Wednesday, July 16, 2025

Relativistic Effects are Apparent, to do with Measurements

Dr. Bee announces 10 Physics Myths You Probably Believe!
@0:19 Quantum particles can be in two places at once
@1:08 Entropy is disorder
@2:28 Black holes suck in matter
@3:18 We all move at the speed of light
@3:49 The cosmological constant was the worst prediction ever
@4:31 Time stops at the speed of light
@5:15 Time only slows apparently
@6:16 Quantum particles exchange information faster than light
@7:40 Einstein was wrong about quantum physics
@8:10 Dark energy is anti-gravity
@9:21 Faster than light travel is incompatible with Einstein's theories
I have some quibbles. Black holes do suck in matter. Just look at a quasar:
A quasar (/ˈkweɪzɑːr/ KWAY-zar) is an extremely luminous active galactic nucleus (AGN). It is sometimes known as a quasi-stellar object, abbreviated QSO. The emission from an AGN is powered by accretion onto a supermassive black hole with a mass ranging from millions to tens of billions of solar masses, surrounded by a gaseous accretion disc. Gas in the disc falling towards the black hole heats up and releases energy in the form of electromagnetic radiation. The radiant energy of quasars is enormous; the most powerful quasars have luminosities thousands of times greater than that of a galaxy such as the Milky Way.
These black holes suck in so much matter that they are the brightest objects in the universe.

Einstein's criticisms of quantum mechanics only make sense if he believed in hidden variable theories, and those were shown impossible by Bell and others. So yes, I think Einstein was wrong.

And faster than light travel is incompatible with relativity. She says you can do it with infinite energy.

My biggest gripe is her explanation of time dilation:

5:00 But it’s not like if you run faster, then time runs slower. 5:05 Time only runs slower if you accelerate. That said, I need to follow this up immediately 5:13 with another common misunderstanding.

4. [It is a myth] That time slows in Einstein’s theory 5:18 is just an illusion or an apparent effect to do with measurements.

5:22 That’s not true. If you have a clock that is accelerated and you compare 5:27 it to one that isn’t accelerated, then the accelerated one ticks slower. An important 5:34 special case of this is sitting still in a gravitational field, as you probably do now, 5:39 because that means you’re accelerated. And the stronger the gravitational 5:44 pull at your location, the slower you age.

This means that for example time on the surface 5:51 of earth passes a little bit more slowly than on the surface of the moon. It’s a measurable, 5:58 real effect. But it’s so tiny that it doesn’t matter unless you need to synchronize something 6:03 to nanosecond accuracy. This is why NASA wants to introduce a moon time that’s separate from 6:10 Earth time, because these two times can’t be synchronized, they just run at different speeds.

This is wrong. The time dilation effect is based on velocity, not acceleration.

This relates to my recent post on Modern Interpretation of Length Contraction. There is likewise more than one way to interpret the time dilation. The preferred interpretation is that it is geometric effect, that shows up as an apparent effect based on how we do time measurements and clock synchronization. She acknowledges at the end that it is only noticeable in synchronizing something.

The geometry is an interpretation, popular from 1908 until today, and it is fair for her to subscribe to another interpretation, such as what Lorentz or Einstein said. But there is no way to make sense out of time dilation being based on acceleration. The formula is given by the Lorentz transformation, and it uses velocity, not acceleration.

Her point about "sitting still in a gravitational field" is indeed a confusing one. The answer is that you a are not really sitting still. You are moving farther away in spacetime from the clocks you want to synchronize with. You are not aging more slowly by sitting still. There is only an apparent effect when you compare to time measured another way.

The effect is usually described in general relativity textbooks, but it is really just special relativity and the equivalence principle. The principle says the gravity is equivalent to acceleration and no gravity. The formulas of special relativity apply to instantaneous velocity, even if velocity is not constant.

On another subject, she previously posted a video on This Experiment Just Ruled Out The Many Worlds Theory, Physicists Claim. Of course, no experiment can prove or disprove many-worlds theory.

Update: Dr. Bee posts The Problem with Eric Weinstein. She says she is friends with him, and coming to his defense.

