Can Dark Matter Explain Black Holes and the Mysterious Planet-Nine?

[Drakkith]

i thought the prediction of the mass was based on all orbits, even the orbit of planet-9 mass. you would need an orbital location of a mass to be able to predict the affects of the other orbits, and vice-versa. so doesn't the model predict the mass required, and its orbit?

It doesn't predict the current location of the planet, but it does predicts its orbit and mass. You don't need the exact position of a large mass to make predictions about what it can do to other objects nearby over time. Just having the orbital properties and the mass is good enough.

 

[DrK]

Firstly, a Black Hole can be of any size or mass.

Secondly, a BH that has the same solar mass as the Sun will have exactly the same gravitational pull as the Sun but will occupy a space relatively small.
If the Sun was replaced by a BH of the same mass, we would orbit it in exactly the same way as we do. We would not be sucked in

 

[Comeback City]

Firstly, a Black Hole can be of any size or mass.

See post #52.

We would not be sucked in

Even though I said this off a misconception, I wasn't referring to replacing our sun with a bh. I was referring to a bh with a huge mass in the place of planet 9.

 

[stoomart]

See post #52.

@Chronos adressed this more directly in post #27.