Hacker News Reader

> [Milgrom's alternative theory:] But far in the outlying areas of the Milky Way, stars would feel a smaller gravitational force than previously thought

Isn't it the opposite?

Dark matter is extra matter which implies extra gravitational force to hold the galaxies together. If you want an alternative to dark matter, shouldn't the alternative theory predict a bigger gravitational force than previously thought?

View on HN

As far as I can understand, you are correct. The problem is that predicted gravitational force at the edge of the galaxies is smaller than observed, so any theory should find a solution for that problem. MOND in my opinion always looked like trying to fit a solution to the observations which will lead to overfit.

So without dark matter explaining the planets not flying out of the system, there is actually less gravitational force, yet they are obviously still not flying out. Why? Simply due to the shape of space.

Reply on news.ycombinator.com