6:53 And this is why this pisses me off so much. Sean totally knows that most of his colleagues 7:00 work on similarly flaky stuff, it’s just been covered up by more working hours. 7:06 The literature is full of papers without proper predictions without Lagrangians, 7:12 ill-defined operators or problems that will be solved in some “future work” that never comes. 7:18 Sean knows that. Everyone in the damned field know that. But normally, no one’s saying anything about 7:26 it. Because they’re all tied up in the same scam. Unless the person who comes up with the idea is 7:32 Eric Weinstein, in which case it’s suddenly hugely offensive and everyone starts yelling.

11:41 In any case, I think what’s really happening here is that a lot of people who work in the 11:47 foundations of physics are very afraid that Eric is exposing how rotten their 11:54 entire field is. This is why they’re trying hard to discredit him. But the truth is 12:00 that that Eric’s idea isn’t any better or worse than all the other crap they’re working on, 12:05 the only difference is that he hasn’t wasted as much of your tax money on it.

Not much of a defense. Weinstein is a charlatan just like all the other theoretical physicists.

The difference is in how Weinstein tries to sell his ideas to the general public. His ideas do not work, and he complains that they are ignored because of corruption.

Monday, July 14, 2025

Death of Logical Positivism

I am a logical positivist. Here is a philosopher defending belief in God, while attacking logical positivism:
[Q] logical 4:39 positivists would say that religious 4:42 language is completely meaningless 4:44 there's no truth value in any of the 4:46 words so it's like almost saying 4:49 gobbleygook

[A] mhm gobbleygook well that's 4:51 an interesting one of course I think the 4:54 thing the problem about logical 4:55 positivism first of all as a formal 4:57 philosophy it's pretty much dead and 4:59 buried now you know certainly in 5:00 philosophy departments and there's a 5:02 simple reason for that because you know 5:04 logical positivism actually has can't 5:08 sustain its own basis you know because 5:10 if the only statements that you can make 5:12 which are valid statements are 5:13 scientific statements then logical 5:15 positivism is not a scientific statement 5:17 and therefore has no basis there's no 5:19 reason to believe that it is the case so 5:21 I think people have likened it you know 5:23 to the classical thing where you're 5:24 sitting on the branch and you're soaring 5:26 the branch but you're just soaring on 5:28 the wrong side and you just fall down 5:29 and I think that's what happened to 5:31 logical positivism and and why it 5:33 eventually just couldn't be sustained

So he believes in God, but says that a belief in scientific statements cannot be sustained!

This is really nutty. He has beliefs in God that are not scientifically and logically provable, and he complains that others have non-provable beliefs.

I would say that he is just stupid, but he is reciting the conventional wisdom of 98% of philosophers.

I got more details on the arguments against logical positivism:

Philosophers largely abandoned logical positivism by the mid-20th century due to a combination of internal flaws and external critiques that exposed its limitations. It’s not entirely "dead" — some of its echoes linger — but as a dominant framework, it’s been relegated to history’s sidelines. Logical positivism, peaking in the 1920s and 1930s with the Vienna Circle (think Moritz Schlick, Rudolf Carnap, Otto Neurath), aimed to make philosophy rigorous by tying meaningful statements to empirical verification. If a claim couldn’t be tested through observation or reduced to logic (like math), it was dismissed as meaningless—metaphysics, ethics, and religion got the axe. It was a bold cleanup of fuzzy thinking, inspired by science’s success.

The cracks showed fast. First, the verification principle—the idea that a statement’s meaning hinges on how it can be empirically verified — turned out to be self-defeating. As critics like Karl Popper pointed out, the principle itself isn’t empirically testable. Is it meaningless, then? This paradox gnawed at its core. Second, scientific practice didn’t match the theory. Thomas Kuhn’s The Structure of Scientific Revolutions (1962) showed science isn’t just a pile of verified facts — it’s messy, paradigm-driven, and full of untestable assumptions. Universal laws (e.g., "all swans are white") can’t be fully verified, only falsified, as Popper argued in the 1930s, pushing his falsificationism as an alternative.

