Posted on 10/08/2025 7:46:10 AM PDT by Red Badger
Chatter Points
* A new model suggests dark matter and dark energy may not be real entities, but effects of changing physical constants.
* Galaxy rotation curves from seven galaxies fit the model using one key parameter: a “turn-off density.”
* The approach also explains supernovae, galaxy clusters, and the cosmic microwave background without exotic matter.
* Challenges remain: galaxies are complex, and no direct evidence yet shows that fundamental constants truly vary.
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A physicist at the University of Ottawa has published research suggesting the universe’s most perplexing mysteries — dark matter and dark energy, which together supposedly account for 95% of everything that exists — could be explained without invoking unseen particles or forces.
Rajendra Gupta’s study, published in the journal Galaxies, proposes that what astronomers have attributed to invisible dark matter for nearly a century could instead result from the fundamental forces of nature weakening as the universe expands. If correct, this might mean scientists have been searching for particles that aren’t needed to explain the data.
Dark matter was first proposed in the 1930s when astronomers noticed galaxies spinning too fast. Their outer edges should fly apart based on visible matter alone, yet they hold together as if gripped by invisible gravitational glue. Dark energy entered the picture in the 1990s when observations showed the universe’s expansion is accelerating. Together, these mysterious components now dominate cosmological models — dark energy at roughly 68% of the universe and dark matter at 27%. Normal matter accounts for a mere 5%.
Gupta’s model reinterprets them as side-effects of evolving constants.
When Constants Aren’t Actually Constant
At the heart of this alternative explanation lies a radical idea: the speed of light, gravitational constant, and other bedrock values of physics aren’t actually constant. Instead, they evolve as the universe expands.
When Gupta incorporates these “covarying coupling constants” into Einstein’s equations that describe cosmic expansion, terms emerge that behave mathematically identical to dark matter and dark energy. The researcher calls these “alpha-matter” and “alpha-energy,” named after the parameter that governs how the constants change.
Here’s where it gets interesting for galaxy rotation. In regions with high concentrations of regular matter, like galaxy center, the alpha parameter approaches zero, meaning only normal physics applies. But in outer, less dense regions of galaxies, alpha increases, and alpha-matter effects become pronounced. This creates additional gravitational pull that mimics what dark matter would do, keeping outer stars moving faster than Newton’s laws alone would predict.
Gupta tested this framework against rotation curves from the SPARC database, which contains high-quality measurements of 175 galaxies. For each galaxy, the model requires determining just one parameter: a “turn-off density” where the transition from normal matter dominance to alpha-matter influence occurs.
Physicists have long believed that the universe is partly made up of dark matter and dark energy. Could it all be an illusion? (© Ulia Koltyrina – stock.adobe.com)
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Testing Against Real Galaxies
The study examined seven galaxies spanning different types and sizes. For NGC 3198, a spiral galaxy about 47 million light-years away, the model reproduced the observed rotation curve using a turn-off density of 2.09 × 10⁻²⁴ grams per cubic centimeter.
Similar fits worked for six other galaxies, from small irregular dwarfs to large spirals. The turn-off densities varied by only about a factor of four across all galaxies, despite their radii varying eightfold. This consistency suggests the parameter may represent something physically meaningful rather than arbitrary adjustment.
Matter density falls off predictably beyond the turn-off point, aligning with observed galaxy properties. The model also makes testable predictions: because alpha-matter’s influence decreases at higher redshifts (looking back in time), early universe galaxies should show rotation curves dominated more by visible matter. Some evidence from observations of distant galaxies has found them more “baryon-dominated” than nearby ones, though this remains debated.
Beyond Galaxy Rotation
Gupta’s framework doesn’t stop at galaxy rotation. In earlier papers, Gupta applied the same framework to supernova data, baryon acoustic oscillations, and the cosmic microwave background. He showed the covarying constants approach can explain why some early galaxies appear surprisingly mature for their age and can reproduce the CMB’s sound horizon without requiring dark energy. This current study focuses specifically on galaxy rotation curves.
