Here: https://arxiv.org/pdf/2503.08733
Only managed a first read, but it seems there's no explanation for the CMB.
Let alone any explanation for the CMB power spectrum peaks...
...therefore I won't bother further ;)
Researcher proposes model replacing dark energy/matter to explain universe
41–50 of 92 posts
Re: Researcher proposes model replacing dark energy/matter to explain universe
#42Earlier quoted context omitted.
The equations that we already have are sufficient to describe the universe to 99.9999999% but they are a hodge podge of several different theories that all work very very well in their respective regime. QM + GR + Lambda CMD + ... But this just doesnt look nice to eye and the mind. The laws of nature "must" be shorter, more symmetric. Thats why we invented Superstrings which solves everything, but can never be tested…
> laws of nature "must" be shorter Coming at this from philosophy of science rather than as a physicist, I feel those quotes around "must". I think you also recognise how that might be a sort of "fundamentally wrong assumption". Imagine your words replayed 50 years in the future, not on physics but applied tp the problem of general AI/sentience. "The equations that we already have are sufficient to describe human tho…
It may be - probably is - a feature of the limits of our mental processes so far.
But there's no good reason to assume the system itself just happens to mirror those limits. It would be very strange if the entire universe worked in inconsistent ways that matched the naive reasoning of some not very interesting animals on an ordinary star in the middle of nowhere.
Re: Researcher proposes model replacing dark energy/matter to explain universe
#43Earlier quoted context omitted.
It doesn't, and the problems have only become more problematic over time, but it's the least bad hypothesis that's broadly accepted. I suspect a generational succession is required for new paradigms to be contemplated. There are many researchers proposing simpler, novel, and testable solutions that seem to go unnoticed. For example, I'm a fan of Alexandre Deur's work. He has some simple and elegant solutions that I'v…
Change happens in physics one funeral at a time.
Very true - but the CMB has outlived quite some funerals.
Re: Researcher proposes model replacing dark energy/matter to explain universe
#44If you ask me, Inflation is far more problematic than the Dark Stuff. Nevertheless, so far it remains the best explanation we have for observed phenomena ¯\_(ツ)_/¯
Re: Researcher proposes model replacing dark energy/matter to explain universe
#45Earlier quoted context omitted.
I’ve never really understood how just adding extra invisible stuff to make the equations work is justified either? It seems more likely there is simply something wrong with the equations.
It doesn't, and the problems have only become more problematic over time, but it's the least bad hypothesis that's broadly accepted. I suspect a generational succession is required for new paradigms to be contemplated. There are many researchers proposing simpler, novel, and testable solutions that seem to go unnoticed. For example, I'm a fan of Alexandre Deur's work. He has some simple and elegant solutions that I'v…
> I suspect a generational succession is required for new paradigms to be contemplated.
There are a constant stream of new paradigms contemplated (including this one!)
The problem is that they’re contemplated, tested and found wanting.
The notion of dark matter (and dark energy, which is a completely different animal) isn’t hanging around because of stubborn professors or a lack of imagination, it’s because nothing better has come along yet.
The good thing about this theory is that it seems easily testable. Maybe it’ll be different.
Re: Researcher proposes model replacing dark energy/matter to explain universe
#46I don't have access to the paper, but it seems to make zero testable predictions and is therefore just mathematical fiction. If it's not falsifiable, it's not science. EDIT: the last sentence is "Given sufficient redshift (or, equivalently, time) resolution effected by the redshift slicing, one might just find that the Hubble diagram exhibits jumps in the redshift distance relation, which would be very revealing." So…
All these papers miss the fact that our main evidence for dark matter (or something like it) is the cosmic microwave background. I see no mention on how this very convoluted model can reproduce it. The evidence is in the oscillations of the primordial plasma seen directly in the CMB. These come from the gravity pulling the plasma and pressure pushing back. Without DM they would be too shallow, DM helps by pulling the…
>All these papers miss the fact that our main evidence for dark matter (or something like it) is the cosmic microwave background. I see no mention on how this very convoluted model can reproduce it.
I am not an astronomer, but IIUC (and I may not), the first evidence for dark matter was posited by Fritz Zwicky[0] in 1933 based on the rotational velocities of galaxies, work by Vera Rubin[1] confirmed Zwicky's hypothesis in more detail decades later.
Since then Rubin's work has repeatedly been confirmed.
And while Penzius and Wilson "discovered" the Cosmic Microwave Background (CMB) a few years before Rubin published her data, (again, IIUC) the CMB was not used as a reliable tool to look for dark matter until better quality data was gathered in the 1980s and 1990s.
[0] https://en.wikipedia.org/wiki/Fritz_Zwicky#Dark_matter
[1] https://en.wikipedia.org/wiki/Vera_Rubin#Rotational_curves
Edit: Clarified prose.
Re: Researcher proposes model replacing dark energy/matter to explain universe
#47If you ask me, Inflation is far more problematic than the Dark Stuff. Nevertheless, so far it remains the best explanation we have for observed phenomena ¯\_(ツ)_/¯
What does inflation explain though? It was proposed as an explanation for CMB spectrum. Anything else?
Re: Researcher proposes model replacing dark energy/matter to explain universe
#48Earlier quoted context omitted.
All these papers miss the fact that our main evidence for dark matter (or something like it) is the cosmic microwave background. I see no mention on how this very convoluted model can reproduce it. The evidence is in the oscillations of the primordial plasma seen directly in the CMB. These come from the gravity pulling the plasma and pressure pushing back. Without DM they would be too shallow, DM helps by pulling the…
>All these papers miss the fact that our main evidence for dark matter (or something like it) is the cosmic microwave background. I see no mention on how this very convoluted model can reproduce it. I am not an astronomer, but IIUC (and I may not), the first evidence for dark matter was posited by Fritz Zwicky[0] in 1933 based on the rotational velocities of galaxies, work by Vera Rubin[1] confirmed Zwicky's hypothes…
They didn't say it was always the main evidence, just that it now is. I'm not personally sure about that either, but it's definitely one of the major lines of evidence.
Re: Researcher proposes model replacing dark energy/matter to explain universe
#49Earlier quoted context omitted.
The phrase "Dark Matter" literally means we don't know and therefore until something testable is postulated and tested (to be fair i believe some candidates have fallen by the wayside over the years as measurement has improved), it's principally equivalent to plugging in a giant X and giving it properties not unlike Fermi's famous elephant curve fitting comment.
Just FYI I have a PhD in cosmology, so no need to explain to me what "Dark Matter" does or doesn't mean, but thanks anyway. It sounds like you saw that video by Angela Collier about how Dark Matter is a set of observations, and while I think it's a good video, it's a bit disingenuous to pretend that working scientists put theories of dark matter and theories of modified gravity in the same category. I know Collier li…
She's done some interesting stuff, but I really hate that Collier video. It seems to have badly muddied the water.
Re: Researcher proposes model replacing dark energy/matter to explain universe
#50If you ask me, Inflation is far more problematic than the Dark Stuff. Nevertheless, so far it remains the best explanation we have for observed phenomena ¯\_(ツ)_/¯
What does inflation explain though? It was proposed as an explanation for CMB spectrum. Anything else?
It's obviously tied pretty closely to any theory of large scale structure formation too