Then came Willard Van Orman Quine’s attack in "Two Dogmas of Empiricism" (1951). He demolished the positivist split between analytic (true by definition) and synthetic (true by observation) statements, arguing that knowledge is a web of interconnected beliefs, not a neat stack of verified bits. No statement is immune to revision, even logic itself—goodbye, positivist certainty. Add Ludwig Wittgenstein’s later work (Philosophical Investigations, 1953), which shifted focus from rigid verification to language as a flexible, social tool, and the positivist dream of a unified scientific language looked naive.

By the 1950s and 1960s, these critiques — plus a growing interest in existentialism, phenomenology, and ordinary language philosophy — left logical positivism battered. Philosophers like A.J. Ayer tried to soften it (his "weak verification" tweak in Language, Truth, and Logic, 1946 edition), but the momentum was gone. The Vienna Circle itself dissolved under Nazi pressure in the 1930s, scattering its thinkers, and postwar philosophy moved on.

Is it dead? Mostly. Its strict form — verificationism and all — has few defenders. But its spirit lives in diluted ways: analytic philosophy still loves clarity and evidence, and some scientists (like Sam Harris) echo its disdain for untestable claims. Yet, as a movement, it’s a relic — killed by its own ambition to purge philosophy of ambiguity, only to find the world too complex for its rules. Today’s thinkers prefer pluralism or pragmatism over positivism’s narrow lens.

The first argument is silly. One can believe in sticking to scientific statements, even if one cannot prove that those are the only meaningful ones. It reminds me of the argument that one cannot be an atheist, without a proof of the non-existence of God. Or that one cannot axiomatize mathematics, without axioms that make math complete. Or that one must accept quantum computation, unless there is a proof that it is impossible.

The second argument is just saying that science is not scientific. Followers of Professor Paradigm Shift portray science as a bunch of fads with no objective validity or progress towards truth.

I criticized the Quine paper. It is a famous philosophy paper, but also a dopey one. It mainly gives some examples of trivial logical paradoxes, based on imprecise use of language, and concludes that logic cannot apply to the real world.

For example, Quine says that "bachelor" means "unmarried man", but if you make that substitution in the sentence "'Bachelor' has less than ten letters.", then you can an incorrect result. Okay, but this example does not prove that logic is worthless.

Saying "growing interest in existentialism" is just code for philosophers becoming increasingly detached from the real world.

This attack on logical positivism reminds me of attacks on axiomatic mathematics. Both attacks say that something should be abandoned because it does not fulfill the naive goals of its early enthusiasts.

You do not have to subscribe to logical positivism, but it is not wrong. It provides a consistent worldview. You could complain that it avoids some metaphysical issues, but it is perfectly fine as far as it goes.

These anti-positivist positions left me disgusted with philosophy. If philosophers simply complained that positivists have a narrower lens, I would say that is a reasonable position. But that is not what they do. They claim that positivism must be rejected entirely because it cannot prove itself correct.

Nothing can prove itself correct. The concept does not even make any sense. Inconsistent systems can prove anything, and that makes them worthless, not desirable. Philosophers should be able to understand that.

I also quibble with Sam Harris being called a scientist. His only connection to science is a UCLA neuroscience degree at age 42 where he wrote his thesis on "The Moral Landscape: How Science Could Determine Human Values." I guess he had to take some science classes, but his thesis sounds like philosophy to me. He never held a science job. He has never does scientific work. He attacks religion as unscientific, but that does not make him a scientist.