The model combines variable constants with a partial “tired light” effect, where photons lose energy during their journey through space. This hybrid “CCC+TL” model produces a Hubble constant value consistent with different measurement methods that have produced conflicting results in standard cosmology.
When applied to galaxy clusters, similar density profiles emerge using the same turn-off density range as individual galaxies. The approach also naturally produces the Tully-Fisher relation, an observed correlation between galaxy mass and rotation speed.
The Challenges Ahead
Modified theories of gravity have proliferated for decades, with MOND (Modified Newtonian Dynamics) being the most well-known. While MOND successfully predicts galaxy rotation curves, it has struggled to explain galaxy clusters, gravitational lensing observations, and the cosmic microwave background without some form of dark matter.
Gupta’s model treats galaxies as spheres for mathematical simplicity, but real galaxies have complex structures — disks, bars, bulges, and irregular features — that this spherical model cannot capture. The paper acknowledges this limitation.
Despite decades of searching, no one has found direct evidence that fundamental constants change over cosmological timescales. Precision measurements from distant quasars have set stringent limits on any variation. Gupta’s framework would need to explain why such variations evade detection in some contexts while producing dramatic effects in others.
The turn-off acceleration that emerges from this model happens to fall close to MOND’s characteristic acceleration scale. Gupta speculates this might not be a coincidence. Perhaps MOND’s empirical success reflects an underlying truth about varying constants, even if the MOND formalism itself is incomplete.
If validated, eliminating dark matter and dark energy would rank among the most consequential revisions to physics in a century. Thousands of researchers worldwide dedicate their careers to detecting dark matter particles through underground experiments, space telescopes, and particle accelerators. All these efforts presume something invisible but physical exists.
Gupta plans to extend the analysis to gravitational lensing and galaxy cluster dynamics in future work. Those tests will prove more challenging because they involve projecting three-dimensional mass distributions along the line of sight.
For now, the cosmic ledger remains unbalanced. Standard cosmology says 95% of the universe consists of invisible components we cannot directly observe. Either that’s correct and we live in a cosmos dominated by exotic substances, or our equations may need revision, pointing to a universe that follows different physical rules than the ones we’ve relied on for nearly a century.
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Paper Summary
Methodology
The research analyzes galaxy rotation curves from the SPARC database using a model based on covarying coupling constants. The approach starts by assuming fundamental constants like the speed of light and gravitational constant evolve with cosmic expansion according to an exponential function governed by a parameter alpha. This modifies the Friedmann equations that describe cosmic evolution, introducing terms that behave like additional matter and energy densities. For individual galaxies, the model treats them as spherically symmetric and uses the observed rotation velocity data to determine the total mass distribution through standard Keplerian mechanics. The key innovation involves a turn-off density parameter: below this density (in galaxy outskirts), the alpha-parameter varies with radius, creating apparent alpha-matter and alpha-energy contributions. Above this density (in galaxy cores), alpha equals zero and only normal matter contributes. By differentiating the mass enclosed within each radius from the rotation curve, then integrating back while accounting for the radially varying alpha-parameter, the model extracts the baryonic mass distribution and compares it to estimates from the SPARC database that combine gas, disk, and bulge measurements.
Results
Seven galaxies were tested spanning irregular dwarfs to large spirals at distances from 6 to 57 megaparsecs. Turn-off densities ranged from 2.09 to 7.96 × 10⁻²⁴ grams per cubic centimeter, varying by only a factor of four despite turn-off radii ranging from 0.35 to 4.9 kiloparsecs. The derived baryonic velocity curves matched the SPARC database estimates reasonably well for six of seven galaxies tested, with NGC 1090 showing poorer agreement at intermediate radii. Beyond the turn-off radius, total matter density scaled as radius to the negative second power when rotation curves remained flat, consistent with observations. Baryonic matter density dropped as radius to the negative fourth power in these regions, matching the Hernquist density profile used in dark matter halo models. Turn-off accelerations calculated as the square of flat rotation velocity divided by turn-off radius fell in the range of 1.76 to 6.43 × 10⁻⁸ centimeters per second squared, similar in magnitude to the MOND acceleration scale of 1.2 × 10⁻⁸ centimeters per second squared.
