Mali, not Malaysia, which has the .my suffix.

Thanks for giving additional explanation. I was trying to keep my reply relatively short and agree with most of what you said.

Although the article is behind a paywall (which is somewhat strange in cosmology, but I digress), you can check other articles by the same author that also use the “varying constants” framework, for example https://arxiv.org/abs/2201.11667. His framework is that the speed of light c, the Planck constant h, the Boltzmann constant k and the Gravitational constant G depend directly on time, or to be more precise, on the expansion factor of the universe.

Thanks for the arxiv link. I was aware that some people did stuff like this (time-varying fundamental constants), but the abstract only speaking of “coupling constants” made me think of Λ (and G), not fundamental constants. There are some theories that motivate a varying speed of light, for example (Hořava–Lifshitz gravity comes to mind), but this doesn’t seem to be motivated by any theory in particular, as far as I can tell. I also agree with you that it seems quite weird to give c, h, and k a time dependence each, only to then have them all be functions of G.

Since this is a time-dependent change, there is no real way to significantly test the hypothesis (unlike the energy-dependent changes).

I’m not sure if I fully agree with this. Shouldn’t varying c, h, and k with time clearly change any observable related to the dispersion of light and gravitational waves, or black body radiation (among many other things)? And if we had access to even just one of those from different times during cosmological evolution (where the change should be much larger than between a few decades in the present), we should in principle be able to check if the proposed scaling law holds quite easily. Of course, the author could always make the variation with time small enough to avoid contradicting experiment (which would make it indeed unfalsifiable in practice), but that seems to go against the main idea of using these time-varying fundamental constants to explain some aspects of cosmological evolution. My guess now would be that the paywalled paper modifies the relation between redshift and time to undo the “damage” done by modifying the constants. Nevertheless, it wouldn’t surprise me much if this kind of scaling is already ruled out implicitly by some data, as I can’t imagine it not affecting a lot of different observables, but maybe I’m also overestimating the experimental cosmological data available at present, or the strength of the variance the author proposes.

According to my understanding, yes. For example, it is usually assumed that there was a period of time shortly after inflation when matter was in a quark-gluon plasma, which would imply a larger strong coupling than today, since a small strong coupling is associated to confinement. There was also the electroweak-epoch, during which the electromagnetic and weak interactions were unified, and the corresponding gauge bosons were massless. The masses of the W and Z bosons can thus also be regarded as time-varying, as well as the electron charge. However, it should be noted that these changes are not all that significant on the cosmological scales under investigation here (e.g. the quark epoch ended at about 10^-6 seconds after the big bang, which is much much less than the age of the universe, and it’s assumed that it still took quite a while before the first stars formed). A time-varying cosmological constant could potentially be much more relevant (and some quantum gravity theories even predict it), and I’ve heard some people suggesting it as a potential solution for the H0 tension. However, I unfortunately can’t access the paper and assess what precisely the author did there, and whether it is in any way similar to what I just mentioned.

He says he has a new way of describing light where it loses energy over time (something weird) and so it explains redshift.

From what I understand, the main idea behind tired light isn’t particularly weird, it’s just that scattering could potentially lead to a redshift as well. The issue is that if you assume enough scattering to explain cosmological redshift you would also get some other effects, which are however not observed. This basically ruled out the original tired light theory by Zwicky from the beginning. The author of this paper seems to try to get around that by combining a smaller amount of “tired light” with time-varying couplings. Unfortunately the paper is behind a paywall and I can’t tell any more details.

He also says universal constants can change (something never observed before that would fundamentally change physics)

No, he says that coupling constants (not sure if that is what you mean by “universal constants” or not) can change, which is a generic consequence of the RG and has in fact been observed in nature (e.g. electron charge or strong coupling, to name just the most famous examples). From a QFT perspective, the cosmological constant is also a coupling, and several quantum gravity theories do in fact generically predict or suggest a time-varying cosmological constant. So this part by itself isn’t really that out there, nor that original for that matter. However, since I can’t access the paper I can’t judge whether the author’s way of varying Λ is reasonable or just a way to fit the data without any physical motivation, and I don’t really know what the article means by “he proposes a constant that accounts for the evolution of the coupling constants”.

and he can explain dark matter

That seems like a more grandiose claim to me, if accurate. Do you have a source for where the author claims that? Although he wouldn’t be the first to do so.

I’m pretty sure this guy isn’t toppling physics today as the bar is set high for whatever evidence he is sharing.

I think this can be said for a lot of popular science article with topics like this. However, in many cases the blame can lie more with the pop-sci journalists who are looking for a cool story and might over-interpret the author’s claims (I guess “physics toppled!!!11” sounds more interesting than “some guy suggests that some data might be fitted in a slightly different way”). Although in this case at least the age of the universe claim does seem to come from the author.

Edit: Judging by another article of the author someone else linked me to further down, it seems that while the author does speak of coupling constants, he really does refer to time-varying fundamental constants. So I must agree with the previous poster on this, it does seem quite a bit more out there than I had originally assumed.