Monday, July 7, 2025

Modern Interpretation of Length Contraction

A confusing question is whether the length contraction of relativity is real. I got this explanation from xAI:
In contemporary physics, length contraction is understood as a consequence of the Lorentz transformation in special relativity, which describes how measurements of space and time differ between inertial reference frames moving relative to one another. The key points of the modern view are:
  • Relativity of Measurements: Length contraction is a real, measurable effect, but it is frame-dependent. If an observer in frame ( S ) measures a rod at rest in frame ( S' ) (moving at velocity ( v ) relative to ( S )), the rod’s length in ( S ) appears shorter by a factor of
    \sqrt{1 - v^2/c^2}
    . This is described by the Lorentz transformation:
    L = L_0 \sqrt{1 - v^2/c^2}
    where
    L_0
    is the proper length (length in the rod’s rest frame), and ( L ) is the contracted length in the observer’s frame.
  • Geometric Perspective: Length contraction is often explained as a consequence of the geometry of Minkowski spacetime, a flat, pseudo-Euclidean four-dimensional manifold with a metric signature (e.g.,
    (+,+,+,-)
    ). The contraction arises because observers in different frames slice spacetime differently, leading to different projections of a worldline’s spatial extent. This geometric view emphasizes the relativity of simultaneity: what one observer measures as a “length” depends on how they define simultaneous events.
  • “Apparent” vs. “Real”: Modern texts avoid calling length contraction “apparent” in the sense of being an illusion, but they emphasize its dependence on the observer’s reference frame. It’s real in the sense that it’s consistently measurable (e.g., a moving object fits into a shorter space in the observer’s frame), but it’s not an intrinsic change to the object itself—its proper length remains invariant. The effect is a result of the geometry of spacetime and the conventions of measurement, not a physical compression. ...
  • Textbook Treatments: Modern relativity texts (e.g., Taylor & Wheeler’s Spacetime Physics or Hartle’s Gravity) describe length contraction as a geometric effect, often using spacetime diagrams to show how different frames yield different lengths. This is closer to Varićak’s geometric interpretation than Lorentz’s physical contraction.

It goes on in detail, saying that Lorentz viewed the contraction as physical, while the modern geometric view was championed by Minkowski and Varicak.

The curious thing is where Einstein stood. Everyone assumes that he had the modern geometric view, but that is completely false. As xAI explains:

The Disagreement:
The core issue was Varićak’s interpretation of length contraction:
  • Varićak’s View: Varićak argued that length contraction in Einstein’s theory was an “apparent” or “psychological” phenomenon, resulting from the convention of clock synchronization and time measurements in different frames. He contrasted this with Lorentz’s theory, where he considered length contraction an “objective” physical effect due to the ether. Varićak’s hyperbolic geometry approach framed relativistic effects in a way that emphasized mathematical elegance and suggested that some phenomena might be observer-dependent artifacts.
  • Einstein’s Criticism: Einstein published a brief rebuttal in 1911, asserting that his interpretation of length contraction was closer to Lorentz’s in that it was a real, measurable effect, not merely apparent or psychological. He argued that length contraction was a direct consequence of the relative motion between frames, as described by the Lorentz transformation, and not contingent on subjective measurement conventions. Einstein likely saw Varićak’s interpretation as undermining the physical reality of relativistic effects, which he considered fundamental to his theory.
This is a surprisingly accurate account of the different views of length contraction. AI is not always right, but it is relying on mainstream sources here.

By 1911, the geometric view of relativity was very well established, and yet Einstein published a disavowal of it.

Einstein had 5 years to learn relativity, and he still did not get it.

There are people who argue that Einstein should be credited for relativity, because Lorentz and Poincare occasionally made reference to an aether or preferred frame, years after Einstein's 1905 paper. But these are not errors, and Einstein also referred to an aether. It is a simple mathematical fact that one can choose a preferred frame without affecting relativity. Cosmologists always do exactly that, using the cosmic microwave background.

Maybe Lorentz rejected the geometric view in 1911, I don't know. It is astounding that Einstein did. The geometric view was the key thing that made relativity better than Lorentz's 1895 theory. If Einstein did not agree with it, then he had nothing over what Lorentz had many years earlier. The geometric view of Minkowski's 1908 paper is what made relativity widely accepted.

Einstein's 1905 paper did have some better formulas than Lorentz's 1895 paper, but no better than Lorentz's 1904 paper. Lorentz already had the key ideas of length contraction and local time in 1895. FitzGerald had the length contraction in 1889, using an argument similar to Einstein's.

I have read a lot of Einstein commentary, but I have never seen the Einstein fans explain why he was still disavowing geometric relativity in 1911. He did not understand or accept what became the modern interpretation.