Limitations
The analysis treats all galaxies as spherically symmetric, but real galaxies exhibit disks, bars, bulges, and irregular morphologies that significantly affect mass distribution and rotation curves. SPARC data points are sparsely and unevenly spaced, making numerical differentiation unreliable and introducing significant uncertainty in derived density profiles. The baryonic mass estimates from SPARC rely on mass-to-light ratios for stellar populations, which contain their own uncertainties and were corrected using nominal values rather than galaxy-specific measurements. Only seven galaxies from the 175-galaxy SPARC sample were analyzed, representing a limited test of the model’s general applicability. The framework predicts alpha-matter contributions should decrease at higher redshifts, but the paper does not include analysis of distant galaxy rotation curves to test this prediction. The model introduces one free parameter per galaxy (turn-off density) despite claims of parameter parsimony, and the physical origin of this parameter remains unclear. Preliminary application to galaxy cluster density profiles used the same simplified approach as for individual galaxies, which may not accurately represent the mass distributions in clusters containing hundreds of galaxies.
Funding and Disclosures
The research received no external funding. No conflicts of interest were declared. The study is an open access article distributed under the Creative Commons Attribution license.
Publication Information
Gupta, R.P. “Testing CCC+TL Cosmology with Galaxy Rotation Curves.” Galaxies 2025, 13, 108. The paper was received May 22, 2025, revised August 13, 2025, accepted September 5, 2025, and published September 12, 2025. The journal article is published by MDPI in Basel, Switzerland, and the digital object identifier is https://doi.org/10.3390/galaxies13050108.
It doesn’t Matter....................
Settled science. Again.
Theoretical physics is imaginative and reflects some of the best thinking that humans are capable of doing. Yet until it is proven by reproducible unbiased experiment as was Einstein’s theories of relativity, it remains speculation that is possibly untrue.
“Dark Matter and Dark Energy May Be Illusions Created by Changing Physics”
very similar to the discredited theory that an invisible, undetectable substance called Ether permeated the universe as the means for the propagation of light ...
The owner is registered in Dover, Delaware. Seems a small operation, but as with so many sites, they seek you -- as data.
Called “brilliant,” “fantastic,” and “spot on” by scientists and researchers, our acclaimed StudyFinds Analysis articles are created using an exclusive AI-based model with complete human oversight by the StudyFinds Editorial Team. For these articles, we use an unparalleled LLM process across multiple systems to analyze entire journal papers, extract data, and create accurate, accessible content. Our writing and editing team proofreads and polishes each and every article before publishing. With recent studies showing that artificial intelligence can interpret scientific research as well as (or even better) than field experts and specialists, StudyFinds was among the earliest to adopt and test this technology before approving its widespread use on our site. We stand by our practice and continuously update our processes to ensure the very highest level of accuracy.They'll grind out article after article, and giving them your name and email -- you are the data they seek -- so they will fill your mail box with lots of "good stuff."
No-one ever claimed dark matter or dark energy were settled science.
Dark Matter Matters
(contributions gladly accepted)
When two bodies are too heavy, you just have to change the gravitational constant of the universe.Q says you have to redefine gravity. | 0:40
Nican | 288 subscribers | 323,031 views | December 11, 2009
I ga e up TNG when Started agreeing with Q.
Just goes to show that science is NEVER settled!
😂
Black matter lives! Or something.
In general, with many exceptions, physicists, mathematicians, self-made billionaires, athletes, entertainers, mothers, sex workers, generally do their most amazing work at around age 26. Then their gifts start to slowly fade. Adjunct Professor Rajendra P. Gupta, physics Ph.D from India, is well past his prime.
???
A physicist explained it to me years ago. Whenever you heard the word “dark” you’re dealing with a placeholder. They can’t explain it so they just call it “dark”. They can’t prove anything about it. It may not exist at all.
When you have to use not one but TWO such placeholders, it tells me its far more likely your model is flawed.
People are claiming *settled science* all the time whenever *science* come sup with something, especially if it’s pushing an agenda.
Nobody can pick or choose what *science* is settled or not because NO science is ever *settled*.
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