And Just Like That… All the Imaginary Dark Matter in the Universe Disappeared

Astromart

And Just Like That… All the Imaginary Dark Matter in the Universe Disappeared

Guy Pirro

August 14, 2023

Excerpt:

A new study of the orbital motions of long-period, widely separated, binary stars (referred to as wide binaries) reports conclusive evidence that standard Newtonian gravity breaks down at extremely low acceleration. The study carried out by Kyu-Hyun Chae, professor of physics and astronomy at Sejong University in Seoul, used up to 26,500 wide binaries within 650 light years as observed by the European Space Agency (ESA) Gaia Space Telescope.

For a key improvement over other studies, Chae’s study focused on calculating gravitational accelerations experienced by binary stars as a function of their separation or, equivalently the orbital period, by a Monte Carlo de-projection of observed sky-projected motions in three-dimensional space. Chae further explains the point: “From the start it seemed clear to me that gravity could be most directly and efficiently tested by calculating accelerations, because the gravitational field itself is an acceleration. My recent research experiences with galactic rotation curves led me to this idea. Galactic disks and wide binaries share some similarity in their orbits, though wide binaries follow highly elongated orbits while hydrogen gas particles in a galactic disk follow nearly circular orbits.”

LINK

========================

Modified gravity?

Modified gravity?

Modified Newtonian Gravity, or MOND has been around for a while. The proponents insist that we don't need dark matter to explain the high rotation of galaxies. We just need to modify the equations of gravity we think we know. However, most scientists don't take it seriously anymore.

Something is causing the extra gravitational lensing outside of galaxy clusters. The bullet cluster mostly killed off MOND for a reason. We also know of seven galaxies that orbit at the lower speeds we would have expected based only on the matter we can see. Apparently, they lack dark matter. If MOND was real, those galaxies couldn't exist.

Based on that other evidence, I suspect that this study will be refuted at some point. (Using statistical methods to de-project the proper motions of the stars sounds fishy to me, though I don't know that much about Monte Carlo algorithms.)

It would be cool to find out something this big about cosmology, but we can't call dark matter "imaginary" based on this alone. This study and that quote will probably be all over the popular press though.

I wish some day we'll have some "like" buttons. I don't feel I can add to this discussion other than with
a joke about
Simulation Theory -- in which we're told all these fine theoretical models will be subject to change
as the software of our simulation may be revised from outside.
Joke:
The Creator must at some point say, "The Buck Stops Here." Give 'em ______, Harry!


MODERATOR comment: You can use the RATE button and even leave a comment in it.

And now the rebuttal is out. Indranil Banik et al say that Chae used too many stars with large measurement errors. If you cut those out, the effect completely disappears. Their similar, but more rigorous study rules out MOND to 15 sigma! Also, Banik was a staunch supporter of MOND until he showed up as the lead author on this paper. The data must be pretty good if it convinced him to switch positions.

Video on this new paper compared to the old one:
https://www.youtube.com/watch?v=HlNSvrYygRc