Re:The Blowtorch Theory: A new model for structure formation...
by thicktarget on Wednesday May 28, 2025 @06:06PM
(#44121074)
>Cold Dark Matter, as used in simulations etc, usually has six free parameters.
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.
As von Neumann once said, "With four parameters I can fit an elephant, and with five I can make him wiggle his trunk."
At this point, with ten, it's basically CGI.
And the model gets tweaked afresh to suit each new observational anomaly. So you can tweak it to fit, say, large galaxies, but then it doesn't fit small galaxies. (The cusp/core problem.) But that's OK, because you can tweak it to fit small galaxies! (But then it won't fit large galaxies.) And on it goes.
A key problem is that, after 50 years of tweaking, it still didn't predict the rapid, efficient structure formation of the early universe as revealed by the James Webb Space Telescope.
Three-stage cosmological natural selection (the parent to Blowtorch Theory) did.
https://theeggandtherock.substack.com/p/predictions-what-the...