A new paper discusses some history:

On Bell's dynamical route to special relativity
Frederick W. Strauch
The Michelson-Morley experiment was published in 1887, and already in 1888 Oliver Heaviside showed that Maxwell's equations implied a contraction of electric fields in the direction of the motion. This inspired FitzGerald, Larmor, and maybe even Lorentz to figure that solid objects might contract, if held together by electromagnetics forces, as we now know that they are. This is the dynamical interpretation that is out of favor today, but it was important historically, and is a legitimate way to understand the contraction.

The paper cites this 2018 paper on The dynamical approach to spacetime theories by Brown and Read. It defends the dynamical view, and describes the geometric view this way:

In the last few decades, the approach has come to life within the philosophy of physics as a reaction to aspects of the ‘angle bracket school’ of spacetime theories, first prominently exposed in the philosophical literature of the 1970s and especially the 1980s.5 The central role of geometry in the treatment of pre-general relativistic theories in this approach has led some philosophers to the view that special relativistic effects such as length contraction and time dilation are ultimately explained by recourse to the geometric structure of Minkowski spacetime, and that all such explanations prior to the 1908 work of Minkowski are either misguided or incomplete.
I guess it is called ‘angle bracket school’ because it takes the metric on Minkowski space as the fundamental covariant object. That was the approach of Poincare in 1905-6 and Minkowski in 1907-8, so I think he means that the approaches of FitzGerald, Lorentz, and Einstein were deficient for not understanding the non-euclidean geometry of Poincare and Minkowski.

The dynamical interpretation is not wrong. It can explain the contraction on a molecular level, using Maxwell's equations. It is just not the modern view that Poincare and Minkowski invented.

Brown and Read start by saying:

In 1940, Einstein offered the following nutshell account of his special theory of relativity (SR):1
The content of the restricted relativity theory can ... be summarised in one sentence: all natural laws must be so conditioned that they are covariant with respect to Lorentz transformations. [17, p. 329]
This innocuous-sounding statement actually represents on Einstein’s part a significant departure from his 1905 ‘principle theory’ approach to SR, based upon the relativity principle, the light postulate, and the isotropy of space. The shift in his thinking did not come about overnight.
This description seems to avoid mentioning light or geometry, but those are implicit.

Poincare and Minkowski proved that Maxwell's equations were covariant with respect to Lorentz transformations. Einstein only showed a version of Lorentz's 1895 theorem about corresponding states.

Brown and Read see this as consistent with their eccentric dynamical views. I would rather rephrase it as saying that all natural laws are well-defined on Minkowski space, which has a Lorentz invariant geometry. It is interesting that Einstein was still not willing to make an explicitly geometrical statement in 1940.

They say:

We expect undergraduates to imbibe in their first course on relativity theory a profound insight largely obscure to all the nineteenth century giants, including Maxwell, Lorentz, Larmor and Poincaré: the physical meaning of inertial coordinate transformations. It was Einstein in 1905 who was the first to understand the physics of such transformations,17 and the fact they are neither a priori nor conventional.
I think they are trying to say that Einstein rejected the idea that the Lorentz transformations were just reflections of the underlying spacetime geometry. They believe the dynamical view is superior to the modern geometrical view, so I guess they are trying to credit Einstein with having a dynamical view. It appears to me that Einstein tried to avoid committing himself to being for or against the dynamical view. For example, he wrote:
One cannot ask whether the contraction should be understood as a consequence of the modification of molecular forces caused by motion or as a kinematic consequence arising from the foundations of the theory of relativity. Both points of view are justified. [letter to Varicak, 1911]
Note that Einstein does not even mention the geometric view. I would say that the contraction should be understood as the divergence between the non-euclidean spacetime geometry, and the more familiar euclidean geometry.

A 1909 paper had credited Einstein with rejecting Lorentz's molecular force contraction, but Einstein disavowed having adopted a view different from Lorentz's.

In the geometric view, aka angle bracket school, the physics is in the geometry. The Lorentz transformation is just a change of coordinates with no real physical significance.

One might similarly argue that Earth longitude being based on the Prime Meridian has no real significance. If you measure longitude you will get numbers that depend on that choice, but the physics of whatever you are observing does not. The superior geometric view is that the physics does not depend on the coordinates, and that a coordinate choice can be mathematically transformed into any other choice, without affecting the physics.