figure out even 5% of those things. How much smarter the founding fathers of quantum mechanics were. They were able not only to understand them but to discover them in the first place – which is an achievement greater than a mere understanding, by many orders of magnitude.
I used to think that MWI was an interpretation, reproducing Copenhagen predictions. Then one's belief in it is a matter of metaphysical preference.

But it is not. MWI predicts nothing, and has no merits at all.

I agree with Lumo here. There are seemingly-competent physicists who endorse MWI, and I have lost all respect for them. MWI is such complete foolishness that anyone who endorses it should not be taken seriously on any scientific matter.

His arguments are somewhat different from the ones I have given here, but the end result is the same. There is no way to turn MWI into a useful theory. It is just a weirdo unscientific fantasy.

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