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Our future, our universe, and other weighty topics


Saturday, September 10, 2022

When Scientists Claim to See Things They Never Saw

For decades scientists "bet the farm" on the Lambda Cold Dark Matter theory, a move which made little sense. There were never any direct observations of any such thing as cold dark matter, so scientists had to claim it was invisible.  And even though cosmologists and astrophysicists believed in it with a fervor, cold dark matter never had any place in the Standard Model of Physics. How ironic that scientists often blast people for having faith in important invisible realities, when they have put such unquestioning faith in things they say are important, invisible and never directly observed: dark matter and dark energy.  Maybe their thinking is: "you can believe in important invisibles but only OUR important invisibles." 

Nowadays some items in the press have been profoundly discouraging to believers in the dogma of dark matter. Specifically: 

ITEM 1: A recent news story entitled "No trace of dark matter halos" quotes a scientist saying that "the number of publications showing incompatibilities between observations and the dark matter paradigm just keeps increasing every year."

ITEM 2:  There recently appeared another science article with a headline of "Dark Matter Doesn't Exist."  That article (by an astrophysics professor) says there are multiple observations showing that dark matter cannot exist. The article says, "We need to scientifically understand why the dark-matter based model, being the most falsified physical theory in the history of humankind, continues to be religiously believed to be true by the vast majority of the modern, highly-educated scientists." This suggests all those dark matter stories we have read for so many years were just ivory tower tall tales.

ITEM 3: A recent paper discussing observations from the James Webb Space Telescope (JWST) notes that "early observations with JWST have led to the discovery of an unexpected large density...of massive galaxies... at extremely high redshifts z ≈ 10, " and finds in its Section 7 that the most-popular model of cosmology (called lambda cold dark matter or LCDM) is "excluded" (in other words, ruled out) at a moderately strong two-sigma level by the latest observations.

ITEM 4: A recent NASA press release announces some report based on 30 years of observations from the Hubble Space Telescope. You would never guess from the press release that the report is one finding a gigantic failure of one of the top theories of modern physical science, the Lambda Cold Dark Matter theory. The failure is also all-but-buried by the corresponding scientific paper, which refers to the observations with the Hubble Space Telescope, and compares them to predictions from the Lambda Cold Dark Matter theory, telling us this (using some jargon that I will translate):

"The inclusion of high-redshift SNe Ia yields H0 = 73.30 ± 1.04 km s−1 Mpc−1 and q0 = −0.51 ± 0.024. We find a 5σ difference with the prediction of H0 from Planck CMB observations under ΛCDM, with no indication that the discrepancy arises from measurement uncertainties or analysis variations considered to date."

The "5σ difference" is a big five sigma difference between the Hubble constant (H0, the universe's expansion rate) as determined by the Hubble telescope observations and the Hubble constant as predicted by the Lambda Cold Dark Matter theory, cryptically referenced as "ΛCDM." On page 54 we are told that the "5σ difference" is one that we would expect to get by chance only one time in a million. 

So it seems the Lambda Cold Dark Matter theory has flopped big time. What the theory predicts about the universe's expansion rate does not match the latest and greatest measurements of that rate. But you cannot find a plain English mention of that flop in either the press release or the scientific paper. The scientific paper mentions the failure of the  Lambda Cold Dark Matter theory, but in a way that could only be understood by a physicist or a cosmologist (or someone like myself who has read cosmology papers for decades). The NASA press release makes no mention of a failure of theory, and fails to even mention the Lambda Cold Dark Matter theory. The NASA press release attempts to suggest the discrepancy may suggest "new physics," rather than frankly telling us that the results suggest we have bad old flopping physics theories. 

How is it that despite such problems and failures, the theory of cold dark matter is still reverently preached in academia, like some religious dogma that each generation of authorities must pass on to the next? What happens is that scientists and science journalists periodically mislead us by claiming that dark matter has been observed.  The reports they give on this topic are very misleading. 

Let us look at a recent example. This summer there appeared a paper entitled "First Identification of a CMB Lensing Signal Produced by 1.5 Million Galaxies at z ∼4: Constraints on Matter Density Fluctuations at High Redshift." On August 2, 2022 a science journalist carelessly reported on this paper by writing a story with the untrue title "Dark  matter from 12 billion years ago detected for the 1st time," which appeared on www.space.com.  No dark matter was actually detected. 

We can unravel some of the wobbly analysis that was occurring by analyzing use of the phrase "dark matter" in the paper. We find this:

(1) The title makes no claim at all about detecting dark matter.

