Is Dark Matter accounted for in Newton's Law of Gravitation?

Newton's Law does not predict accurately at all. Newton couldn't account for the orbital motion of Mercury because it didn't take into account Relativistic consideration just in our own solar system.

Newton's law of gravitation originated when no one knew about dark matter. When you apply it to local orbit systems, i.e. planetary systems and star systems, it works perfectly fine. Dark matter is a negligible fraction of the total mass of an entire planetary system, no matter how you guess that dark matter is distributed within an order of magnitude of its average distribution.

It is when you try to apply Newton's law of gravity to galaxies as a whole, that you encounter a problem. It seems as if the galaxy would need more matter than is evidenced by the visible stuff (stars, planets, gas/dust lanes, stellar remnants, etc), to keep the outer rims orbiting at their observed rates...even within our own galaxy.

Dark matter is just the name that we give to that matter that only shows evidence of itself by gravity. As it fits in to Newton's law of gravity, it isn't part of the big G...it is part of one of the m's.

If you model Dark Matter as a non-collisional fluid, then Newton's Laws predict its dynamics just fine.

The remarkable thing about Dark Matter is its existence, not the way it interacts via gravity.

Uniontera number 11-1, hope it helps.

Existence is the time expressed by light itself. http://www.youtube.com/watch?v=AN1jTwHUC7E

1. Arrow A is the laser work. (Same time work)

2. Arrow B is the reason of gravity. (also, Higgs boson individually / Different time work)

3. The rose line is the beginning light. (result from Bible)

4. The existence of different time. (result from relativity of light)

5. 2 dimension is not a space. (result from 2-axis, math)

6. Universe came from nothing. (result from No.5 / cf. Playing with bubbles)

6-1. A barrier[posititon] exist between the inner and outer bubbles. But universe do not have that barrier. (Cause of Inertia / Reason of Sun / Position of Antimatter / cf. Expansion)

6-2. Nothing is not a no existence. No existence is a zero dimension. There is two zero dimension. One has a position. The other doesn't have a position. These different positions were connected by something. That "something" is not a what but a way. (Cause of Light)

7. Progress / Event / Probability is a time. (This is my trinity.)

8. Wave-particle duality of light, creation & evolution, uncertainty principle, etc. (result from No.7)

9. Coalescing of different time. (Cause of Rotation & Spin / Equator has plenty of time.)

10. Your so-called black hole is a wholly condensed time. (cf. Kerr spacetime)

11. The reason of "your so-called magnetic field". (result from step3 and 4)

11-1. The reason of "your so-called dark matter". (result from step3 to 4 / Energy-Mass duality / cf. Dark energy "step4 to 3")

12. The reason of "your so-called electric field". (result from the crack of time / Same time's crack is a different time's coalescing. / Cause of Static electricity)

13. Your so-called "space" is a crack of time. (result from No.12 / Cause of Lightning)

14. Boundary is a crack of space. (result from No.13 / Same space's crack is a different time's contact. / Cause of Superfluid / cf. Fractal)

15. Boundary is nothing. Your so-called hole is a boundary itself. Also, nothing is K=0 temperature. (result from No.14 / cf. Calabi-Yau, Hilbert space)

16. This is a wall of your so-called fire. (result from No.15) - copyright ⓒ uniontera

Our nonsense has come from one time. Uniontera is a key.

English is not my first language, sorry!

If it is difficult to understand, just remember & enjoy "Hand touching everything is a time". This is the only one result of uniontera.

I think Newton's law works quite well for galaxies. The law just says that force = G M1 M2 / R^2. It doesn't say what the masses (M1 and M2) are. If you want to analyze galaxies, you just need to include all the mass of the galaxy, including dark matter.

Newton's laws work well for small systems like our solar system.

Not for structures on the scale of galaxies and the universe.