It's like knowing for a fact that 1+2=9, and fixing the problem by inferring an invisible 6
Dark matter rings would pull very hard on the planet, as well as not interacting with the planet.
Isn't that self-contradictory? If it pulls, it's interacting (albeit possibly through gravity only).
Nobody knows what it is, except for a mathematical entity that needs to be added to make the universe behave as observed within the framework of current theories.
It's like knowing for a fact that 1+2=9, and fixing the problem by inferring an invisible 6
It's as infuriating as the incompatibility of relativity and quantum mechanics. And it's not pretty.
Gravity is a strange force, in that it's much weaker than all the other forces. Much weaker than it should be in order to be symmetrical. It doesn't seem to cooperate well with the other forces either, which is what stands in the way of a grand unified theory (of everything). The elusive graviton has still not been detected. There's no evidence that gravity obeys the same quantum mechanical laws as everything else.
Stephen Hawking once said that the majority of gravity may be acting in a higher spatial dimension which we can't directly perceive, and that only a small part of it acts in the spacetime we work with. If that's so, perhaps the remaining majority of gravity acting in the higher dimension is still able to affect this spacetime, through a mechanism we don't quite understand. In other words, our known universe could be behaving as though there were more mass than there actually is. At least in the sense of matter as we know it.
Dark matter would be the 'shadow' of a higher-dimensional structure projected onto spacetime. Space itself might exhibit the properties of mass under certain circumstances - it could be that it only happens where spacetime reaches a certain degree of 'flatness'. It could have to do with the constant creation and annihilation of particle pairs, which takes place everywhere all the time, but might behave differently well away from a gravity well.
Whatever dark matter is, it acts as if it has mass, which again means that astronomy's data derived from doppler shifting of light gets messed up if we look through the dark matter.
Bands of dark matter could actually explain why the redshifting of by far the most galaxies seems to be quantized at specific fractions or multiples of 72km/s. After all, there's no conceivable good reason for galaxies to obey an arbitrary limitation like that; they should be having a nice and even spread of velocities; according to Hubble's law, they should be moving away faster the farther away they are. But the redshift values come in discreet 'speed lanes'.
http://ldolphin.org/tifftshift.htmlWe may have misinterpreted redshifting as being due to movement away, rather than the passage of light through something (dark matter) which exerts gravitational force on the light.
The universe might not be expanding after all, or at least not at the rate we think, and since the currently accepted rate of expansion is only just over the rate which makes the difference between endless expansion and an eventual big crunch, even a slight effect could push it back into big crunch territory. That would be a big deal.
It's all highly speculative. All we know is that we need dark matter in some capacity, or Einstein and Newton were both quite devastatingly wrong. Well, actually, not wrong per se, but reduced to the level of geocentric cosmology in the sense that it works fine for most things but does not represent reality as it really is.