(2) The abstract of the paper makes it sound as if dark matter was detected, stating "We report the first detection of the dark matter distribution around Lyman break galaxies (LBGs) at high redshift through the Cosmic Microwave Background (CMB) lensing measurements with the public Planck PR3 κ map."

(3) The text of the paper makes no claim about observing dark matter. 

Let me back up claim (3) made above. I will quote all of the uses of the phrase "dark matter" in the text of the paper (the part below the abstract). There are only three uses of that phrase, which are quoted below:

(1) "Since galaxies are formed in dark matter halos through gas cooling, such an interplay can be studied by measuring the connection between dark matter halos and galaxies [see reviews by 1, 2]."

(2) "Galaxy-galaxy lensing, the cross-correlation between galaxy positions and weak lensing shear of background galaxies, is rapidly emerging as another powerful probe because it enables the direct measurement of dark matter distribution around galaxies [e.g., 8–11]"

(3) "In the halo model approach, the convergence profile is composed of 1-halo and 2-halo terms; κ(θ) = κ1h(θ) + κ2h(θ), where κ1h(θ) and κ2h(θ) are the contribution from dark matter halos around galaxies and neighboring halos, respectively."   

Those are the only references the body of the paper make to dark matter. None of them contain any mention of a detection or observation of dark matter. And the title of the paper makes no claim to have observed dark matter. Statement (2) above is incorrect: you cannot make "a direct measurement" of dark matter by studying "galaxy-galaxy" gravitational lensing.  So why did the abstract of the paper claim "we report the first detection of the dark matter distribution around Lyman break galaxies"? What seems to have gone on is that the scientists saw some sort of something, and interpreted what they saw within some speculative theoretical framework ("the halo model approach") assuming dark matter. That's rather like some believer that animal ghosts live in the clouds describing his latest cloud photo, and describing it as a nice photo of an animal ghost in the sky. 

This kind of thing goes on all the time. Nowadays very many scientists make claims in both the titles of their papers and the abstracts of their papers that are not justified by any observations mentioned in their papers. If dark matter had been detected, it would have been the scientific find of the decade, and we cannot believe that such a detection would go unmentioned in the title of the paper "First Identification of a CMB Lensing Signal Produced by 1.5 Million Galaxies at z ∼4: Constraints on Matter Density Fluctuations at High Redshift." All that occurred was some believers in dark matter seeing something and speculating that it was dark matter, which should not be confused with a dark matter observation. 

The extremely questionable space.com story on this paper is filled with dubious boasts that seems to be coming in equal amounts from the writer of the story and a scientist who is quoted. The reader is given the impression that dark matter was detected. No such thing occurred. Scientists merely saw some kind of gravitational lensing effect, and interpreted what they saw within some speculative framework involving a belief in dark matter. It was like some believer in magic fairies seeing a heavy rainstorm, and saying, "My, my, the magic fairies are very busy today producing rainfall." 

On August 30 we had a science story entitled "We don’t know if dark matter exists. So why do astronomers keep looking?" The story (written by a postdoctoral fellow) told us this: 

" 'Dark matter' is just a hypothesis. Physicists and astronomers may be chasing a phantom – but that doesn’t stop us from looking."

This was 28 days after www.space.com had reported on August 2 that dark matter had been detected. What explains the discrepancy? The likely explanation is that the August 2 story was baloney, and that no one has detected any dark matter. 

In 2018 there appeared this statement in the journal Science about a long-made claim of dark matter detection that didn't hold up:

"For 2 decades, physicists with an experiment called DAMA have claimed that particles of dark matter—the unseen stuff whose gravity appears to bind our galaxy—are bumping into atomic nuclei in their subterranean particle detector, even as other dark matter hunts come up empty. Now, physicists with a detector called COSINE-100, designed to mimic DAMA, present the most direct refutation yet of the findings. And in 2020, theorists identified a way in which the DAMA signal could have arisen inadvertently in the team’s analysis."

In 2021 it was reported that the DAMA claims had been even more thoroughly shot down. We read this statement:

"At last, the critical test has been performed: a completely independent team, ANAIS, has carried out an identical experiment to DAMA/LIBRA, replicating the study and testing its validity. With three complete years of data collected, ANAIS has ruled out the DAMA/LIBRA results in a model-independent way to better than 99% confidence. The world’s most controversial dark matter experiment has been busted, and it’s an incredible success for the scientific method."

