Dr. Hossenfelder is back on MOND

[Dennis P Brown]

Well, didn't take long and the observational data is piling up and striking down Dark Matter (no surprise, it doesn't exist.) Turns out the rotation of stars around a galaxy follows MOND's predictions out to a million light years. That is impossible for the theory of Dark Matter.

See:https://www.youtube.com/watch?v=n33aurhg788

[Richard Hull]

When the emperor is seen to have no clothes, Sabine is willing to point the finger.

Richard Hull

[Dennis P Brown]

As we have previously discussed here in the forum, some have claimed there has been no real revolution in physics since something like the 1930's (that decade saw the massive advancement of QM with the beginnings of Field Theory.) Well, I get the feeling this is going to change.

If this paper holds, then it looks like Dr. Vera Cooper Rubin's amazing discovery in the early 1970's about galaxy rotation not following any know gravitational law will once more be at the forefront of physics. So the extremely "ad-hoc" idea of Dark Matter that was created to cover this serious problem in our most basic understanding of "force" laws can no longer 'fix' this issue. Of course, the "Dark Matter" idea has been, of late, failing time after time over many observations for many systems - not just this one new observation. Through, this observational data presents a very serious problem since it undermines the existence of any type of "dark Matter", no matter its properties.

Again, if further work continues to support this peer reviewed paper (or no errors are discovered after the fact), then this problem between galaxy rotation vs. planetary rotation undermines the very foundations of physics as currently understood. I'd think that might lead to some new physics or certainly novel approaches finally using quantum mechanics.

[Rich Gorski]

MOND has its problems too. It does well in its original form to explain the rotation versus distance problem of galaxies and traces the observational data nicely but it has problems predicting things like gravitational lensing and motions of galaxies within galactic clusters. Theres also a problem with MOND being able to predict the gravitation wave speed in the CMB. MOND must be further modified (and made more complex) to fit these other observational data such as adding additional gravitation fields… one vector and one scalar. Crazy… this is well beyond my limited understanding. Also I haven’t heard of a mechanism to explain why the gravitation effect changes from 1/R^2 to 1/R in the low acceleration regime. Dark matter on the other hand can easily explain all these things but had the big problem that no one has yet been able to find the stuff.

So, at this point I don’t know which camp I’m in but I guess I’m leaning towards the dark matter explanation only because it’s simpler. They just have to identify the particle.

Rich G.

[Dennis P Brown]

I too find issues with MOND. Their belief in the change in gravitational properties with decreasing acceleration values (deep space) strikes me as unsupported in the extreme. I certainly reject that idea until it can be shown consistent with existing physics. Needless to say, I suspect that is not a difficult hill to climb - even climbing said hill in a gravitational field on a planet rather then one in deep space