8 ms·

but... this is not true? McGaugh himself [1] mentions that there are mass discrepancies even using MOND analysis, and that this favors the dark matter paradigm

but... this is not true? McGaugh himself [1] mentions that there are mass discrepancies even using MOND analysis, and that this favors the dark matter paradigm [2]. [1] https://twitter.com/dudedarkmatter/status/1094526391620722688 https://twitter.com/dudedarkmatter/status/109452639162072268... [2] https://twitter.com/DudeDarkmatter/status/1094527929994932224 https://twitter.com/DudeDarkmatter/status/109452792999493222... certainly, these are still open questions in cosmology

sahil50 5y ago
The tweets above are good questions! This is how to do science! Meanwhile it's good to restate the obvious. Modified gravity (MOND), where acceleration at galactic scales isn't just GM/R^2 but modeled as sqrt(GM/R^2 * cH/(2pi)), works for 100s of galaxies, and is more precise than cold dark matter (CDM). Modified gravity only has one free parameter. cH/(2pi) = c^2 / 87 bly.
- 8note 5y ago
  Can the free parameter be described by something other than dark matter though? Or does it only put more constraints on what the dark matter is.
  - sahil50 5y ago
    Indeed. More detail here. https://news.ycombinator.com/item?id=29915004 https://news.ycombinator.com/item?id=29915004 Perhaps the "dark matter" of a galaxy is the rest of the galaxies of the universe.