On the same page the scientist author makes the self-contradictory claim that "while the astrophysical evidence supporting the existence of dark matter is overwhelming, every experiment designed and built to directly detect whatever particle might be responsible for dark matter has come up empty." The first part of the statement is false, and is contradicted by the second part of the statement. This just goes to show that no matter how many erroneous claims about dark matter have been revealed, scientists will just keep speaking carelessly on this topic. 

A notable example of scientists claiming to see things they never saw was when scientists in the BICEP2 project claimed with a great fanfare a few years ago that they had discovered evidence of gravitational waves from the very early universe. It is now generally recognized that such observations can be plausibly explained as something entirely different: mere dust observations. 

In the world of neuroscience, we get some examples of scientists claiming to see things they never saw. Over the course of a week, some scientists will cause a rodent to learn something, by doing something such as fear conditioning an animal so that it associates a metal shock plate with an electrical shock. Then the scientists will examine some very tiny synapses  in the animal, and look for some tiny bit of brain matter that is very slightly different after the animal was taught something. The scientists will then claim that they have observed an engram, some cells or synapses where a memory was stored. The observations never justify such a claim. Synaptic matter in the brain is constantly changing, because of what is called random remodeling. The average lifetimes of proteins in the brain are only a few weeks or less. Synapses are attached to dendritic spines that often have short lifetimes, and change their shapes or disappear over the space of a few weeks. If you examine some tiny part of an animal's brain (a few synapses), looking for changes over the course of a week, you will very often see changes even if the animal has not learned anything. So observing some very tiny change somewhere in a brain never justifies a claim that an engram (a storage place of a new memory) has been observed. 

Discussing erroneous ideas about a "depression gene," a psychiatrist commented on a case of scientists seeing things that were not there:

"First, what bothers me isn’t just that people said 5-HTTLPR mattered and it didn’t. It’s that we built whole imaginary edifices, whole castles in the air on top of this idea of 5-HTTLPR mattering. We 'figured out' how 5-HTTLPR exerted its effects, what parts of the brain it was active in, what sorts of things it interacted with, how its effects were enhanced or suppressed by the effects of other imaginary depression genes. This isn’t just an explorer coming back from the Orient and claiming there are unicorns there. It’s the explorer describing the life cycle of unicorns, what unicorns eat, all the different subspecies of unicorn, which cuts of unicorn meat are tastiest, and a blow-by-blow account of a wrestling match between unicorns and Bigfoot." 

A very common case of scientists claiming to see things they never saw is when neuroscientists claim without warrant to have observed "neural representations." We have robust evidence for only one type of representation in the brain: the low-level chemical representation in genes, where particular sets of nucleotides represent particular amino acids, according to the representation rules of the genetic code. Such representation occurs in the DNA of most cells (neurons as well as hundreds of other types of cells). There is no robust evidence for any other type of representation in the brain. No encoding system comparable to the genetic code but outside of DNA has ever been discovered in the brain. But neuroscientists just love to talk about "neural representations," as if brains had little depictions of things experienced or observed.  Whenever neuroscientists claim to have seen such a thing, they have no robust evidence to back up such a claim. As a paper states, "We still lack a clear, universal and widely accepted view on what it means for a nervous system to represent something, on what makes a neural activity a representation, and on what is represented." 

In the paper "The Dubious Credibility of Scientific Studies" by Natalie Ferrante of Stanford University, we read this:

"The current process of undertaking, implementing, reviewing, and finally publishing a scientific study is riddled with flaws, as study results are subjected to many biases and interpretations at every level between inception and publication. As a result, when these studies finally reach the public, they are often depicted in ways that fail to reflect the genuine results and are at times utterly incorrect. Industries touting their products, scientists influenced by grants and prestige, reviewers adhering to personal
political agendas, and journalists pressed to sell papers all in turn contribute to the inherently skewed depiction of scientific results to the public. These factors have allowed for a highly unpredictable credibility in scientific reporting, an observation that has been highly overlooked and disregarded. The dissemination and publicity of this incorrect or skewed information, which is believed to be scientifically accurate, can have a detrimental effect on the public in their everyday lives." 

Be skeptical when scientists have a passionate belief in X, and then claim that some shadowy thing they dimly detected (which could be any of a large variety of things) was an observation of X. 

science misinformation

1 comment:

  1. From the first time I read any detailed report of Dark Matter Theory, I thought to myself, it is not dark (it is transparent), and it is not matter (it passes through matter, and passes through itself), therefore, whatever is causing the strange observations of galactic rotation, it should be renamed, Anomalous Gravity Source. This may itself turn out to be a misnomer, but it fits the data better than "Dark Matter."

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