Newtonian mechanics is limitless.

It doesn't have limit of speed of objects.

In it velocity of object can go up to infinity.

 

Modern physics has limit - speed of light.

Not "wrong", not "inaccurate"? Could you please tell me the appropriate word that should be used?

 

The problem is not really one of accuracy. For many applications, Newtonian calculations will be more accurate than you could possibly measure. It is more about "domain of applicability" - once you get to certain velocities and energy (or mass) levels, then purely Newtonian calculations will start to give the wrong answers. Exactly where this cut off point is depends on what you are trying to calculate and how precisely.

To add to others great explanation of the limitation of Newtonian mechanics; sometimes it just isn't the right tool for the job at hand. Remember science is the construction of models and relationships that allow us to describe nature - once you know what you want to investigate you pick the tool from your toolbox that most easily and accurately allows you to make predictions, check observations, and further your knowledge. For the most part when dealing with normal size stuff and at speeds within human experience Newtonian mechanics is so close to perfect that it isn't worth worrying about

 

And it is these limitations which show us where we might expand our science; have a readup on the precession of mercury.

Then I better study Newtonian Physics. Let`s come back to the topic. I think there must be a theory that would explain this. Maybe the answer is hidden in where we live-Space. The smallest thing in the world is the largest thing in the world-Space. You can somehow imagine the string or quarks is a sphere of space line that grip and combine well. This is my pure thought-it needs all of your calculation. i don`t think I have the ability to calculate this high energy physics all by myself.