>I don't see why couldn't put that in space, today.

Because the electronics are not built for space. Space rated electronics is about a decade behind their ground based siblings. Radiation is one of the most problematic, degrading electronics and disrupting digital memory. You also need petabytes of temp storage. Which, again, doesn't exist. For reference, JWST carries a 70 GB solid state recorder, I think Roman has about 1 TB. Then there is all the cooling, which is difficult in space. Saying there are some start-up considering computing is not the same as it being possible to order a system like this today.

The question is not could it theoretically be done, but can it be done on even the sorts of budget of a space science mission. And the answer to that is no. SKA pushes computing and technology to the limit on the Earth, where these things are much more advanced.

> MOND’s also been around since the early 1980s, but, in 2021, it finally developed a model – the Aether-Scalar-Tensor framework, or AeST – which ALSO maps perfectly onto the acoustic peaks revealed by WMAP and Planck. (It does it by proposing a new vector field and scalar field that duplicate the effects of Cold Dark Matter in the early universe

This doesn't contradict what I said. These models are not simply removing DM, I said people have tried with modified gravity models like these. First the models which fit the CMB were engineered to do, and each model has many more free parameters than dark matter. And note they have replaced invisible matter with an invisible matter-like field, it's not a simplification. Remembering that cold dark matter predicted these features, with fewer parameters and it is a physical model, not merely a fit. People have run simulations with the more basic MOND models, to find it cannot form realistic structure. Generally it forms structure more quickly than standard cosmology. Finding they need to add dark matter to their already modified gravity models to get something reasonable.

https://arxiv.org/abs/2007.00555

https://arxiv.org/abs/2305.05696

https://arxiv.org/abs/1309.6094

https://alvinng4.github.io/grav_sim/examples/cosmic_structur...

These simulations take their simple initial conditions from the Cosmic Microwave Background fluctuations, but models without dark matter fail to match the observed CMB. There are no major baryon-only simulations because cosmology doesn't work without DM, and you have nothing to start from. You need a quantitative model which works on some level to even begin, people have tried with modified gravity models.

That is not correct. LCDM as a cosmology is described by 6 parameters mostly for CMB analyses, but this is much more than just CDM. These parameters include the amount of normal matter, the cosmological constant, the amount of dark matter, reionization, the Hubble constant and two parameters which describe the initial fluctuations. CDM only has one parameter in the model, its density. As you can see there aren't many nobs to turn. These parameters are also fixed to observational values. And if you think you can fit all modern cosmological data with a physically-meaningful model and fewer parameters then go ahead.

To demonstrate you can even reproduce the Cosmic Web you have to actually run some calculations, or simulations. How do you know AGN bubbles produce a universe that looks anything like ours? The author dismisses simulations as "not science", while paradoxically using them as the only representation of the cosmic web in the article. These simulations have a lot of value, they demonstrate that standard cosmology and normal gravity has no problem forming voids and filaments. These simulations have been compared to countless new observations, which this model cannot because it's purely qualitative. The article says these simulations are worthless because they don't work from first principles, this is a practical limitation that you cannot simulate galaxies down to the resolution of atoms on any existing computer. You have to make some simplifications. The structure of the cosmic web is seen in all of them, even going back to very early simulations, it doesn't depend on these assumptions.

And at the end of the article we go back to the problem of dark matter, and find out the author has no explanation for rotation curves or other classical tests of DM. So despite bashing DM cosmology, this model explains none of the pillars of evidence for dark matter. At some point in developing an idea like this you need to actually start applying physics, either with calculations or simulations. Every new hypothesis is perfect before it has been subjected to rigor and analysis.