The end of the world as we know it

[MadMojoMonkey]

Things don't take sudden turns for no reason, though. Let's say an object drifts close to a black hole, and that causes a sudden change in its path. Well, if we know the black hole is there, and know its mass, then we can calculate the object's path before it was under the influence of the black hole.

If we are aware of all gravitational factors, and accurately know its velocity and location, not only would we know if it turned, but when, and to how much of a degree.

If you're simply stating Newton's Laws in your own way, then I don't intend to disagree with you.

If you're saying that an object changed motion, therefore a net force was acting on it, therefore there is a source of that net force, then that sounds like it's physics, to me.

However,
If the black hole observes it (in QM, observation is interaction), and we learn of it by observing the black hole, then your postulate that we can know about it w/o observation is not elucidated by this argument. We are using a transitive observation method, to be sure, but we are still observing it.

The only reason it's not 100% is because we can't measure both its location and velocity accurately thanks to the uncertainty principle. If we could, it would be 100%.

The uncertainty principle sets a universal bare minimum of uncertainty, but it is not the actual uncertainty. In practice, the actual uncertainty is many orders of magnitude higher than the minimum. This is because there is observer uncertainty, measurement tool uncertainty, statistical variance in the data collected, etc.

And considering we're talking about a planet, and not an atom, the accuracy of our calculations is extremely close to 100%, like all of the point nines.

This much is pretty true. If we're talking about a planet, then we can make certain assertions to its past, based on observing its present. However, and it's vital to know, that these assertions only bear any fruit by comparing them to other observations.

The bare bones, philosophical statement, "We cannot know for certain what has happened if we have not observed the happening." is still, rigorously, uncontested by the scientific method.